app: update TopMost comment

TopMost is also supported on Windows.

Signed-off-by: qiannian <qianniancn@gmail.com>

.builds/apple.yml

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: Unlicense OR MIT
-image: debian/testing
+image: debian/stable
 packages:
  - clang
  - cmake
@@ -29,7 +29,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl -s https://dl.google.com/go/go1.22.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl -s https://dl.google.com/go/go1.24.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - prepare_toolchain: |
      mkdir -p $APPLE_TOOLCHAIN_ROOT
      cd $APPLE_TOOLCHAIN_ROOT

.builds/freebsd.yml

@@ -16,7 +16,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl https://dl.google.com/go/go1.22.2.freebsd-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl https://dl.google.com/go/go1.24.2.freebsd-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - test_gio: |
      cd gio
      go test ./...

.builds/linux.yml

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: Unlicense OR MIT
-image: debian/testing
+image: debian/stable
 packages:
  - curl
  - pkg-config
@@ -18,6 +18,12 @@ packages:
  - libxinerama-dev
  - libxi-dev
  - libxxf86vm-dev
+ - libegl-mesa0
+ - libglx-mesa0
+ - libgl1-mesa-dri
+ - mesa-libgallium
+ - libgbm1
+ - libegl1
  - mesa-vulkan-drivers
  - wine
  - xvfb
@@ -40,7 +46,7 @@ secrets:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl -s https://dl.google.com/go/go1.22.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl -s https://dl.google.com/go/go1.24.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - check_gofmt: |
      cd gio
      test -z "$(gofmt -s -l .)"
@@ -60,7 +66,7 @@ tasks:
  - add_32bit_arch: |
      sudo dpkg --add-architecture i386
      sudo apt-get update
-     sudo apt-get install -y "libwayland-dev:i386" "libx11-dev:i386" "libx11-xcb-dev:i386" "libxkbcommon-dev:i386" "libxkbcommon-x11-dev:i386" "libgles2-mesa-dev:i386" "libegl1-mesa-dev:i386" "libffi-dev:i386" "libvulkan-dev:i386" "libxcursor-dev:i386"
+     sudo apt-get install -y "libwayland-dev:i386" "libx11-dev:i386" "libx11-xcb-dev:i386" "libxkbcommon-dev:i386" "libxkbcommon-x11-dev:i386" "libgles2-mesa-dev:i386" "libegl1-mesa-dev:i386" "libffi-dev:i386" "libvulkan-dev:i386" "libxcursor-dev:i386" "libegl-mesa0:i386" "libglx-mesa0:i386" "libgbm1:i386" "mesa-libgallium:i386" "libgl1-mesa-dri:i386"
  - test_gio: |
      cd gio
      go test -race ./...

.builds/openbsd.yml

@@ -10,7 +10,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl https://dl.google.com/go/go1.22.2.src.tar.gz | tar -C /home/build/sdk -xzf -
+     curl https://dl.google.com/go/go1.24.2.src.tar.gz | tar -C /home/build/sdk -xzf -
      cd /home/build/sdk/go/src
      ./make.bash
  - test_gio: |

app/GioActivity.java

@@ -4,6 +4,7 @@ package org.gioui;
 
 import android.app.Activity;
 import android.os.Bundle;
+import android.content.Intent;
 import android.content.res.Configuration;
 import android.view.ViewGroup;
 import android.view.View;
@@ -29,6 +30,7 @@ public final class GioActivity extends Activity {
 
             layer.addView(view);
             setContentView(layer);
+            onNewIntent(this.getIntent());
 	}
 
 	@Override public void onDestroy() {
@@ -46,6 +48,16 @@ public final class GioActivity extends Activity {
 		super.onStop();
 	}
 
+	@Override public void onPause() {
+        super.onPause();
+        view.pause();
+	}
+
+	@Override public void onResume() {
+        super.onResume();
+        view.resume();
+	}
+
 	@Override public void onConfigurationChanged(Configuration c) {
 		super.onConfigurationChanged(c);
 		view.configurationChanged();
@@ -60,4 +72,9 @@ public final class GioActivity extends Activity {
 		if (!view.backPressed())
 			super.onBackPressed();
 	}
+
+	@Override protected void onNewIntent(Intent intent) {
+		super.onNewIntent(intent);
+		view.onIntentEvent(intent);
+	}
 }

app/GioView.java

@@ -12,6 +12,7 @@ import android.app.Fragment;
 import android.app.FragmentManager;
 import android.app.FragmentTransaction;
 import android.content.Context;
+import android.content.Intent;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Matrix;
@@ -61,7 +62,6 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 	private static boolean jniLoaded;
 
 	private final SurfaceHolder.Callback surfCallbacks;
-	private final View.OnFocusChangeListener focusCallback;
 	private final InputMethodManager imm;
 	private final float scrollXScale;
 	private final float scrollYScale;
@@ -113,12 +113,6 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 		nhandle = onCreateView(this);
 		setFocusable(true);
 		setFocusableInTouchMode(true);
-		focusCallback = new View.OnFocusChangeListener() {
-			@Override public void onFocusChange(View v, boolean focus) {
-				GioView.this.onFocusChange(nhandle, focus);
-			}
-		};
-		setOnFocusChangeListener(focusCallback);
 		surfCallbacks = new SurfaceHolder.Callback() {
 			@Override public void surfaceCreated(SurfaceHolder holder) {
 				// Ignore; surfaceChanged is guaranteed to be called immediately after this.
@@ -315,6 +309,15 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 		window.setAttributes(layoutParams);
 	}
 
+	protected void onIntentEvent(Intent intent) {
+		if (intent == null) {
+			return;
+		}
+		if (intent.getData() != null) {
+			this.onOpenURI(nhandle, intent.getData().toString());
+		}
+	}
+
 	@Override protected boolean dispatchHoverEvent(MotionEvent event) {
 		if (!accessManager.isTouchExplorationEnabled()) {
 			return super.dispatchHoverEvent(event);
@@ -472,6 +475,18 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 		}
 	}
 
+	public void pause() {
+		if (nhandle != 0) {
+		    onFocusChange(nhandle, false);
+        }
+	}
+
+	public void resume() {
+		if (nhandle != 0) {
+		    onFocusChange(nhandle, true);
+        }
+	}
+
 	public void destroy() {
 		if (nhandle != 0) {
 			onDestroyView(nhandle);
@@ -553,6 +568,7 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 	static private native void onExitTouchExploration(long handle);
 	static private native void onA11yFocus(long handle, int viewId);
 	static private native void onClearA11yFocus(long handle, int viewId);
+	static private native void onOpenURI(long handle, String uri);
 	static private native void imeSetSnippet(long handle, int start, int end);
 	static private native String imeSnippet(long handle);
 	static private native int imeSnippetStart(long handle);

app/app.go

@@ -3,7 +3,10 @@
 package app
 
 import (
+	"gioui.org/io/event"
+	"golang.org/x/net/idna"
 	"image"
+	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -56,6 +59,15 @@ type FrameEvent struct {
 	Source input.Source
 }
 
+// URLEvent is generated for external requests to open a URL. Unlike window specific events,
+// it is delivered through the [Events] iterator.
+//
+// In order to receive URLEvents the program must register one or more URL schemes. A scheme can
+// be registered using gogio, with the `-schemes` flag.
+type URLEvent struct {
+	URL *url.URL
+}
+
 // ViewEvent provides handles to the underlying window objects for the
 // current display protocol.
 type ViewEvent interface {
@@ -118,8 +130,7 @@ func NewContext(ops *op.Ops, e FrameEvent) layout.Context {
 // On iOS NSDocumentDirectory is queried.
 // For Android Context.getFilesDir is used.
 //
-// BUG: DataDir blocks on Android until init functions
+// BUG: On Android, DataDir panics if called before main.
-// have completed.
 func DataDir() (string, error) {
 	return dataDir()
 }
@@ -136,7 +147,29 @@ func Main() {
 	osMain()
 }
 
+// Events is an iterator that yields events that are not specific to any window,
+// such as [URLEvent]. It never returns.
+//
+// Events must be called by the main goroutine, and replaces the
+// call to [Main].
+func Events(yield func(event.Event) bool) {
+	yieldGlobalEvent = yield
+	osMain()
+}
+
+var yieldGlobalEvent func(evt event.Event) bool
+
+func processGlobalEvent(evt event.Event) {
+	if yieldGlobalEvent == nil {
+		return
+	}
+	if !yieldGlobalEvent(evt) {
+		yieldGlobalEvent = nil
+	}
+}
+
 func (FrameEvent) ImplementsEvent() {}
+func (URLEvent) ImplementsEvent()   {}
 
 func init() {
 	if extraArgs != "" {
@@ -147,3 +180,20 @@ func init() {
 		ID = filepath.Base(os.Args[0])
 	}
 }
+
+// newURLEvent creates a URLEvent from a raw URL string, handling Punycode decoding.
+func newURLEvent(rawurl string) (URLEvent, error) {
+	u, err := url.Parse(rawurl)
+	if err != nil {
+		return URLEvent{}, err
+	}
+	u.Host, err = idna.Punycode.ToUnicode(u.Hostname())
+	if err != nil {
+		return URLEvent{}, err
+	}
+	u, err = url.Parse(u.String())
+	if err != nil {
+		return URLEvent{}, err
+	}
+	return URLEvent{URL: u}, nil
+}

app/datadir.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build !android
-// +build !android
 
 package app
 

app/doc.go

@@ -48,7 +48,7 @@ For example, to display a blank but otherwise functional window:
 
 	func main() {
 		go func() {
-			w := app.NewWindow()
+			w := new(app.Window)
 			for {
 				w.Event()
 			}
@@ -56,6 +56,11 @@ For example, to display a blank but otherwise functional window:
 		app.Main()
 	}
 
+# Events
+
+The [Events] iterator yields app-specific events such as [URLEvent]. [Window.Event]
+yields events that target a particular window.
+
 # Permissions
 
 The packages under gioui.org/app/permission should be imported

app/egl_wayland.go

@@ -38,7 +38,24 @@ func init() {
 		if err != nil {
 			return nil, err
 		}
-		return &wlContext{Context: ctx, win: w}, nil
+
+		surf, width, height := w.surface()
+		if surf == nil {
+			return nil, errors.New("wayland: no surface")
+		}
+		eglWin := C.wl_egl_window_create(surf, C.int(width), C.int(height))
+		if eglWin == nil {
+			return nil, errors.New("wayland: wl_egl_window_create failed")
+		}
+		eglSurf := egl.NativeWindowType(uintptr(unsafe.Pointer(eglWin)))
+		if err := ctx.CreateSurface(eglSurf); err != nil {
+			return nil, err
+		}
+		// We're in charge of the frame callbacks, don't let eglSwapBuffers
+		// wait for callbacks that may never arrive.
+		ctx.EnableVSync(false)
+
+		return &wlContext{Context: ctx, win: w, eglWin: eglWin}, nil
 	}
 }
 
@@ -54,31 +71,11 @@ func (c *wlContext) Release() {
 }
 
 func (c *wlContext) Refresh() error {
-	c.Context.ReleaseSurface()
-	if c.eglWin != nil {
-		C.wl_egl_window_destroy(c.eglWin)
-		c.eglWin = nil
-	}
 	surf, width, height := c.win.surface()
 	if surf == nil {
 		return errors.New("wayland: no surface")
 	}
-	eglWin := C.wl_egl_window_create(surf, C.int(width), C.int(height))
+	C.wl_egl_window_resize(c.eglWin, C.int(width), C.int(height), 0, 0)
-	if eglWin == nil {
-		return errors.New("wayland: wl_egl_window_create failed")
-	}
-	c.eglWin = eglWin
-	eglSurf := egl.NativeWindowType(uintptr(unsafe.Pointer(eglWin)))
-	if err := c.Context.CreateSurface(eglSurf); err != nil {
-		return err
-	}
-	if err := c.Context.MakeCurrent(); err != nil {
-		return err
-	}
-	defer c.Context.ReleaseCurrent()
-	// We're in charge of the frame callbacks, don't let eglSwapBuffers
-	// wait for callbacks that may never arrive.
-	c.Context.EnableVSync(false)
 	return nil
 }
 

app/gl_ios.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build darwin && ios && nometal
-// +build darwin,ios,nometal
 
 package app
 

app/gl_macos.go

@@ -1,14 +1,12 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build darwin && !ios && nometal
-// +build darwin,!ios,nometal
 
 package app
 
 import (
 	"errors"
 	"runtime"
-
 	"unsafe"
 
 	"gioui.org/gpu"

app/ime.go

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: Unlicense OR MIT
+
 package app
 
 import (
 	"unicode"
 	"unicode/utf16"
+	"unicode/utf8"
 
 	"gioui.org/io/input"
 	"gioui.org/io/key"
@@ -116,3 +118,28 @@ func (e *editorState) RunesIndex(chars int) int {
 	// Assume runes after snippets are one UTF-16 character each.
 	return runes + chars
 }
+
+// areSnippetsConsistent reports whether the content of the old snippet is
+// consistent with the content of the new.
+func areSnippetsConsistent(old, new key.Snippet) bool {
+	// Compute the overlapping range.
+	r := old.Range
+	r.Start = max(r.Start, new.Start)
+	r.End = max(r.End, r.Start)
+	r.End = min(r.End, new.End)
+	return snippetSubstring(old, r) == snippetSubstring(new, r)
+}
+
+func snippetSubstring(s key.Snippet, r key.Range) string {
+	for r.Start > s.Start && r.Start < s.End {
+		_, n := utf8.DecodeRuneInString(s.Text)
+		s.Text = s.Text[n:]
+		s.Start++
+	}
+	for r.End < s.End && r.End > s.Start {
+		_, n := utf8.DecodeLastRuneInString(s.Text)
+		s.Text = s.Text[:len(s.Text)-n]
+		s.End--
+	}
+	return s.Text
+}

app/ime_test.go

@@ -1,11 +1,9 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-//go:build go1.18
-// +build go1.18
-
 package app
 
 import (
+	"gioui.org/f32"
 	"testing"
 	"unicode/utf8"
 
@@ -40,6 +38,7 @@ func FuzzIME(f *testing.F) {
 		r.Frame(gtx.Ops)
 
 		var state editorState
+		state.Selection.Transform = f32.AffineId()
 		const (
 			cmdReplace = iota
 			cmdSelect
@@ -139,6 +138,7 @@ func FuzzIME(f *testing.F) {
 
 func TestEditorIndices(t *testing.T) {
 	var s editorState
+	s.Selection.Transform = f32.AffineId()
 	const str = "Hello, 😀"
 	s.Snippet = key.Snippet{
 		Text: str,

app/internal/windows/windows.go

@@ -108,6 +108,80 @@ type MonitorInfo struct {
 	Flags    uint32
 }
 
+type CopyDataStruct struct {
+	DwData uintptr
+	CbData uint32
+	LpData uintptr
+}
+
+type POINTER_INPUT_TYPE int32
+
+const (
+	PT_POINTER  POINTER_INPUT_TYPE = 1
+	PT_TOUCH    POINTER_INPUT_TYPE = 2
+	PT_PEN      POINTER_INPUT_TYPE = 3
+	PT_MOUSE    POINTER_INPUT_TYPE = 4
+	PT_TOUCHPAD POINTER_INPUT_TYPE = 5
+)
+
+type POINTER_INFO_POINTER_FLAGS int32
+
+const (
+	POINTER_FLAG_NEW            POINTER_INFO_POINTER_FLAGS = 0x00000001
+	POINTER_FLAG_INRANGE        POINTER_INFO_POINTER_FLAGS = 0x00000002
+	POINTER_FLAG_INCONTACT      POINTER_INFO_POINTER_FLAGS = 0x00000004
+	POINTER_FLAG_FIRSTBUTTON    POINTER_INFO_POINTER_FLAGS = 0x00000010
+	POINTER_FLAG_SECONDBUTTON   POINTER_INFO_POINTER_FLAGS = 0x00000020
+	POINTER_FLAG_THIRDBUTTON    POINTER_INFO_POINTER_FLAGS = 0x00000040
+	POINTER_FLAG_FOURTHBUTTON   POINTER_INFO_POINTER_FLAGS = 0x00000080
+	POINTER_FLAG_FIFTHBUTTON    POINTER_INFO_POINTER_FLAGS = 0x00000100
+	POINTER_FLAG_PRIMARY        POINTER_INFO_POINTER_FLAGS = 0x00002000
+	POINTER_FLAG_CONFIDENCE     POINTER_INFO_POINTER_FLAGS = 0x00004000
+	POINTER_FLAG_CANCELED       POINTER_INFO_POINTER_FLAGS = 0x00008000
+	POINTER_FLAG_DOWN           POINTER_INFO_POINTER_FLAGS = 0x00010000
+	POINTER_FLAG_UPDATE         POINTER_INFO_POINTER_FLAGS = 0x00020000
+	POINTER_FLAG_UP             POINTER_INFO_POINTER_FLAGS = 0x00040000
+	POINTER_FLAG_WHEEL          POINTER_INFO_POINTER_FLAGS = 0x00080000
+	POINTER_FLAG_HWHEEL         POINTER_INFO_POINTER_FLAGS = 0x00100000
+	POINTER_FLAG_CAPTURECHANGED POINTER_INFO_POINTER_FLAGS = 0x00200000
+	POINTER_FLAG_HASTRANSFORM   POINTER_INFO_POINTER_FLAGS = 0x00400000
+)
+
+type POINTER_BUTTON_CHANGE_TYPE int32
+
+const (
+	POINTER_CHANGE_NONE              POINTER_BUTTON_CHANGE_TYPE = 0
+	POINTER_CHANGE_FIRSTBUTTON_DOWN  POINTER_BUTTON_CHANGE_TYPE = 1
+	POINTER_CHANGE_FIRSTBUTTON_UP    POINTER_BUTTON_CHANGE_TYPE = 2
+	POINTER_CHANGE_SECONDBUTTON_DOWN POINTER_BUTTON_CHANGE_TYPE = 3
+	POINTER_CHANGE_SECONDBUTTON_UP   POINTER_BUTTON_CHANGE_TYPE = 4
+	POINTER_CHANGE_THIRDBUTTON_DOWN  POINTER_BUTTON_CHANGE_TYPE = 5
+	POINTER_CHANGE_THIRDBUTTON_UP    POINTER_BUTTON_CHANGE_TYPE = 6
+	POINTER_CHANGE_FOURTHBUTTON_DOWN POINTER_BUTTON_CHANGE_TYPE = 7
+	POINTER_CHANGE_FOURTHBUTTON_UP   POINTER_BUTTON_CHANGE_TYPE = 8
+	POINTER_CHANGE_FIFTHBUTTON_DOWN  POINTER_BUTTON_CHANGE_TYPE = 9
+	POINTER_CHANGE_FIFTHBUTTON_UP    POINTER_BUTTON_CHANGE_TYPE = 10
+)
+
+type PointerInfo struct {
+	PointerType           POINTER_INPUT_TYPE
+	PointerId             uint32
+	FrameId               uint32
+	PointerFlags          POINTER_INFO_POINTER_FLAGS
+	SourceDevice          syscall.Handle
+	HwndTarget            syscall.Handle
+	PtPixelLocation       Point
+	PtHimetricLocation    Point
+	PtPixelLocationRaw    Point
+	PtHimetricLocationRaw Point
+	DwTime                uint32
+	HistoryCount          uint32
+	InputData             int32
+	DwKeyStates           uint32
+	PerformanceCount      uint64
+	ButtonChangeType      POINTER_BUTTON_CHANGE_TYPE
+}
+
 const (
 	TRUE = 1
 
@@ -133,7 +207,9 @@ const (
 	CFS_POINT        = 0x0002
 	CFS_CANDIDATEPOS = 0x0040
 
-	HWND_TOPMOST = ^(uint32(1) - 1) // -1
+	HWND_TOP       = syscall.Handle(0)
+	HWND_TOPMOST   = ^(syscall.Handle(1) - 1) // -1
+	HWND_NOTOPMOST = ^(syscall.Handle(2) - 1) // -2
 
 	HTCAPTION     = 2
 	HTCLIENT      = 1
@@ -244,45 +320,52 @@ const (
 
 	UNICODE_NOCHAR = 65535
 
-	WM_CANCELMODE           = 0x001F
+	WM_CANCELMODE            = 0x001F
-	WM_CHAR                 = 0x0102
+	WM_CHAR                  = 0x0102
-	WM_CLOSE                = 0x0010
+	WM_CLOSE                 = 0x0010
-	WM_CREATE               = 0x0001
+	WM_COPYDATA              = 0x004A
-	WM_DPICHANGED           = 0x02E0
+	WM_CREATE                = 0x0001
-	WM_DESTROY              = 0x0002
+	WM_DPICHANGED            = 0x02E0
-	WM_ERASEBKGND           = 0x0014
+	WM_DESTROY               = 0x0002
-	WM_GETMINMAXINFO        = 0x0024
+	WM_ERASEBKGND            = 0x0014
-	WM_IME_COMPOSITION      = 0x010F
+	WM_GETMINMAXINFO         = 0x0024
-	WM_IME_ENDCOMPOSITION   = 0x010E
+	WM_IME_COMPOSITION       = 0x010F
-	WM_IME_STARTCOMPOSITION = 0x010D
+	WM_IME_ENDCOMPOSITION    = 0x010E
-	WM_KEYDOWN              = 0x0100
+	WM_IME_STARTCOMPOSITION  = 0x010D
-	WM_KEYUP                = 0x0101
+	WM_KEYDOWN               = 0x0100
-	WM_KILLFOCUS            = 0x0008
+	WM_KEYUP                 = 0x0101
-	WM_LBUTTONDOWN          = 0x0201
+	WM_KILLFOCUS             = 0x0008
-	WM_LBUTTONUP            = 0x0202
+	WM_LBUTTONDOWN           = 0x0201
-	WM_MBUTTONDOWN          = 0x0207
+	WM_LBUTTONUP             = 0x0202
-	WM_MBUTTONUP            = 0x0208
+	WM_MBUTTONDOWN           = 0x0207
-	WM_MOUSEMOVE            = 0x0200
+	WM_MBUTTONUP             = 0x0208
-	WM_MOUSEWHEEL           = 0x020A
+	WM_MOUSEMOVE             = 0x0200
-	WM_MOUSEHWHEEL          = 0x020E
+	WM_MOUSEWHEEL            = 0x020A
-	WM_NCACTIVATE           = 0x0086
+	WM_MOUSEHWHEEL           = 0x020E
-	WM_NCHITTEST            = 0x0084
+	WM_NCACTIVATE            = 0x0086
-	WM_NCCALCSIZE           = 0x0083
+	WM_NCHITTEST             = 0x0084
-	WM_PAINT                = 0x000F
+	WM_NCCALCSIZE            = 0x0083
-	WM_QUIT                 = 0x0012
+	WM_PAINT                 = 0x000F
-	WM_SETCURSOR            = 0x0020
+	WM_POINTERCAPTURECHANGED = 0x024C
-	WM_SETFOCUS             = 0x0007
+	WM_POINTERDOWN           = 0x0246
-	WM_SHOWWINDOW           = 0x0018
+	WM_POINTERUP             = 0x0247
-	WM_SIZE                 = 0x0005
+	WM_POINTERUPDATE         = 0x0245
-	WM_STYLECHANGED         = 0x007D
+	WM_POINTERWHEEL          = 0x024E
-	WM_SYSKEYDOWN           = 0x0104
+	WM_POINTERHWHEEL         = 0x024F
-	WM_SYSKEYUP             = 0x0105
+	WM_QUIT                  = 0x0012
-	WM_RBUTTONDOWN          = 0x0204
+	WM_RBUTTONDOWN           = 0x0204
-	WM_RBUTTONUP            = 0x0205
+	WM_RBUTTONUP             = 0x0205
-	WM_TIMER                = 0x0113
+	WM_SETCURSOR             = 0x0020
-	WM_UNICHAR              = 0x0109
+	WM_SETFOCUS              = 0x0007
-	WM_USER                 = 0x0400
+	WM_SHOWWINDOW            = 0x0018
-	WM_WINDOWPOSCHANGED     = 0x0047
+	WM_SIZE                  = 0x0005
+	WM_STYLECHANGED          = 0x007D
+	WM_SYSKEYDOWN            = 0x0104
+	WM_SYSKEYUP              = 0x0105
+	WM_TIMER                 = 0x0113
+	WM_UNICHAR               = 0x0109
+	WM_USER                  = 0x0400
+	WM_WINDOWPOSCHANGED      = 0x0047
 
 	WS_CLIPCHILDREN     = 0x02000000
 	WS_CLIPSIBLINGS     = 0x04000000
@@ -345,7 +428,9 @@ var (
 	_DefWindowProc               = user32.NewProc("DefWindowProcW")
 	_DestroyWindow               = user32.NewProc("DestroyWindow")
 	_DispatchMessage             = user32.NewProc("DispatchMessageW")
+	_FindWindow                  = user32.NewProc("FindWindowW")
 	_EmptyClipboard              = user32.NewProc("EmptyClipboard")
+	_EnableMouseInPointer        = user32.NewProc("EnableMouseInPointer")
 	_GetWindowRect               = user32.NewProc("GetWindowRect")
 	_GetClientRect               = user32.NewProc("GetClientRect")
 	_GetClipboardData            = user32.NewProc("GetClipboardData")
@@ -355,6 +440,7 @@ var (
 	_GetMessage                  = user32.NewProc("GetMessageW")
 	_GetMessageTime              = user32.NewProc("GetMessageTime")
 	_GetMonitorInfo              = user32.NewProc("GetMonitorInfoW")
+	_GetPointerInfo              = user32.NewProc("GetPointerInfo")
 	_GetSystemMetrics            = user32.NewProc("GetSystemMetrics")
 	_GetWindowLong               = user32.NewProc("GetWindowLongPtrW")
 	_GetWindowLong32             = user32.NewProc("GetWindowLongW")
@@ -372,9 +458,11 @@ var (
 	_PostQuitMessage             = user32.NewProc("PostQuitMessage")
 	_ReleaseCapture              = user32.NewProc("ReleaseCapture")
 	_RegisterClassExW            = user32.NewProc("RegisterClassExW")
+	_RegisterTouchWindow         = user32.NewProc("RegisterTouchWindow")
 	_ReleaseDC                   = user32.NewProc("ReleaseDC")
 	_ScreenToClient              = user32.NewProc("ScreenToClient")
 	_ShowWindow                  = user32.NewProc("ShowWindow")
+	_SendMessage                 = user32.NewProc("SendMessageW")
 	_SetCapture                  = user32.NewProc("SetCapture")
 	_SetCursor                   = user32.NewProc("SetCursor")
 	_SetClipboardData            = user32.NewProc("SetClipboardData")
@@ -427,7 +515,10 @@ func CloseClipboard() error {
 }
 
 func CreateWindowEx(dwExStyle uint32, lpClassName uint16, lpWindowName string, dwStyle uint32, x, y, w, h int32, hWndParent, hMenu, hInstance syscall.Handle, lpParam uintptr) (syscall.Handle, error) {
-	wname := syscall.StringToUTF16Ptr(lpWindowName)
+	wname, err := syscall.UTF16PtrFromString(lpWindowName)
+	if err != nil {
+		return 0, fmt.Errorf("CreateWindowEx failed: %v", err)
+	}
 	hwnd, _, err := _CreateWindowEx.Call(
 		uintptr(dwExStyle),
 		uintptr(lpClassName),
@@ -445,6 +536,31 @@ func CreateWindowEx(dwExStyle uint32, lpClassName uint16, lpWindowName string, d
 	return syscall.Handle(hwnd), nil
 }
 
+func GetPointerInfo(pointerId uint32) (PointerInfo, error) {
+	var info PointerInfo
+	r1, _, err := _GetPointerInfo.Call(uintptr(pointerId), uintptr(unsafe.Pointer(&info)))
+	if r1 == 0 {
+		return PointerInfo{}, fmt.Errorf("GetPointerInfo failed: %v", err)
+	}
+	return info, nil
+}
+
+func RegisterTouchWindow(hwnd syscall.Handle, flags uint32) error {
+	r1, _, err := _RegisterTouchWindow.Call(uintptr(hwnd), uintptr(flags))
+	if r1 == 0 {
+		return fmt.Errorf("RegisterTouchWindow failed: %v", err)
+	}
+	return nil
+}
+
+func EnableMouseInPointer(enable uint) error {
+	r1, _, err := _EnableMouseInPointer.Call(uintptr(enable))
+	if r1 == 0 {
+		return fmt.Errorf("EnableMouseInPointer failed: %v", err)
+	}
+	return nil
+}
+
 func DefWindowProc(hwnd syscall.Handle, msg uint32, wparam, lparam uintptr) uintptr {
 	r, _, _ := _DefWindowProc.Call(uintptr(hwnd), uintptr(msg), wparam, lparam)
 	return r
@@ -474,6 +590,18 @@ func EmptyClipboard() error {
 	return nil
 }
 
+func FindWindow(lpClassName string) (syscall.Handle, error) {
+	className, err := syscall.UTF16PtrFromString(lpClassName)
+	if err != nil {
+		return 0, fmt.Errorf("FindWindow failed: %v", err)
+	}
+	hwnd, _, err := _FindWindow.Call(uintptr(unsafe.Pointer(className)), 0)
+	if hwnd == 0 {
+		return 0, fmt.Errorf("FindWindow failed: %v", err)
+	}
+	return syscall.Handle(hwnd), nil
+}
+
 func GetWindowRect(hwnd syscall.Handle) Rect {
 	var r Rect
 	_GetWindowRect.Call(uintptr(hwnd), uintptr(unsafe.Pointer(&r)))
@@ -656,7 +784,7 @@ func SetWindowPlacement(hwnd syscall.Handle, wp *WindowPlacement) {
 	_SetWindowPlacement.Call(uintptr(hwnd), uintptr(unsafe.Pointer(wp)))
 }
 
-func SetWindowPos(hwnd syscall.Handle, hwndInsertAfter uint32, x, y, dx, dy int32, style uintptr) {
+func SetWindowPos(hwnd, hwndInsertAfter syscall.Handle, x, y, dx, dy int32, style uintptr) {
 	_SetWindowPos.Call(uintptr(hwnd), uintptr(hwndInsertAfter),
 		uintptr(x), uintptr(y),
 		uintptr(dx), uintptr(dy),
@@ -665,7 +793,10 @@ func SetWindowPos(hwnd syscall.Handle, hwndInsertAfter uint32, x, y, dx, dy int3
 }
 
 func SetWindowText(hwnd syscall.Handle, title string) {
-	wname := syscall.StringToUTF16Ptr(title)
+	wname, err := syscall.UTF16PtrFromString(title)
+	if err != nil {
+		panic(err)
+	}
 	_SetWindowText.Call(uintptr(hwnd), uintptr(unsafe.Pointer(wname)))
 }
 
@@ -781,6 +912,14 @@ func ReleaseDC(hdc syscall.Handle) {
 	_ReleaseDC.Call(uintptr(hdc))
 }
 
+func SendMessage(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) error {
+	r, _, err := _SendMessage.Call(uintptr(hwnd), uintptr(msg), wParam, lParam)
+	if r == 0 {
+		return fmt.Errorf("SendMessage failed: %v", err)
+	}
+	return nil
+}
+
 func SetForegroundWindow(hwnd syscall.Handle) {
 	_SetForegroundWindow.Call(uintptr(hwnd))
 }

app/log_ios.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build darwin && ios
-// +build darwin,ios
 
 package app
 

app/metal_darwin.go

@@ -96,7 +96,7 @@ func newMtlContext(w *window) (*mtlContext, error) {
 		return nil, errors.New("metal: CAMetalLayer construction failed")
 	}
 	queue := C.newCommandQueue(dev)
-	if layer == 0 {
+	if queue == 0 {
 		C.CFRelease(dev)
 		C.CFRelease(layer)
 		return nil, errors.New("metal: [MTLDevice newCommandQueue] failed")

app/metal_ios.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build !nometal
-// +build !nometal
 
 package app
 

app/os.go

@@ -45,7 +45,9 @@ type Config struct {
 	CustomRenderer bool
 	// Decorated reports whether window decorations are provided automatically.
 	Decorated bool
-	// Focused reports whether has the keyboard focus.
+	// TopMost windows render above all other non-top-most windows.
+	TopMost bool
+	// Focused reports whether the window is focused.
 	Focused bool
 	// decoHeight is the height of the fallback decoration for platforms such
 	// as Wayland that may need fallback client-side decorations.

app/os_android.go

@@ -136,6 +136,8 @@ import (
 	"unicode/utf16"
 	"unsafe"
 
+	"gioui.org/io/transfer"
+
 	"gioui.org/internal/f32color"
 	"gioui.org/op"
 
@@ -146,7 +148,6 @@ import (
 	"gioui.org/io/pointer"
 	"gioui.org/io/semantic"
 	"gioui.org/io/system"
-	"gioui.org/io/transfer"
 	"gioui.org/unit"
 )
 
@@ -217,8 +218,6 @@ type AndroidViewEvent struct {
 
 type jvalue uint64 // The largest JNI type fits in 64 bits.
 
-var dataDirChan = make(chan string, 1)
-
 var android struct {
 	// mu protects all fields of this structure. However, once a
 	// non-nil jvm is returned from javaVM, all the other fields may
@@ -294,8 +293,7 @@ var mainWindow = newWindowRendezvous()
 var mainFuncs = make(chan func(env *C.JNIEnv), 1)
 
 var (
-	dataDirOnce sync.Once
+	dataPath string
-	dataPath    string
 )
 
 var (
@@ -342,9 +340,9 @@ func (w *window) NewContext() (context, error) {
 }
 
 func dataDir() (string, error) {
-	dataDirOnce.Do(func() {
+	if dataPath == "" {
-		dataPath = <-dataDirChan
+		panic("DataDir isn't valid before main")
-	})
+	}
 	return dataPath, nil
 }
 
@@ -397,7 +395,7 @@ func Java_org_gioui_Gio_runGoMain(env *C.JNIEnv, class C.jclass, jdataDir C.jbyt
 		os.Setenv("HOME", dataDir)
 	}
 
-	dataDirChan <- dataDir
+	dataPath = dataDir
 	C.jni_ReleaseByteArrayElements(env, jdataDir, dirBytes)
 
 	runMain()
@@ -664,6 +662,15 @@ func Java_org_gioui_GioView_onClearA11yFocus(env *C.JNIEnv, class C.jclass, view
 	}
 }
 
+//export Java_org_gioui_GioView_onOpenURI
+func Java_org_gioui_GioView_onOpenURI(env *C.JNIEnv, class C.jclass, view C.jlong, uri C.jstring) {
+	evt, err := newURLEvent(goString(env, uri))
+	if err != nil {
+		return
+	}
+	processGlobalEvent(evt)
+}
+
 func (w *window) ProcessEvent(e event.Event) {
 	w.processEvent(e)
 }
@@ -1318,6 +1325,7 @@ func findClass(env *C.JNIEnv, name string) C.jclass {
 }
 
 func osMain() {
+	select {}
 }
 
 func newWindow(window *callbacks, options []Option) {

app/os_darwin.go

@@ -5,7 +5,7 @@ package app
 /*
 #include <Foundation/Foundation.h>
 
-__attribute__ ((visibility ("hidden"))) void gio_wakeupMainThread(void);
+__attribute__ ((visibility ("hidden"))) void gio_runOnMain(uintptr_t h);
 __attribute__ ((visibility ("hidden"))) CFTypeRef gio_createDisplayLink(void);
 __attribute__ ((visibility ("hidden"))) void gio_releaseDisplayLink(CFTypeRef dl);
 __attribute__ ((visibility ("hidden"))) int gio_startDisplayLink(CFTypeRef dl);
@@ -40,8 +40,10 @@ static CFTypeRef newNSString(unichar *chars, NSUInteger length) {
 }
 */
 import "C"
+
 import (
 	"errors"
+	"runtime/cgo"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -73,8 +75,6 @@ type displayLink struct {
 // displayLinks maps CFTypeRefs to *displayLinks.
 var displayLinks sync.Map
 
-var mainFuncs = make(chan func(), 1)
-
 func isMainThread() bool {
 	return bool(C.isMainThread())
 }
@@ -85,22 +85,15 @@ func runOnMain(f func()) {
 		f()
 		return
 	}
-	go func() {
+	C.gio_runOnMain(C.uintptr_t(cgo.NewHandle(f)))
-		mainFuncs <- f
-		C.gio_wakeupMainThread()
-	}()
 }
 
-//export gio_dispatchMainFuncs
+//export gio_runFunc
-func gio_dispatchMainFuncs() {
+func gio_runFunc(h C.uintptr_t) {
-	for {
+	handle := cgo.Handle(h)
-		select {
+	defer handle.Delete()
-		case f := <-mainFuncs:
+	f := handle.Value().(func())
-			f()
+	f()
-		default:
-			return
-		}
-	}
 }
 
 // nsstringToString converts a NSString to a Go string.

app/os_darwin.m

@@ -4,8 +4,8 @@
 
 #include "_cgo_export.h"
 
-void gio_wakeupMainThread(void) {
+void gio_runOnMain(uintptr_t h) {
 	dispatch_async(dispatch_get_main_queue(), ^{
-		gio_dispatchMainFuncs();
+		gio_runFunc(h);
 	});
 }

app/os_ios.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build darwin && ios
-// +build darwin,ios
 
 package app
 
@@ -405,11 +404,12 @@ const (
 )
 
 func osMain() {
-	if !isMainThread() {
-		panic("app.Main must be run on the main goroutine")
-	}
 	switch mainMode {
 	case mainModeUndefined:
+		if !isMainThread() {
+			panic("app.Main must be run on the main goroutine")
+		}
+
 		mainMode = mainModeExe
 		var argv []*C.char
 		for _, arg := range os.Args {
@@ -423,6 +423,16 @@ func osMain() {
 	case mainModeLibrary:
 		// Do nothing, we're embedded as a library.
 	}
+	select {}
+}
+
+//export gio_onOpenURI
+func gio_onOpenURI(uri C.CFTypeRef) {
+	evt, err := newURLEvent(nsstringToString(uri))
+	if err != nil {
+		return
+	}
+	processGlobalEvent(evt)
 }
 
 //export gio_runMain

app/os_ios.m

@@ -134,23 +134,59 @@ NSArray<UIKeyCommand *> *_keyCommands;
     return gio_layerClass();
 }
 - (void)willMoveToWindow:(UIWindow *)newWindow {
+	self.contentScaleFactor = newWindow.screen.nativeScale;
+    if (@available(iOS 13.0, *)) {
+        [self registerSceneNotifications:newWindow];
+    }else{
+        [self registerWindowNotifications:newWindow];
+    }
+}
+
+- (void)registerSceneNotifications:(UIWindow *)newWindow {
+        if (self.window != nil) {
+            [[NSNotificationCenter defaultCenter] removeObserver:self
+                                                  name:UISceneDidActivateNotification
+                                                  object:self.window.windowScene];
+            [[NSNotificationCenter defaultCenter] removeObserver:self
+                                                  name:UISceneWillDeactivateNotification
+                                                  object:self.window.windowScene];
+        }
+        [[NSNotificationCenter defaultCenter] addObserver:self
+                                              selector:@selector(onSceneDidActivate:)
+                                              name:UISceneDidActivateNotification
+                                              object:newWindow.windowScene];
+
+        [[NSNotificationCenter defaultCenter] addObserver:self
+                                              selector:@selector(onSceneWillDeactivate:)
+                                              name:UISceneWillDeactivateNotification
+                                              object:newWindow.windowScene];
+}
+
+- (void)onSceneDidActivate:(NSNotification *)note API_AVAILABLE(ios(13.0)){
+    onFocus(self.handle, YES);
+}
+
+- (void)onSceneWillDeactivate:(NSNotification *)note API_AVAILABLE(ios(13.0)){
+    onFocus(self.handle, NO);
+}
+
+- (void)registerWindowNotifications:(UIWindow *)newWindow {
 	if (self.window != nil) {
 		[[NSNotificationCenter defaultCenter] removeObserver:self
-														name:UIWindowDidBecomeKeyNotification
+											  name:UIWindowDidBecomeKeyNotification
-													  object:self.window];
+										      object:self.window];
 		[[NSNotificationCenter defaultCenter] removeObserver:self
-														name:UIWindowDidResignKeyNotification
+											  name:UIWindowDidResignKeyNotification
-													  object:self.window];
+											  object:self.window];
 	}
-	self.contentScaleFactor = newWindow.screen.nativeScale;
 	[[NSNotificationCenter defaultCenter] addObserver:self
-											 selector:@selector(onWindowDidBecomeKey:)
+										  selector:@selector(onWindowDidBecomeKey:)
-												 name:UIWindowDidBecomeKeyNotification
+										  name:UIWindowDidBecomeKeyNotification
-											   object:newWindow];
+										  object:newWindow];
 	[[NSNotificationCenter defaultCenter] addObserver:self
-											 selector:@selector(onWindowDidResignKey:)
+										  selector:@selector(onWindowDidResignKey:)
-												 name:UIWindowDidResignKeyNotification
+										  name:UIWindowDidResignKeyNotification
-											   object:newWindow];
+										  object:newWindow];
 }
 
 - (void)onWindowDidBecomeKey:(NSNotification *)note {
@@ -293,6 +329,10 @@ void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle) {
 	[self.window makeKeyAndVisible];
 	return YES;
 }
+- (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<UIApplicationOpenURLOptionsKey, id> *)options {
+    gio_onOpenURI((__bridge CFTypeRef)url.absoluteString);
+	return YES;
+}
 @end
 
 int gio_applicationMain(int argc, char *argv[]) {

app/os_js.go

@@ -53,7 +53,8 @@ type window struct {
 	screenOrientation     js.Value
 	cleanfuncs            []func()
 	touches               []js.Value
-	composing             bool
+	composing             int
+	lastCursor            int
 	requestFocus          bool
 
 	config    Config
@@ -84,6 +85,7 @@ func newWindow(win *callbacks, options []Option) {
 		clipboard: js.Global().Get("navigator").Get("clipboard"),
 		wakeups:   make(chan struct{}, 1),
 		w:         win,
+		composing: -1,
 	}
 	w.w.SetDriver(w)
 	w.requestAnimationFrame = w.window.Get("requestAnimationFrame")
@@ -130,8 +132,10 @@ func getContainer(doc js.Value) js.Value {
 }
 
 func createTextArea(doc js.Value) js.Value {
-	tarea := doc.Call("createElement", "input")
+	tarea := doc.Call("createElement", "textarea")
 	style := tarea.Get("style")
+	// Position absolute so left/top coordinates actually place the element
+	style.Set("position", "absolute")
 	style.Set("width", "1px")
 	style.Set("height", "1px")
 	style.Set("opacity", "0")
@@ -141,6 +145,12 @@ func createTextArea(doc js.Value) js.Value {
 	tarea.Set("autocorrect", "off")
 	tarea.Set("autocapitalize", "off")
 	tarea.Set("spellcheck", false)
+	// Enable multiline text input for better composition support on some browsers.
+	tarea.Set("rows", 1)
+	style.Set("resize", "none")
+	style.Set("overflow", "hidden")
+	style.Set("white-space", "pre-wrap")
+	style.Set("word-break", "normal")
 	return tarea
 }
 
@@ -263,7 +273,15 @@ func (w *window) addEventListeners() {
 		return nil
 	})
 	w.addEventListener(w.tarea, "blur", func(this js.Value, args []js.Value) interface{} {
+		if w.composing != -1 {
+			// If we're composing, try to cancel.
+			// On Javascript is not possible to cancel the composition once started.
+			w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
+			w.composing = -1
+		}
+
 		w.config.Focused = false
+		w.lastCursor = 0 // Reset cursor tracking on blur
 		w.processEvent(ConfigEvent{Config: w.config})
 		w.blur()
 		return nil
@@ -277,19 +295,205 @@ func (w *window) addEventListeners() {
 		return nil
 	})
 	w.addEventListener(w.tarea, "compositionstart", func(this js.Value, args []js.Value) interface{} {
-		w.composing = true
+		st := w.w.EditorState()
+		sel := st.Selection.Range
+		if sel.Start == -1 {
+			sel.Start = 0
+			sel.End = 0
+		}
+		w.w.SetEditorSnippet(key.Range{Start: sel.Start, End: sel.End})
+		w.composing = sel.Start
 		return nil
 	})
 	w.addEventListener(w.tarea, "compositionend", func(this js.Value, args []js.Value) interface{} {
-		w.composing = false
+		finalText := w.tarea.Get("value").String()
-		w.flushInput()
+
+		if w.composing != -1 && finalText != "" {
+			// Replace the entire composition range with the final text.
+			compEnd := w.composing + utf8.RuneCountInString(finalText)
+			replaceRange := key.Range{Start: w.composing, End: compEnd}
+			w.w.EditorReplace(replaceRange, finalText)
+			w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
+
+			// Position cursor after the final composition text.
+			newEnd := w.composing + utf8.RuneCountInString(finalText)
+			w.w.SetEditorSelection(key.Range{Start: newEnd, End: newEnd})
+		}
+
+		w.composing = -1
+		w.tarea.Set("value", "")
 		return nil
 	})
 	w.addEventListener(w.tarea, "input", func(this js.Value, args []js.Value) interface{} {
-		if w.composing {
+		e := args[0]
-			return nil
+		inputType := e.Get("inputType").String()
+
+		dataVal := e.Get("data")
+		var data string
+		if dataVal.Truthy() {
+			data = dataVal.String()
 		}
-		w.flushInput()
+
+		// Get the current textarea value.
+		tareaValue := w.tarea.Get("value").String()
+		st := w.w.EditorState()
+
+		sel := st.Selection.Range
+		var absStart, absEnd int
+
+		snippetStart := st.Snippet.Range.Start
+		snippetEnd := st.Snippet.Range.End
+
+		cursorPos := sel.Start
+		selectionEnd := sel.End
+		if cursorPos < 0 {
+			cursorPos = 0
+			selectionEnd = 0
+		}
+
+		// Check if we need to expand the snippet to include the range.
+		if st.Snippet.Range.Start == 0 && st.Snippet.Range.End == 0 && tareaValue != "" {
+			// Empty snippet - set it to include the selection/cursor.
+			w.w.SetEditorSnippet(key.Range{Start: cursorPos, End: selectionEnd})
+			absStart = cursorPos
+			absEnd = selectionEnd
+		} else if cursorPos < snippetStart || selectionEnd > snippetEnd {
+			// Selection is outside the snippet
+			newStart := snippetStart
+			newEnd := snippetEnd
+			if cursorPos < newStart {
+				newStart = cursorPos
+			}
+			if selectionEnd > newEnd {
+				newEnd = selectionEnd
+			}
+			w.w.SetEditorSnippet(key.Range{Start: newStart, End: newEnd})
+			// Refresh state after snippet update.
+			st = w.w.EditorState()
+			// Use the selection range directly.
+			absStart = cursorPos
+			absEnd = selectionEnd
+		} else {
+			// Selection is within snippet to absolute positions.
+			absStart = cursorPos
+			absEnd = selectionEnd
+		}
+
+		switch inputType {
+		case "insertCompositionText":
+			if w.composing == -1 {
+				break
+			}
+
+			compEnd := absEnd
+			if compEnd < w.composing {
+				compEnd = w.composing
+			}
+			replaceRange := key.Range{Start: w.composing, End: compEnd}
+			w.w.EditorReplace(replaceRange, data)
+
+			newEnd := w.composing + utf8.RuneCountInString(data)
+			w.w.SetComposingRegion(key.Range{Start: w.composing, End: newEnd})
+			w.w.SetEditorSelection(key.Range{Start: newEnd, End: newEnd})
+
+		case "deleteContentBackward", "deleteContentForward", "deleteByCut":
+			if w.composing != -1 {
+				compEnd := w.composing + utf8.RuneCountInString(tareaValue)
+				replaceRange := key.Range{Start: w.composing, End: compEnd}
+				w.w.EditorReplace(replaceRange, tareaValue)
+
+				newEnd := w.composing + utf8.RuneCountInString(tareaValue)
+				w.w.SetComposingRegion(key.Range{Start: w.composing, End: newEnd})
+				w.w.SetEditorSelection(key.Range{Start: newEnd, End: newEnd})
+			} else {
+				replaceRange := key.Range{Start: absStart, End: absEnd}
+				w.w.EditorReplace(replaceRange, "")
+				w.w.SetEditorSelection(key.Range{Start: absStart, End: absStart})
+			}
+
+		case "insertReplacementText":
+			if w.composing != -1 {
+				// During composition, replace the entire composition.
+				compEnd := w.composing + utf8.RuneCountInString(data)
+				replaceRange := key.Range{Start: w.composing, End: compEnd}
+				w.w.EditorReplace(replaceRange, data)
+
+				newEnd := w.composing + utf8.RuneCountInString(data)
+				w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
+				w.w.SetEditorSelection(key.Range{Start: newEnd, End: newEnd})
+				w.composing = -1
+				w.lastCursor = newEnd
+			} else {
+				// Safari sends "insertReplacementText" for autocorrect, but the cursor is at the end of the word, so we need to find the word start.
+				insertLen := utf8.RuneCountInString(data)
+				wordStart := absStart
+
+				if absStart > snippetStart {
+					relPos := absStart - snippetStart
+					snippetRunes := []rune(st.Snippet.Text)
+
+					for i := relPos - 1; i >= 0; i-- {
+						if i >= len(snippetRunes) {
+							continue
+						}
+						r := snippetRunes[i]
+						if r == ' ' || r == '\t' || r == '\n' || r == '\r' {
+							break
+						}
+						wordStart = snippetStart + i
+					}
+				}
+
+				replaceRange := key.Range{Start: wordStart, End: absStart}
+				w.w.EditorReplace(replaceRange, data)
+
+				newCursor := wordStart + insertLen
+				w.w.SetEditorSelection(key.Range{Start: newCursor, End: newCursor})
+				w.lastCursor = newCursor
+			}
+
+		case "insertText":
+			if w.composing != -1 {
+				compEnd := w.composing + utf8.RuneCountInString(data)
+				replaceRange := key.Range{Start: w.composing, End: compEnd}
+				w.w.EditorReplace(replaceRange, data)
+
+				newEnd := w.composing + utf8.RuneCountInString(data)
+				w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
+				w.w.SetEditorSelection(key.Range{Start: newEnd, End: newEnd})
+				w.composing = -1
+				w.lastCursor = newEnd
+			} else {
+				insertLen := utf8.RuneCountInString(data)
+				replaceRange := key.Range{Start: absStart, End: absStart}
+				if absStart != absEnd {
+					replaceRange = key.Range{Start: absStart, End: absEnd}
+				}
+
+				newCursor := replaceRange.Start + insertLen
+				w.w.EditorReplace(replaceRange, data)
+				w.w.SetEditorSelection(key.Range{Start: newCursor, End: newCursor})
+				w.lastCursor = newCursor
+			}
+
+		default: // paste and other input types
+			if w.composing != -1 {
+				compEnd := w.composing + utf8.RuneCountInString(tareaValue)
+				replaceRange := key.Range{Start: w.composing, End: compEnd}
+				w.w.EditorReplace(replaceRange, tareaValue)
+
+				newEnd := w.composing + utf8.RuneCountInString(tareaValue)
+				w.w.SetComposingRegion(key.Range{Start: w.composing, End: newEnd})
+				w.w.SetEditorSelection(key.Range{Start: newEnd, End: newEnd})
+			} else {
+				replaceRange := key.Range{Start: absStart, End: absEnd}
+				w.w.EditorReplace(replaceRange, tareaValue)
+
+				newCursor := absStart + utf8.RuneCountInString(tareaValue)
+				w.w.SetEditorSelection(key.Range{Start: newCursor, End: newCursor})
+			}
+		}
+
 		return nil
 	})
 	w.addEventListener(w.tarea, "paste", func(this js.Value, args []js.Value) interface{} {
@@ -306,12 +510,6 @@ func (w *window) addHistory() {
 	w.browserHistory.Call("pushState", nil, nil, w.window.Get("location").Get("href"))
 }
 
-func (w *window) flushInput() {
-	val := w.tarea.Get("value").String()
-	w.tarea.Set("value", "")
-	w.w.EditorInsert(string(val))
-}
-
 func (w *window) blur() {
 	w.tarea.Call("blur")
 	w.requestFocus = false
@@ -343,11 +541,49 @@ func (w *window) keyboard(hint key.InputHint) {
 		m = "text"
 	}
 	w.tarea.Set("inputMode", m)
+
+	// Update autocomplete / autocorrect attributes.
+	var autocomplete, autocorrect, autocapitalize string
+	var spellcheck bool
+
+	switch hint {
+	case key.HintAny, key.HintText:
+		autocomplete, autocorrect, autocapitalize, spellcheck = "on", "on", "on", true
+	case key.HintEmail:
+		autocomplete, autocorrect, autocapitalize, spellcheck = "email", "off", "off", false
+	case key.HintURL:
+		autocomplete, autocorrect, autocapitalize, spellcheck = "url", "off", "off", false
+	case key.HintTelephone:
+		autocomplete, autocorrect, autocapitalize, spellcheck = "tel", "off", "off", false
+	case key.HintPassword:
+		autocomplete, autocorrect, autocapitalize, spellcheck = "current-password", "off", "off", false
+	default: // key.HintNumeric and others
+		autocomplete, autocorrect, autocapitalize, spellcheck = "off", "off", "off", false
+	}
+
+	w.tarea.Set("autocomplete", autocomplete)
+	w.tarea.Set("autocorrect", autocorrect)
+	w.tarea.Set("autocapitalize", autocapitalize)
+	w.tarea.Set("spellcheck", spellcheck)
 }
 
 func (w *window) keyEvent(e js.Value, ks key.State) {
 	k := e.Get("key").String()
+
 	if n, ok := translateKey(k); ok {
+		if ks == key.Press {
+			isMod := n == key.NameAlt || n == key.NameCommand || n == key.NameCtrl || n == key.NameShift || n == key.NameSuper
+			isFunc := n == key.NameUpArrow || n == key.NameDownArrow || n == key.NameLeftArrow || n == key.NameRightArrow ||
+				n == key.NamePageUp || n == key.NamePageDown || n == key.NameHome || n == key.NameEnd ||
+				n == key.NameEscape || n == key.NameReturn || n == key.NameEnter || n == key.NameTab ||
+				n == key.NameDeleteBackward || n == key.NameDeleteForward
+
+			if isMod || isFunc {
+				// Gio will request the browser to change the selection/carret position natively.
+				e.Call("preventDefault")
+			}
+		}
+
 		cmd := key.Event{
 			Name:      n,
 			Modifiers: modifiersFor(e),
@@ -414,6 +650,12 @@ func modifiersFor(e js.Value) key.Modifiers {
 	if e.Call("getModifierState", "Shift").Bool() {
 		mods |= key.ModShift
 	}
+	if e.Call("getModifierState", "Meta").Bool() {
+		mods |= key.ModCommand
+	}
+	if e.Call("getModifierState", "OS").Bool() {
+		mods |= key.ModSuper
+	}
 	return mods
 }
 
@@ -434,6 +676,9 @@ func (w *window) touchEvent(kind pointer.Kind, e js.Value) {
 	if e.Get("ctrlKey").Bool() {
 		mods |= key.ModCtrl
 	}
+	if e.Get("metaKey").Bool() {
+		mods |= key.ModCommand
+	}
 	for i := 0; i < n; i++ {
 		touch := changedTouches.Index(i)
 		pid := w.touchIDFor(touch)
@@ -521,7 +766,90 @@ func (w *window) funcOf(f func(this js.Value, args []js.Value) interface{}) js.F
 	return jsf
 }
 
-func (w *window) EditorStateChanged(old, new editorState) {}
+func (w *window) EditorStateChanged(old, new editorState) {
+	if w.composing != -1 {
+		// Do not interfere with browser state while composing.
+		// On Javascript is not possible to cancel the composition once started!
+		return
+	}
+
+	// Update textarea value to match the snippet.
+	if old.Snippet != new.Snippet {
+		w.tarea.Set("value", new.Snippet.Text)
+	}
+
+	// Update selection to match Gio's selection.
+	if old.Selection.Range != new.Selection.Range || old.Snippet != new.Snippet {
+		if new.Selection.Range.Start != -1 && new.Selection.Range.End != -1 {
+			// Calculate selection positions relative to snippet start.
+			// The textarea contains only the snippet text.
+			snippetStart := new.Snippet.Range.Start
+			snippetEnd := new.Snippet.Range.End
+
+			selStart := new.Selection.Range.Start
+			selEnd := new.Selection.Range.End
+			if selStart < snippetStart {
+				selStart = snippetStart
+			}
+			if selStart > snippetEnd {
+				selStart = snippetEnd
+			}
+			if selEnd < snippetStart {
+				selEnd = snippetStart
+			}
+			if selEnd > snippetEnd {
+				selEnd = snippetEnd
+			}
+
+			// Convert absolute rune positions to UTF-16 positions for the textarea.
+			startUTF16 := new.UTF16Index(selStart)
+			endUTF16 := new.UTF16Index(selEnd)
+
+			// Convert to snippet-relative UTF-16 positions.
+			snippetStartUTF16 := new.UTF16Index(snippetStart)
+			start := startUTF16 - snippetStartUTF16
+			end := endUTF16 - snippetStartUTF16
+
+			if start < 0 {
+				start = 0
+			}
+			if end < 0 {
+				end = 0
+			}
+
+			// Calculate max UTF-16 length of snippet text.
+			textLen := new.UTF16Index(snippetEnd) - snippetStartUTF16
+			if start > textLen {
+				start = textLen
+			}
+			if end > textLen {
+				end = textLen
+			}
+
+			if start > end {
+				start, end = end, start
+			}
+
+			w.tarea.Set("selectionStart", start)
+			w.tarea.Set("selectionEnd", end)
+		}
+	}
+
+	// Move DOM element to position the caret.
+	if old.Selection.Caret != new.Selection.Caret || old.Selection.Transform != new.Selection.Transform {
+		pos := new.Selection.Transform.Transform(new.Selection.Caret.Pos.Add(f32.Pt(0, new.Selection.Caret.Descent)))
+		bounds := w.cnv.Call("getBoundingClientRect")
+		left := bounds.Get("left").Float() + float64(pos.X)/float64(w.scale)
+		top := bounds.Get("top").Float() + float64(pos.Y-new.Selection.Caret.Ascent)/float64(w.scale)
+		height := float64(new.Selection.Caret.Ascent+new.Selection.Caret.Descent) / float64(w.scale)
+
+		style := w.tarea.Get("style")
+		style.Set("left", fmt.Sprintf("%fpx", left))
+		style.Set("top", fmt.Sprintf("%fpx", top))
+		style.Set("height", fmt.Sprintf("%fpx", height))
+		style.Set("width", "1px")
+	}
+}
 
 func (w *window) SetAnimating(anim bool) {
 	w.animating = anim
@@ -535,10 +863,9 @@ func (w *window) ReadClipboard() {
 	if w.clipboard.IsUndefined() {
 		return
 	}
-	if w.clipboard.Get("readText").IsUndefined() {
+	if w.clipboard.Get("readText").Truthy() {
-		return
+		w.clipboard.Call("readText").Call("then", w.clipboardCallback)
 	}
-	w.clipboard.Call("readText", w.clipboard).Call("then", w.clipboardCallback)
 }
 
 func (w *window) WriteClipboard(mime string, s []byte) {
@@ -621,6 +948,13 @@ func (w *window) ShowTextInput(show bool) {
 	if show {
 		w.focus()
 	} else {
+		// If we're composing, end composition first by clearing the textarea.
+		// That is a attempt to force the browser to end composition.
+		if w.composing != -1 {
+			w.tarea.Set("value", "")
+			w.composing = -1
+			w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
+		}
 		w.blur()
 	}
 }

app/os_macos.go

@@ -40,8 +40,9 @@ import (
 #define MOUSE_SCROLL 4
 
 __attribute__ ((visibility ("hidden"))) void gio_main(void);
+__attribute__ ((visibility ("hidden"))) void gio_init(void);
 __attribute__ ((visibility ("hidden"))) CFTypeRef gio_createView(int presentWithTrans);
-__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight);
+__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height);
 __attribute__ ((visibility ("hidden"))) void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle);
 
 static void writeClipboard(CFTypeRef str) {
@@ -192,6 +193,7 @@ static void setMaxSize(CFTypeRef windowRef, CGFloat width, CGFloat height) {
 	@autoreleasepool {
 		NSWindow* window = (__bridge NSWindow *)windowRef;
 		window.contentMaxSize = NSMakeSize(width, height);
+		window.maxFullScreenContentSize = NSMakeSize(width, height);
 	}
 }
 
@@ -239,6 +241,13 @@ static void setTitle(CFTypeRef windowRef, CFTypeRef titleRef) {
 	}
 }
 
+static void setWindowLevel(CFTypeRef windowRef, NSWindowLevel level) {
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		window.level = level;
+	}
+}
+
 static int isWindowZoomed(CFTypeRef windowRef) {
 	@autoreleasepool {
 		NSWindow *window = (__bridge NSWindow *)windowRef;
@@ -333,6 +342,8 @@ import "C"
 func init() {
 	// Darwin requires that UI operations happen on the main thread only.
 	runtime.LockOSThread()
+	// Register launch finished listener.
+	C.gio_init()
 }
 
 // AppKitViewEvent notifies the client of changes to the window AppKit handles.
@@ -491,6 +502,9 @@ func (w *window) Configure(options []Option) {
 		barTrans = C.YES
 		titleVis = C.NSWindowTitleHidden
 	}
+	if cnf.TopMost {
+		C.setWindowLevel(window, C.NSFloatingWindowLevel)
+	}
 	C.setWindowTitlebarAppearsTransparent(window, barTrans)
 	C.setWindowTitleVisibility(window, titleVis)
 	C.setWindowStyleMask(window, mask)
@@ -534,7 +548,7 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 }
 
 func (w *window) EditorStateChanged(old, new editorState) {
-	if old.Selection.Range != new.Selection.Range || old.Snippet != new.Snippet {
+	if old.Selection.Range != new.Selection.Range || !areSnippetsConsistent(old.Snippet, new.Snippet) {
 		C.discardMarkedText(w.view)
 		w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
 	}
@@ -892,7 +906,7 @@ func gio_firstRectForCharacterRange(h C.uintptr_t, crng C.NSRange, actual C.NSRa
 	// Transform to NSView local coordinates (lower left origin, undo backing scale).
 	scale := 1. / float32(C.getViewBackingScale(w.view))
 	height := float32(C.viewHeight(w.view))
-	local := f32.Affine2D{}.Scale(f32.Pt(0, 0), f32.Pt(scale, -scale)).Offset(f32.Pt(0, height))
+	local := f32.AffineId().Scale(f32.Pt(0, 0), f32.Pt(scale, -scale)).Offset(f32.Pt(0, height))
 	t := local.Mul(sel.Transform)
 	bounds := f32.Rectangle{
 		Min: t.Transform(sel.Pos.Sub(f32.Pt(0, sel.Ascent))),
@@ -993,6 +1007,16 @@ func gio_onFinishLaunching() {
 	close(launched)
 }
 
+//export gio_onOpenURI
+func gio_onOpenURI(uri C.CFTypeRef) {
+	evt, err := newURLEvent(nsstringToString(uri))
+	if err != nil {
+		return
+	}
+
+	processGlobalEvent(evt)
+}
+
 func newWindow(win *callbacks, options []Option) {
 	<-launched
 	res := make(chan struct{})
@@ -1010,7 +1034,7 @@ func newWindow(win *callbacks, options []Option) {
 			w.ProcessEvent(DestroyEvent{Err: err})
 			return
 		}
-		window := C.gio_createWindow(w.view, C.CGFloat(cnf.Size.X), C.CGFloat(cnf.Size.Y), 0, 0, 0, 0)
+		window := C.gio_createWindow(w.view, C.CGFloat(cnf.Size.X), C.CGFloat(cnf.Size.Y))
 		// Release our reference now that the NSWindow has it.
 		C.CFRelease(w.view)
 		w.Configure(options)

app/os_macos.m

@@ -369,7 +369,7 @@ void gio_setCursor(NSUInteger curID) {
 	}
 }
 
-CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGFloat minWidth, CGFloat minHeight, CGFloat maxWidth, CGFloat maxHeight) {
+CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height) {
 	@autoreleasepool {
 		NSRect rect = NSMakeRect(0, 0, width, height);
 		NSUInteger styleMask = NSTitledWindowMask |
@@ -381,12 +381,6 @@ CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGF
 													   styleMask:styleMask
 														 backing:NSBackingStoreBuffered
 														   defer:NO];
-		if (minWidth > 0 || minHeight > 0) {
-			window.contentMinSize = NSMakeSize(minWidth, minHeight);
-		}
-		if (maxWidth > 0 || maxHeight > 0) {
-			window.contentMaxSize = NSMakeSize(maxWidth, maxHeight);
-		}
 		[window setAcceptsMouseMovedEvents:YES];
 		NSView *view = (__bridge NSView *)viewRef;
 		[window setContentView:view];
@@ -426,7 +420,11 @@ void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle) {
 - (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
 	[NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
 	[NSApp activateIgnoringOtherApps:YES];
-	gio_onFinishLaunching();
+}
+- (void)application:(NSApplication *)application openURLs:(NSArray<NSURL *> *)urls {
+	for (NSURL *url in urls) {
+		gio_onOpenURI((__bridge CFTypeRef)url.absoluteString);
+	}
 }
 @end
 
@@ -457,3 +455,25 @@ void gio_main() {
 		[NSApp run];
 	}
 }
+
+@interface AppListener : NSObject
+@end
+
+static AppListener *appListener;
+
+@implementation AppListener
+- (void)launchFinished:(NSNotification *)notification {
+	appListener = nil;
+	gio_onFinishLaunching();
+}
+@end
+
+void gio_init() {
+	@autoreleasepool {
+		appListener = [[AppListener alloc] init];
+		[[NSNotificationCenter defaultCenter] addObserver:appListener
+												 selector:@selector(launchFinished:)
+													 name:NSApplicationDidFinishLaunchingNotification
+												   object:nil];
+	}
+}

app/os_unix.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build (linux && !android) || freebsd || openbsd
-// +build linux,!android freebsd openbsd
 
 package app
 

app/os_wayland.go

@@ -116,6 +116,8 @@ type wlSeat struct {
 
 	// The most recent input serial.
 	serial C.uint32_t
+	// The most recent pointer enter serial.
+	pointerSerial C.uint32_t
 
 	pointerFocus  *window
 	keyboardFocus *window
@@ -154,7 +156,6 @@ type repeatState struct {
 type window struct {
 	w          *callbacks
 	disp       *wlDisplay
-	seat       *wlSeat
 	surf       *C.struct_wl_surface
 	wmSurf     *C.struct_xdg_surface
 	topLvl     *C.struct_xdg_toplevel
@@ -851,8 +852,8 @@ func gio_onTouchCancel(data unsafe.Pointer, touch *C.struct_wl_touch) {
 func gio_onPointerEnter(data unsafe.Pointer, pointer *C.struct_wl_pointer, serial C.uint32_t, surf *C.struct_wl_surface, x, y C.wl_fixed_t) {
 	s := callbackLoad(data).(*wlSeat)
 	s.serial = serial
+	s.pointerSerial = serial
 	w := callbackLoad(unsafe.Pointer(surf)).(*window)
-	w.seat = s
 	s.pointerFocus = w
 	w.setCursor(pointer, serial)
 	w.lastPos = f32.Point{X: fromFixed(x), Y: fromFixed(y)}
@@ -861,9 +862,9 @@ func gio_onPointerEnter(data unsafe.Pointer, pointer *C.struct_wl_pointer, seria
 //export gio_onPointerLeave
 func gio_onPointerLeave(data unsafe.Pointer, p *C.struct_wl_pointer, serial C.uint32_t, surf *C.struct_wl_surface) {
 	w := callbackLoad(unsafe.Pointer(surf)).(*window)
-	w.seat = nil
 	s := callbackLoad(data).(*wlSeat)
 	s.serial = serial
+	s.pointerFocus = nil
 	if w.inCompositor {
 		w.inCompositor = false
 		w.ProcessEvent(pointer.Event{Kind: pointer.Cancel})
@@ -883,11 +884,13 @@ func gio_onPointerButton(data unsafe.Pointer, p *C.struct_wl_pointer, serial, t,
 	s := callbackLoad(data).(*wlSeat)
 	s.serial = serial
 	w := s.pointerFocus
-	// From linux-event-codes.h.
+	// From Linux: include/uapi/linux/input-event-codes.h
 	const (
 		BTN_LEFT   = 0x110
 		BTN_RIGHT  = 0x111
 		BTN_MIDDLE = 0x112
+		BTN_SIDE   = 0x113
+		BTN_EXTRA  = 0x114
 	)
 	var btn pointer.Buttons
 	switch wbtn {
@@ -897,6 +900,10 @@ func gio_onPointerButton(data unsafe.Pointer, p *C.struct_wl_pointer, serial, t,
 		btn = pointer.ButtonSecondary
 	case BTN_MIDDLE:
 		btn = pointer.ButtonTertiary
+	case BTN_SIDE:
+		btn = pointer.ButtonQuaternary
+	case BTN_EXTRA:
+		btn = pointer.ButtonQuinary
 	default:
 		return
 	}
@@ -963,6 +970,9 @@ func gio_onPointerAxis(data unsafe.Pointer, p *C.struct_wl_pointer, t, axis C.ui
 func gio_onPointerFrame(data unsafe.Pointer, p *C.struct_wl_pointer) {
 	s := callbackLoad(data).(*wlSeat)
 	w := s.pointerFocus
+	if w == nil {
+		return
+	}
 	w.flushScroll()
 	w.flushFling()
 }
@@ -1143,16 +1153,17 @@ func (w *window) Perform(actions system.Action) {
 }
 
 func (w *window) move(serial C.uint32_t) {
-	s := w.seat
+	s := w.disp.seat
-	if !w.inCompositor && s != nil {
+	if w.inCompositor || s.pointerFocus != w {
-		w.inCompositor = true
+		return
-		C.xdg_toplevel_move(w.topLvl, s.seat, serial)
 	}
+	w.inCompositor = true
+	C.xdg_toplevel_move(w.topLvl, s.seat, serial)
 }
 
 func (w *window) resize(serial, edge C.uint32_t) {
-	s := w.seat
+	s := w.disp.seat
-	if w.inCompositor || s == nil {
+	if w.inCompositor || s.pointerFocus != w {
 		return
 	}
 	w.inCompositor = true
@@ -1165,11 +1176,12 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 }
 
 func (w *window) updateCursor() {
-	ptr := w.disp.seat.pointer
+	s := w.disp.seat
-	if ptr == nil {
+	ptr := s.pointer
+	if ptr == nil || s.pointerFocus != w {
 		return
 	}
-	w.setCursor(ptr, w.serial)
+	w.setCursor(ptr, s.pointerSerial)
 }
 
 func (w *window) setCursor(pointer *C.struct_wl_pointer, serial C.uint32_t) {
@@ -1178,7 +1190,7 @@ func (w *window) setCursor(pointer *C.struct_wl_pointer, serial C.uint32_t) {
 		c = w.cursor.cursor
 	}
 	if c == nil {
-		C.wl_pointer_set_cursor(pointer, w.serial, nil, 0, 0)
+		C.wl_pointer_set_cursor(pointer, serial, nil, 0, 0)
 		return
 	}
 	// Get images[0].

app/os_windows.go

@@ -5,8 +5,12 @@ package app
 import (
 	"errors"
 	"fmt"
+	"gioui.org/io/transfer"
+	syscall "golang.org/x/sys/windows"
+	"golang.org/x/sys/windows/registry"
 	"image"
 	"io"
+	"os"
 	"runtime"
 	"sort"
 	"strings"
@@ -16,8 +20,6 @@ import (
 	"unicode/utf8"
 	"unsafe"
 
-	syscall "golang.org/x/sys/windows"
-
 	"gioui.org/app/internal/windows"
 	"gioui.org/op"
 	"gioui.org/unit"
@@ -28,7 +30,6 @@ import (
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
-	"gioui.org/io/transfer"
 )
 
 type Win32ViewEvent struct {
@@ -36,10 +37,9 @@ type Win32ViewEvent struct {
 }
 
 type window struct {
-	hwnd        syscall.Handle
+	hwnd syscall.Handle
-	hdc         syscall.Handle
+	hdc  syscall.Handle
-	w           *callbacks
+	w    *callbacks
-	pointerBtns pointer.Buttons
 
 	// cursorIn tracks whether the cursor was inside the window according
 	// to the most recent WM_SETCURSOR.
@@ -57,6 +57,8 @@ type window struct {
 
 const _WM_WAKEUP = windows.WM_USER + iota
 
+const copyDataURLType = 0xffffff00
+
 type gpuAPI struct {
 	priority    int
 	initializer func(w *window) (context, error)
@@ -82,6 +84,7 @@ var resources struct {
 }
 
 func osMain() {
+	processURLEvent(startupURI())
 	select {}
 }
 
@@ -133,13 +136,19 @@ func initResources() error {
 	}
 	resources.cursor = c
 	icon, _ := windows.LoadImage(hInst, iconID, windows.IMAGE_ICON, 0, 0, windows.LR_DEFAULTSIZE|windows.LR_SHARED)
+
+	appid, err := syscall.UTF16PtrFromString(ID)
+	if err != nil {
+		return err
+	}
+
 	wcls := windows.WndClassEx{
 		CbSize:        uint32(unsafe.Sizeof(windows.WndClassEx{})),
 		Style:         windows.CS_HREDRAW | windows.CS_VREDRAW | windows.CS_OWNDC,
 		LpfnWndProc:   syscall.NewCallback(windowProc),
 		HInstance:     hInst,
 		HIcon:         icon,
-		LpszClassName: syscall.StringToUTF16Ptr("GioWindow"),
+		LpszClassName: appid,
 	}
 	cls, err := windows.RegisterClassEx(&wcls)
 	if err != nil {
@@ -175,6 +184,12 @@ func (w *window) init() error {
 	if err != nil {
 		return err
 	}
+	if err := windows.RegisterTouchWindow(hwnd, 0); err != nil {
+		return err
+	}
+	if err := windows.EnableMouseInPointer(1); err != nil {
+		return err
+	}
 	w.hdc, err = windows.GetDC(hwnd)
 	if err != nil {
 		windows.DestroyWindow(hwnd)
@@ -265,18 +280,32 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 				return 0
 			}
 		}
-	case windows.WM_LBUTTONDOWN:
+	case windows.WM_POINTERDOWN, windows.WM_POINTERUP, windows.WM_POINTERUPDATE, windows.WM_POINTERCAPTURECHANGED:
-		w.pointerButton(pointer.ButtonPrimary, true, lParam, getModifiers())
+		pid := getPointerIDwParam(wParam)
-	case windows.WM_LBUTTONUP:
+		pi, err := windows.GetPointerInfo(uint32(pid))
-		w.pointerButton(pointer.ButtonPrimary, false, lParam, getModifiers())
+		if err != nil {
-	case windows.WM_RBUTTONDOWN:
+			panic(err)
-		w.pointerButton(pointer.ButtonSecondary, true, lParam, getModifiers())
+		}
-	case windows.WM_RBUTTONUP:
+		switch msg {
-		w.pointerButton(pointer.ButtonSecondary, false, lParam, getModifiers())
+		case windows.WM_POINTERDOWN:
-	case windows.WM_MBUTTONDOWN:
+			windows.SetCapture(w.hwnd)
-		w.pointerButton(pointer.ButtonTertiary, true, lParam, getModifiers())
+		case windows.WM_POINTERUP:
-	case windows.WM_MBUTTONUP:
+			windows.ReleaseCapture()
-		w.pointerButton(pointer.ButtonTertiary, false, lParam, getModifiers())
+		}
+
+		kind := pointer.Move
+		switch pi.ButtonChangeType {
+		case windows.POINTER_CHANGE_FIRSTBUTTON_DOWN, windows.POINTER_CHANGE_SECONDBUTTON_DOWN, windows.POINTER_CHANGE_THIRDBUTTON_DOWN, windows.POINTER_CHANGE_FOURTHBUTTON_DOWN, windows.POINTER_CHANGE_FIFTHBUTTON_DOWN:
+			kind = pointer.Press
+		case windows.POINTER_CHANGE_FIRSTBUTTON_UP, windows.POINTER_CHANGE_SECONDBUTTON_UP, windows.POINTER_CHANGE_THIRDBUTTON_UP, windows.POINTER_CHANGE_FOURTHBUTTON_UP, windows.POINTER_CHANGE_FIFTHBUTTON_UP:
+			kind = pointer.Release
+		}
+
+		if (pi.PointerFlags&windows.POINTER_FLAG_CANCELED != 0) || (msg == windows.WM_POINTERCAPTURECHANGED) {
+			kind = pointer.Cancel
+		}
+
+		w.pointerUpdate(pi, pid, kind, lParam)
 	case windows.WM_CANCELMODE:
 		w.ProcessEvent(pointer.Event{
 			Kind: pointer.Cancel,
@@ -296,20 +325,9 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		np := windows.Point{X: int32(x), Y: int32(y)}
 		windows.ScreenToClient(w.hwnd, &np)
 		return w.hitTest(int(np.X), int(np.Y))
-	case windows.WM_MOUSEMOVE:
+	case windows.WM_POINTERWHEEL:
-		x, y := coordsFromlParam(lParam)
-		p := f32.Point{X: float32(x), Y: float32(y)}
-		w.ProcessEvent(pointer.Event{
-			Kind:      pointer.Move,
-			Source:    pointer.Mouse,
-			Position:  p,
-			Buttons:   w.pointerBtns,
-			Time:      windows.GetMessageTime(),
-			Modifiers: getModifiers(),
-		})
-	case windows.WM_MOUSEWHEEL:
 		w.scrollEvent(wParam, lParam, false, getModifiers())
-	case windows.WM_MOUSEHWHEEL:
+	case windows.WM_POINTERHWHEEL:
 		w.scrollEvent(wParam, lParam, true, getModifiers())
 	case windows.WM_DESTROY:
 		w.ProcessEvent(Win32ViewEvent{})
@@ -351,8 +369,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		w.update()
 	case windows.WM_WINDOWPOSCHANGED:
 		w.update()
-	case windows.WM_SIZE:
+		return 0
-		w.update()
 	case windows.WM_GETMINMAXINFO:
 		mm := (*windows.MinMaxInfo)(unsafe.Pointer(lParam))
 
@@ -395,6 +412,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		icaret := image.Pt(int(caret.X+.5), int(caret.Y+.5))
 		windows.ImmSetCompositionWindow(imc, icaret.X, icaret.Y)
 		windows.ImmSetCandidateWindow(imc, icaret.X, icaret.Y)
+		return windows.TRUE
 	case windows.WM_IME_COMPOSITION:
 		imc := windows.ImmGetContext(w.hwnd)
 		if imc == 0 {
@@ -438,6 +456,20 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 	case windows.WM_IME_ENDCOMPOSITION:
 		w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
 		return windows.TRUE
+	case windows.WM_COPYDATA:
+		data := (*windows.CopyDataStruct)(unsafe.Pointer(lParam))
+		switch data.DwData {
+		case copyDataURLType:
+			if schemesURI == "" {
+				return windows.TRUE
+			}
+
+			uri := syscall.UTF16PtrToString((*uint16)(unsafe.Pointer(data.LpData)))
+			if processURLEvent(uri) {
+				w.Perform(system.ActionRaise)
+			}
+			return windows.TRUE
+		}
 	}
 
 	return windows.DefWindowProc(hwnd, msg, wParam, lParam)
@@ -463,34 +495,32 @@ func getModifiers() key.Modifiers {
 // hitTest returns the non-client area hit by the point, needed to
 // process WM_NCHITTEST.
 func (w *window) hitTest(x, y int) uintptr {
-	if w.config.Mode != Windowed {
+	if w.config.Mode == Windowed {
-		// Only windowed mode should allow resizing.
+		// Check for resize handle before system actions; otherwise it can be impossible to
-		return windows.HTCLIENT
+		// resize a custom-decorations window when the system move area is flush with the
-	}
+		// edge of the window.
-	// Check for resize handle before system actions; otherwise it can be impossible to
+		top := y <= w.borderSize.Y
-	// resize a custom-decorations window when the system move area is flush with the
+		bottom := y >= w.config.Size.Y-w.borderSize.Y
-	// edge of the window.
+		left := x <= w.borderSize.X
-	top := y <= w.borderSize.Y
+		right := x >= w.config.Size.X-w.borderSize.X
-	bottom := y >= w.config.Size.Y-w.borderSize.Y
+		switch {
-	left := x <= w.borderSize.X
+		case top && left:
-	right := x >= w.config.Size.X-w.borderSize.X
+			return windows.HTTOPLEFT
-	switch {
+		case top && right:
-	case top && left:
+			return windows.HTTOPRIGHT
-		return windows.HTTOPLEFT
+		case bottom && left:
-	case top && right:
+			return windows.HTBOTTOMLEFT
-		return windows.HTTOPRIGHT
+		case bottom && right:
-	case bottom && left:
+			return windows.HTBOTTOMRIGHT
-		return windows.HTBOTTOMLEFT
+		case top:
-	case bottom && right:
+			return windows.HTTOP
-		return windows.HTBOTTOMRIGHT
+		case bottom:
-	case top:
+			return windows.HTBOTTOM
-		return windows.HTTOP
+		case left:
-	case bottom:
+			return windows.HTLEFT
-		return windows.HTBOTTOM
+		case right:
-	case left:
+			return windows.HTRIGHT
-		return windows.HTLEFT
+		}
-	case right:
-		return windows.HTRIGHT
 	}
 	p := f32.Pt(float32(x), float32(y))
 	if a, ok := w.w.ActionAt(p); ok && a == system.ActionMove {
@@ -499,34 +529,28 @@ func (w *window) hitTest(x, y int) uintptr {
 	return windows.HTCLIENT
 }
 
-func (w *window) pointerButton(btn pointer.Buttons, press bool, lParam uintptr, kmods key.Modifiers) {
+func (w *window) pointerUpdate(pi windows.PointerInfo, pid pointer.ID, kind pointer.Kind, lParam uintptr) {
 	if !w.config.Focused {
 		windows.SetFocus(w.hwnd)
 	}
 
-	var kind pointer.Kind
+	src := pointer.Touch
-	if press {
+	if pi.PointerType == windows.PT_MOUSE {
-		kind = pointer.Press
+		src = pointer.Mouse
-		if w.pointerBtns == 0 {
-			windows.SetCapture(w.hwnd)
-		}
-		w.pointerBtns |= btn
-	} else {
-		kind = pointer.Release
-		w.pointerBtns &^= btn
-		if w.pointerBtns == 0 {
-			windows.ReleaseCapture()
-		}
 	}
+
 	x, y := coordsFromlParam(lParam)
-	p := f32.Point{X: float32(x), Y: float32(y)}
+	np := windows.Point{X: int32(x), Y: int32(y)}
+	windows.ScreenToClient(w.hwnd, &np)
+	p := f32.Point{X: float32(np.X), Y: float32(np.Y)}
 	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
-		Source:    pointer.Mouse,
+		Source:    src,
 		Position:  p,
-		Buttons:   w.pointerBtns,
+		PointerID: pid,
+		Buttons:   getPointerButtons(pi),
 		Time:      windows.GetMessageTime(),
-		Modifiers: kmods,
+		Modifiers: getModifiers(),
 	})
 }
 
@@ -537,6 +561,12 @@ func coordsFromlParam(lParam uintptr) (int, int) {
 }
 
 func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.Modifiers) {
+	pid := getPointerIDwParam(wParam)
+	pi, err := windows.GetPointerInfo(uint32(pid))
+	if err != nil {
+		panic(err)
+	}
+
 	x, y := coordsFromlParam(lParam)
 	// The WM_MOUSEWHEEL coordinates are in screen coordinates, in contrast
 	// to other mouse events.
@@ -559,7 +589,7 @@ func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.
 		Kind:      pointer.Scroll,
 		Source:    pointer.Mouse,
 		Position:  p,
-		Buttons:   w.pointerBtns,
+		Buttons:   getPointerButtons(pi),
 		Scroll:    sp,
 		Modifiers: kmods,
 		Time:      windows.GetMessageTime(),
@@ -669,7 +699,13 @@ func (w *window) ReadClipboard() {
 	w.readClipboard()
 }
 
-func (w *window) readClipboard() error {
+func (w *window) readClipboard() (cerr error) {
+	defer func() {
+		if cerr != nil {
+			w.processDataEvent("")
+		}
+	}()
+
 	if err := windows.OpenClipboard(w.hwnd); err != nil {
 		return err
 	}
@@ -684,13 +720,17 @@ func (w *window) readClipboard() error {
 	}
 	defer windows.GlobalUnlock(mem)
 	content := gowindows.UTF16PtrToString((*uint16)(unsafe.Pointer(ptr)))
+	w.processDataEvent(content)
+	return nil
+}
+
+func (w *window) processDataEvent(content string) {
 	w.ProcessEvent(transfer.DataEvent{
 		Type: "application/text",
 		Open: func() io.ReadCloser {
 			return io.NopCloser(strings.NewReader(content))
 		},
 	})
-	return nil
 }
 
 func (w *window) Configure(options []Option) {
@@ -707,7 +747,16 @@ func (w *window) Configure(options []Option) {
 	style := windows.GetWindowLong(w.hwnd, windows.GWL_STYLE)
 	var showMode int32
 	var x, y, width, height int32
-	swpStyle := uintptr(windows.SWP_NOZORDER | windows.SWP_FRAMECHANGED)
+	swpStyle := uintptr(windows.SWP_FRAMECHANGED)
+	if cnf.TopMost == w.config.TopMost {
+		// Don't change the z-order if TopMost didn't change.
+		swpStyle |= windows.SWP_NOZORDER
+	}
+	hwndAfter := windows.HWND_NOTOPMOST
+	if cnf.TopMost {
+		hwndAfter = windows.HWND_TOPMOST
+	}
+	w.config.TopMost = cnf.TopMost
 	winStyle := uintptr(windows.WS_OVERLAPPEDWINDOW)
 	style &^= winStyle
 	switch cnf.Mode {
@@ -750,8 +799,17 @@ func (w *window) Configure(options []Option) {
 		swpStyle |= windows.SWP_NOMOVE | windows.SWP_NOSIZE
 		showMode = windows.SW_SHOWMAXIMIZED
 	}
+
+	// Disable window resizing if MinSize and MaxSize are equal.
+	if cnf.MaxSize != (image.Point{}) && cnf.MinSize == cnf.MaxSize {
+		style &^= windows.WS_MAXIMIZEBOX
+		style &^= windows.WS_THICKFRAME
+	}
+
+	// Note: these invocation all trigger the windows callback method which may process a pending system.ActionCenter
+	// action, so SetWindowPos should come first so as to not "overwrite" system.ActionCenter.
+	windows.SetWindowPos(w.hwnd, hwndAfter, x, y, width, height, swpStyle)
 	windows.SetWindowLong(w.hwnd, windows.GWL_STYLE, style)
-	windows.SetWindowPos(w.hwnd, 0, x, y, width, height, swpStyle)
 	windows.ShowWindow(w.hwnd, showMode)
 }
 
@@ -871,19 +929,15 @@ func (w *window) Perform(acts system.Action) {
 			y := (mi.Bottom - mi.Top - dy) / 2
 			windows.SetWindowPos(w.hwnd, 0, x, y, dx, dy, windows.SWP_NOZORDER|windows.SWP_FRAMECHANGED)
 		case system.ActionRaise:
-			w.raise()
+			windows.SetForegroundWindow(w.hwnd)
+			windows.SetWindowPos(w.hwnd, windows.HWND_TOP, 0, 0, 0, 0,
+				windows.SWP_NOMOVE|windows.SWP_NOSIZE|windows.SWP_SHOWWINDOW)
 		case system.ActionClose:
 			windows.PostMessage(w.hwnd, windows.WM_CLOSE, 0, 0)
 		}
 	})
 }
 
-func (w *window) raise() {
-	windows.SetForegroundWindow(w.hwnd)
-	windows.SetWindowPos(w.hwnd, windows.HWND_TOPMOST, 0, 0, 0, 0,
-		windows.SWP_NOMOVE|windows.SWP_NOSIZE|windows.SWP_SHOWWINDOW)
-}
-
 func convertKeyCode(code uintptr) (key.Name, bool) {
 	if '0' <= code && code <= '9' || 'A' <= code && code <= 'Z' {
 		return key.Name(rune(code)), true
@@ -993,3 +1047,257 @@ func (Win32ViewEvent) ImplementsEvent()     {}
 func (w Win32ViewEvent) Valid() bool {
 	return w != (Win32ViewEvent{})
 }
+
+// LOWORD (minwindef.h)
+func loWord(val uint32) uint16 {
+	return uint16(val & 0xFFFF)
+}
+
+// GET_POINTERID_WPARAM (winuser.h)
+func getPointerIDwParam(wParam uintptr) pointer.ID {
+	return pointer.ID(loWord(uint32(wParam)))
+}
+
+func getPointerButtons(pi windows.PointerInfo) pointer.Buttons {
+	var btns pointer.Buttons
+
+	if pi.PointerFlags&windows.POINTER_FLAG_FIRSTBUTTON != 0 {
+		btns |= pointer.ButtonPrimary
+	} else {
+		btns &^= pointer.ButtonPrimary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_SECONDBUTTON != 0 {
+		btns |= pointer.ButtonSecondary
+	} else {
+		btns &^= pointer.ButtonSecondary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_THIRDBUTTON != 0 {
+		btns |= pointer.ButtonTertiary
+	} else {
+		btns &^= pointer.ButtonTertiary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_FOURTHBUTTON != 0 {
+		btns |= pointer.ButtonQuaternary
+	} else {
+		btns &^= pointer.ButtonQuaternary
+	}
+	if pi.PointerFlags&windows.POINTER_FLAG_FIFTHBUTTON != 0 {
+		btns |= pointer.ButtonQuinary
+	} else {
+		btns &^= pointer.ButtonQuinary
+	}
+
+	return btns
+}
+
+// schemesURI is a list of schemes, comma separated, that must be
+// defined using -X compiler ldflag, that used in gogio.
+var schemesURI string
+
+func init() {
+	if schemesURI == "" {
+		return
+	}
+
+	currentSchemes := strings.Split(schemesURI, ",")
+	oldSchemes := registeredSchemes(ID)
+
+	for _, s := range currentSchemes {
+		for i, o := range oldSchemes {
+			if s == o {
+				oldSchemes = append(oldSchemes[:i], oldSchemes[i+1:]...)
+				break
+			}
+		}
+	}
+
+	if len(oldSchemes) > 0 {
+		go unregisterSchemes(ID, oldSchemes)
+	}
+
+	if len(currentSchemes) == 0 {
+		return
+	}
+
+	// On Windows, launching the app using a URI will start a new instance of the app,
+	// a new window. That behavior, by default, doesn't align with iOS/Android/macOS, where
+	// the deeplink sends the event to the running app (if any). We are emulating it.
+	if hwnd, _ := windows.FindWindow(ID); hwnd != 0 {
+		if u := startupURI(); u != "" {
+			broadcastURI(hwnd, u)
+		}
+		os.Exit(0)
+		return
+	}
+
+	go registerSchemes(ID, currentSchemes)
+}
+
+func startupURI() string {
+	if len(os.Args) == 3 && os.Args[1] == "-gio_launch_url" {
+		return os.Args[2]
+	}
+	return ""
+}
+
+func processURLEvent(rawurl string) bool {
+	if rawurl == "" {
+		return false
+	}
+
+	evt, err := newURLEvent(rawurl)
+	if err != nil {
+		return false
+	}
+
+	for _, scheme := range strings.Split(schemesURI, ",") {
+		if strings.EqualFold(scheme, evt.URL.Scheme) {
+			processGlobalEvent(evt)
+			return true
+		}
+	}
+
+	return false
+}
+
+func broadcastURI(hwnd syscall.Handle, uri string) {
+	data, err := syscall.UTF16FromString(uri)
+	if err != nil {
+		return // Only happens if uri contains NULL character.
+	}
+
+	pinner := new(runtime.Pinner)
+	defer pinner.Unpin()
+	pinner.Pin(unsafe.Pointer(&data[0]))
+
+	msg := &windows.CopyDataStruct{
+		DwData: copyDataURLType,
+		CbData: uint32(len(data) * int(unsafe.Sizeof(data[0]))),
+		LpData: uintptr(unsafe.Pointer(unsafe.SliceData(data))),
+	}
+	pinner.Pin(unsafe.Pointer(msg))
+
+	// SendMessage blocks until the message is processed.
+	windows.SendMessage(hwnd, windows.WM_COPYDATA, 0, uintptr(unsafe.Pointer(msg)))
+}
+
+func registeredSchemes(appid string) []string {
+	meta, err := registry.OpenKey(registry.CURRENT_USER, `Software\\`+appid, registry.ALL_ACCESS)
+	if err != nil {
+		return nil
+	}
+	defer meta.Close()
+
+	schemes, _, _ := meta.GetStringsValue("URISchemes")
+	return schemes
+}
+
+func registerSchemes(appid string, schemes []string) error {
+	reg := func(scheme string) error {
+		key, existent, err := registry.CreateKey(registry.CURRENT_USER, `Software\\Classes\\`+scheme, registry.ALL_ACCESS)
+		if err != nil {
+			return err
+		}
+		defer key.Close()
+
+		if existent {
+			// Check if the existent key belongs to the current application
+			id, _, err := key.GetStringValue("appid")
+			if err != nil || id != appid {
+				return fmt.Errorf("scheme %s already registered by another application", scheme)
+			}
+		}
+
+		path, err := os.Executable()
+		if err != nil {
+			return err
+		}
+
+		if err = key.SetStringValue("", "URL:"+scheme+" Protocol"); err != nil {
+			return err
+		}
+		if err = key.SetStringValue("URL Protocol", ""); err != nil {
+			return err
+		}
+		if err = key.SetStringValue("appid", appid); err != nil {
+			return err
+		}
+
+		icon, _, err := registry.CreateKey(key, `DefaultIcon`, registry.ALL_ACCESS)
+		if err != nil {
+			return err
+		}
+		defer icon.Close()
+
+		if err = icon.SetStringValue("", `"`+path+`",1`); err != nil {
+			return err
+		}
+
+		cmd, _, err := registry.CreateKey(key, `shell\\open\\command`, registry.ALL_ACCESS)
+		if err != nil {
+			return err
+		}
+		defer cmd.Close()
+
+		if err = cmd.SetStringValue("", `"`+path+`" -gio_launch_url "%1"`); err != nil {
+			return err
+		}
+
+		return nil
+	}
+
+	for _, scheme := range schemes {
+		if scheme == "" {
+			continue // just in case
+		}
+		if err := reg(scheme); err != nil {
+			return err
+		}
+	}
+
+	meta, _, err := registry.CreateKey(registry.CURRENT_USER, `Software\\`+appid, registry.ALL_ACCESS)
+	if err != nil {
+		return err
+	}
+	defer meta.Close()
+
+	if err = meta.SetStringsValue("URISchemes", schemes); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func unregisterSchemes(appid string, schemes []string) {
+	classes, err := registry.OpenKey(registry.CURRENT_USER, `Software\\Classes`, registry.ALL_ACCESS)
+	if err != nil {
+		return
+	}
+	defer classes.Close()
+
+	for _, scheme := range schemes {
+		if scheme == "" {
+			continue // just in case
+		}
+
+		key, err := registry.OpenKey(classes, scheme, registry.ALL_ACCESS)
+		if err != nil {
+			continue
+		}
+
+		id, _, err := key.GetStringValue("appid")
+		if err == nil && id != appid {
+			continue
+		}
+
+		for _, k := range []string{`DefaultIcon`, `shell\\open\\command`, `shell\\open`, `shell`} {
+			registry.DeleteKey(key, k)
+		}
+
+		if err := key.Close(); err != nil {
+			continue
+		}
+
+		registry.DeleteKey(classes, scheme)
+	}
+}

app/os_x11.go

@@ -26,6 +26,7 @@ package app
 
 */
 import "C"
+
 import (
 	"errors"
 	"fmt"
@@ -751,9 +752,7 @@ func (h *x11EventHandler) handleEvents() bool {
 	return redraw
 }
 
-var (
+var x11Threads sync.Once
-	x11Threads sync.Once
-)
 
 func init() {
 	x11Driver = newX11Window

app/permission/microphone/main.go

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+/*
+Package microphone implements permissions to access microphone hardware.
+
+# Android
+
+The following entries will be added to AndroidManifest.xml:
+
+	<uses-permission android:name="android.permission.RECORD_AUDIO"/>
+
+RECORD_AUDIO is a "dangerous" permission. See documentation for package
+gioui.org/app/permission for more information.
+*/
+package microphone

app/runmain.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build android || (darwin && ios)
-// +build android darwin,ios
 
 package app
 
@@ -25,6 +24,6 @@ func runMain() {
 		// Indirect call, since the linker does not know the address of main when
 		// laying down this package.
 		fn := mainMain
-		fn()
+		go fn()
 	})
 }

app/vulkan_android.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build !novulkan
-// +build !novulkan
 
 package app
 

app/window.go

@@ -439,15 +439,13 @@ func (c *callbacks) EditorState() editorState {
 
 func (c *callbacks) SetComposingRegion(r key.Range) {
 	c.w.imeState.compose = r
+	c.w.driver.ProcessEvent(key.CompositionEvent(r))
 }
 
 func (c *callbacks) EditorInsert(text string) {
 	sel := c.w.imeState.Selection.Range
 	c.EditorReplace(sel, text)
-	start := sel.Start
+	start := min(sel.End, sel.Start)
-	if sel.End < start {
-		start = sel.End
-	}
 	sel.Start = start + utf8.RuneCountInString(text)
 	sel.End = sel.Start
 	c.SetEditorSelection(sel)
@@ -972,6 +970,15 @@ func Decorated(enabled bool) Option {
 	}
 }
 
+// TopMost windows will be rendered above all other non-top-most windows.
+//
+// TopMost windows are supported on macOS, Windows.
+func TopMost(enabled bool) Option {
+	return func(_ unit.Metric, cnf *Config) {
+		cnf.TopMost = enabled
+	}
+}
+
 // flushEvent is sent to detect when the user program
 // has completed processing of all prior events. Its an
 // [io/event.Event] but only for internal use.

f32/affine.go

@@ -30,6 +30,15 @@ func NewAffine2D(sx, hx, ox, hy, sy, oy float32) Affine2D {
 	}
 }
 
+// AffineId returns an identity transformation matrix that represents no transformation
+// when applied.
+func AffineId() Affine2D {
+	return NewAffine2D(
+		1, 0, 0,
+		0, 1, 0,
+	)
+}
+
 // Offset the transformation.
 func (a Affine2D) Offset(offset Point) Affine2D {
 	return Affine2D{
@@ -114,7 +123,7 @@ func (a Affine2D) Elems() (sx, hx, ox, hy, sy, oy float32) {
 
 // Split a transform into two parts, one which is pure offset and the
 // other representing the scaling, shearing and rotation part.
-func (a *Affine2D) Split() (srs Affine2D, offset Point) {
+func (a Affine2D) Split() (srs Affine2D, offset Point) {
 	return Affine2D{
 		a: a.a, b: a.b, c: 0,
 		d: a.d, e: a.e, f: 0,

f32/affine_test.go

@@ -27,11 +27,11 @@ func TestTransformOffset(t *testing.T) {
 	p := Point{X: 1, Y: 2}
 	o := Point{X: 2, Y: -3}
 
-	r := Affine2D{}.Offset(o).Transform(p)
+	r := AffineId().Offset(o).Transform(p)
 	if !eq(r, Pt(3, -1)) {
 		t.Errorf("offset transformation mismatch: have %v, want {3 -1}", r)
 	}
-	i := Affine2D{}.Offset(o).Invert().Transform(r)
+	i := AffineId().Offset(o).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("offset transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -51,6 +51,9 @@ func TestString(t *testing.T) {
 		}, {
 			in:  NewAffine2D(29.142342, 31.4123412, 37.53152, 43.51324213, 47.123412, 53.14312342),
 			exp: "[[29.1423 31.4123 37.5315] [43.5132 47.1234 53.1431]]",
+		}, {
+			in:  AffineId(),
+			exp: "[[1 0 0] [0 1 0]]",
 		},
 	}
 	for _, test := range tests {
@@ -64,11 +67,11 @@ func TestTransformScale(t *testing.T) {
 	p := Point{X: 1, Y: 2}
 	s := Point{X: -1, Y: 2}
 
-	r := Affine2D{}.Scale(Point{}, s).Transform(p)
+	r := AffineId().Scale(Point{}, s).Transform(p)
 	if !eq(r, Pt(-1, 4)) {
 		t.Errorf("scale transformation mismatch: have %v, want {-1 4}", r)
 	}
-	i := Affine2D{}.Scale(Point{}, s).Invert().Transform(r)
+	i := AffineId().Scale(Point{}, s).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("scale transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -78,11 +81,11 @@ func TestTransformRotate(t *testing.T) {
 	p := Point{X: 1, Y: 0}
 	a := float32(math.Pi / 2)
 
-	r := Affine2D{}.Rotate(Point{}, a).Transform(p)
+	r := AffineId().Rotate(Point{}, a).Transform(p)
 	if !eq(r, Pt(0, 1)) {
 		t.Errorf("rotate transformation mismatch: have %v, want {0 1}", r)
 	}
-	i := Affine2D{}.Rotate(Point{}, a).Invert().Transform(r)
+	i := AffineId().Rotate(Point{}, a).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("rotate transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -91,11 +94,11 @@ func TestTransformRotate(t *testing.T) {
 func TestTransformShear(t *testing.T) {
 	p := Point{X: 1, Y: 1}
 
-	r := Affine2D{}.Shear(Point{}, math.Pi/4, 0).Transform(p)
+	r := AffineId().Shear(Point{}, math.Pi/4, 0).Transform(p)
 	if !eq(r, Pt(2, 1)) {
 		t.Errorf("shear transformation mismatch: have %v, want {2 1}", r)
 	}
-	i := Affine2D{}.Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
+	i := AffineId().Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("shear transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -107,11 +110,11 @@ func TestTransformMultiply(t *testing.T) {
 	s := Point{X: -1, Y: 2}
 	a := float32(-math.Pi / 2)
 
-	r := Affine2D{}.Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Transform(p)
+	r := AffineId().Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Transform(p)
 	if !eq(r, Pt(1, 3)) {
 		t.Errorf("complex transformation mismatch: have %v, want {1 3}", r)
 	}
-	i := Affine2D{}.Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
+	i := AffineId().Offset(o).Scale(Point{}, s).Rotate(Point{}, a).Shear(Point{}, math.Pi/4, 0).Invert().Transform(r)
 	if !eq(i, p) {
 		t.Errorf("complex transformation inverse mismatch: have %v, want %v", i, p)
 	}
@@ -163,7 +166,7 @@ func TestPrimes(t *testing.T) {
 func TestTransformScaleAround(t *testing.T) {
 	p := Pt(-1, -1)
 	target := Pt(-6, -13)
-	pt := Affine2D{}.Scale(Pt(4, 5), Pt(2, 3)).Transform(p)
+	pt := AffineId().Scale(Pt(4, 5), Pt(2, 3)).Transform(p)
 	if !eq(pt, target) {
 		t.Log(pt, "!=", target)
 		t.Error("Scale not as expected")
@@ -172,7 +175,7 @@ func TestTransformScaleAround(t *testing.T) {
 
 func TestTransformRotateAround(t *testing.T) {
 	p := Pt(-1, -1)
-	pt := Affine2D{}.Rotate(Pt(1, 1), -math.Pi/2).Transform(p)
+	pt := AffineId().Rotate(Pt(1, 1), -math.Pi/2).Transform(p)
 	target := Pt(-1, 3)
 	if !eq(pt, target) {
 		t.Log(pt, "!=", target)
@@ -181,12 +184,12 @@ func TestTransformRotateAround(t *testing.T) {
 }
 
 func TestMulOrder(t *testing.T) {
-	A := Affine2D{}.Offset(Pt(100, 100))
+	A := AffineId().Offset(Pt(100, 100))
-	B := Affine2D{}.Scale(Point{}, Pt(2, 2))
+	B := AffineId().Scale(Point{}, Pt(2, 2))
 	_ = A
 	_ = B
 
-	T1 := Affine2D{}.Offset(Pt(100, 100)).Scale(Point{}, Pt(2, 2))
+	T1 := AffineId().Offset(Pt(100, 100)).Scale(Point{}, Pt(2, 2))
 	T2 := B.Mul(A)
 
 	if T1 != T2 {
@@ -199,9 +202,9 @@ func TestMulOrder(t *testing.T) {
 func BenchmarkTransformOffset(b *testing.B) {
 	p := Point{X: 1, Y: 2}
 	o := Point{X: 0.5, Y: 0.5}
-	aff := Affine2D{}.Offset(o)
+	aff := AffineId().Offset(o)
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		p = aff.Transform(p)
 	}
 	_ = p
@@ -210,8 +213,8 @@ func BenchmarkTransformOffset(b *testing.B) {
 func BenchmarkTransformScale(b *testing.B) {
 	p := Point{X: 1, Y: 2}
 	s := Point{X: 0.5, Y: 0.5}
-	aff := Affine2D{}.Scale(Point{}, s)
+	aff := AffineId().Scale(Point{}, s)
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		p = aff.Transform(p)
 	}
 	_ = p
@@ -220,36 +223,163 @@ func BenchmarkTransformScale(b *testing.B) {
 func BenchmarkTransformRotate(b *testing.B) {
 	p := Point{X: 1, Y: 2}
 	a := float32(math.Pi / 2)
-	aff := Affine2D{}.Rotate(Point{}, a)
+	aff := AffineId().Rotate(Point{}, a)
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		p = aff.Transform(p)
 	}
 	_ = p
 }
 
 func BenchmarkTransformTranslateMultiply(b *testing.B) {
-	a := Affine2D{}.Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5})
+	t := AffineId().Offset(Point{X: 0.5, Y: 0.5})
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		a = a.Mul(t)
 	}
 }
 
 func BenchmarkTransformScaleMultiply(b *testing.B) {
-	a := Affine2D{}.Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5}).Scale(Point{}, Point{X: 0.4, Y: -0.5})
+	t := AffineId().Offset(Point{X: 0.5, Y: 0.5}).Scale(Point{}, Point{X: 0.4, Y: -0.5})
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		a = a.Mul(t)
 	}
 }
 
 func BenchmarkTransformMultiply(b *testing.B) {
-	a := Affine2D{}.Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5}).Rotate(Point{}, math.Pi/7)
+	t := AffineId().Offset(Point{X: 0.5, Y: 0.5}).Rotate(Point{}, math.Pi/7)
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		a = a.Mul(t)
 	}
 }
+
+func TestNewAffine2D(t *testing.T) {
+	tests := []struct {
+		sx, hx, ox, hy, sy, oy float32
+		expected               Affine2D
+	}{
+		{1, 0, 0, 0, 1, 0, AffineId()},
+		{2, 0, 5, 0, 3, 7, Affine2D{a: 1, b: 0, c: 5, d: 0, e: 2, f: 7}},
+		{-1, 2, 3, 4, -5, 6, Affine2D{a: -2, b: 2, c: 3, d: 4, e: -6, f: 6}},
+	}
+
+	for i, test := range tests {
+		got := NewAffine2D(test.sx, test.hx, test.ox, test.hy, test.sy, test.oy)
+		if !eqaff(got, test.expected) {
+			t.Errorf(
+				"Test %d: NewAffine2D(%v, %v, %v, %v, %v, %v) = %v, want %v",
+				i, test.sx, test.hx, test.ox, test.hy, test.sy, test.oy, got, test.expected,
+			)
+		}
+	}
+}
+
+func TestAffineId(t *testing.T) {
+	id := AffineId()
+
+	testPoints := []Point{
+		{0, 0},
+		{1, 0},
+		{0, 1},
+		{-1, -1},
+		{10, 20},
+	}
+
+	for _, p := range testPoints {
+		transformed := id.Transform(p)
+		if !eq(transformed, p) {
+			t.Errorf("Identity transform changed point: %v -> %v", p, transformed)
+		}
+	}
+}
+
+func TestElems(t *testing.T) {
+	tests := []struct {
+		aff                    Affine2D
+		sx, hx, ox, hy, sy, oy float32
+	}{
+		{AffineId(), 1, 0, 0, 0, 1, 0},
+		{Affine2D{a: 1, b: 2, c: 3, d: 4, e: 5, f: 6}, 2, 2, 3, 4, 6, 6},
+		{NewAffine2D(7, 8, 9, 10, 11, 12), 7, 8, 9, 10, 11, 12},
+	}
+
+	for i, test := range tests {
+		sx, hx, ox, hy, sy, oy := test.aff.Elems()
+		if sx != test.sx || hx != test.hx || ox != test.ox ||
+			hy != test.hy || sy != test.sy || oy != test.oy {
+			t.Errorf(
+				"Test %d: %v.Elems() = (%v, %v, %v, %v, %v, %v), want (%v, %v, %v, %v, %v, %v)",
+				i, test.aff, sx, hx, ox, hy, sy, oy, test.sx, test.hx, test.ox, test.hy, test.sy, test.oy,
+			)
+		}
+	}
+}
+
+func TestSplit(t *testing.T) {
+	tests := []struct {
+		aff            Affine2D
+		expectedSRS    Affine2D
+		expectedOffset Point
+	}{
+		{
+			AffineId(),
+			AffineId(),
+			Point{0, 0},
+		},
+		{
+			Affine2D{a: 1, b: 2, c: 3, d: 4, e: 5, f: 6},
+			Affine2D{a: 1, b: 2, c: 0, d: 4, e: 5, f: 0},
+			Point{3, 6},
+		},
+		{
+			NewAffine2D(2, 0, 10, 0, 3, 20),
+			NewAffine2D(2, 0, 0, 0, 3, 0),
+			Point{10, 20},
+		},
+	}
+
+	for i, test := range tests {
+		srs, offset := test.aff.Split()
+		if !eqaff(srs, test.expectedSRS) || !eq(offset, test.expectedOffset) {
+			t.Errorf(
+				"Test %d: %v.Split() = (%v, %v), want (%v, %v)",
+				i, test.aff, srs, offset, test.expectedSRS, test.expectedOffset,
+			)
+		}
+	}
+}
+
+func TestShear(t *testing.T) {
+	p := Pt(2, 3)
+	origin := Pt(1, 1)
+
+	shearX := AffineId().Shear(origin, math.Pi/4, 0)
+	resultX := shearX.Transform(p)
+	expectedX := Pt(4, 3)
+
+	if !eq(resultX, expectedX) {
+		t.Errorf("Shear around origin in X: got %v, want %v", resultX, expectedX)
+	}
+
+	inverseX := shearX.Invert().Transform(resultX)
+	if !eq(inverseX, p) {
+		t.Errorf("Inverse shear X: got %v, want %v", inverseX, p)
+	}
+
+	shearY := AffineId().Shear(origin, 0, math.Pi/4)
+	resultY := shearY.Transform(p)
+	expectedY := Pt(2, 4)
+
+	if !eq(resultY, expectedY) {
+		t.Errorf("Shear around origin in Y: got %v, want %v", resultY, expectedY)
+	}
+
+	inverseY := shearY.Invert().Transform(resultY)
+	if !eq(inverseY, p) {
+		t.Errorf("Inverse shear Y: got %v, want %v", inverseY, p)
+	}
+}

flake.lock

@@ -1,86 +1,25 @@
 {
   "nodes": {
-    "android": {
-      "inputs": {
-        "devshell": "devshell",
-        "flake-utils": "flake-utils",
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1733430059,
-        "narHash": "sha256-o3O5tjrMMebRLuHQt7BbEw3jZgWRW5vnOptNXv8WdO4=",
-        "owner": "tadfisher",
-        "repo": "android-nixpkgs",
-        "rev": "d2f3c1ea99c0bea9d28a0e59daeb482f50d4cd35",
-        "type": "github"
-      },
-      "original": {
-        "owner": "tadfisher",
-        "repo": "android-nixpkgs",
-        "type": "github"
-      }
-    },
-    "devshell": {
-      "inputs": {
-        "nixpkgs": [
-          "android",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1728330715,
-        "narHash": "sha256-xRJ2nPOXb//u1jaBnDP56M7v5ldavjbtR6lfGqSvcKg=",
-        "owner": "numtide",
-        "repo": "devshell",
-        "rev": "dd6b80932022cea34a019e2bb32f6fa9e494dfef",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "devshell",
-        "type": "github"
-      }
-    },
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1733261153,
+        "lastModified": 1747953325,
-        "narHash": "sha256-eq51hyiaIwtWo19fPEeE0Zr2s83DYMKJoukNLgGGpek=",
+        "narHash": "sha256-y2ZtlIlNTuVJUZCqzZAhIw5rrKP4DOSklev6c8PyCkQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "b681065d0919f7eb5309a93cea2cfa84dec9aa88",
+        "rev": "55d1f923c480dadce40f5231feb472e81b0bab48",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-24.11",
+        "ref": "nixos-25.05",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
-        "android": "android",
+        "nixpkgs": "nixpkgs",
-        "nixpkgs": "nixpkgs"
+        "utils": "utils"
       }
     },
     "systems": {
@@ -97,6 +36,24 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -3,42 +3,38 @@
   description = "Gio build environment";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
-    android.url = "github:tadfisher/android-nixpkgs";
+    utils.url = "github:numtide/flake-utils";
-    android.inputs.nixpkgs.follows = "nixpkgs";
   };
 
-  outputs = { self, nixpkgs, android }:
+  outputs = { self, nixpkgs, utils }:
-    let
+    utils.lib.eachDefaultSystem (system:
-      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      let
-      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
+        pkgs = import nixpkgs {
-    in
+          inherit system;
-    {
+
-      devShells = forAllSystems
+          # allow unfree Android packages.
-        (system:
+          config.allowUnfree = true;
-          let
+          # accept the Android SDK license.
-            pkgs = import nixpkgs {
+          config.android_sdk.accept_license = true; 
-              inherit system;
+        };
+      in {
+        devShells = let
+          android-sdk = let
+            androidComposition = pkgs.androidenv.composeAndroidPackages {
+              platformVersions = [ "latest" ];
+              abiVersions = [ "armeabi-v7a" "arm64-v8a" ];
+               # Omit the deprecated tools package.
+              toolsVersion = null;
+              includeNDK = true;
             };
-            android-sdk = android.sdk.${system} (sdkPkgs: with sdkPkgs;
+          in androidComposition.androidsdk;
-              [
+        in {
-                build-tools-31-0-0
+          default = with pkgs;
-                cmdline-tools-latest
+            mkShell (rec {
-                platform-tools
+              ANDROID_HOME = "${android-sdk}/libexec/android-sdk";
-                platforms-android-31
+              packages = [ android-sdk jdk clang ]
-                ndk-bundle
+                ++ (if stdenv.isLinux then [
-              ]);
-          in
-          {
-            default = with pkgs; mkShell
-              ({
-                ANDROID_SDK_ROOT = "${android-sdk}/share/android-sdk";
-                JAVA_HOME = jdk17.home;
-                packages = [
-                  android-sdk
-                  jdk17
-                  clang
-                ] ++ (if stdenv.isLinux then [
                   vulkan-headers
                   libxkbcommon
                   wayland
@@ -47,11 +43,12 @@
                   xorg.libXfixes
                   libGL
                   pkg-config
-                ] else [ ]);
+                ] else
-              } // (if stdenv.isLinux then {
+                  [ ]);
-                LD_LIBRARY_PATH = "${vulkan-loader}/lib";
+            } // (if stdenv.isLinux then {
-              } else { }));
+              LD_LIBRARY_PATH = "${vulkan-loader}/lib";
-          }
+            } else
-        );
+              { }));
-    };
+        };
+      });
 }

font/opentype/opentype.go

@@ -106,7 +106,7 @@ func parseLoader(ld *opentype.Loader) (*fontapi.Font, giofont.Font, error) {
 // Face many be invoked any number of times and is safe so long as each return value is
 // only used by one goroutine.
 func (f Face) Face() *fontapi.Face {
-	return &fontapi.Face{Font: f.face}
+	return fontapi.NewFace(f.face)
 }
 
 // FontFace returns a text.Font with populated font metadata for the

gesture/gesture.go

@@ -61,12 +61,8 @@ func (h *Hover) Update(q input.Source) bool {
 				h.entered = false
 			}
 		case pointer.Enter:
-			if !h.entered {
+			h.pid = e.PointerID
-				h.pid = e.PointerID
+			h.entered = true
-			}
-			if h.pid == e.PointerID {
-				h.entered = true
-			}
 		}
 	}
 	return h.entered
@@ -222,12 +218,7 @@ func (c *Click) Update(q input.Source) (ClickEvent, bool) {
 			if e.Source == pointer.Mouse && e.Buttons != pointer.ButtonPrimary {
 				break
 			}
-			if !c.hovered {
+			c.pid = e.PointerID
-				c.pid = e.PointerID
-			}
-			if c.pid != e.PointerID {
-				break
-			}
 			c.pressed = true
 			if e.Time-c.clickedAt < doubleClickDuration {
 				c.clicks++
@@ -322,6 +313,8 @@ func (s *Scroll) Update(cfg unit.Metric, q input.Source, t time.Time, axis Axis,
 				s.scroll += e.Scroll.X
 			case Vertical:
 				s.scroll += e.Scroll.Y
+			case Both:
+				s.scroll += e.Scroll.X + e.Scroll.Y
 			}
 			iscroll := int(s.scroll)
 			s.scroll -= float32(iscroll)
@@ -353,10 +346,15 @@ func (s *Scroll) Update(cfg unit.Metric, q input.Source, t time.Time, axis Axis,
 }
 
 func (s *Scroll) val(axis Axis, p f32.Point) float32 {
-	if axis == Horizontal {
+	switch axis {
+	case Horizontal:
 		return p.X
-	} else {
+	case Vertical:
 		return p.Y
+	case Both:
+		return p.X + p.Y
+	default:
+		return 0
 	}
 }
 

gesture/gesture_test.go

@@ -100,6 +100,78 @@ func TestMouseClicks(t *testing.T) {
 	}
 }
 
+func TestClickPointerIDReassignment(t *testing.T) {
+	// A Click must accept a Press from a PointerID that differs from the
+	// one its hovered state was previously associated with. Some backends
+	// reassign a single physical pointer's ID over its lifetime — e.g. the
+	// Windows pointer API across focus changes — and locking the gesture
+	// to the first observed ID would silently drop every subsequent press.
+	//
+	// The sequence below puts the gesture into the buggy state through
+	// public events alone: a press under PointerID 1 starts an active
+	// press cycle, a Move under PointerID 2 arrives mid-press (which the
+	// router routes as an Enter for PID 2 but the gesture's Enter handler
+	// is a no-op for pid while pressed), then PID 1 releases. After this,
+	// the router has the gesture entered for PID 2 (so the next event
+	// under PID 2 won't trigger another Enter) but the gesture itself
+	// still has pid=1.
+	var click Click
+	var ops op.Ops
+	rect := image.Rect(0, 0, 100, 100)
+	stack := clip.Rect(rect).Push(&ops)
+	click.Add(&ops)
+	stack.Pop()
+
+	var r input.Router
+	click.Update(r.Source())
+	r.Frame(&ops)
+
+	drain := func() {
+		for {
+			if _, ok := click.Update(r.Source()); !ok {
+				return
+			}
+		}
+	}
+
+	// Press under PointerID 1.
+	r.Queue(
+		pointer.Event{Kind: pointer.Move, Source: pointer.Mouse, Position: f32.Pt(50, 50), PointerID: 1},
+		pointer.Event{Kind: pointer.Press, Source: pointer.Mouse, Buttons: pointer.ButtonPrimary, Position: f32.Pt(50, 50), PointerID: 1},
+	)
+	drain()
+
+	// Move under PointerID 2 while PointerID 1 is still pressed. The
+	// router records the gesture as entered for PointerID 2 but the
+	// gesture's Enter handler is a no-op for pid because c.pressed.
+	r.Queue(pointer.Event{Kind: pointer.Move, Source: pointer.Mouse, Position: f32.Pt(50, 50), PointerID: 2})
+	drain()
+
+	// Release PointerID 1. PointerID 1's press tracking ends; the
+	// gesture's recorded pid stays at 1.
+	r.Queue(pointer.Event{Kind: pointer.Release, Source: pointer.Mouse, Position: f32.Pt(50, 50), PointerID: 1})
+	drain()
+
+	// Press under PointerID 2. The router won't refire Enter for PID 2
+	// (the gesture is already in PID 2's entered set), so the gesture's
+	// only chance to refresh its pid is the Press handler itself.
+	r.Queue(pointer.Event{Kind: pointer.Press, Source: pointer.Mouse, Buttons: pointer.ButtonPrimary, Position: f32.Pt(50, 50), PointerID: 2})
+
+	var sawPress bool
+	for {
+		ev, ok := click.Update(r.Source())
+		if !ok {
+			break
+		}
+		if ev.Kind == KindPress {
+			sawPress = true
+		}
+	}
+	if !sawPress {
+		t.Fatal("expected KindPress for press under reassigned PointerID; gesture dropped the press because of stale recorded pid")
+	}
+}
+
 func mouseClickEvents(times ...time.Duration) []event.Event {
 	press := pointer.Event{
 		Kind:    pointer.Press,

go.mod

@@ -1,14 +1,16 @@
 module gioui.org
 
-go 1.21
+go 1.24.0
 
 require (
 	eliasnaur.com/font v0.0.0-20230308162249-dd43949cb42d
 	gioui.org/shader v1.0.8
-	github.com/go-text/typesetting v0.2.1
+	github.com/go-text/typesetting v0.3.4
-	golang.org/x/exp v0.0.0-20240707233637-46b078467d37
+	golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0
-	golang.org/x/exp/shiny v0.0.0-20240707233637-46b078467d37
+	golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0
-	golang.org/x/image v0.18.0
+	golang.org/x/image v0.26.0
-	golang.org/x/sys v0.22.0
+	golang.org/x/sys v0.39.0
-	golang.org/x/text v0.16.0
+	golang.org/x/text v0.32.0
 )
+
+require golang.org/x/net v0.48.0

go.sum

@@ -3,17 +3,19 @@ eliasnaur.com/font v0.0.0-20230308162249-dd43949cb42d/go.mod h1:OYVuxibdk9OSLX8v
 gioui.org/cpu v0.0.0-20210808092351-bfe733dd3334/go.mod h1:A8M0Cn5o+vY5LTMlnRoK3O5kG+rH0kWfJjeKd9QpBmQ=
 gioui.org/shader v1.0.8 h1:6ks0o/A+b0ne7RzEqRZK5f4Gboz2CfG+mVliciy6+qA=
 gioui.org/shader v1.0.8/go.mod h1:mWdiME581d/kV7/iEhLmUgUK5iZ09XR5XpduXzbePVM=
-github.com/go-text/typesetting v0.2.1 h1:x0jMOGyO3d1qFAPI0j4GSsh7M0Q3Ypjzr4+CEVg82V8=
+github.com/go-text/typesetting v0.3.4 h1:YYurUOtEb9kGSOz4uE3k4OpBGsp1dDL8+fjCeaFamAU=
-github.com/go-text/typesetting v0.2.1/go.mod h1:mTOxEwasOFpAMBjEQDhdWRckoLLeI/+qrQeBCTGEt6M=
+github.com/go-text/typesetting v0.3.4/go.mod h1:4qZCQphq4KSgGTAeI0uMEkVbROgfah8BuyF5LRYr7XY=
-github.com/go-text/typesetting-utils v0.0.0-20241103174707-87a29e9e6066 h1:qCuYC+94v2xrb1PoS4NIDe7DGYtLnU2wWiQe9a1B1c0=
+github.com/go-text/typesetting-utils v0.0.0-20260223113751-2d88ac90dae3 h1:drBZzMgdYPbmyXqOto4YhhJGrFIQCX94FpR4MzTCsos=
-github.com/go-text/typesetting-utils v0.0.0-20241103174707-87a29e9e6066/go.mod h1:DDxDdQEnB70R8owOx3LVpEFvpMK9eeH1o2r0yZhFI9o=
+github.com/go-text/typesetting-utils v0.0.0-20260223113751-2d88ac90dae3/go.mod h1:3/62I4La/HBRX9TcTpBj4eipLiwzf+vhI+7whTc9V7o=
-golang.org/x/exp v0.0.0-20240707233637-46b078467d37 h1:uLDX+AfeFCct3a2C7uIWBKMJIR3CJMhcgfrUAqjRK6w=
+golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0 h1:R84qjqJb5nVJMxqWYb3np9L5ZsaDtB+a39EqjV0JSUM=
-golang.org/x/exp v0.0.0-20240707233637-46b078467d37/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
+golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0/go.mod h1:S9Xr4PYopiDyqSyp5NjCrhFrqg6A5zA2E/iPHPhqnS8=
-golang.org/x/exp/shiny v0.0.0-20240707233637-46b078467d37 h1:SOSg7+sueresE4IbmmGM60GmlIys+zNX63d6/J4CMtU=
+golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0 h1:tMSqXTK+AQdW3LpCbfatHSRPHeW6+2WuxaVQuHftn80=
-golang.org/x/exp/shiny v0.0.0-20240707233637-46b078467d37/go.mod h1:3F+MieQB7dRYLTmnncoFbb1crS5lfQoTfDgQy6K4N0o=
+golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0/go.mod h1:ygj7T6vSGhhm/9yTpOQQNvuAUFziTH7RUiH74EoE2C8=
-golang.org/x/image v0.18.0 h1:jGzIakQa/ZXI1I0Fxvaa9W7yP25TqT6cHIHn+6CqvSQ=
+golang.org/x/image v0.26.0 h1:4XjIFEZWQmCZi6Wv8BoxsDhRU3RVnLX04dToTDAEPlY=
-golang.org/x/image v0.18.0/go.mod h1:4yyo5vMFQjVjUcVk4jEQcU9MGy/rulF5WvUILseCM2E=
+golang.org/x/image v0.26.0/go.mod h1:lcxbMFAovzpnJxzXS3nyL83K27tmqtKzIJpctK8YO5c=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
+golang.org/x/net v0.48.0 h1:zyQRTTrjc33Lhh0fBgT/H3oZq9WuvRR5gPC70xpDiQU=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/net v0.48.0/go.mod h1:+ndRgGjkh8FGtu1w1FGbEC31if4VrNVMuKTgcAAnQRY=
-golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
-golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
+golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=

gpu/clip.go

@@ -19,10 +19,10 @@ type quadSplitter struct {
 
 func encodeQuadTo(data []byte, meta uint32, from, ctrl, to f32.Point) {
 	// inlined code:
-	//   encodeVertex(data, meta, -1, 1, from, ctrl, to)
+	//   encodeVertex(data, meta, 1, -1, from, ctrl, to)
 	//   encodeVertex(data[vertStride:], meta, 1, 1, from, ctrl, to)
 	//   encodeVertex(data[vertStride*2:], meta, -1, -1, from, ctrl, to)
-	//   encodeVertex(data[vertStride*3:], meta, 1, -1, from, ctrl, to)
+	//   encodeVertex(data[vertStride*3:], meta, -1, 1, from, ctrl, to)
 	// this code needs to stay in sync with `vertex.encode`.
 
 	bo := binary.LittleEndian
@@ -48,10 +48,10 @@ func encodeQuadTo(data []byte, meta uint32, from, ctrl, to f32.Point) {
 }
 
 const (
-	nwCorner = 1*0.25 + 0*0.5
+	nwCorner = 1*0.5 + 0*0.25
-	neCorner = 1*0.25 + 1*0.5
+	neCorner = 1*0.5 + 1*0.25
-	swCorner = 0*0.25 + 0*0.5
+	swCorner = 0*0.5 + 0*0.25
-	seCorner = 0*0.25 + 1*0.5
+	seCorner = 0*0.5 + 1*0.25
 )
 
 func encodeVertex(data []byte, meta uint32, cornerx, cornery int16, from, ctrl, to f32.Point) {

gpu/clip_test.go

@@ -10,7 +10,7 @@ import (
 
 func BenchmarkEncodeQuadTo(b *testing.B) {
 	var data [vertStride * 4]byte
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		v := float32(i)
 		encodeQuadTo(data[:], 123,
 			f32.Point{X: v, Y: v},

gpu/gpu.go

@@ -15,6 +15,7 @@ import (
 	"image/color"
 	"math"
 	"reflect"
+	"slices"
 	"time"
 	"unsafe"
 
@@ -189,7 +190,7 @@ const (
 // imageOpData is the shadow of paint.ImageOp.
 type imageOpData struct {
 	src    *image.RGBA
-	handle interface{}
+	handle any
 	filter byte
 }
 
@@ -200,7 +201,7 @@ type linearGradientOpData struct {
 	color2 color.NRGBA
 }
 
-func decodeImageOp(data []byte, refs []interface{}) imageOpData {
+func decodeImageOp(data []byte, refs []any) imageOpData {
 	handle := refs[1]
 	if handle == nil {
 		return imageOpData{}
@@ -547,7 +548,7 @@ func newBlitter(ctx driver.Device) *blitter {
 	b.texUniforms = new(blitTexUniforms)
 	b.linearGradientUniforms = new(blitLinearGradientUniforms)
 	pipelines, err := createColorPrograms(ctx, gio.Shader_blit_vert, gio.Shader_blit_frag,
-		[3]interface{}{b.colUniforms, b.linearGradientUniforms, b.texUniforms},
+		[3]any{b.colUniforms, b.linearGradientUniforms, b.texUniforms},
 	)
 	if err != nil {
 		panic(err)
@@ -565,7 +566,7 @@ func (b *blitter) release() {
 	}
 }
 
-func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.Sources, uniforms [3]interface{}) (pipelines [2][3]*pipeline, err error) {
+func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.Sources, uniforms [3]any) (pipelines [2][3]*pipeline, err error) {
 	defer func() {
 		if err != nil {
 			for _, p := range pipelines {
@@ -822,7 +823,7 @@ func (r *renderer) packLayers(layers []opacityLayer) []opacityLayer {
 			layers[l.parent].clip = b.Union(l.clip)
 		}
 		if l.clip.Empty() {
-			layers = append(layers[:i], layers[i+1:]...)
+			layers = slices.Delete(layers, i, i+1)
 		}
 	}
 	// Pack layers.
@@ -871,7 +872,7 @@ func (r *renderer) drawLayers(layers []opacityLayer, ops []imageOp) {
 		r.drawOps(true, l.clip.Min.Mul(-1), l.clip.Size(), ops[l.opStart:l.opEnd])
 		sr := f32.FRect(v)
 		uvScale, uvOffset := texSpaceTransform(sr, f.size)
-		uvTrans := f32.Affine2D{}.Scale(f32.Point{}, uvScale).Offset(uvOffset)
+		uvTrans := f32.AffineId().Scale(f32.Point{}, uvScale).Offset(uvOffset)
 		// Replace layer ops with one textured op.
 		ops[l.opStart] = imageOp{
 			clip: l.clip,
@@ -956,7 +957,9 @@ func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey opKey, bounds
 
 func (d *drawOps) save(id int, state f32.Affine2D) {
 	if extra := id - len(d.states) + 1; extra > 0 {
-		d.states = append(d.states, make([]f32.Affine2D, extra)...)
+		for range extra {
+			d.states = append(d.states, f32.AffineId())
+		}
 	}
 	d.states[id] = state
 }
@@ -971,12 +974,13 @@ func (k opKey) SetTransform(t f32.Affine2D) opKey {
 }
 
 func (d *drawOps) collectOps(r *ops.Reader, viewport f32.Rectangle) {
-	var (
+	var quads quadsOp
-		quads quadsOp
+	state := drawState{
-		state drawState
+		t: f32.AffineId(),
-	)
+	}
 	reset := func() {
 		state = drawState{
+			t:     f32.AffineId(),
 			color: color.NRGBA{A: 0xff},
 		}
 	}
@@ -1032,7 +1036,7 @@ loop:
 			op.Decode(encOp.Data)
 			quads.key.outline = op.Outline
 			bounds := f32.FRect(op.Bounds)
-			trans, off := state.t.Split()
+			trans, off := transformOffset(state.t)
 			if len(quads.aux) > 0 {
 				// There is a clipping path, build the gpu data and update the
 				// cache key such that it will be equal only if the transform is the
@@ -1055,6 +1059,7 @@ loop:
 			} else {
 				quads.aux, bounds, _ = d.boundsForTransformedRect(bounds, trans)
 				quads.key = opKey{Key: encOp.Key}
+				quads.key = quads.key.SetTransform(trans)
 			}
 			d.addClipPath(&state, quads.aux, quads.key, bounds, off)
 			quads = quadsOp{}
@@ -1078,7 +1083,7 @@ loop:
 			// Transform (if needed) the painting rectangle and if so generate a clip path,
 			// for those cases also compute a partialTrans that maps texture coordinates between
 			// the new bounding rectangle and the transformed original paint rectangle.
-			t, off := state.t.Split()
+			t, off := transformOffset(state.t)
 			// Fill the clip area, unless the material is a (bounded) image.
 			// TODO: Find a tighter bound.
 			inf := float32(1e6)
@@ -1100,7 +1105,7 @@ loop:
 				// The paint operation is sheared or rotated, add a clip path representing
 				// this transformed rectangle.
 				k := opKey{Key: encOp.Key}
-				k.SetTransform(t) // TODO: This call has no effect.
+				k = k.SetTransform(t)
 				d.addClipPath(&state, clipData, k, bnd, off)
 			}
 
@@ -1161,6 +1166,7 @@ func expandPathOp(p *pathOp, clip image.Rectangle) {
 func (d *drawState) materialFor(rect f32.Rectangle, off f32.Point, partTrans f32.Affine2D, clip image.Rectangle) material {
 	m := material{
 		opacity: 1.,
+		uvTrans: f32.AffineId(),
 	}
 	switch d.matType {
 	case materialColor:
@@ -1194,7 +1200,7 @@ func (d *drawState) materialFor(rect f32.Rectangle, off f32.Point, partTrans f32
 		sr.Min.Y += float32(clip.Min.Y-dr.Min.Y) * sdy / dy
 		sr.Max.Y -= float32(dr.Max.Y-clip.Max.Y) * sdy / dy
 		uvScale, uvOffset := texSpaceTransform(sr, sz)
-		m.uvTrans = partTrans.Mul(f32.Affine2D{}.Scale(f32.Point{}, uvScale).Offset(uvOffset))
+		m.uvTrans = partTrans.Mul(f32.AffineId().Scale(f32.Point{}, uvScale).Offset(uvOffset))
 		m.data = d.image
 	}
 	return m
@@ -1315,7 +1321,7 @@ func (b *blitter) blit(mat materialType, fbo bool, col f32color.RGBA, col1, col2
 
 // newUniformBuffer creates a new GPU uniform buffer backed by the
 // structure uniformBlock points to.
-func newUniformBuffer(b driver.Device, uniformBlock interface{}) *uniformBuffer {
+func newUniformBuffer(b driver.Device, uniformBlock any) *uniformBuffer {
 	ref := reflect.ValueOf(uniformBlock)
 	// Determine the size of the uniforms structure, *uniforms.
 	size := ref.Elem().Type().Size()
@@ -1369,7 +1375,7 @@ func gradientSpaceTransform(clip image.Rectangle, off f32.Point, stop1, stop2 f3
 
 	// TODO: optimize
 	zp := f32.Point{}
-	return f32.Affine2D{}.
+	return f32.AffineId().
 		Scale(zp, layout.FPt(clip.Size())).            // scale to pixel space
 		Offset(zp.Sub(off).Add(layout.FPt(clip.Min))). // offset to clip space
 		Offset(zp.Sub(stop1)).                         // offset to first stop point
@@ -1519,12 +1525,10 @@ func decodeToOutlineQuads(qs *quadSplitter, tr f32.Affine2D, pathData []byte) {
 
 // create GPU vertices for transformed r, find the bounds and establish texture transform.
 func (d *drawOps) boundsForTransformedRect(r f32.Rectangle, tr f32.Affine2D) (aux []byte, bnd f32.Rectangle, ptr f32.Affine2D) {
-	if isPureOffset(tr) {
+	ptr = f32.AffineId()
-		// fast-path to allow blitting of pure rectangles
+	if tr == f32.AffineId() {
-		_, _, ox, _, _, oy := tr.Elems()
+		// fast-path to allow blitting of pure rectangles.
-		off := f32.Pt(ox, oy)
+		bnd = r
-		bnd.Min = r.Min.Add(off)
-		bnd.Max = r.Max.Add(off)
 		return
 	}
 
@@ -1571,12 +1575,19 @@ func (d *drawOps) boundsForTransformedRect(r f32.Rectangle, tr f32.Affine2D) (au
 	sx, sy := P2.X-P3.X, P2.Y-P3.Y
 	ptr = f32.NewAffine2D(sx, P2.X-P1.X, P1.X-sx, sy, P2.Y-P1.Y, P1.Y-sy).Invert()
 
-	return
+	return aux, bnd, ptr
 }
 
-func isPureOffset(t f32.Affine2D) bool {
+// transformOffset a transform into two parts, one which is pure integer offset
-	a, b, _, d, e, _ := t.Elems()
+// and the other representing the scaling, shearing and rotation and fractional
-	return a == 1 && b == 0 && d == 0 && e == 1
+// offset.
+func transformOffset(t f32.Affine2D) (f32.Affine2D, f32.Point) {
+	sx, hx, ox, hy, sy, oy := t.Elems()
+	iox, fox := math.Modf(float64(ox))
+	ioy, foy := math.Modf(float64(oy))
+	ft := f32.NewAffine2D(sx, hx, float32(fox), hy, sy, float32(foy))
+	ip := f32.Pt(float32(iox), float32(ioy))
+	return ft, ip
 }
 
 func newShaders(ctx driver.Device, vsrc, fsrc shader.Sources) (vert driver.VertexShader, frag driver.FragmentShader, err error) {

gpu/headless/driver_test.go

@@ -21,8 +21,10 @@ import (
 
 var dumpImages = flag.Bool("saveimages", false, "save test images")
 
-var clearCol = color.NRGBA{A: 0xff, R: 0xde, G: 0xad, B: 0xbe}
+var (
-var clearColExpect = f32color.NRGBAToRGBA(clearCol)
+	clearCol       = color.NRGBA{A: 0xff, R: 0xde, G: 0xad, B: 0xbe}
+	clearColExpect = f32color.NRGBAToRGBA(clearCol)
+)
 
 func TestFramebufferClear(t *testing.T) {
 	b := newDriver(t)
@@ -202,5 +204,5 @@ func saveImage(file string, img image.Image) error {
 	if err := png.Encode(&buf, img); err != nil {
 		return err
 	}
-	return os.WriteFile(file, buf.Bytes(), 0666)
+	return os.WriteFile(file, buf.Bytes(), 0o666)
 }

gpu/headless/headless_egl.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build linux || freebsd || openbsd
-// +build linux freebsd openbsd
 
 package headless
 

gpu/internal/d3d11/d3d11_windows.go

@@ -152,9 +152,7 @@ func newDirect3D11Device(api driver.Direct3D11) (driver.Device, error) {
 }
 
 func (b *Backend) BeginFrame(target driver.RenderTarget, clear bool, viewport image.Point) driver.Texture {
-	var (
+	var renderTarget *d3d11.RenderTargetView
-		renderTarget *d3d11.RenderTargetView
-	)
 	if target != nil {
 		switch t := target.(type) {
 		case driver.Direct3D11RenderTarget:
@@ -229,10 +227,7 @@ func (b *Backend) NewTexture(format driver.TextureFormat, width, height int, min
 		// Flags required by ID3D11DeviceContext::GenerateMips.
 		bindFlags |= d3d11.BIND_SHADER_RESOURCE | d3d11.BIND_RENDER_TARGET
 		miscFlags |= d3d11.RESOURCE_MISC_GENERATE_MIPS
-		dim := width
+		dim := max(height, width)
-		if height > dim {
-			dim = height
-		}
 		log2 := 32 - bits.LeadingZeros32(uint32(dim)) - 1
 		nmipmaps = log2 + 1
 	}
@@ -802,7 +797,7 @@ func (t *Texture) ReadPixels(src image.Rectangle, pixels []byte, stride int) err
 	mapSize := dstPitch * h
 	data := sliceOf(resMap.PData, mapSize)
 	width := w * 4
-	for r := 0; r < h; r++ {
+	for r := range h {
 		pixels := pixels[r*srcPitch:]
 		copy(pixels[:width], data[r*dstPitch:])
 	}

gpu/internal/driver/driver.go

@@ -96,8 +96,10 @@ type BlendFactor uint8
 
 type Topology uint8
 
-type TextureFilter uint8
+type (
-type TextureFormat uint8
+	TextureFilter uint8
+	TextureFormat uint8
+)
 
 type BufferBinding uint8
 
@@ -217,7 +219,7 @@ func flipImageY(stride, height int, pixels []byte) {
 	// Flip image in y-direction. OpenGL's origin is in the lower
 	// left corner.
 	row := make([]uint8, stride)
-	for y := 0; y < height/2; y++ {
+	for y := range height / 2 {
 		y1 := height - y - 1
 		dest := y1 * stride
 		src := y * stride

gpu/internal/opengl/opengl.go

@@ -8,6 +8,7 @@ import (
 	"image"
 	"math/bits"
 	"runtime"
+	"slices"
 	"strings"
 	"time"
 	"unsafe"
@@ -717,10 +718,7 @@ func (b *Backend) NewTexture(format driver.TextureFormat, width, height int, min
 	if mipmap {
 		nmipmaps := 1
 		if mipmap {
-			dim := width
+			dim := max(height, width)
-			if height > dim {
-				dim = height
-			}
 			log2 := 32 - bits.LeadingZeros32(uint32(dim)) - 1
 			nmipmaps = log2 + 1
 		}
@@ -1132,7 +1130,7 @@ func (b *Backend) setupVertexArrays() {
 		enabled[inp.Location] = true
 		b.glstate.vertexAttribPointer(b.funcs, buf.obj, inp.Location, l.Size, gltyp, false, p.layout.Stride, buf.offset+l.Offset)
 	}
-	for i := 0; i < max; i++ {
+	for i := range max {
 		b.glstate.setVertexAttribArray(b.funcs, i, enabled[i])
 	}
 }
@@ -1175,7 +1173,7 @@ func (t *texture) ReadPixels(src image.Rectangle, pixels []byte, stride int) err
 	} else {
 		tmp := make([]byte, w*h*4)
 		t.backend.funcs.ReadPixels(src.Min.X, src.Min.Y, w, h, gl.RGBA, gl.UNSIGNED_BYTE, tmp)
-		for y := 0; y < h; y++ {
+		for y := range h {
 			copy(pixels[y*stride:], tmp[y*w*4:])
 		}
 	}
@@ -1357,12 +1355,7 @@ func alphaTripleFor(ver [2]int) textureTriple {
 }
 
 func hasExtension(exts []string, ext string) bool {
-	for _, e := range exts {
+	return slices.Contains(exts, ext)
-		if ext == e {
-			return true
-		}
-	}
-	return false
 }
 
 func firstBufferType(typ driver.BufferBinding) gl.Enum {

gpu/internal/rendertest/bench_test.go

@@ -66,8 +66,8 @@ func BenchmarkDrawUICached(b *testing.B) {
 	defer w.Release()
 	drawCore(gtx, th)
 	w.Frame(gtx.Ops)
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		w.Frame(gtx.Ops)
 	}
 	finishBenchmark(b, w)
@@ -83,12 +83,12 @@ func BenchmarkDrawUI(b *testing.B) {
 	drawCore(gtx, th)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		resetOps(gtx)
 
 		off := float32(math.Mod(float64(i)/10, 10))
-		t := op.Affine(f32.Affine2D{}.Offset(f32.Pt(off, off))).Push(gtx.Ops)
+		t := op.Affine(f32.AffineId().Offset(f32.Pt(off, off))).Push(gtx.Ops)
 
 		drawCore(gtx, th)
 
@@ -105,12 +105,12 @@ func BenchmarkDrawUITransformed(b *testing.B) {
 	drawCore(gtx, th)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		resetOps(gtx)
 
 		angle := float32(math.Mod(float64(i)/1000, 0.05))
-		a := f32.Affine2D{}.Shear(f32.Point{}, angle, angle).Rotate(f32.Point{}, angle)
+		a := f32.AffineId().Shear(f32.Point{}, angle, angle).Rotate(f32.Point{}, angle)
 		t := op.Affine(a).Push(gtx.Ops)
 
 		drawCore(gtx, th)
@@ -130,8 +130,8 @@ func Benchmark1000Circles(b *testing.B) {
 	draw1000Circles(gtx)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		resetOps(gtx)
 		draw1000Circles(gtx)
 		w.Frame(gtx.Ops)
@@ -147,8 +147,8 @@ func Benchmark1000CirclesInstanced(b *testing.B) {
 	draw1000CirclesInstanced(gtx)
 	w.Frame(gtx.Ops)
 	b.ReportAllocs()
-	b.ResetTimer()
+
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		resetOps(gtx)
 		draw1000CirclesInstanced(gtx)
 		w.Frame(gtx.Ops)
@@ -158,9 +158,9 @@ func Benchmark1000CirclesInstanced(b *testing.B) {
 
 func draw1000Circles(gtx layout.Context) {
 	ops := gtx.Ops
-	for x := 0; x < 100; x++ {
+	for x := range 100 {
 		op.Offset(image.Pt(x*10, 0)).Add(ops)
-		for y := 0; y < 10; y++ {
+		for y := range 10 {
 			paint.FillShape(ops,
 				color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
 				clip.RRect{Rect: image.Rect(0, 0, 10, 10), NE: 5, SE: 5, SW: 5, NW: 5}.Op(ops),
@@ -179,9 +179,9 @@ func draw1000CirclesInstanced(gtx layout.Context) {
 	cl.Pop()
 	c := r.Stop()
 
-	for x := 0; x < 100; x++ {
+	for x := range 100 {
 		op.Offset(image.Pt(x*10, 0)).Add(ops)
-		for y := 0; y < 10; y++ {
+		for y := range 10 {
 			paint.ColorOp{Color: color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120}}.Add(ops)
 			c.Add(ops)
 			op.Offset(image.Pt(0, 100)).Add(ops)
@@ -204,9 +204,9 @@ func drawIndividualShapes(gtx layout.Context, th *material.Theme) chan op.CallOp
 	go func() {
 		ops := &op1
 		c := op.Record(ops)
-		for x := 0; x < 9; x++ {
+		for x := range 9 {
 			op.Offset(image.Pt(x*50, 0)).Add(ops)
-			for y := 0; y < 9; y++ {
+			for y := range 9 {
 				paint.FillShape(ops,
 					color.NRGBA{R: 100 + uint8(x), G: 100 + uint8(y), B: 100, A: 120},
 					clip.RRect{Rect: image.Rect(0, 0, 25, 25), NE: 10, SE: 10, SW: 10, NW: 10}.Op(ops),
@@ -233,8 +233,8 @@ func drawShapeInstances(gtx layout.Context, th *material.Theme) chan op.CallOp {
 
 		squares.Add(ops)
 		rad := float32(0)
-		for x := 0; x < 20; x++ {
+		for x := range 20 {
-			for y := 0; y < 20; y++ {
+			for y := range 20 {
 				t := op.Offset(image.Pt(x*50+25, y*50+25)).Push(ops)
 				c.Add(ops)
 				t.Pop()
@@ -253,7 +253,7 @@ func drawText(gtx layout.Context, th *material.Theme) chan op.CallOp {
 		c := op.Record(ops)
 
 		txt := material.H6(th, "")
-		for x := 0; x < 40; x++ {
+		for x := range 40 {
 			txt.Text = textRows[x]
 			t := op.Offset(image.Pt(0, 24*x)).Push(ops)
 			gtx.Ops = ops

gpu/internal/rendertest/clip_test.go

@@ -40,6 +40,25 @@ func TestPaintClippedRect(t *testing.T) {
 	})
 }
 
+func TestPaintClippedRectOffset(t *testing.T) {
+	run(t, func(o *op.Ops) {
+		defer op.Affine(f32.AffineId().Offset(f32.Pt(0.5, 0.5))).Push(o).Pop()
+		defer clip.RRect{Rect: image.Rect(25, 25, 60, 60)}.Push(o).Pop()
+		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
+	}, func(r result) {
+		r.expect(0, 0, transparent)
+		r.expect(24, 35, transparent)
+		r.expect(24, 24, transparent)
+		r.expect(25, 25, color.RGBA{R: 137, A: 64})
+		r.expect(25, 35, color.RGBA{R: 187, A: 128})
+		r.expect(35, 25, color.RGBA{R: 187, A: 128})
+		r.expect(50, 50, color.RGBA{R: 137, A: 64})
+		r.expect(51, 51, transparent)
+		r.expect(50, 0, transparent)
+		r.expect(10, 50, transparent)
+	})
+}
+
 func TestPaintClippedCircle(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		const r = 10
@@ -132,8 +151,7 @@ func TestTexturedStrokeClipped(t *testing.T) {
 		defer clip.RRect{Rect: image.Rect(-30, -30, 60, 60)}.Push(o).Pop()
 		defer op.Offset(image.Pt(-10, -10)).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func TestTexturedStroke(t *testing.T) {
@@ -146,8 +164,7 @@ func TestTexturedStroke(t *testing.T) {
 		}.Op().Push(o).Pop()
 		defer op.Offset(image.Pt(-10, -10)).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func TestPaintClippedTexture(t *testing.T) {
@@ -178,7 +195,6 @@ func TestStrokedPathZeroWidth(t *testing.T) {
 			paint.Fill(o, red)
 			cl.Pop()
 		}
-
 	}, func(r result) {
 		r.expect(0, 0, transparent)
 		r.expect(10, 50, colornames.Black)
@@ -252,8 +268,7 @@ func TestPathReuse(t *testing.T) {
 		stroke := clip.Stroke{Path: spec, Width: 3}.Op().Push(o)
 		paint.Fill(o, color.NRGBA{B: 0xFF, A: 0xFF})
 		stroke.Pop()
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func TestPathInterleave(t *testing.T) {
@@ -290,6 +305,22 @@ func TestStrokedRect(t *testing.T) {
 				Width: 5,
 			}.Op(),
 		)
-	}, func(r result) {
+	}, nil)
-	})
+}
+
+func TestInstancedRects(t *testing.T) {
+	run(t, func(o *op.Ops) {
+		macro := op.Record(o)
+		clip := clip.Rect{Max: image.Pt(20, 20)}.Push(o)
+		paint.ColorOp{Color: color.NRGBA{R: 0x80, A: 0xFF}}.Add(o)
+		paint.PaintOp{}.Add(o)
+		clip.Pop()
+		c := macro.Stop()
+
+		for range 2 {
+			op.Affine(f32.AffineId().Rotate(f32.Pt(0, 0), .2)).Add(o)
+			c.Add(o)
+			op.Offset(image.Pt(20, 20)).Add(o)
+		}
+	}, nil)
 }

gpu/internal/rendertest/render_test.go

@@ -24,7 +24,6 @@ func TestTransformMacro(t *testing.T) {
 	c := constSqPath()
 
 	run(t, func(o *op.Ops) {
-
 		// render the first Stacked item
 		m1 := op.Record(o)
 		dr := image.Rect(0, 0, 128, 50)
@@ -88,10 +87,10 @@ func TestNoClipFromPaint(t *testing.T) {
 	// ensure that a paint operation does not pollute the state
 	// by leaving any clip paths in place.
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Rotate(f32.Pt(20, 20), math.Pi/4)
+		a := f32.AffineId().Rotate(f32.Pt(20, 20), math.Pi/4)
 		defer op.Affine(a).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(10, 10, 30, 30)).Op())
-		a = f32.Affine2D{}.Rotate(f32.Pt(20, 20), -math.Pi/4)
+		a = f32.AffineId().Rotate(f32.Pt(20, 20), -math.Pi/4)
 		defer op.Affine(a).Push(o).Pop()
 
 		paint.FillShape(o, black, clip.Rect(image.Rect(0, 0, 50, 50)).Op())
@@ -110,7 +109,7 @@ func TestDeferredPaint(t *testing.T) {
 		paint.PaintOp{}.Add(o)
 		cl.Pop()
 
-		t := op.Affine(f32.Affine2D{}.Offset(f32.Pt(20, 20))).Push(o)
+		t := op.Affine(f32.AffineId().Offset(f32.Pt(20, 20))).Push(o)
 		m := op.Record(o)
 		cl2 := clip.Rect(image.Rect(0, 0, 80, 80)).Op().Push(o)
 		paint.ColorOp{Color: color.NRGBA{A: 0x60, R: 0xff, G: 0xff}}.Add(o)
@@ -120,12 +119,11 @@ func TestDeferredPaint(t *testing.T) {
 		op.Defer(o, paintMacro)
 		t.Pop()
 
-		defer op.Affine(f32.Affine2D{}.Offset(f32.Pt(10, 10))).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Offset(f32.Pt(10, 10))).Push(o).Pop()
 		defer clip.Rect(image.Rect(0, 0, 80, 80)).Op().Push(o).Pop()
 		paint.ColorOp{Color: color.NRGBA{A: 0x60, B: 0xff}}.Add(o)
 		paint.PaintOp{}.Add(o)
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 func constSqPath() clip.Op {
@@ -143,8 +141,10 @@ func constSqPath() clip.Op {
 
 func constSqCirc() clip.Op {
 	innerOps := new(op.Ops)
-	return clip.RRect{Rect: image.Rect(0, 0, 40, 40),
+	return clip.RRect{
-		NW: 20, NE: 20, SW: 20, SE: 20}.Op(innerOps)
+		Rect: image.Rect(0, 0, 40, 40),
+		NW:   20, NE: 20, SW: 20, SE: 20,
+	}.Op(innerOps)
 }
 
 func drawChild(ops *op.Ops, text clip.Op) op.CallOp {
@@ -260,7 +260,7 @@ func TestLinearGradient(t *testing.T) {
 				Color2: g.To,
 			}.Add(ops)
 			cl := clip.RRect{Rect: gr.Round()}.Push(ops)
-			t1 := op.Affine(f32.Affine2D{}.Offset(pixelAligned.Min)).Push(ops)
+			t1 := op.Affine(f32.AffineId().Offset(pixelAligned.Min)).Push(ops)
 			t2 := scale(pixelAligned.Dx()/128, 1).Push(ops)
 			paint.PaintOp{}.Add(ops)
 			t2.Pop()
@@ -323,7 +323,7 @@ func TestLinearGradientAngled(t *testing.T) {
 		cl = clip.Rect(image.Rect(0, 64, 64, 128)).Push(ops)
 		paint.PaintOp{}.Add(ops)
 		cl.Pop()
-	}, func(r result) {})
+	}, nil)
 }
 
 func TestZeroImage(t *testing.T) {
@@ -363,7 +363,7 @@ func TestImageRGBA_ScaleLinear(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		w := newWindow(t, 128, 128)
 		defer clip.Rect{Max: image.Pt(128, 128)}.Push(o).Pop()
-		op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
+		op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
 
 		im := image.NewRGBA(image.Rect(0, 0, 2, 2))
 		im.Set(0, 0, colornames.Red)
@@ -397,7 +397,7 @@ func TestImageRGBA_ScaleLinear(t *testing.T) {
 func TestImageRGBA_ScaleNearest(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		w := newWindow(t, 128, 128)
-		op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
+		op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(64, 64))).Add(o)
 
 		im := image.NewRGBA(image.Rect(0, 0, 2, 2))
 		im.Set(0, 0, colornames.Red)
@@ -492,8 +492,7 @@ func TestOpacity(t *testing.T) {
 		opc3 := paint.PushOpacity(ops, .6)
 		paint.FillShape(ops, color.NRGBA{B: 255, A: 255}, clip.Ellipse(image.Rectangle{Min: image.Pt(20+20, 10), Max: image.Pt(50+64, 128)}).Op(ops))
 		opc3.Pop()
-	}, func(r result) {
+	}, nil)
-	})
 }
 
 // lerp calculates linear interpolation with color b and p.

gpu/internal/rendertest/transform_test.go

@@ -29,7 +29,7 @@ func TestPaintOffset(t *testing.T) {
 
 func TestPaintRotate(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Rotate(f32.Pt(40, 40), -math.Pi/8)
+		a := f32.AffineId().Rotate(f32.Pt(40, 40), -math.Pi/8)
 		defer op.Affine(a).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(20, 20, 60, 60)).Op())
 	}, func(r result) {
@@ -42,7 +42,7 @@ func TestPaintRotate(t *testing.T) {
 
 func TestPaintShear(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Shear(f32.Point{}, math.Pi/4, 0)
+		a := f32.AffineId().Shear(f32.Point{}, math.Pi/4, 0)
 		defer op.Affine(a).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 40, 40)).Op())
 	}, func(r result) {
@@ -79,7 +79,7 @@ func TestClipOffset(t *testing.T) {
 
 func TestClipScale(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(2, 2)).Offset(f32.Pt(10, 10))
+		a := f32.AffineId().Scale(f32.Point{}, f32.Pt(2, 2)).Offset(f32.Pt(10, 10))
 		defer op.Affine(a).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(10, 10, 20, 20)}.Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 1000, 1000)).Op())
@@ -93,7 +93,7 @@ func TestClipScale(t *testing.T) {
 
 func TestClipRotate(t *testing.T) {
 	run(t, func(o *op.Ops) {
-		defer op.Affine(f32.Affine2D{}.Rotate(f32.Pt(40, 40), -math.Pi/4)).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Rotate(f32.Pt(40, 40), -math.Pi/4)).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(30, 30, 50, 50)}.Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 40, 100, 100)).Op())
 	}, func(r result) {
@@ -121,7 +121,7 @@ func TestOffsetScaleTexture(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		defer op.Offset(image.Pt(15, 15)).Push(o).Pop()
 		squares.Add(o)
-		defer op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(2, 1))).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(2, 1))).Push(o).Pop()
 		defer scale(50.0/512, 50.0/512).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
 	}, func(r result) {
@@ -133,7 +133,7 @@ func TestOffsetScaleTexture(t *testing.T) {
 func TestRotateTexture(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		squares.Add(o)
-		a := f32.Affine2D{}.Offset(f32.Pt(30, 30)).Rotate(f32.Pt(40, 40), math.Pi/4)
+		a := f32.AffineId().Offset(f32.Pt(30, 30)).Rotate(f32.Pt(40, 40), math.Pi/4)
 		defer op.Affine(a).Push(o).Pop()
 		defer scale(20.0/512, 20.0/512).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
@@ -146,10 +146,10 @@ func TestRotateTexture(t *testing.T) {
 func TestRotateClipTexture(t *testing.T) {
 	run(t, func(o *op.Ops) {
 		squares.Add(o)
-		a := f32.Affine2D{}.Rotate(f32.Pt(40, 40), math.Pi/8)
+		a := f32.AffineId().Rotate(f32.Pt(40, 40), math.Pi/8)
 		defer op.Affine(a).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(30, 30, 50, 50)}.Push(o).Pop()
-		defer op.Affine(f32.Affine2D{}.Offset(f32.Pt(10, 10))).Push(o).Pop()
+		defer op.Affine(f32.AffineId().Offset(f32.Pt(10, 10))).Push(o).Pop()
 		defer scale(60.0/512, 60.0/512).Push(o).Pop()
 		paint.PaintOp{}.Add(o)
 	}, func(r result) {
@@ -168,7 +168,7 @@ func TestComplicatedTransform(t *testing.T) {
 
 		defer clip.RRect{Rect: image.Rect(0, 0, 100, 100), SE: 50, SW: 50, NW: 50, NE: 50}.Push(o).Pop()
 
-		a := f32.Affine2D{}.Shear(f32.Point{}, math.Pi/4, 0)
+		a := f32.AffineId().Shear(f32.Point{}, math.Pi/4, 0)
 		defer op.Affine(a).Push(o).Pop()
 		defer clip.RRect{Rect: image.Rect(0, 0, 50, 40)}.Push(o).Pop()
 
@@ -182,13 +182,13 @@ func TestComplicatedTransform(t *testing.T) {
 func TestTransformOrder(t *testing.T) {
 	// check the ordering of operations bot in affine and in gpu stack.
 	run(t, func(o *op.Ops) {
-		a := f32.Affine2D{}.Offset(f32.Pt(64, 64))
+		a := f32.AffineId().Offset(f32.Pt(64, 64))
 		defer op.Affine(a).Push(o).Pop()
 
-		b := f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(8, 8))
+		b := f32.AffineId().Scale(f32.Point{}, f32.Pt(8, 8))
 		defer op.Affine(b).Push(o).Pop()
 
-		c := f32.Affine2D{}.Offset(f32.Pt(-10, -10)).Scale(f32.Point{}, f32.Pt(0.5, 0.5))
+		c := f32.AffineId().Offset(f32.Pt(-10, -10)).Scale(f32.Point{}, f32.Pt(0.5, 0.5))
 		defer op.Affine(c).Push(o).Pop()
 		paint.FillShape(o, red, clip.Rect(image.Rect(0, 0, 20, 20)).Op())
 	}, func(r result) {

gpu/internal/rendertest/util_test.go

@@ -49,8 +49,8 @@ func buildSquares(size int) paint.ImageOp {
 	sub := size / 4
 	im := image.NewNRGBA(image.Rect(0, 0, size, size))
 	c1, c2 := image.NewUniform(colornames.Green), image.NewUniform(colornames.Blue)
-	for r := 0; r < 4; r++ {
+	for r := range 4 {
-		for c := 0; c < 4; c++ {
+		for c := range 4 {
 			c1, c2 = c2, c1
 			draw.Draw(im, image.Rect(r*sub, c*sub, r*sub+sub, c*sub+sub), c1, image.Point{}, draw.Over)
 		}
@@ -78,7 +78,7 @@ func run(t *testing.T, f func(o *op.Ops), c func(r result)) {
 	var img *image.RGBA
 	var err error
 	ops := new(op.Ops)
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		ops.Reset()
 		img, err = drawImage(t, 128, ops, f)
 		if err != nil {
@@ -90,7 +90,9 @@ func run(t *testing.T, f func(o *op.Ops), c func(r result)) {
 			name := fmt.Sprintf("%s-%d-bad.png", t.Name(), i)
 			saveImage(t, name, img)
 		}
-		c(result{t: t, img: img})
+		if c != nil {
+			c(result{t: t, img: img})
+		}
 	}
 }
 
@@ -151,7 +153,7 @@ func verifyRef(t *testing.T, img *image.RGBA, frame int) (ok bool) {
 	}
 	path = filepath.Join("refs", path+".png")
 	if *dumpImages {
-		if err := os.MkdirAll(filepath.Dir(path), 0766); err != nil {
+		if err := os.MkdirAll(filepath.Dir(path), 0o766); err != nil {
 			if !os.IsExist(err) {
 				t.Error(err)
 				return
@@ -285,7 +287,7 @@ func saveImage(t testing.TB, file string, img *image.RGBA) {
 		t.Error(err)
 		return
 	}
-	if err := os.WriteFile(file, buf.Bytes(), 0666); err != nil {
+	if err := os.WriteFile(file, buf.Bytes(), 0o666); err != nil {
 		t.Error(err)
 		return
 	}
@@ -300,5 +302,5 @@ func newWindow(t testing.TB, width, height int) *headless.Window {
 }
 
 func scale(sx, sy float32) op.TransformOp {
-	return op.Affine(f32.Affine2D{}.Scale(f32.Point{}, f32.Pt(sx, sy)))
+	return op.Affine(f32.AffineId().Scale(f32.Point{}, f32.Pt(sx, sy)))
 }

gpu/pack_test.go

@@ -10,10 +10,10 @@ import (
 func BenchmarkPacker(b *testing.B) {
 	var p packer
 	p.maxDims = image.Point{X: 4096, Y: 4096}
-	for i := 0; i < b.N; i++ {
+	for i := 0; b.Loop(); i++ {
 		p.clear()
 		p.newPage()
-		for k := 0; k < 500; k++ {
+		for k := range 500 {
 			_, ok := p.tryAdd(xy(k))
 			if !ok {
 				b.Fatal("add failed", i, k, xy(k))

gpu/path.go

@@ -150,7 +150,7 @@ func newCoverer(ctx driver.Device) *coverer {
 	c.texUniforms = new(coverTexUniforms)
 	c.linearGradientUniforms = new(coverLinearGradientUniforms)
 	pipelines, err := createColorPrograms(ctx, gio.Shader_cover_vert, gio.Shader_cover_frag,
-		[3]interface{}{c.colUniforms, c.linearGradientUniforms, c.texUniforms},
+		[3]any{c.colUniforms, c.linearGradientUniforms, c.texUniforms},
 	)
 	if err != nil {
 		panic(err)
@@ -162,7 +162,7 @@ func newCoverer(ctx driver.Device) *coverer {
 func newStenciler(ctx driver.Device) *stenciler {
 	// Allocate a suitably large index buffer for drawing paths.
 	indices := make([]uint16, pathBatchSize*6)
-	for i := 0; i < pathBatchSize; i++ {
+	for i := range pathBatchSize {
 		i := uint16(i)
 		indices[i*6+0] = i*4 + 0
 		indices[i*6+1] = i*4 + 1

internal/byteslice/byteslice.go

@@ -10,7 +10,7 @@ import (
 )
 
 // Struct returns a byte slice view of a struct.
-func Struct(s interface{}) []byte {
+func Struct(s any) []byte {
 	v := reflect.ValueOf(s)
 	sz := int(v.Elem().Type().Size())
 	return unsafe.Slice((*byte)(unsafe.Pointer(v.Pointer())), sz)
@@ -27,7 +27,7 @@ func Uint32(s []uint32) []byte {
 }
 
 // Slice returns a byte slice view of a slice.
-func Slice(s interface{}) []byte {
+func Slice(s any) []byte {
 	v := reflect.ValueOf(s)
 	first := v.Index(0)
 	sz := int(first.Type().Size())

internal/debug/debug.go

@@ -34,7 +34,7 @@ func Parse() {
 		}
 		print := false
 		silent := false
-		for _, part := range strings.Split(val, ",") {
+		for part := range strings.SplitSeq(val, ",") {
 			switch part {
 			case textSubsystem:
 				Text.Store(true)

internal/egl/egl.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"runtime"
+	"slices"
 	"strings"
 
 	"gioui.org/gpu"
@@ -154,12 +155,7 @@ func (c *Context) EnableVSync(enable bool) {
 }
 
 func hasExtension(exts []string, ext string) bool {
-	for _, e := range exts {
+	return slices.Contains(exts, ext)
-		if ext == e {
-			return true
-		}
-	}
-	return false
 }
 
 func createContext(disp _EGLDisplay) (*eglContext, error) {

internal/egl/egl_windows.go

@@ -41,14 +41,10 @@ var (
 	_eglWaitClient          *syscall.Proc
 )
 
-var loadOnce sync.Once
+var loadOnce = sync.OnceValue(loadDLLs)
 
 func loadEGL() error {
-	var err error
+	return loadOnce()
-	loadOnce.Do(func() {
-		err = loadDLLs()
-	})
-	return err
 }
 
 func loadDLLs() error {
@@ -186,6 +182,6 @@ func eglWaitClient() bool {
 
 // issue34474KeepAlive calls runtime.KeepAlive as a
 // workaround for golang.org/issue/34474.
-func issue34474KeepAlive(v interface{}) {
+func issue34474KeepAlive(v any) {
 	runtime.KeepAlive(v)
 }

internal/f32/f32.go

@@ -19,6 +19,8 @@ type Affine2D = f32.Affine2D
 
 var NewAffine2D = f32.NewAffine2D
 
+var AffineId = f32.AffineId
+
 // A Rectangle contains the points (X, Y) where Min.X <= X < Max.X,
 // Min.Y <= Y < Max.Y.
 type Rectangle struct {

internal/f32color/f32colorgen/main.go

@@ -16,7 +16,7 @@ func main() {
 	flag.Parse()
 
 	var b bytes.Buffer
-	printf := func(content string, args ...interface{}) {
+	printf := func(content string, args ...any) {
 		fmt.Fprintf(&b, content, args...)
 	}
 
@@ -42,7 +42,7 @@ func main() {
 		panic(err)
 	}
 
-	err = os.WriteFile(*out, data, 0755)
+	err = os.WriteFile(*out, data, 0o755)
 	if err != nil {
 		panic(err)
 	}

internal/f32color/rgba_test.go

@@ -41,17 +41,17 @@ var sink RGBA
 
 func BenchmarkLinearFromSRGB(b *testing.B) {
 	b.Run("opaque", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
+		for i := 0; b.Loop(); i++ {
 			sink = LinearFromSRGB(color.NRGBA{R: byte(i), G: byte(i >> 8), B: byte(i >> 16), A: 0xFF})
 		}
 	})
 	b.Run("translucent", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
+		for i := 0; b.Loop(); i++ {
 			sink = LinearFromSRGB(color.NRGBA{R: byte(i), G: byte(i >> 8), B: byte(i >> 16), A: 0x50})
 		}
 	})
 	b.Run("transparent", func(b *testing.B) {
-		for i := 0; i < b.N; i++ {
+		for i := 0; b.Loop(); i++ {
 			sink = LinearFromSRGB(color.NRGBA{R: byte(i), G: byte(i >> 8), B: byte(i >> 16), A: 0x00})
 		}
 	})

internal/fling/extrapolation.go

@@ -90,7 +90,7 @@ func (e *Extrapolation) Estimate() Estimate {
 	first := e.get(0)
 	t := first.t
 	// Walk backwards collecting samples.
-	for i := 0; i < len(e.samples); i++ {
+	for i := range e.samples {
 		p := e.get(-i)
 		age := first.t - p.t
 		if age >= maxAge || t-p.t >= maxSampleGap {
@@ -172,9 +172,9 @@ func decomposeQR(A *matrix) (*matrix, *matrix, bool) {
 	// https://en.wikipedia.org/wiki/Gram%E2%80%93Schmidt_process
 	Q := newMatrix(A.rows, A.cols)  // Column-major.
 	Rt := newMatrix(A.rows, A.rows) // R transposed, row-major.
-	for i := 0; i < Q.rows; i++ {
+	for i := range Q.rows {
 		// Copy A column.
-		for j := 0; j < Q.cols; j++ {
+		for j := range Q.cols {
 			Q.set(i, j, A.get(i, j))
 		}
 		// Subtract projections. Note that int the projection
@@ -184,9 +184,9 @@ func decomposeQR(A *matrix) (*matrix, *matrix, bool) {
 		// the normalized column e replaces u, where <e, e> = 1:
 		//
 		// proje a = <e, a>/<e, e> e = <e, a> e
-		for j := 0; j < i; j++ {
+		for j := range i {
 			d := dot(Q.col(j), Q.col(i))
-			for k := 0; k < Q.cols; k++ {
+			for k := range Q.cols {
 				Q.set(i, k, Q.get(i, k)-d*Q.get(j, k))
 			}
 		}
@@ -197,7 +197,7 @@ func decomposeQR(A *matrix) (*matrix, *matrix, bool) {
 			return nil, nil, false
 		}
 		invNorm := 1 / n
-		for j := 0; j < Q.cols; j++ {
+		for j := range Q.cols {
 			Q.set(i, j, Q.get(i, j)*invNorm)
 		}
 		// Update Rt.
@@ -261,8 +261,8 @@ func (m *matrix) approxEqual(m2 *matrix) bool {
 		return false
 	}
 	const epsilon = 0.00001
-	for row := 0; row < m.rows; row++ {
+	for row := range m.rows {
-		for col := 0; col < m.cols; col++ {
+		for col := range m.cols {
 			d := m2.get(row, col) - m.get(row, col)
 			if d < -epsilon || d > epsilon {
 				return false
@@ -278,8 +278,8 @@ func (m *matrix) transpose() *matrix {
 		cols: m.rows,
 		data: make([]float32, len(m.data)),
 	}
-	for i := 0; i < m.rows; i++ {
+	for i := range m.rows {
-		for j := 0; j < m.cols; j++ {
+		for j := range m.cols {
 			t.set(j, i, m.get(i, j))
 		}
 	}
@@ -295,10 +295,10 @@ func (m *matrix) mul(m2 *matrix) *matrix {
 		cols: m2.cols,
 		data: make([]float32, m.rows*m2.cols),
 	}
-	for i := 0; i < mm.rows; i++ {
+	for i := range mm.rows {
-		for j := 0; j < mm.cols; j++ {
+		for j := range mm.cols {
 			var v float32
-			for k := 0; k < m.rows; k++ {
+			for k := range m.rows {
 				v += m.get(k, j) * m2.get(i, k)
 			}
 			mm.set(i, j, v)
@@ -309,8 +309,8 @@ func (m *matrix) mul(m2 *matrix) *matrix {
 
 func (m *matrix) String() string {
 	var b strings.Builder
-	for i := 0; i < m.rows; i++ {
+	for i := range m.rows {
-		for j := 0; j < m.cols; j++ {
+		for j := range m.cols {
 			v := m.get(i, j)
 			b.WriteString(strconv.FormatFloat(float64(v), 'g', -1, 32))
 			b.WriteString(", ")

internal/gl/gl_js.go

@@ -247,9 +247,11 @@ func (f *Functions) getExtension(name string) js.Value {
 func (f *Functions) ActiveTexture(t Enum) {
 	f._activeTexture.Invoke(int(t))
 }
+
 func (f *Functions) AttachShader(p Program, s Shader) {
 	f._attachShader.Invoke(js.Value(p), js.Value(s))
 }
+
 func (f *Functions) BeginQuery(target Enum, query Query) {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		f._beginQuery.Invoke(int(target), js.Value(query))
@@ -257,36 +259,47 @@ func (f *Functions) BeginQuery(target Enum, query Query) {
 		f.EXT_disjoint_timer_query.Call("beginQueryEXT", int(target), js.Value(query))
 	}
 }
+
 func (f *Functions) BindAttribLocation(p Program, a Attrib, name string) {
 	f._bindAttribLocation.Invoke(js.Value(p), int(a), name)
 }
+
 func (f *Functions) BindBuffer(target Enum, b Buffer) {
 	f._bindBuffer.Invoke(int(target), js.Value(b))
 }
+
 func (f *Functions) BindBufferBase(target Enum, index int, b Buffer) {
 	f._bindBufferBase.Invoke(int(target), index, js.Value(b))
 }
+
 func (f *Functions) BindFramebuffer(target Enum, fb Framebuffer) {
 	f._bindFramebuffer.Invoke(int(target), js.Value(fb))
 }
+
 func (f *Functions) BindRenderbuffer(target Enum, rb Renderbuffer) {
 	f._bindRenderbuffer.Invoke(int(target), js.Value(rb))
 }
+
 func (f *Functions) BindTexture(target Enum, t Texture) {
 	f._bindTexture.Invoke(int(target), js.Value(t))
 }
+
 func (f *Functions) BindImageTexture(unit int, t Texture, level int, layered bool, layer int, access, format Enum) {
 	panic("not implemented")
 }
+
 func (f *Functions) BindVertexArray(a VertexArray) {
 	panic("not supported")
 }
+
 func (f *Functions) BlendEquation(mode Enum) {
 	f._blendEquation.Invoke(int(mode))
 }
+
 func (f *Functions) BlendFuncSeparate(srcRGB, dstRGB, srcA, dstA Enum) {
 	f._blendFunc.Invoke(int(srcRGB), int(dstRGB), int(srcA), int(dstA))
 }
+
 func (f *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 	if data == nil {
 		f._bufferData.Invoke(int(target), size, int(usage))
@@ -297,9 +310,11 @@ func (f *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 		f._bufferData.Invoke(int(target), f.byteArrayOf(data), int(usage))
 	}
 }
+
 func (f *Functions) BufferSubData(target Enum, offset int, src []byte) {
 	f._bufferSubData.Invoke(int(target), offset, f.byteArrayOf(src))
 }
+
 func (f *Functions) CheckFramebufferStatus(target Enum) Enum {
 	status := Enum(f._checkFramebufferStatus.Invoke(int(target)).Int())
 	if status != FRAMEBUFFER_COMPLETE && f.Ctx.Call("isContextLost").Bool() {
@@ -308,54 +323,71 @@ func (f *Functions) CheckFramebufferStatus(target Enum) Enum {
 	}
 	return status
 }
+
 func (f *Functions) Clear(mask Enum) {
 	f._clear.Invoke(int(mask))
 }
+
 func (f *Functions) ClearColor(red, green, blue, alpha float32) {
 	f._clearColor.Invoke(red, green, blue, alpha)
 }
+
 func (f *Functions) ClearDepthf(d float32) {
 	f._clearDepth.Invoke(d)
 }
+
 func (f *Functions) CompileShader(s Shader) {
 	f._compileShader.Invoke(js.Value(s))
 }
+
 func (f *Functions) CopyTexSubImage2D(target Enum, level, xoffset, yoffset, x, y, width, height int) {
 	f._copyTexSubImage2D.Invoke(int(target), level, xoffset, yoffset, x, y, width, height)
 }
+
 func (f *Functions) CreateBuffer() Buffer {
 	return Buffer(f._createBuffer.Invoke())
 }
+
 func (f *Functions) CreateFramebuffer() Framebuffer {
 	return Framebuffer(f._createFramebuffer.Invoke())
 }
+
 func (f *Functions) CreateProgram() Program {
 	return Program(f._createProgram.Invoke())
 }
+
 func (f *Functions) CreateQuery() Query {
 	return Query(f._createQuery.Invoke())
 }
+
 func (f *Functions) CreateRenderbuffer() Renderbuffer {
 	return Renderbuffer(f._createRenderbuffer.Invoke())
 }
+
 func (f *Functions) CreateShader(ty Enum) Shader {
 	return Shader(f._createShader.Invoke(int(ty)))
 }
+
 func (f *Functions) CreateTexture() Texture {
 	return Texture(f._createTexture.Invoke())
 }
+
 func (f *Functions) CreateVertexArray() VertexArray {
 	panic("not supported")
 }
+
 func (f *Functions) DeleteBuffer(v Buffer) {
 	f._deleteBuffer.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteFramebuffer(v Framebuffer) {
 	f._deleteFramebuffer.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteProgram(p Program) {
 	f._deleteProgram.Invoke(js.Value(p))
 }
+
 func (f *Functions) DeleteQuery(query Query) {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		f._deleteQuery.Invoke(js.Value(query))
@@ -363,45 +395,59 @@ func (f *Functions) DeleteQuery(query Query) {
 		f.EXT_disjoint_timer_query.Call("deleteQueryEXT", js.Value(query))
 	}
 }
+
 func (f *Functions) DeleteShader(s Shader) {
 	f._deleteShader.Invoke(js.Value(s))
 }
+
 func (f *Functions) DeleteRenderbuffer(v Renderbuffer) {
 	f._deleteRenderbuffer.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteTexture(v Texture) {
 	f._deleteTexture.Invoke(js.Value(v))
 }
+
 func (f *Functions) DeleteVertexArray(a VertexArray) {
 	panic("not implemented")
 }
+
 func (f *Functions) DepthFunc(fn Enum) {
 	f._depthFunc.Invoke(int(fn))
 }
+
 func (f *Functions) DepthMask(mask bool) {
 	f._depthMask.Invoke(mask)
 }
+
 func (f *Functions) DisableVertexAttribArray(a Attrib) {
 	f._disableVertexAttribArray.Invoke(int(a))
 }
+
 func (f *Functions) Disable(cap Enum) {
 	f._disable.Invoke(int(cap))
 }
+
 func (f *Functions) DrawArrays(mode Enum, first, count int) {
 	f._drawArrays.Invoke(int(mode), first, count)
 }
+
 func (f *Functions) DrawElements(mode Enum, count int, ty Enum, offset int) {
 	f._drawElements.Invoke(int(mode), count, int(ty), offset)
 }
+
 func (f *Functions) DispatchCompute(x, y, z int) {
 	panic("not implemented")
 }
+
 func (f *Functions) Enable(cap Enum) {
 	f._enable.Invoke(int(cap))
 }
+
 func (f *Functions) EnableVertexAttribArray(a Attrib) {
 	f._enableVertexAttribArray.Invoke(int(a))
 }
+
 func (f *Functions) EndQuery(target Enum) {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		f._endQuery.Invoke(int(target))
@@ -409,28 +455,36 @@ func (f *Functions) EndQuery(target Enum) {
 		f.EXT_disjoint_timer_query.Call("endQueryEXT", int(target))
 	}
 }
+
 func (f *Functions) Finish() {
 	f._finish.Invoke()
 }
+
 func (f *Functions) Flush() {
 	f._flush.Invoke()
 }
+
 func (f *Functions) FramebufferRenderbuffer(target, attachment, renderbuffertarget Enum, renderbuffer Renderbuffer) {
 	f._framebufferRenderbuffer.Invoke(int(target), int(attachment), int(renderbuffertarget), js.Value(renderbuffer))
 }
+
 func (f *Functions) FramebufferTexture2D(target, attachment, texTarget Enum, t Texture, level int) {
 	f._framebufferTexture2D.Invoke(int(target), int(attachment), int(texTarget), js.Value(t), level)
 }
+
 func (f *Functions) GenerateMipmap(target Enum) {
 	f._generateMipmap.Invoke(int(target))
 }
+
 func (f *Functions) GetError() Enum {
 	// Avoid slow getError calls. See gio#179.
 	return 0
 }
+
 func (f *Functions) GetRenderbufferParameteri(target, pname Enum) int {
 	return paramVal(f._getRenderbufferParameteri.Invoke(int(pname)))
 }
+
 func (f *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname Enum) int {
 	if !f.isWebGL2 && pname == FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING {
 		// FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING is only available on WebGL 2
@@ -438,6 +492,7 @@ func (f *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname
 	}
 	return paramVal(f._getFramebufferAttachmentParameter.Invoke(int(target), int(attachment), int(pname)))
 }
+
 func (f *Functions) GetBinding(pname Enum) Object {
 	obj := f._getParameter.Invoke(int(pname))
 	if !obj.Truthy() {
@@ -445,6 +500,7 @@ func (f *Functions) GetBinding(pname Enum) Object {
 	}
 	return Object(obj)
 }
+
 func (f *Functions) GetBindingi(pname Enum, idx int) Object {
 	obj := f._getIndexedParameter.Invoke(int(pname), idx)
 	if !obj.Truthy() {
@@ -452,6 +508,7 @@ func (f *Functions) GetBindingi(pname Enum, idx int) Object {
 	}
 	return Object(obj)
 }
+
 func (f *Functions) GetInteger(pname Enum) int {
 	if !f.isWebGL2 {
 		switch pname {
@@ -461,9 +518,11 @@ func (f *Functions) GetInteger(pname Enum) int {
 	}
 	return paramVal(f._getParameter.Invoke(int(pname)))
 }
+
 func (f *Functions) GetFloat(pname Enum) float32 {
 	return float32(f._getParameter.Invoke(int(pname)).Float())
 }
+
 func (f *Functions) GetInteger4(pname Enum) [4]int {
 	arr := f._getParameter.Invoke(int(pname))
 	var res [4]int
@@ -472,6 +531,7 @@ func (f *Functions) GetInteger4(pname Enum) [4]int {
 	}
 	return res
 }
+
 func (f *Functions) GetFloat4(pname Enum) [4]float32 {
 	arr := f._getParameter.Invoke(int(pname))
 	var res [4]float32
@@ -480,12 +540,15 @@ func (f *Functions) GetFloat4(pname Enum) [4]float32 {
 	}
 	return res
 }
+
 func (f *Functions) GetProgrami(p Program, pname Enum) int {
 	return paramVal(f._getProgramParameter.Invoke(js.Value(p), int(pname)))
 }
+
 func (f *Functions) GetProgramInfoLog(p Program) string {
 	return f._getProgramInfoLog.Invoke(js.Value(p)).String()
 }
+
 func (f *Functions) GetQueryObjectuiv(query Query, pname Enum) uint {
 	if !f.EXT_disjoint_timer_query_webgl2.IsNull() {
 		return uint(paramVal(f._getQueryParameter.Invoke(js.Value(query), int(pname))))
@@ -493,12 +556,15 @@ func (f *Functions) GetQueryObjectuiv(query Query, pname Enum) uint {
 		return uint(paramVal(f.EXT_disjoint_timer_query.Call("getQueryObjectEXT", js.Value(query), int(pname))))
 	}
 }
+
 func (f *Functions) GetShaderi(s Shader, pname Enum) int {
 	return paramVal(f._getShaderParameter.Invoke(js.Value(s), int(pname)))
 }
+
 func (f *Functions) GetShaderInfoLog(s Shader) string {
 	return f._getShaderInfoLog.Invoke(js.Value(s)).String()
 }
+
 func (f *Functions) GetString(pname Enum) string {
 	switch pname {
 	case EXTENSIONS:
@@ -512,15 +578,19 @@ func (f *Functions) GetString(pname Enum) string {
 		return f._getParameter.Invoke(int(pname)).String()
 	}
 }
+
 func (f *Functions) GetUniformBlockIndex(p Program, name string) uint {
 	return uint(paramVal(f._getUniformBlockIndex.Invoke(js.Value(p), name)))
 }
+
 func (f *Functions) GetUniformLocation(p Program, name string) Uniform {
 	return Uniform(f._getUniformLocation.Invoke(js.Value(p), name))
 }
+
 func (f *Functions) GetVertexAttrib(index int, pname Enum) int {
 	return paramVal(f._getVertexAttrib.Invoke(index, int(pname)))
 }
+
 func (f *Functions) GetVertexAttribBinding(index int, pname Enum) Object {
 	obj := f._getVertexAttrib.Invoke(index, int(pname))
 	if !obj.Truthy() {
@@ -528,9 +598,11 @@ func (f *Functions) GetVertexAttribBinding(index int, pname Enum) Object {
 	}
 	return Object(obj)
 }
+
 func (f *Functions) GetVertexAttribPointer(index int, pname Enum) uintptr {
 	return uintptr(f._getVertexAttribOffset.Invoke(index, int(pname)).Int())
 }
+
 func (f *Functions) InvalidateFramebuffer(target, attachment Enum) {
 	fn := f.Ctx.Get("invalidateFramebuffer")
 	if !fn.IsUndefined() {
@@ -541,74 +613,97 @@ func (f *Functions) InvalidateFramebuffer(target, attachment Enum) {
 		f._invalidateFramebuffer.Invoke(int(target), f.int32Buf)
 	}
 }
+
 func (f *Functions) IsEnabled(cap Enum) bool {
 	return f._isEnabled.Invoke(int(cap)).Truthy()
 }
+
 func (f *Functions) LinkProgram(p Program) {
 	f._linkProgram.Invoke(js.Value(p))
 }
+
 func (f *Functions) PixelStorei(pname Enum, param int) {
 	f._pixelStorei.Invoke(int(pname), param)
 }
+
 func (f *Functions) MemoryBarrier(barriers Enum) {
 	panic("not implemented")
 }
+
 func (f *Functions) MapBufferRange(target Enum, offset, length int, access Enum) []byte {
 	panic("not implemented")
 }
+
 func (f *Functions) RenderbufferStorage(target, internalformat Enum, width, height int) {
 	f._renderbufferStorage.Invoke(int(target), int(internalformat), width, height)
 }
+
 func (f *Functions) ReadPixels(x, y, width, height int, format, ty Enum, data []byte) {
 	ba := f.byteArrayOf(data)
 	f._readPixels.Invoke(x, y, width, height, int(format), int(ty), ba)
 	js.CopyBytesToGo(data, ba)
 }
+
 func (f *Functions) Scissor(x, y, width, height int32) {
 	f._scissor.Invoke(x, y, width, height)
 }
+
 func (f *Functions) ShaderSource(s Shader, src string) {
 	f._shaderSource.Invoke(js.Value(s), src)
 }
+
 func (f *Functions) TexImage2D(target Enum, level int, internalFormat Enum, width, height int, format, ty Enum) {
 	f._texImage2D.Invoke(int(target), int(level), int(internalFormat), int(width), int(height), 0, int(format), int(ty), nil)
 }
+
 func (f *Functions) TexStorage2D(target Enum, levels int, internalFormat Enum, width, height int) {
 	f._texStorage2D.Invoke(int(target), levels, int(internalFormat), width, height)
 }
+
 func (f *Functions) TexSubImage2D(target Enum, level int, x, y, width, height int, format, ty Enum, data []byte) {
 	f._texSubImage2D.Invoke(int(target), level, x, y, width, height, int(format), int(ty), f.byteArrayOf(data))
 }
+
 func (f *Functions) TexParameteri(target, pname Enum, param int) {
 	f._texParameteri.Invoke(int(target), int(pname), int(param))
 }
+
 func (f *Functions) UniformBlockBinding(p Program, uniformBlockIndex uint, uniformBlockBinding uint) {
 	f._uniformBlockBinding.Invoke(js.Value(p), int(uniformBlockIndex), int(uniformBlockBinding))
 }
+
 func (f *Functions) Uniform1f(dst Uniform, v float32) {
 	f._uniform1f.Invoke(js.Value(dst), v)
 }
+
 func (f *Functions) Uniform1i(dst Uniform, v int) {
 	f._uniform1i.Invoke(js.Value(dst), v)
 }
+
 func (f *Functions) Uniform2f(dst Uniform, v0, v1 float32) {
 	f._uniform2f.Invoke(js.Value(dst), v0, v1)
 }
+
 func (f *Functions) Uniform3f(dst Uniform, v0, v1, v2 float32) {
 	f._uniform3f.Invoke(js.Value(dst), v0, v1, v2)
 }
+
 func (f *Functions) Uniform4f(dst Uniform, v0, v1, v2, v3 float32) {
 	f._uniform4f.Invoke(js.Value(dst), v0, v1, v2, v3)
 }
+
 func (f *Functions) UseProgram(p Program) {
 	f._useProgram.Invoke(js.Value(p))
 }
+
 func (f *Functions) UnmapBuffer(target Enum) bool {
 	panic("not implemented")
 }
+
 func (f *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride, offset int) {
 	f._vertexAttribPointer.Invoke(int(dst), size, int(ty), normalized, stride, offset)
 }
+
 func (f *Functions) Viewport(x, y, width, height int) {
 	f._viewport.Invoke(x, y, width, height)
 }

internal/gl/gl_windows.go

@@ -223,7 +223,7 @@ type Functions struct {
 	uintptrs [100]uintptr
 }
 
-type Context interface{}
+type Context any
 
 func NewFunctions(ctx Context, forceES bool) (*Functions, error) {
 	if ctx != nil {
@@ -239,45 +239,58 @@ func NewFunctions(ctx Context, forceES bool) (*Functions, error) {
 func (c *Functions) ActiveTexture(t Enum) {
 	syscall.Syscall(_glActiveTexture.Addr(), 1, uintptr(t), 0, 0)
 }
+
 func (c *Functions) AttachShader(p Program, s Shader) {
 	syscall.Syscall(_glAttachShader.Addr(), 2, uintptr(p.V), uintptr(s.V), 0)
 }
+
 func (f *Functions) BeginQuery(target Enum, query Query) {
 	syscall.Syscall(_glBeginQuery.Addr(), 2, uintptr(target), uintptr(query.V), 0)
 }
+
 func (c *Functions) BindAttribLocation(p Program, a Attrib, name string) {
 	cname := cString(name)
 	c0 := &cname[0]
 	syscall.Syscall(_glBindAttribLocation.Addr(), 3, uintptr(p.V), uintptr(a), uintptr(unsafe.Pointer(c0)))
 	issue34474KeepAlive(c)
 }
+
 func (c *Functions) BindBuffer(target Enum, b Buffer) {
 	syscall.Syscall(_glBindBuffer.Addr(), 2, uintptr(target), uintptr(b.V), 0)
 }
+
 func (c *Functions) BindBufferBase(target Enum, index int, b Buffer) {
 	syscall.Syscall(_glBindBufferBase.Addr(), 3, uintptr(target), uintptr(index), uintptr(b.V))
 }
+
 func (c *Functions) BindFramebuffer(target Enum, fb Framebuffer) {
 	syscall.Syscall(_glBindFramebuffer.Addr(), 2, uintptr(target), uintptr(fb.V), 0)
 }
+
 func (c *Functions) BindRenderbuffer(target Enum, rb Renderbuffer) {
 	syscall.Syscall(_glBindRenderbuffer.Addr(), 2, uintptr(target), uintptr(rb.V), 0)
 }
+
 func (f *Functions) BindImageTexture(unit int, t Texture, level int, layered bool, layer int, access, format Enum) {
 	panic("not implemented")
 }
+
 func (c *Functions) BindTexture(target Enum, t Texture) {
 	syscall.Syscall(_glBindTexture.Addr(), 2, uintptr(target), uintptr(t.V), 0)
 }
+
 func (c *Functions) BindVertexArray(a VertexArray) {
 	syscall.Syscall(_glBindVertexArray.Addr(), 1, uintptr(a.V), 0, 0)
 }
+
 func (c *Functions) BlendEquation(mode Enum) {
 	syscall.Syscall(_glBlendEquation.Addr(), 1, uintptr(mode), 0, 0)
 }
+
 func (c *Functions) BlendFuncSeparate(srcRGB, dstRGB, srcA, dstA Enum) {
 	syscall.Syscall6(_glBlendFuncSeparate.Addr(), 4, uintptr(srcRGB), uintptr(dstRGB), uintptr(srcA), uintptr(dstA), 0, 0)
 }
+
 func (c *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 	var p unsafe.Pointer
 	if len(data) > 0 {
@@ -285,6 +298,7 @@ func (c *Functions) BufferData(target Enum, size int, usage Enum, data []byte) {
 	}
 	syscall.Syscall6(_glBufferData.Addr(), 4, uintptr(target), uintptr(size), uintptr(p), uintptr(usage), 0, 0)
 }
+
 func (f *Functions) BufferSubData(target Enum, offset int, src []byte) {
 	if n := len(src); n > 0 {
 		s0 := &src[0]
@@ -292,93 +306,118 @@ func (f *Functions) BufferSubData(target Enum, offset int, src []byte) {
 		issue34474KeepAlive(s0)
 	}
 }
+
 func (c *Functions) CheckFramebufferStatus(target Enum) Enum {
 	s, _, _ := syscall.Syscall(_glCheckFramebufferStatus.Addr(), 1, uintptr(target), 0, 0)
 	return Enum(s)
 }
+
 func (c *Functions) Clear(mask Enum) {
 	syscall.Syscall(_glClear.Addr(), 1, uintptr(mask), 0, 0)
 }
+
 func (c *Functions) ClearColor(red, green, blue, alpha float32) {
 	syscall.Syscall6(_glClearColor.Addr(), 4, uintptr(math.Float32bits(red)), uintptr(math.Float32bits(green)), uintptr(math.Float32bits(blue)), uintptr(math.Float32bits(alpha)), 0, 0)
 }
+
 func (c *Functions) ClearDepthf(d float32) {
 	syscall.Syscall(_glClearDepthf.Addr(), 1, uintptr(math.Float32bits(d)), 0, 0)
 }
+
 func (c *Functions) CompileShader(s Shader) {
 	syscall.Syscall(_glCompileShader.Addr(), 1, uintptr(s.V), 0, 0)
 }
+
 func (f *Functions) CopyTexSubImage2D(target Enum, level, xoffset, yoffset, x, y, width, height int) {
 	syscall.Syscall9(_glCopyTexSubImage2D.Addr(), 8, uintptr(target), uintptr(level), uintptr(xoffset), uintptr(yoffset), uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0)
 }
+
 func (f *Functions) GenerateMipmap(target Enum) {
 	syscall.Syscall(_glGenerateMipmap.Addr(), 1, uintptr(target), 0, 0)
 }
+
 func (c *Functions) CreateBuffer() Buffer {
 	var buf uintptr
 	syscall.Syscall(_glGenBuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&buf)), 0)
 	return Buffer{uint(buf)}
 }
+
 func (c *Functions) CreateFramebuffer() Framebuffer {
 	var fb uintptr
 	syscall.Syscall(_glGenFramebuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&fb)), 0)
 	return Framebuffer{uint(fb)}
 }
+
 func (c *Functions) CreateProgram() Program {
 	p, _, _ := syscall.Syscall(_glCreateProgram.Addr(), 0, 0, 0, 0)
 	return Program{uint(p)}
 }
+
 func (f *Functions) CreateQuery() Query {
 	var q uintptr
 	syscall.Syscall(_glGenQueries.Addr(), 2, 1, uintptr(unsafe.Pointer(&q)), 0)
 	return Query{uint(q)}
 }
+
 func (c *Functions) CreateRenderbuffer() Renderbuffer {
 	var rb uintptr
 	syscall.Syscall(_glGenRenderbuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&rb)), 0)
 	return Renderbuffer{uint(rb)}
 }
+
 func (c *Functions) CreateShader(ty Enum) Shader {
 	s, _, _ := syscall.Syscall(_glCreateShader.Addr(), 1, uintptr(ty), 0, 0)
 	return Shader{uint(s)}
 }
+
 func (c *Functions) CreateTexture() Texture {
 	var t uintptr
 	syscall.Syscall(_glGenTextures.Addr(), 2, 1, uintptr(unsafe.Pointer(&t)), 0)
 	return Texture{uint(t)}
 }
+
 func (c *Functions) CreateVertexArray() VertexArray {
 	var t uintptr
 	syscall.Syscall(_glGenVertexArrays.Addr(), 2, 1, uintptr(unsafe.Pointer(&t)), 0)
 	return VertexArray{uint(t)}
 }
+
 func (c *Functions) DeleteBuffer(v Buffer) {
 	syscall.Syscall(_glDeleteBuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v)), 0)
 }
+
 func (c *Functions) DeleteFramebuffer(v Framebuffer) {
 	syscall.Syscall(_glDeleteFramebuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0)
 }
+
 func (c *Functions) DeleteProgram(p Program) {
 	syscall.Syscall(_glDeleteProgram.Addr(), 1, uintptr(p.V), 0, 0)
 }
+
 func (f *Functions) DeleteQuery(query Query) {
 	syscall.Syscall(_glDeleteQueries.Addr(), 2, 1, uintptr(unsafe.Pointer(&query.V)), 0)
 }
+
 func (c *Functions) DeleteShader(s Shader) {
 	syscall.Syscall(_glDeleteShader.Addr(), 1, uintptr(s.V), 0, 0)
 }
+
 func (c *Functions) DeleteRenderbuffer(v Renderbuffer) {
 	syscall.Syscall(_glDeleteRenderbuffers.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0)
 }
+
 func (c *Functions) DeleteTexture(v Texture) {
 	syscall.Syscall(_glDeleteTextures.Addr(), 2, 1, uintptr(unsafe.Pointer(&v.V)), 0)
 }
+
 func (f *Functions) DeleteVertexArray(array VertexArray) {
 	syscall.Syscall(_glDeleteVertexArrays.Addr(), 2, 1, uintptr(unsafe.Pointer(&array.V)), 0)
 }
+
 func (c *Functions) DepthFunc(f Enum) {
 	syscall.Syscall(_glDepthFunc.Addr(), 1, uintptr(f), 0, 0)
 }
+
 func (c *Functions) DepthMask(mask bool) {
 	var m uintptr
 	if mask {
@@ -386,42 +425,55 @@ func (c *Functions) DepthMask(mask bool) {
 	}
 	syscall.Syscall(_glDepthMask.Addr(), 1, m, 0, 0)
 }
+
 func (c *Functions) DisableVertexAttribArray(a Attrib) {
 	syscall.Syscall(_glDisableVertexAttribArray.Addr(), 1, uintptr(a), 0, 0)
 }
+
 func (c *Functions) Disable(cap Enum) {
 	syscall.Syscall(_glDisable.Addr(), 1, uintptr(cap), 0, 0)
 }
+
 func (c *Functions) DrawArrays(mode Enum, first, count int) {
 	syscall.Syscall(_glDrawArrays.Addr(), 3, uintptr(mode), uintptr(first), uintptr(count))
 }
+
 func (c *Functions) DrawElements(mode Enum, count int, ty Enum, offset int) {
 	syscall.Syscall6(_glDrawElements.Addr(), 4, uintptr(mode), uintptr(count), uintptr(ty), uintptr(offset), 0, 0)
 }
+
 func (f *Functions) DispatchCompute(x, y, z int) {
 	panic("not implemented")
 }
+
 func (c *Functions) Enable(cap Enum) {
 	syscall.Syscall(_glEnable.Addr(), 1, uintptr(cap), 0, 0)
 }
+
 func (c *Functions) EnableVertexAttribArray(a Attrib) {
 	syscall.Syscall(_glEnableVertexAttribArray.Addr(), 1, uintptr(a), 0, 0)
 }
+
 func (f *Functions) EndQuery(target Enum) {
 	syscall.Syscall(_glEndQuery.Addr(), 1, uintptr(target), 0, 0)
 }
+
 func (c *Functions) Finish() {
 	syscall.Syscall(_glFinish.Addr(), 0, 0, 0, 0)
 }
+
 func (c *Functions) Flush() {
 	syscall.Syscall(_glFlush.Addr(), 0, 0, 0, 0)
 }
+
 func (c *Functions) FramebufferRenderbuffer(target, attachment, renderbuffertarget Enum, renderbuffer Renderbuffer) {
 	syscall.Syscall6(_glFramebufferRenderbuffer.Addr(), 4, uintptr(target), uintptr(attachment), uintptr(renderbuffertarget), uintptr(renderbuffer.V), 0, 0)
 }
+
 func (c *Functions) FramebufferTexture2D(target, attachment, texTarget Enum, t Texture, level int) {
 	syscall.Syscall6(_glFramebufferTexture2D.Addr(), 5, uintptr(target), uintptr(attachment), uintptr(texTarget), uintptr(t.V), uintptr(level), 0)
 }
+
 func (f *Functions) GetUniformBlockIndex(p Program, name string) uint {
 	cname := cString(name)
 	c0 := &cname[0]
@@ -429,24 +481,30 @@ func (f *Functions) GetUniformBlockIndex(p Program, name string) uint {
 	issue34474KeepAlive(c0)
 	return uint(u)
 }
+
 func (c *Functions) GetBinding(pname Enum) Object {
 	return Object{uint(c.GetInteger(pname))}
 }
+
 func (c *Functions) GetBindingi(pname Enum, idx int) Object {
 	return Object{uint(c.GetIntegeri(pname, idx))}
 }
+
 func (c *Functions) GetError() Enum {
 	e, _, _ := syscall.Syscall(_glGetError.Addr(), 0, 0, 0, 0)
 	return Enum(e)
 }
+
 func (c *Functions) GetRenderbufferParameteri(target, pname Enum) int {
 	syscall.Syscall(_glGetRenderbufferParameteriv.Addr(), 3, uintptr(target), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetFramebufferAttachmentParameteri(target, attachment, pname Enum) int {
 	syscall.Syscall6(_glGetFramebufferAttachmentParameteriv.Addr(), 4, uintptr(target), uintptr(attachment), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0, 0)
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetInteger4(pname Enum) [4]int {
 	syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0)
 	var r [4]int
@@ -455,28 +513,34 @@ func (c *Functions) GetInteger4(pname Enum) [4]int {
 	}
 	return r
 }
+
 func (c *Functions) GetInteger(pname Enum) int {
 	syscall.Syscall(_glGetIntegerv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])), 0)
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetIntegeri(pname Enum, idx int) int {
 	syscall.Syscall(_glGetIntegeri_v.Addr(), 3, uintptr(pname), uintptr(idx), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetFloat(pname Enum) float32 {
 	syscall.Syscall(_glGetFloatv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.float32s[0])), 0)
 	return c.float32s[0]
 }
+
 func (c *Functions) GetFloat4(pname Enum) [4]float32 {
 	syscall.Syscall(_glGetFloatv.Addr(), 2, uintptr(pname), uintptr(unsafe.Pointer(&c.float32s[0])), 0)
 	var r [4]float32
 	copy(r[:], c.float32s[:])
 	return r
 }
+
 func (c *Functions) GetProgrami(p Program, pname Enum) int {
 	syscall.Syscall(_glGetProgramiv.Addr(), 3, uintptr(p.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetProgramInfoLog(p Program) string {
 	n := c.GetProgrami(p, INFO_LOG_LENGTH)
 	if n == 0 {
@@ -486,24 +550,29 @@ func (c *Functions) GetProgramInfoLog(p Program) string {
 	syscall.Syscall6(_glGetProgramInfoLog.Addr(), 4, uintptr(p.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0)
 	return string(buf)
 }
+
 func (c *Functions) GetQueryObjectuiv(query Query, pname Enum) uint {
 	syscall.Syscall(_glGetQueryObjectuiv.Addr(), 3, uintptr(query.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return uint(c.int32s[0])
 }
+
 func (c *Functions) GetShaderi(s Shader, pname Enum) int {
 	syscall.Syscall(_glGetShaderiv.Addr(), 3, uintptr(s.V), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
 }
+
 func (c *Functions) GetShaderInfoLog(s Shader) string {
 	n := c.GetShaderi(s, INFO_LOG_LENGTH)
 	buf := make([]byte, n)
 	syscall.Syscall6(_glGetShaderInfoLog.Addr(), 4, uintptr(s.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0)
 	return string(buf)
 }
+
 func (c *Functions) GetString(pname Enum) string {
 	s, _, _ := syscall.Syscall(_glGetString.Addr(), 1, uintptr(pname), 0, 0)
 	return windows.BytePtrToString((*byte)(unsafe.Pointer(s)))
 }
+
 func (c *Functions) GetUniformLocation(p Program, name string) Uniform {
 	cname := cString(name)
 	c0 := &cname[0]
@@ -511,6 +580,7 @@ func (c *Functions) GetUniformLocation(p Program, name string) Uniform {
 	issue34474KeepAlive(c0)
 	return Uniform{int(u)}
 }
+
 func (c *Functions) GetVertexAttrib(index int, pname Enum) int {
 	syscall.Syscall(_glGetVertexAttribiv.Addr(), 3, uintptr(index), uintptr(pname), uintptr(unsafe.Pointer(&c.int32s[0])))
 	return int(c.int32s[0])
@@ -524,6 +594,7 @@ func (c *Functions) GetVertexAttribPointer(index int, pname Enum) uintptr {
 	syscall.Syscall(_glGetVertexAttribPointerv.Addr(), 3, uintptr(index), uintptr(pname), uintptr(unsafe.Pointer(&c.uintptrs[0])))
 	return c.uintptrs[0]
 }
+
 func (c *Functions) InvalidateFramebuffer(target, attachment Enum) {
 	addr := _glInvalidateFramebuffer.Addr()
 	if addr == 0 {
@@ -532,77 +603,99 @@ func (c *Functions) InvalidateFramebuffer(target, attachment Enum) {
 	}
 	syscall.Syscall(addr, 3, uintptr(target), 1, uintptr(unsafe.Pointer(&attachment)))
 }
+
 func (f *Functions) IsEnabled(cap Enum) bool {
 	u, _, _ := syscall.Syscall(_glIsEnabled.Addr(), 1, uintptr(cap), 0, 0)
 	return u == TRUE
 }
+
 func (c *Functions) LinkProgram(p Program) {
 	syscall.Syscall(_glLinkProgram.Addr(), 1, uintptr(p.V), 0, 0)
 }
+
 func (c *Functions) PixelStorei(pname Enum, param int) {
 	syscall.Syscall(_glPixelStorei.Addr(), 2, uintptr(pname), uintptr(param), 0)
 }
+
 func (f *Functions) MemoryBarrier(barriers Enum) {
 	panic("not implemented")
 }
+
 func (f *Functions) MapBufferRange(target Enum, offset, length int, access Enum) []byte {
 	panic("not implemented")
 }
+
 func (f *Functions) ReadPixels(x, y, width, height int, format, ty Enum, data []byte) {
 	d0 := &data[0]
 	syscall.Syscall9(_glReadPixels.Addr(), 7, uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0)), 0, 0)
 	issue34474KeepAlive(d0)
 }
+
 func (c *Functions) RenderbufferStorage(target, internalformat Enum, width, height int) {
 	syscall.Syscall6(_glRenderbufferStorage.Addr(), 4, uintptr(target), uintptr(internalformat), uintptr(width), uintptr(height), 0, 0)
 }
+
 func (c *Functions) Scissor(x, y, width, height int32) {
 	syscall.Syscall6(_glScissor.Addr(), 4, uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0, 0)
 }
+
 func (c *Functions) ShaderSource(s Shader, src string) {
 	var n uintptr = uintptr(len(src))
 	psrc := &src
 	syscall.Syscall6(_glShaderSource.Addr(), 4, uintptr(s.V), 1, uintptr(unsafe.Pointer(psrc)), uintptr(unsafe.Pointer(&n)), 0, 0)
 	issue34474KeepAlive(psrc)
 }
+
 func (f *Functions) TexImage2D(target Enum, level int, internalFormat Enum, width int, height int, format Enum, ty Enum) {
 	syscall.Syscall9(_glTexImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(internalFormat), uintptr(width), uintptr(height), 0, uintptr(format), uintptr(ty), 0)
 }
+
 func (f *Functions) TexStorage2D(target Enum, levels int, internalFormat Enum, width, height int) {
 	syscall.Syscall6(_glTexStorage2D.Addr(), 5, uintptr(target), uintptr(levels), uintptr(internalFormat), uintptr(width), uintptr(height), 0)
 }
+
 func (c *Functions) TexSubImage2D(target Enum, level int, x, y, width, height int, format, ty Enum, data []byte) {
 	d0 := &data[0]
 	syscall.Syscall9(_glTexSubImage2D.Addr(), 9, uintptr(target), uintptr(level), uintptr(x), uintptr(y), uintptr(width), uintptr(height), uintptr(format), uintptr(ty), uintptr(unsafe.Pointer(d0)))
 	issue34474KeepAlive(d0)
 }
+
 func (c *Functions) TexParameteri(target, pname Enum, param int) {
 	syscall.Syscall(_glTexParameteri.Addr(), 3, uintptr(target), uintptr(pname), uintptr(param))
 }
+
 func (f *Functions) UniformBlockBinding(p Program, uniformBlockIndex uint, uniformBlockBinding uint) {
 	syscall.Syscall(_glUniformBlockBinding.Addr(), 3, uintptr(p.V), uintptr(uniformBlockIndex), uintptr(uniformBlockBinding))
 }
+
 func (c *Functions) Uniform1f(dst Uniform, v float32) {
 	syscall.Syscall(_glUniform1f.Addr(), 2, uintptr(dst.V), uintptr(math.Float32bits(v)), 0)
 }
+
 func (c *Functions) Uniform1i(dst Uniform, v int) {
 	syscall.Syscall(_glUniform1i.Addr(), 2, uintptr(dst.V), uintptr(v), 0)
 }
+
 func (c *Functions) Uniform2f(dst Uniform, v0, v1 float32) {
 	syscall.Syscall(_glUniform2f.Addr(), 3, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)))
 }
+
 func (c *Functions) Uniform3f(dst Uniform, v0, v1, v2 float32) {
 	syscall.Syscall6(_glUniform3f.Addr(), 4, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)), uintptr(math.Float32bits(v2)), 0, 0)
 }
+
 func (c *Functions) Uniform4f(dst Uniform, v0, v1, v2, v3 float32) {
 	syscall.Syscall6(_glUniform4f.Addr(), 5, uintptr(dst.V), uintptr(math.Float32bits(v0)), uintptr(math.Float32bits(v1)), uintptr(math.Float32bits(v2)), uintptr(math.Float32bits(v3)), 0)
 }
+
 func (c *Functions) UseProgram(p Program) {
 	syscall.Syscall(_glUseProgram.Addr(), 1, uintptr(p.V), 0, 0)
 }
+
 func (f *Functions) UnmapBuffer(target Enum) bool {
 	panic("not implemented")
 }
+
 func (c *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride, offset int) {
 	var norm uintptr
 	if normalized {
@@ -610,6 +703,7 @@ func (c *Functions) VertexAttribPointer(dst Attrib, size int, ty Enum, normalize
 	}
 	syscall.Syscall6(_glVertexAttribPointer.Addr(), 6, uintptr(dst), uintptr(size), uintptr(ty), norm, uintptr(stride), uintptr(offset))
 }
+
 func (c *Functions) Viewport(x, y, width, height int) {
 	syscall.Syscall6(_glViewport.Addr(), 4, uintptr(x), uintptr(y), uintptr(width), uintptr(height), 0, 0)
 }
@@ -622,6 +716,6 @@ func cString(s string) []byte {
 
 // issue34474KeepAlive calls runtime.KeepAlive as a
 // workaround for golang.org/issue/34474.
-func issue34474KeepAlive(v interface{}) {
+func issue34474KeepAlive(v any) {
 	runtime.KeepAlive(v)
 }

internal/gl/types.go

@@ -1,5 +1,4 @@
 //go:build !js
-// +build !js
 
 package gl
 

internal/ops/ops.go

@@ -18,7 +18,7 @@ type Ops struct {
 	// data contains the serialized operations.
 	data []byte
 	// refs hold external references for operations.
-	refs []interface{}
+	refs []any
 	// stringRefs provides space for string references, pointers to which will
 	// be stored in refs. Storing a string directly in refs would cause a heap
 	// allocation, to store the string header in an interface value. The backing
@@ -256,7 +256,7 @@ func PopOp(o *Ops, kind StackKind, sid StackID, macroID uint32) {
 	o.stacks[kind].pop(sid)
 }
 
-func Write1(o *Ops, n int, ref1 interface{}) []byte {
+func Write1(o *Ops, n int, ref1 any) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.refs = append(o.refs, ref1)
 	return o.data[len(o.data)-n:]
@@ -269,20 +269,20 @@ func Write1String(o *Ops, n int, ref1 string) []byte {
 	return o.data[len(o.data)-n:]
 }
 
-func Write2(o *Ops, n int, ref1, ref2 interface{}) []byte {
+func Write2(o *Ops, n int, ref1, ref2 any) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.refs = append(o.refs, ref1, ref2)
 	return o.data[len(o.data)-n:]
 }
 
-func Write2String(o *Ops, n int, ref1 interface{}, ref2 string) []byte {
+func Write2String(o *Ops, n int, ref1 any, ref2 string) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.stringRefs = append(o.stringRefs, ref2)
 	o.refs = append(o.refs, ref1, &o.stringRefs[len(o.stringRefs)-1])
 	return o.data[len(o.data)-n:]
 }
 
-func Write3(o *Ops, n int, ref1, ref2, ref3 interface{}) []byte {
+func Write3(o *Ops, n int, ref1, ref2, ref3 any) []byte {
 	o.data = append(o.data, make([]byte, n)...)
 	o.refs = append(o.refs, ref1, ref2, ref3)
 	return o.data[len(o.data)-n:]

internal/ops/reader.go

@@ -20,7 +20,7 @@ type Reader struct {
 type EncodedOp struct {
 	Key  Key
 	Data []byte
-	Refs []interface{}
+	Refs []any
 }
 
 // Key is a unique key for a given op.
@@ -175,7 +175,7 @@ func (op *opMacroDef) decode(data []byte) {
 	op.endpc.refs = bo.Uint32(data[5:])
 }
 
-func (m *macroOp) decode(data []byte, refs []interface{}) {
+func (m *macroOp) decode(data []byte, refs []any) {
 	if len(data) < TypeCallLen || len(refs) < 1 || OpType(data[0]) != TypeCall {
 		panic("invalid op")
 	}

internal/stroke/stroke.go

@@ -87,7 +87,7 @@ func (qs *StrokeQuads) lineTo(pt f32.Point) {
 func (qs *StrokeQuads) arc(f1, f2 f32.Point, angle float32) {
 	pen := qs.pen()
 	m, segments := ArcTransform(pen, f1.Add(pen), f2.Add(pen), angle)
-	for i := 0; i < segments; i++ {
+	for range segments {
 		p0 := qs.pen()
 		p1 := m.Transform(p0)
 		p2 := m.Transform(p1)
@@ -327,13 +327,26 @@ func strokePathNorm(p0, p1, p2 f32.Point, t, d float32) f32.Point {
 func rot90CW(p f32.Point) f32.Point { return f32.Pt(+p.Y, -p.X) }
 
 func normPt(p f32.Point, l float32) f32.Point {
-	if (p.X == 0 && p.Y == l) || (p.Y == 0 && p.X == l) {
+	if (p.X == 0 && p.Y == 0) || l == 0 {
-		return f32.Point{X: p.X, Y: p.Y}
+		return f32.Point{}
+	}
+	isVerticalUnit := p.X == 0 && (p.Y == l || p.Y == -l)
+	isHorizontalUnit := p.Y == 0 && (p.X == l || p.X == -l)
+	if isVerticalUnit || isHorizontalUnit {
+		if math.Signbit(float64(l)) {
+			return f32.Point{X: -p.X, Y: -p.Y}
+		} else {
+			return f32.Point{X: p.X, Y: p.Y}
+		}
 	}
 	d := math.Hypot(float64(p.X), float64(p.Y))
 	l64 := float64(l)
 	if math.Abs(d-l64) < 1e-10 {
-		return f32.Point{}
+		if math.Signbit(float64(l)) {
+			return f32.Point{X: -p.X, Y: -p.Y}
+		} else {
+			return f32.Point{X: p.X, Y: p.Y}
+		}
 	}
 	n := float32(l64 / d)
 	return f32.Point{X: p.X * n, Y: p.Y * n}
@@ -440,7 +453,6 @@ func flattenQuadBezier(qs StrokeQuads, p0, p1, p2 f32.Point, d, flatness float32
 }
 
 func (qs *StrokeQuads) addLine(p0, ctrl, p1 f32.Point, t, d float32) {
-
 	switch i := len(*qs); i {
 	case 0:
 		p0 = p0.Add(strokePathNorm(p0, ctrl, p1, 0, d))
@@ -473,7 +485,6 @@ func quadInterp(p, q f32.Point, t float32) f32.Point {
 // quadBezierSplit returns the pair of triplets (from,ctrl,to) Bézier curve,
 // split before (resp. after) the provided parametric t value.
 func quadBezierSplit(p0, p1, p2 f32.Point, t float32) (f32.Point, f32.Point, f32.Point, f32.Point, f32.Point, f32.Point) {
-
 	var (
 		b0 = p0
 		b1 = quadInterp(p0, p1, t)
@@ -577,12 +588,10 @@ func ArcTransform(p, f1, f2 f32.Point, angle float32) (transform f32.Affine2D, s
 		}
 	}
 
-	var (
+	θ := angle / float32(segments)
-		θ   = angle / float32(segments)
+	ref := f32.AffineId() // transform from absolute frame to ellipse-based one
-		ref f32.Affine2D // transform from absolute frame to ellipse-based one
+	rot := f32.AffineId() // rotation matrix for each segment
-		rot f32.Affine2D // rotation matrix for each segment
+	inv := f32.AffineId() // transform from ellipse-based frame to absolute one
-		inv f32.Affine2D // transform from ellipse-based frame to absolute one
-	)
 	center := f32.Point{
 		X: 0.5 * (f1.X + f2.X),
 		Y: 0.5 * (f1.Y + f2.Y),

internal/stroke/stroke_test.go

@@ -9,6 +9,111 @@ import (
 	"gioui.org/internal/f32"
 )
 
+func TestNormPt(t *testing.T) {
+	type scenario struct {
+		l           float32
+		ptIn, ptOut f32.Point
+	}
+
+	scenarios := []scenario{
+		// l!=0 && X=Y=0
+		{l: 10, ptIn: f32.Point{X: 0, Y: 0}, ptOut: f32.Point{X: 0, Y: 0}},
+		{l: -10, ptIn: f32.Point{X: 0, Y: 0}, ptOut: f32.Point{X: 0, Y: 0}},
+
+		// l>0 & X
+		{l: +20, ptIn: f32.Point{X: +30, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: +20, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: +10, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: -10, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: -20, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: +20, ptIn: f32.Point{X: -30, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+
+		// l<0 & X
+		{l: -20, ptIn: f32.Point{X: +30, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: +20, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: +10, Y: 0}, ptOut: f32.Point{X: -20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: -10, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: -20, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+		{l: -20, ptIn: f32.Point{X: -30, Y: 0}, ptOut: f32.Point{X: +20, Y: 0}},
+
+		// l>0 & Y
+		{l: +20, ptIn: f32.Point{X: 0, Y: +30}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: +20}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: +10}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: -10}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: -20}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: +20, ptIn: f32.Point{X: 0, Y: -30}, ptOut: f32.Point{X: 0, Y: -20}},
+
+		// l<0 & Y
+		{l: -20, ptIn: f32.Point{X: 0, Y: +30}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: +20}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: +10}, ptOut: f32.Point{X: 0, Y: -20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: -10}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: -20}, ptOut: f32.Point{X: 0, Y: +20}},
+		{l: -20, ptIn: f32.Point{X: 0, Y: -30}, ptOut: f32.Point{X: 0, Y: +20}},
+
+		// l>0 && X=Y
+		{l: +20, ptIn: f32.Point{X: +90, Y: +90}, ptOut: f32.Point{X: +14.142137, Y: +14.142137}},
+		{l: +20, ptIn: f32.Point{X: +30, Y: +30}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: +20, Y: +20}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: +10, Y: +10}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -10, Y: -10}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -20, Y: -20}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -30, Y: -30}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -90, Y: -90}, ptOut: f32.Point{X: -14.142137, Y: -14.142137}},
+
+		// l>0 && X=-Y
+		{l: +20, ptIn: f32.Point{X: +90, Y: -90}, ptOut: f32.Point{X: +14.142137, Y: -14.142137}},
+		{l: +20, ptIn: f32.Point{X: +30, Y: -30}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: +20, Y: -20}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: +10, Y: -10}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: +20, ptIn: f32.Point{X: -10, Y: +10}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -20, Y: +20}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -30, Y: +30}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: +20, ptIn: f32.Point{X: -90, Y: +90}, ptOut: f32.Point{X: -14.142137, Y: +14.142137}},
+
+		// l<0 && X=Y
+		{l: -20, ptIn: f32.Point{X: +90, Y: +90}, ptOut: f32.Point{X: -14.142137, Y: -14.142137}},
+		{l: -20, ptIn: f32.Point{X: +30, Y: +30}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: +20, Y: +20}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: +10, Y: +10}, ptOut: f32.Point{X: -14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -10, Y: -10}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -20, Y: -20}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -30, Y: -30}, ptOut: f32.Point{X: +14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -90, Y: -90}, ptOut: f32.Point{X: +14.142137, Y: +14.142137}},
+
+		// l<0 && X=-Y
+		{l: -20, ptIn: f32.Point{X: +90, Y: -90}, ptOut: f32.Point{X: -14.142137, Y: +14.142137}},
+		{l: -20, ptIn: f32.Point{X: +30, Y: -30}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: +20, Y: -20}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: +10, Y: -10}, ptOut: f32.Point{X: -14.142136, Y: +14.142136}},
+		{l: -20, ptIn: f32.Point{X: -10, Y: +10}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -20, Y: +20}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -30, Y: +30}, ptOut: f32.Point{X: +14.142136, Y: -14.142136}},
+		{l: -20, ptIn: f32.Point{X: -90, Y: +90}, ptOut: f32.Point{X: +14.142137, Y: -14.142137}},
+
+		// l!=0 && Hypot=l
+		{l: 5, ptIn: f32.Point{X: 3, Y: 4}, ptOut: f32.Point{X: 3, Y: 4}},
+		{l: 5, ptIn: f32.Point{X: 3, Y: -4}, ptOut: f32.Point{X: 3, Y: -4}},
+		{l: 5, ptIn: f32.Point{X: -3, Y: -4}, ptOut: f32.Point{X: -3, Y: -4}},
+		{l: 5, ptIn: f32.Point{X: -3, Y: 4}, ptOut: f32.Point{X: -3, Y: 4}},
+		{l: -5, ptIn: f32.Point{X: 3, Y: 4}, ptOut: f32.Point{X: -3, Y: -4}},
+		{l: -5, ptIn: f32.Point{X: 3, Y: -4}, ptOut: f32.Point{X: -3, Y: 4}},
+		{l: -5, ptIn: f32.Point{X: -3, Y: -4}, ptOut: f32.Point{X: 3, Y: 4}},
+		{l: -5, ptIn: f32.Point{X: -3, Y: 4}, ptOut: f32.Point{X: 3, Y: -4}},
+	}
+
+	for i, s := range scenarios {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			actual := normPt(s.ptIn, s.l)
+			if actual != s.ptOut {
+				t.Errorf("in: %v*%v, expected: %v, actual: %v", s.l, s.ptIn, s.ptOut, actual)
+			}
+		})
+
+	}
+}
+
 func BenchmarkSplitCubic(b *testing.B) {
 	type scenario struct {
 		segments               int
@@ -47,12 +152,11 @@ func BenchmarkSplitCubic(b *testing.B) {
 	}
 
 	for _, s := range scenarios {
-		s := s
 		b.Run(strconv.Itoa(s.segments), func(b *testing.B) {
 			from, ctrl0, ctrl1, to := s.from, s.ctrl0, s.ctrl1, s.to
 			quads := make([]QuadSegment, s.segments)
 			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
+			for b.Loop() {
 				quads = SplitCubic(from, ctrl0, ctrl1, to, quads[:0])
 			}
 			if len(quads) != s.segments {

internal/vk/vulkan.go

@@ -385,6 +385,7 @@ static VkResult vkQueuePresentKHR(PFN_vkQueuePresentKHR f, VkQueue queue, const
 }
 */
 import "C"
+
 import (
 	"errors"
 	"fmt"
@@ -1167,7 +1168,6 @@ func CreateFramebuffer(d Device, rp RenderPass, view ImageView, width, height in
 		return nilFramebuffer, fmt.Errorf("vulkan: vkCreateFramebuffer: %w", err)
 	}
 	return fbo, nil
-
 }
 
 func DestroyFramebuffer(d Device, f Framebuffer) {

internal/vk/vulkan_android.go

@@ -17,6 +17,7 @@ static VkResult vkCreateAndroidSurfaceKHR(PFN_vkCreateAndroidSurfaceKHR f, VkIns
 }
 */
 import "C"
+
 import (
 	"fmt"
 	"unsafe"

internal/vk/vulkan_wayland.go

@@ -19,6 +19,7 @@ static VkResult vkCreateWaylandSurfaceKHR(PFN_vkCreateWaylandSurfaceKHR f, VkIns
 }
 */
 import "C"
+
 import (
 	"fmt"
 	"unsafe"

internal/vk/vulkan_x11.go

@@ -17,6 +17,7 @@ static VkResult vkCreateXlibSurfaceKHR(PFN_vkCreateXlibSurfaceKHR f, VkInstance
 }
 */
 import "C"
+
 import (
 	"fmt"
 	"unsafe"

io/event/event.go

@@ -10,7 +10,7 @@ import (
 
 // Tag is the stable identifier for an event handler.
 // For a handler h, the tag is typically &h.
-type Tag interface{}
+type Tag any
 
 // Event is the marker interface for events.
 type Event interface {

io/input/clipboard.go

@@ -4,6 +4,7 @@ package input
 
 import (
 	"io"
+	"slices"
 
 	"gioui.org/io/clipboard"
 	"gioui.org/io/event"
@@ -60,10 +61,8 @@ func (q *clipboardQueue) ProcessWriteClipboard(req clipboard.WriteCmd) {
 }
 
 func (q *clipboardQueue) ProcessReadClipboard(state clipboardState, tag event.Tag) clipboardState {
-	for _, k := range state.receivers {
+	if slices.Contains(state.receivers, tag) {
-		if k == tag {
+		return state
-			return state
-		}
 	}
 	n := len(state.receivers)
 	state.receivers = append(state.receivers[:n:n], tag)

io/input/clipboard_test.go

@@ -52,7 +52,7 @@ func TestQueueProcessReadClipboard(t *testing.T) {
 	assertClipboardReadCmd(t, r, 1)
 	ops.Reset()
 
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		// No ReadCmd
 		// One receiver must still wait for response
 

io/input/key.go

@@ -4,6 +4,7 @@ package input
 
 import (
 	"image"
+	"slices"
 	"sort"
 
 	"gioui.org/f32"
@@ -280,6 +281,7 @@ func (q *keyQueue) Focus(handlers map[event.Tag]*handler, state keyState, focus
 		return state, nil
 	}
 	state.content = EditorState{}
+	state.content.Selection.Transform = f32.AffineId()
 	var evts []taggedEvent
 	if state.focus != nil {
 		evts = append(evts, taggedEvent{tag: state.focus, event: key.FocusEvent{Focus: false}})
@@ -304,10 +306,8 @@ func (s keyState) softKeyboard(show bool) keyState {
 }
 
 func (k *keyFilter) Add(f key.Filter) {
-	for _, f2 := range *k {
+	if slices.Contains(*k, f) {
-		if f == f2 {
+		return
-			return
-		}
 	}
 	*k = append(*k, f)
 }

io/input/pointer.go

@@ -5,6 +5,7 @@ package input
 import (
 	"image"
 	"io"
+	"slices"
 
 	"gioui.org/f32"
 	f32internal "gioui.org/internal/f32"
@@ -143,7 +144,9 @@ const (
 )
 
 func (c *pointerCollector) resetState() {
-	c.state = collectState{}
+	c.state = collectState{
+		t: f32.AffineId(),
+	}
 	c.nodeStack = c.nodeStack[:0]
 	// Pop every node except the root.
 	if len(c.q.hitTree) > 0 {
@@ -257,6 +260,11 @@ func (q *pointerQueue) grab(state pointerState, req pointer.GrabCmd) (pointerSta
 		if !p.pressed || p.id != req.ID {
 			continue
 		}
+		// Verify that the grabber is among the handlers.
+		found := slices.Contains(p.handlers, req.Tag)
+		if !found {
+			continue
+		}
 		// Drop other handlers that lost their grab.
 		for i := len(p.handlers) - 1; i >= 0; i-- {
 			if tag := p.handlers[i]; tag != req.Tag {
@@ -282,17 +290,13 @@ func (c *pointerCollector) inputOp(tag event.Tag, state *pointerHandler) {
 func (p *pointerFilter) Add(f event.Filter) {
 	switch f := f.(type) {
 	case transfer.SourceFilter:
-		for _, m := range p.sourceMimes {
+		if slices.Contains(p.sourceMimes, f.Type) {
-			if m == f.Type {
+			return
-				return
-			}
 		}
 		p.sourceMimes = append(p.sourceMimes, f.Type)
 	case transfer.TargetFilter:
-		for _, m := range p.targetMimes {
+		if slices.Contains(p.targetMimes, f.Type) {
-			if m == f.Type {
+			return
-				return
-			}
 		}
 		p.targetMimes = append(p.targetMimes, f.Type)
 	case pointer.Filter:
@@ -309,16 +313,12 @@ func (p *pointerFilter) Matches(e event.Event) bool {
 	case transfer.CancelEvent, transfer.InitiateEvent:
 		return len(p.sourceMimes) > 0 || len(p.targetMimes) > 0
 	case transfer.RequestEvent:
-		for _, t := range p.sourceMimes {
+		if slices.Contains(p.sourceMimes, e.Type) {
-			if t == e.Type {
+			return true
-				return true
-			}
 		}
 	case transfer.DataEvent:
-		for _, t := range p.targetMimes {
+		if slices.Contains(p.targetMimes, e.Type) {
-			if t == e.Type {
+			return true
-				return true
-			}
 		}
 	}
 	return false
@@ -413,7 +413,7 @@ func (q *pointerQueue) offerData(handlers map[event.Tag]*handler, state pointerS
 				},
 			}})
 		}
-		state.pointers = append([]pointerInfo{}, state.pointers...)
+		state.pointers = slices.Clone(state.pointers)
 		state.pointers[i], evts = q.deliverTransferCancelEvent(handlers, p, evts)
 		break
 	}
@@ -605,7 +605,7 @@ func (q *pointerQueue) reset() {
 	for k, ids := range q.semantic.contentIDs {
 		for i := len(ids) - 1; i >= 0; i-- {
 			if !ids[i].used {
-				ids = append(ids[:i], ids[i+1:]...)
+				ids = slices.Delete(ids, i, i+1)
 			} else {
 				ids[i].used = false
 			}
@@ -636,7 +636,7 @@ func (q *pointerQueue) Frame(handlers map[event.Tag]*handler, state pointerState
 		changed := false
 		p, evts, state.cursor, changed = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, p.last)
 		if changed {
-			state.pointers = append([]pointerInfo{}, state.pointers...)
+			state.pointers = slices.Clone(state.pointers)
 			state.pointers[i] = p
 		}
 	}
@@ -739,6 +739,10 @@ func (q *pointerQueue) Push(handlers map[event.Tag]*handler, state pointerState,
 		state.pointers = nil
 		return state, evts
 	}
+	if e.Kind == pointer.Scroll {
+		// Scroll events are not bound to a pointer; see pointer.Event.PointerID.
+		return state, q.deliverScrollEvent(handlers, evts, e)
+	}
 	state, pidx := state.pointerOf(e)
 	p := state.pointers[pidx]
 
@@ -756,14 +760,13 @@ func (q *pointerQueue) Push(handlers map[event.Tag]*handler, state pointerState,
 		if p.pressed {
 			p, evts = q.deliverDragEvent(handlers, p, evts)
 		}
+	case pointer.Leave:
+		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
 	case pointer.Release:
 		evts = q.deliverEvent(handlers, p, evts, e)
 		p.pressed = false
 		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
 		p, evts = q.deliverDropEvent(handlers, p, evts)
-	case pointer.Scroll:
-		p, evts, state.cursor, _ = q.deliverEnterLeaveEvents(handlers, state.cursor, p, evts, e)
-		evts = q.deliverEvent(handlers, p, evts, e)
 	default:
 		panic("unsupported pointer event type")
 	}
@@ -772,19 +775,29 @@ func (q *pointerQueue) Push(handlers map[event.Tag]*handler, state pointerState,
 
 	if !p.pressed && len(p.entered) == 0 {
 		// No longer need to track pointer.
-		state.pointers = append(state.pointers[:pidx:pidx], state.pointers[pidx+1:]...)
+		state.pointers = slices.Concat(state.pointers[:pidx:pidx], state.pointers[pidx+1:])
 	} else {
-		state.pointers = append([]pointerInfo{}, state.pointers...)
+		state.pointers = slices.Clone(state.pointers)
 		state.pointers[pidx] = p
 	}
 	return state, evts
 }
 
+// deliverScrollEvent delivers scroll events to the handlers hit by the event coordinate.
+func (q *pointerQueue) deliverScrollEvent(handlers map[event.Tag]*handler, evts []taggedEvent, e pointer.Event) []taggedEvent {
+	var hits []event.Tag
+	q.hitTest(e.Position, func(n *hitNode) bool {
+		if _, ok := handlers[n.tag]; ok {
+			hits = addHandler(hits, n.tag)
+		}
+		return true
+	})
+	return q.deliverEvent(handlers, pointerInfo{handlers: hits}, evts, e)
+}
+
 func (q *pointerQueue) deliverEvent(handlers map[event.Tag]*handler, p pointerInfo, evts []taggedEvent, e pointer.Event) []taggedEvent {
-	foremost := true
 	if p.pressed && len(p.handlers) == 1 {
 		e.Priority = pointer.Grabbed
-		foremost = false
 	}
 	scroll := e.Scroll
 	for _, k := range p.handlers {
@@ -803,10 +816,6 @@ func (q *pointerQueue) deliverEvent(handlers map[event.Tag]*handler, p pointerIn
 			scroll, e.Scroll = f.clampScroll(scroll)
 		}
 		e := e
-		if foremost {
-			foremost = false
-			e.Priority = pointer.Foremost
-		}
 		e.Position = q.invTransform(h.pointer.areaPlusOne-1, e.Position)
 		evts = append(evts, taggedEvent{event: e, tag: k})
 	}
@@ -816,7 +825,7 @@ func (q *pointerQueue) deliverEvent(handlers map[event.Tag]*handler, p pointerIn
 func (q *pointerQueue) deliverEnterLeaveEvents(handlers map[event.Tag]*handler, cursor pointer.Cursor, p pointerInfo, evts []taggedEvent, e pointer.Event) (pointerInfo, []taggedEvent, pointer.Cursor, bool) {
 	changed := false
 	var hits []event.Tag
-	if e.Source != pointer.Mouse && !p.pressed && e.Kind != pointer.Press {
+	if e.Kind == pointer.Leave || e.Source != pointer.Mouse && !p.pressed && e.Kind != pointer.Press {
 		// Consider non-mouse pointers leaving when they're released.
 	} else {
 		var transSrc *pointerFilter
@@ -970,10 +979,8 @@ func searchTag(tags []event.Tag, tag event.Tag) (int, bool) {
 
 // addHandler adds tag to the slice if not present.
 func addHandler(tags []event.Tag, tag event.Tag) []event.Tag {
-	for _, t := range tags {
+	if slices.Contains(tags, tag) {
-		if t == tag {
+		return tags
-			return tags
-		}
 	}
 	return append(tags, tag)
 }
@@ -981,10 +988,8 @@ func addHandler(tags []event.Tag, tag event.Tag) []event.Tag {
 // firstMimeMatch returns the first type match between src and tgt.
 func firstMimeMatch(src, tgt *pointerFilter) (first string, matched bool) {
 	for _, m1 := range tgt.targetMimes {
-		for _, m2 := range src.sourceMimes {
+		if slices.Contains(src.sourceMimes, m1) {
-			if m1 == m2 {
+			return m1, true
-				return m1, true
-			}
 		}
 	}
 	return "", false

io/input/pointer_test.go

@@ -97,6 +97,39 @@ func TestPointerDragNegative(t *testing.T) {
 	assertEventPointerTypeSequence(t, events(&r, -1, f), pointer.Enter, pointer.Press, pointer.Leave, pointer.Drag)
 }
 
+func TestIgnoredGrab(t *testing.T) {
+	handler1 := new(int)
+	handler2 := new(int)
+	var ops op.Ops
+
+	filter := func(t event.Tag) event.Filter {
+		return pointer.Filter{Target: t, Kinds: pointer.Press | pointer.Release | pointer.Cancel}
+	}
+
+	event.Op(&ops, handler1)
+	event.Op(&ops, handler2)
+	var r Router
+	assertEventPointerTypeSequence(t, events(&r, -1, filter(handler1)), pointer.Cancel)
+	assertEventPointerTypeSequence(t, events(&r, -1, filter(handler2)), pointer.Cancel)
+	r.Frame(&ops)
+	r.Queue(
+		pointer.Event{
+			Kind:     pointer.Press,
+			Position: f32.Pt(50, 50),
+		},
+		pointer.Event{
+			Kind:     pointer.Release,
+			Position: f32.Pt(50, 50),
+		},
+	)
+	assertEventPointerTypeSequence(t, events(&r, 1, filter(handler1)), pointer.Press)
+	assertEventPointerTypeSequence(t, events(&r, 1, filter(handler2)), pointer.Press)
+	r.Source().Execute(pointer.GrabCmd{Tag: handler1})
+	r.Source().Execute(pointer.GrabCmd{Tag: handler2})
+	assertEventPointerTypeSequence(t, events(&r, 1, filter(handler1)), pointer.Release)
+	assertEventPointerTypeSequence(t, events(&r, 1, filter(handler2)), pointer.Cancel)
+}
+
 func TestPointerGrab(t *testing.T) {
 	handler1 := new(int)
 	handler2 := new(int)
@@ -222,6 +255,45 @@ func TestPointerMove(t *testing.T) {
 	assertEventPointerTypeSequence(t, events(&r, -1, filter(handler2)), pointer.Enter, pointer.Move, pointer.Leave, pointer.Cancel)
 }
 
+func TestPointerLeave(t *testing.T) {
+	handler := new(int)
+	var ops op.Ops
+
+	filter := pointer.Filter{
+		Target: handler,
+		Kinds:  pointer.Move | pointer.Enter | pointer.Leave | pointer.Cancel,
+	}
+	defer clip.Rect(image.Rect(0, 0, 100, 100)).Push(&ops).Pop()
+	event.Op(&ops, handler)
+
+	var r Router
+	events(&r, -1, filter)
+	r.Frame(&ops)
+	r.Queue(
+		pointer.Event{
+			Kind:      pointer.Move,
+			Source:    pointer.Mouse,
+			PointerID: 1,
+			Position:  f32.Pt(50, 50),
+		},
+		pointer.Event{
+			Kind:      pointer.Leave,
+			Source:    pointer.Mouse,
+			PointerID: 1,
+			Position:  f32.Pt(50, 50),
+		},
+	)
+	assertEventPointerTypeSequence(t, events(&r, -1, filter), pointer.Enter, pointer.Move, pointer.Leave)
+
+	r.Queue(pointer.Event{
+		Kind:      pointer.Move,
+		Source:    pointer.Mouse,
+		PointerID: 1,
+		Position:  f32.Pt(50, 50),
+	})
+	assertEventPointerTypeSequence(t, events(&r, -1, filter), pointer.Enter, pointer.Move)
+}
+
 func TestPointerTypes(t *testing.T) {
 	handler := new(int)
 	var ops op.Ops
@@ -367,9 +439,9 @@ func TestPointerPriority(t *testing.T) {
 	assertEventPointerTypeSequence(t, hev1, pointer.Scroll, pointer.Scroll)
 	assertEventPointerTypeSequence(t, hev2, pointer.Scroll)
 	assertEventPointerTypeSequence(t, hev3, pointer.Scroll)
-	assertEventPriorities(t, hev1, pointer.Shared, pointer.Foremost)
+	assertEventPriorities(t, hev1, pointer.Shared, pointer.Shared)
-	assertEventPriorities(t, hev2, pointer.Foremost)
+	assertEventPriorities(t, hev2, pointer.Shared)
-	assertEventPriorities(t, hev3, pointer.Foremost)
+	assertEventPriorities(t, hev3, pointer.Shared)
 	assertScrollEvent(t, hev1[0], f32.Pt(30, 0))
 	assertScrollEvent(t, hev2[0], f32.Pt(20, 0))
 	assertScrollEvent(t, hev1[1], f32.Pt(50, 0))
@@ -678,26 +750,31 @@ func TestCursor(t *testing.T) {
 		cursors []pointer.Cursor
 		want    pointer.Cursor
 	}{
-		{label: "no movement",
+		{
+			label:   "no movement",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			want:    pointer.CursorDefault,
 		},
-		{label: "move inside",
+		{
+			label:   "move inside",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			events:  _at(50, 50),
 			want:    pointer.CursorPointer,
 		},
-		{label: "move outside",
+		{
+			label:   "move outside",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			events:  _at(200, 200),
 			want:    pointer.CursorDefault,
 		},
-		{label: "move back inside",
+		{
+			label:   "move back inside",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			events:  _at(50, 50),
 			want:    pointer.CursorPointer,
 		},
-		{label: "send key events while inside",
+		{
+			label:   "send key events while inside",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			events: []event.Event{
 				key.Event{Name: "A", State: key.Press},
@@ -705,7 +782,8 @@ func TestCursor(t *testing.T) {
 			},
 			want: pointer.CursorPointer,
 		},
-		{label: "send key events while outside",
+		{
+			label:   "send key events while outside",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			events: append(
 				_at(200, 200),
@@ -714,7 +792,8 @@ func TestCursor(t *testing.T) {
 			),
 			want: pointer.CursorDefault,
 		},
-		{label: "add new input on top while inside",
+		{
+			label:   "add new input on top while inside",
 			cursors: []pointer.Cursor{pointer.CursorPointer, pointer.CursorCrosshair},
 			events: append(
 				_at(50, 50),
@@ -725,7 +804,8 @@ func TestCursor(t *testing.T) {
 			),
 			want: pointer.CursorCrosshair,
 		},
-		{label: "remove input on top while inside",
+		{
+			label:   "remove input on top while inside",
 			cursors: []pointer.Cursor{pointer.CursorPointer},
 			events: append(
 				_at(50, 50),
@@ -1110,7 +1190,7 @@ func TestPartialEvent(t *testing.T) {
 		key.FocusEvent{}, pointer.Event{Kind: pointer.Press, Source: pointer.Mouse, Priority: pointer.Shared})
 	r.Source().Execute(key.FocusCmd{Tag: 1})
 	assertEventSequence(t, events(&r, -1, pointer.Filter{Target: 2, Kinds: pointer.Press}),
-		pointer.Event{Kind: pointer.Press, Source: pointer.Mouse, Priority: pointer.Foremost})
+		pointer.Event{Kind: pointer.Press, Source: pointer.Mouse, Priority: pointer.Shared})
 }
 
 // offer satisfies io.ReadCloser for use in data transfers.
@@ -1256,7 +1336,7 @@ func BenchmarkRouterAdd(b *testing.B) {
 		handlerCount := i
 		b.Run(fmt.Sprintf("%d-handlers", i), func(b *testing.B) {
 			handlers := make([]event.Tag, handlerCount)
-			for i := 0; i < handlerCount; i++ {
+			for i := range handlerCount {
 				h := new(int)
 				*h = i
 				handlers[i] = h
@@ -1278,7 +1358,7 @@ func BenchmarkRouterAdd(b *testing.B) {
 			r.Frame(&ops)
 			b.ReportAllocs()
 			b.ResetTimer()
-			for i := 0; i < b.N; i++ {
+			for b.Loop() {
 				r.Queue(
 					pointer.Event{
 						Kind:     pointer.Move,
@@ -1304,3 +1384,40 @@ func events(r *Router, n int, filters ...event.Filter) []event.Event {
 	}
 	return events
 }
+
+// TestPointerScrollDoesNotTrackPointer queues two events over two cursor
+// regions. The Move puts the live pointer over the button (CursorPointer);
+// the Scroll happens over the cell (CursorText) and must not update the
+// cursor.
+func TestPointerScrollDoesNotTrackPointer(t *testing.T) {
+	var ops op.Ops
+
+	button := clip.Rect(image.Rect(0, 0, 50, 50)).Push(&ops)
+	pointer.CursorPointer.Add(&ops)
+	button.Pop()
+
+	cell := clip.Rect(image.Rect(100, 0, 200, 50)).Push(&ops)
+	pointer.CursorText.Add(&ops)
+	cell.Pop()
+
+	var r Router
+	r.Frame(&ops)
+	r.Queue(
+		pointer.Event{
+			Kind:     pointer.Move,
+			Source:   pointer.Mouse,
+			Position: f32.Pt(25, 25),
+		},
+		pointer.Event{
+			Kind:     pointer.Scroll,
+			Source:   pointer.Mouse,
+			Position: f32.Pt(150, 25),
+			Scroll:   f32.Pt(0, 1),
+		},
+	)
+
+	if got, want := r.Cursor(), pointer.CursorPointer; got != want {
+		t.Errorf("got %q, want %q (scroll position must not update the cursor; "+
+			"the live pointer's last position is what determines it)", got, want)
+	}
+}

io/input/router.go

@@ -5,6 +5,7 @@ package input
 import (
 	"image"
 	"io"
+	"slices"
 	"strings"
 	"time"
 
@@ -62,7 +63,8 @@ type Router struct {
 // Source implements the interface between a Router and user interface widgets.
 // The zero-value Source is disabled.
 type Source struct {
-	r *Router
+	r        *Router
+	disabled bool
 }
 
 // Command represents a request such as moving the focus, or initiating a clipboard read.
@@ -171,30 +173,38 @@ func (q *Router) Source() Source {
 
 // Execute a command.
 func (s Source) Execute(c Command) {
-	if !s.enabled() {
+	if !s.Enabled() {
 		return
 	}
 	s.r.execute(c)
 }
 
-// enabled reports whether the source is enabled. Only enabled
+// Disabled returns a copy of this source that don't deliver any events.
-// Sources deliver events and respond to commands.
+func (s Source) Disabled() Source {
-func (s Source) enabled() bool {
+	s2 := s
-	return s.r != nil
+	s2.disabled = true
+	return s2
+}
+
+// Enabled reports whether the source is enabled. Only enabled
+// Sources deliver events.
+func (s Source) Enabled() bool {
+	return s.r != nil && !s.disabled
 }
 
 // Focused reports whether tag is focused, according to the most recent
 // [key.FocusEvent] delivered.
 func (s Source) Focused(tag event.Tag) bool {
-	if !s.enabled() {
+	if !s.Enabled() {
 		return false
 	}
 	return s.r.state().keyState.focus == tag
 }
 
 // Event returns the next event that matches at least one of filters.
+// If the source is disabled, no events will be reported.
 func (s Source) Event(filters ...event.Filter) (event.Event, bool) {
-	if !s.enabled() {
+	if !s.Enabled() {
 		return nil, false
 	}
 	return s.r.Event(filters...)
@@ -293,7 +303,7 @@ func (q *Router) Event(filters ...event.Filter) (event.Event, bool) {
 				}
 			}
 			if match {
-				change.events = append(change.events[:j], change.events[j+1:]...)
+				change.events = slices.Delete(change.events, j, j+1)
 				// Fast forward state to last matched.
 				q.collapseState(i)
 				return evt.event, true
@@ -409,7 +419,7 @@ func (f *filter) Merge(f2 filter) {
 
 func (f *filter) Matches(e event.Event) bool {
 	switch e.(type) {
-	case key.FocusEvent, key.SnippetEvent, key.EditEvent, key.SelectionEvent:
+	case key.FocusEvent, key.SnippetEvent, key.EditEvent, key.SelectionEvent, key.CompositionEvent:
 		return f.focusable
 	default:
 		return f.pointer.Matches(e)
@@ -453,6 +463,13 @@ func (q *Router) processEvent(e event.Event, system bool) {
 			evts = append(evts, taggedEvent{tag: f, event: e})
 		}
 		q.changeState(e, state, evts)
+	case key.CompositionEvent:
+		e = key.CompositionEvent(rangeNorm(key.Range(e)))
+		var evts []taggedEvent
+		if f := state.focus; f != nil {
+			evts = append(evts, taggedEvent{tag: f, event: e})
+		}
+		q.changeState(e, state, evts)
 	case key.EditEvent, key.FocusEvent, key.SelectionEvent:
 		var evts []taggedEvent
 		if f := state.focus; f != nil {
@@ -618,11 +635,11 @@ func (q *Router) RevealFocus(viewport image.Rectangle) {
 	viewport = q.pointer.queue.ClipFor(area, viewport)
 
 	topleft := bounds.Min.Sub(viewport.Min)
-	topleft = max(topleft, bounds.Max.Sub(viewport.Max))
+	topleft = maxPoint(topleft, bounds.Max.Sub(viewport.Max))
-	topleft = min(image.Pt(0, 0), topleft)
+	topleft = minPoint(image.Pt(0, 0), topleft)
 	bottomright := bounds.Max.Sub(viewport.Max)
-	bottomright = min(bottomright, bounds.Min.Sub(viewport.Min))
+	bottomright = minPoint(bottomright, bounds.Min.Sub(viewport.Min))
-	bottomright = max(image.Pt(0, 0), bottomright)
+	bottomright = maxPoint(image.Pt(0, 0), bottomright)
 	s := topleft
 	if s.X == 0 {
 		s.X = bottomright.X
@@ -649,7 +666,7 @@ func (q *Router) ScrollFocus(dist image.Point) {
 	}))
 }
 
-func max(p1, p2 image.Point) image.Point {
+func maxPoint(p1, p2 image.Point) image.Point {
 	m := p1
 	if p2.X > m.X {
 		m.X = p2.X
@@ -660,7 +677,7 @@ func max(p1, p2 image.Point) image.Point {
 	return m
 }
 
-func min(p1, p2 image.Point) image.Point {
+func minPoint(p1, p2 image.Point) image.Point {
 	m := p1
 	if p2.X < m.X {
 		m.X = p2.X
@@ -769,13 +786,15 @@ func (q *Router) collect() {
 	pc.Reset()
 	kq := &q.key.queue
 	q.key.queue.Reset()
-	var t f32.Affine2D
+	t := f32.AffineId()
 	for encOp, ok := q.reader.Decode(); ok; encOp, ok = q.reader.Decode() {
 		switch ops.OpType(encOp.Data[0]) {
 		case ops.TypeSave:
 			id := ops.DecodeSave(encOp.Data)
 			if extra := id - len(q.savedTrans) + 1; extra > 0 {
-				q.savedTrans = append(q.savedTrans, make([]f32.Affine2D, extra)...)
+				for range extra {
+					q.savedTrans = append(q.savedTrans, f32.AffineId())
+				}
 			}
 			q.savedTrans[id] = t
 		case ops.TypeLoad:

io/input/router_test.go

@@ -15,7 +15,7 @@ func TestNoFilterAllocs(t *testing.T) {
 		s := r.Source()
 		b.ReportAllocs()
 		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			s.Event(pointer.Filter{})
 		}
 	})

io/input/semantic_test.go

@@ -125,7 +125,7 @@ func verifyTree(t *testing.T, parent SemanticID, n SemanticNode) {
 }
 
 func printTree(indent int, n SemanticNode) {
-	for i := 0; i < indent; i++ {
+	for range indent {
 		fmt.Print("\t")
 	}
 	fmt.Printf("%d: %+v\n", n.ID, n.Desc)

io/key/key.go

@@ -77,6 +77,9 @@ type Caret struct {
 // SelectionEvent is generated when an input method changes the selection.
 type SelectionEvent Range
 
+// CompositionEvent is generated when an input method changes the composing range.
+type CompositionEvent Range
+
 // SnippetEvent is generated when the snippet range is updated by an
 // input method.
 type SnippetEvent Range
@@ -243,11 +246,12 @@ func (h InputHintOp) Add(o *op.Ops) {
 	data[1] = byte(h.Hint)
 }
 
-func (EditEvent) ImplementsEvent()      {}
+func (EditEvent) ImplementsEvent()        {}
-func (Event) ImplementsEvent()          {}
+func (Event) ImplementsEvent()            {}
-func (FocusEvent) ImplementsEvent()     {}
+func (FocusEvent) ImplementsEvent()       {}
-func (SnippetEvent) ImplementsEvent()   {}
+func (CompositionEvent) ImplementsEvent() {}
-func (SelectionEvent) ImplementsEvent() {}
+func (SnippetEvent) ImplementsEvent()     {}
+func (SelectionEvent) ImplementsEvent()   {}
 
 func (FocusCmd) ImplementsCommand()        {}
 func (SoftKeyboardCmd) ImplementsCommand() {}

io/key/mod.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-//go:build !darwin
+//go:build !darwin && !js
-// +build !darwin
 
 package key
 

io/key/mod_js.go

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package key
+
+import (
+	"strings"
+	"syscall/js"
+)
+
+// ModShortcut is the platform's shortcut modifier, usually the ctrl
+// modifier. On Apple platforms it is the cmd key.
+var ModShortcut = ModCtrl
+
+// ModShortcut is the platform's alternative shortcut modifier,
+// usually the ctrl modifier. On Apple platforms it is the alt modifier.
+var ModShortcutAlt = ModCtrl
+
+func init() {
+	nav := js.Global().Get("navigator")
+	if !nav.Truthy() {
+		return // Almost impossible to happen
+	}
+
+	platform := ""
+	if p := nav.Get("platform"); p.Truthy() {
+		platform = p.String()
+	}
+	platform = strings.ToLower(platform)
+
+	// Based on https://developer.mozilla.org/en-US/docs/Web/API/Navigator/platform#examples
+	for _, darwinPlatform := range []string{"mac", "iphone", "ipad", "ipod"} {
+		if strings.HasPrefix(platform, darwinPlatform) {
+			ModShortcut = ModCommand
+			ModShortcutAlt = ModAlt
+			return
+		}
+	}
+}

io/pointer/pointer.go

@@ -19,7 +19,9 @@ type Event struct {
 	Source Source
 	// PointerID is the id for the pointer and can be used
 	// to track a particular pointer from Press to
-	// Release or Cancel.
+	// Release. Populated for Press, Release, Move, Drag,
+	// Enter, Leave, and Cancel; Scroll events are not
+	// bound to a tracked pointer and leave it zero.
 	PointerID ID
 	// Priority is the priority of the receiving handler
 	// for this event.
@@ -43,8 +45,7 @@ type Event struct {
 
 // PassOp sets the pass-through mode. InputOps added while the pass-through
 // mode is set don't block events to siblings.
-type PassOp struct {
+type PassOp struct{}
-}
 
 // PassStack represents a PassOp on the pass stack.
 type PassStack struct {
@@ -207,9 +208,6 @@ const (
 	// Shared priority is for handlers that
 	// are part of a matching set larger than 1.
 	Shared Priority = iota
-	// Foremost priority is like Shared, but the
-	// handler is the foremost of the matching set.
-	Foremost
 	// Grabbed is used for matching sets of size 1.
 	Grabbed
 )
@@ -223,6 +221,12 @@ const (
 	ButtonSecondary
 	// ButtonTertiary is the tertiary button, usually the middle button.
 	ButtonTertiary
+	// ButtonQuaternary is the fourth button, usually used for browser
+	// navigation (backward)
+	ButtonQuaternary
+	// ButtonQuinary is the fifth button, usually used for browser
+	// navigation (forward)
+	ButtonQuinary
 )
 
 func (s ScrollRange) Union(s2 ScrollRange) ScrollRange {
@@ -295,8 +299,6 @@ func (p Priority) String() string {
 	switch p {
 	case Shared:
 		return "Shared"
-	case Foremost:
-		return "Foremost"
 	case Grabbed:
 		return "Grabbed"
 	default:
@@ -332,6 +334,12 @@ func (b Buttons) String() string {
 	if b.Contain(ButtonTertiary) {
 		strs = append(strs, "ButtonTertiary")
 	}
+	if b.Contain(ButtonQuaternary) {
+		strs = append(strs, "ButtonQuaternary")
+	}
+	if b.Contain(ButtonQuinary) {
+		strs = append(strs, "ButtonQuinary")
+	}
 	return strings.Join(strs, "|")
 }
 

layout/alloc_test.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 //go:build !race
-// +build !race
 
 package layout
 

layout/context.go

@@ -5,7 +5,6 @@ package layout
 import (
 	"time"
 
-	"gioui.org/io/event"
 	"gioui.org/io/input"
 	"gioui.org/io/system"
 	"gioui.org/op"
@@ -29,7 +28,10 @@ type Context struct {
 	// Interested users must look up and populate these values manually.
 	Locale system.Locale
 
-	disabled bool
+	// Values is a map of program global data associated with the context.
+	// It is not for use by widgets.
+	Values map[string]any
+
 	input.Source
 	*op.Ops
 }
@@ -44,21 +46,8 @@ func (c Context) Sp(v unit.Sp) int {
 	return c.Metric.Sp(v)
 }
 
-func (c Context) Event(filters ...event.Filter) (event.Event, bool) {
-	if c.disabled {
-		return nil, false
-	}
-	return c.Source.Event(filters...)
-}
-
-// Enabled reports whether this context is enabled. Disabled contexts
-// don't report events.
-func (c Context) Enabled() bool {
-	return !c.disabled
-}
-
 // Disabled returns a copy of this context that don't deliver any events.
 func (c Context) Disabled() Context {
-	c.disabled = true
+	c.Source = c.Source.Disabled()
 	return c
 }

layout/flex.go

@@ -22,6 +22,8 @@ type Flex struct {
 	// size of Flexed children. If WeightSum is zero, the sum
 	// of all Flexed weights is used.
 	WeightSum float32
+	// Gap is the space in pixels between children.
+	Gap int
 }
 
 // FlexChild is the descriptor for a Flex child.
@@ -30,10 +32,6 @@ type FlexChild struct {
 	weight float32
 
 	widget Widget
-
-	// Scratch space.
-	call op.CallOp
-	dims Dimensions
 }
 
 // Spacing determine the spacing mode for a Flex.
@@ -86,8 +84,30 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 	mainMin, mainMax := f.Axis.mainConstraint(cs)
 	crossMin, crossMax := f.Axis.crossConstraint(cs)
 	remaining := mainMax
+	// Reserve space for gaps between children.
+	if len(children) > 1 && f.Gap > 0 {
+		totalGap := f.Gap * (len(children) - 1)
+		remaining -= totalGap
+		if remaining < 0 {
+			remaining = 0
+		}
+	}
 	var totalWeight float32
 	cgtx := gtx
+	// Note: previously the scratch space was inside FlexChild.
+	// child.call.Add(gtx.Ops) confused the go escape analysis and caused the
+	// entired children slice to be allocated on the heap, including all widgets
+	// in it. This produced a lot of object allocations. Now the scratch space
+	// is separate from children, and for cases len(children) <= 32, we will
+	// allocate the scratch space on the stack. For cases len(children) > 32,
+	// only the scratch space gets allocated from the heap, during append.
+	type scratchSpace struct {
+		call op.CallOp
+		dims Dimensions
+	}
+	var scratchArray [32]scratchSpace
+	scratch := scratchArray[:0]
+	scratch = append(scratch, make([]scratchSpace, len(children))...)
 	// Lay out Rigid children.
 	for i, child := range children {
 		if child.flex {
@@ -104,8 +124,8 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 		if remaining < 0 {
 			remaining = 0
 		}
-		children[i].call = c
+		scratch[i].call = c
-		children[i].dims = dims
+		scratch[i].dims = dims
 	}
 	if w := f.WeightSum; w != 0 {
 		totalWeight = w
@@ -139,19 +159,22 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 		if remaining < 0 {
 			remaining = 0
 		}
-		children[i].call = c
+		scratch[i].call = c
-		children[i].dims = dims
+		scratch[i].dims = dims
 	}
 	maxCross := crossMin
 	var maxBaseline int
-	for _, child := range children {
+	for _, scratchChild := range scratch {
-		if c := f.Axis.Convert(child.dims.Size).Y; c > maxCross {
+		if c := f.Axis.Convert(scratchChild.dims.Size).Y; c > maxCross {
 			maxCross = c
 		}
-		if b := child.dims.Size.Y - child.dims.Baseline; b > maxBaseline {
+		if b := scratchChild.dims.Size.Y - scratchChild.dims.Baseline; b > maxBaseline {
 			maxBaseline = b
 		}
 	}
+	if len(children) > 1 && f.Gap > 0 {
+		size += f.Gap * (len(children) - 1)
+	}
 	var space int
 	if mainMin > size {
 		space = mainMin - size
@@ -169,8 +192,8 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 			mainSize += space / (len(children) * 2)
 		}
 	}
-	for i, child := range children {
+	for i, scratchChild := range scratch {
-		dims := child.dims
+		dims := scratchChild.dims
 		b := dims.Size.Y - dims.Baseline
 		var cross int
 		switch f.Alignment {
@@ -185,10 +208,11 @@ func (f Flex) Layout(gtx Context, children ...FlexChild) Dimensions {
 		}
 		pt := f.Axis.Convert(image.Pt(mainSize, cross))
 		trans := op.Offset(pt).Push(gtx.Ops)
-		child.call.Add(gtx.Ops)
+		scratchChild.call.Add(gtx.Ops)
 		trans.Pop()
 		mainSize += f.Axis.Convert(dims.Size).X
 		if i < len(children)-1 {
+			mainSize += f.Gap
 			switch f.Spacing {
 			case SpaceEvenly:
 				mainSize += space / (1 + len(children))

layout/layout_test.go

@@ -44,6 +44,106 @@ func TestFlex(t *testing.T) {
 	}
 }
 
+func TestFlexGap(t *testing.T) {
+	gtx := Context{
+		Ops: new(op.Ops),
+		Constraints: Constraints{
+			Max: image.Pt(100, 100),
+		},
+	}
+
+	// Two 20px children with 10px gap = 50px total.
+	dims := Flex{Gap: 10}.Layout(gtx,
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(20, 10)}
+		}),
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(20, 10)}
+		}),
+	)
+	if got, exp := dims.Size.X, 50; got != exp {
+		t.Errorf("two rigid children with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Three children: gap added between each pair.
+	dims = Flex{Gap: 5}.Layout(gtx,
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(10, 10)}
+		}),
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(10, 10)}
+		}),
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(10, 10)}
+		}),
+	)
+	if got, exp := dims.Size.X, 40; got != exp {
+		t.Errorf("three rigid children with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Single child: no gap added.
+	dims = Flex{Gap: 10}.Layout(gtx,
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(20, 10)}
+		}),
+	)
+	if got, exp := dims.Size.X, 20; got != exp {
+		t.Errorf("single child with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Gap with flexed children: gap is reserved from available space.
+	dims = Flex{Gap: 10}.Layout(gtx,
+		Flexed(1, func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(gtx.Constraints.Max.X, 10)}
+		}),
+		Flexed(1, func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(gtx.Constraints.Max.X, 10)}
+		}),
+	)
+	// 100px max - 10px gap = 90px for flex; 45px each.
+	if got, exp := dims.Size.X, 100; got != exp {
+		t.Errorf("flexed children with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Vertical axis with gap.
+	dims = Flex{Axis: Vertical, Gap: 15}.Layout(gtx,
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(10, 20)}
+		}),
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(10, 20)}
+		}),
+	)
+	if got, exp := dims.Size.Y, 55; got != exp {
+		t.Errorf("vertical with gap: got height %d, expected %d", got, exp)
+	}
+}
+
+func TestFlexGapConstraints(t *testing.T) {
+	gtx := Context{
+		Ops: new(op.Ops),
+		Constraints: Constraints{
+			Max: image.Pt(100, 100),
+		},
+	}
+
+	// Verify that flexed children receive constraints with gap accounted for.
+	var flexMax int
+	Flex{Gap: 10}.Layout(gtx,
+		Rigid(func(gtx Context) Dimensions {
+			return Dimensions{Size: image.Pt(30, 10)}
+		}),
+		Flexed(1, func(gtx Context) Dimensions {
+			flexMax = gtx.Constraints.Max.X
+			return Dimensions{Size: image.Pt(gtx.Constraints.Max.X, 10)}
+		}),
+	)
+	// 100 - 10 (gap) - 30 (rigid) = 60 remaining for flex.
+	if got, exp := flexMax, 60; got != exp {
+		t.Errorf("flex constraint with gap: got %d, expected %d", got, exp)
+	}
+}
+
 func TestDirection(t *testing.T) {
 	max := image.Pt(100, 100)
 	for _, tc := range []struct {

layout/list.go

@@ -29,6 +29,10 @@ type List struct {
 	ScrollToEnd bool
 	// Alignment is the cross axis alignment of list elements.
 	Alignment Alignment
+	// ScrollAnyAxis allows any scroll axis to scroll the list, not just the main axis.
+	ScrollAnyAxis bool
+	// Gap is the space in pixels between children.
+	Gap int
 
 	cs          Constraints
 	scroll      gesture.Scroll
@@ -128,7 +132,7 @@ func (l *List) Layout(gtx Context, len int, w ListElement) Dimensions {
 	}
 
 	if numLaidOut > 0 {
-		l.Position.Length = laidOutTotalLength * len / numLaidOut
+		l.Position.Length = laidOutTotalLength*len/numLaidOut + l.Gap*(len-1)
 	} else {
 		l.Position.Length = 0
 	}
@@ -159,12 +163,19 @@ func (l *List) update(gtx Context) {
 			max = 0
 		}
 	}
+
 	xrange := pointer.ScrollRange{Min: min, Max: max}
 	yrange := pointer.ScrollRange{}
-	if l.Axis == Vertical {
+
+	axis := gesture.Axis(l.Axis)
+	if l.ScrollAnyAxis {
+		axis = gesture.Both
+		yrange = xrange
+	} else if l.Axis == Vertical {
 		xrange, yrange = yrange, xrange
 	}
-	d := l.scroll.Update(gtx.Metric, gtx.Source, gtx.Now, gesture.Axis(l.Axis), xrange, yrange)
+	d := l.scroll.Update(gtx.Metric, gtx.Source, gtx.Now, axis, xrange, yrange)
+
 	l.scrollDelta = d
 	l.Position.Offset += d
 }
@@ -214,11 +225,11 @@ func (l *List) nextDir() iterationDir {
 	if len(l.children) > 0 {
 		if l.Position.First > 0 {
 			firstChild := l.children[0]
-			firstSize = l.Axis.Convert(firstChild.size).X
+			firstSize = l.Axis.Convert(firstChild.size).X + l.Gap
 		}
 		if last < l.len {
 			lastChild := l.children[len(l.children)-1]
-			lastSize = l.Axis.Convert(lastChild.size).X
+			lastSize = l.Axis.Convert(lastChild.size).X + l.Gap
 		}
 	}
 	switch {
@@ -236,6 +247,9 @@ func (l *List) nextDir() iterationDir {
 func (l *List) end(dims Dimensions, call op.CallOp) {
 	child := scrollChild{dims.Size, call}
 	mainSize := l.Axis.Convert(child.size).X
+	if len(l.children) > 0 {
+		l.maxSize += l.Gap
+	}
 	l.maxSize += mainSize
 	switch l.dir {
 	case iterateForward:
@@ -245,7 +259,7 @@ func (l *List) end(dims Dimensions, call op.CallOp) {
 		copy(l.children[1:], l.children)
 		l.children[0] = child
 		l.Position.First--
-		l.Position.Offset += mainSize
+		l.Position.Offset += mainSize + l.Gap
 	default:
 		panic("call Next before End")
 	}
@@ -270,7 +284,7 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 			break
 		}
 		l.Position.First++
-		l.Position.Offset -= mainSize
+		l.Position.Offset -= mainSize + l.Gap
 		first = child
 		children = children[1:]
 	}
@@ -282,6 +296,9 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 		if c := sz.Y; c > maxCross {
 			maxCross = c
 		}
+		if i > 0 {
+			size += l.Gap
+		}
 		size += sz.X
 		if size >= mainMax {
 			if i < len(children)-1 {
@@ -308,10 +325,6 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 			cross = (maxCross - sz.Y) / 2
 		}
 		childSize := sz.X
-		min := pos
-		if min < 0 {
-			min = 0
-		}
 		pt := l.Axis.Convert(image.Pt(pos, cross))
 		trans := op.Offset(pt).Push(ops)
 		child.call.Add(ops)
@@ -321,14 +334,19 @@ func (l *List) layout(ops *op.Ops, macro op.MacroOp) Dimensions {
 	// Lay out leading invisible child.
 	if first != (scrollChild{}) {
 		sz := l.Axis.Convert(first.size)
-		pos -= sz.X
+		pos -= sz.X + l.Gap
 		layout(first)
+		pos += l.Gap
 	}
-	for _, child := range children {
+	for i, child := range children {
+		if i > 0 {
+			pos += l.Gap
+		}
 		layout(child)
 	}
 	// Lay out trailing invisible child.
 	if last != (scrollChild{}) {
+		pos += l.Gap
 		layout(last)
 	}
 	atStart := l.Position.First == 0 && l.Position.Offset <= 0

layout/list_test.go

@@ -88,7 +88,8 @@ func TestListPosition(t *testing.T) {
 		{label: "1 visible 0 hidden", num: 1, count: 1, last: 10},
 		{label: "2 visible 0 hidden", num: 2, count: 2},
 		{label: "2 visible 1 hidden", num: 3, count: 2},
-		{label: "3 visible 0 hidden small scroll", num: 3, count: 3, offset: 5, last: -5,
+		{
+			label: "3 visible 0 hidden small scroll", num: 3, count: 3, offset: 5, last: -5,
 			scroll: _s(
 				pointer.Event{
 					Source:   pointer.Mouse,
@@ -107,8 +108,10 @@ func TestListPosition(t *testing.T) {
 					Kind:     pointer.Release,
 					Position: f32.Pt(5, 0),
 				},
-			)},
+			),
-		{label: "3 visible 0 hidden small scroll 2", num: 3, count: 3, offset: 3, last: -7,
+		},
+		{
+			label: "3 visible 0 hidden small scroll 2", num: 3, count: 3, offset: 3, last: -7,
 			scroll: _s(
 				pointer.Event{
 					Source:   pointer.Mouse,
@@ -127,8 +130,10 @@ func TestListPosition(t *testing.T) {
 					Kind:     pointer.Release,
 					Position: f32.Pt(5, 0),
 				},
-			)},
+			),
-		{label: "2 visible 1 hidden large scroll", num: 3, count: 2, first: 1,
+		},
+		{
+			label: "2 visible 1 hidden large scroll", num: 3, count: 2, first: 1,
 			scroll: _s(
 				pointer.Event{
 					Source:   pointer.Mouse,
@@ -147,7 +152,8 @@ func TestListPosition(t *testing.T) {
 					Kind:     pointer.Release,
 					Position: f32.Pt(15, 0),
 				},
-			)},
+			),
+		},
 	} {
 		t.Run(tc.label, func(t *testing.T) {
 			gtx.Ops.Reset()
@@ -178,6 +184,93 @@ func TestListPosition(t *testing.T) {
 	}
 }
 
+func TestListGap(t *testing.T) {
+	gtx := Context{
+		Ops: new(op.Ops),
+		Constraints: Constraints{
+			Max: image.Pt(100, 20),
+		},
+	}
+
+	// Two 10px children with 5px gap: total 25px.
+	l := List{Gap: 5}
+	dims := l.Layout(gtx, 2, func(gtx Context, idx int) Dimensions {
+		return Dimensions{Size: image.Pt(10, 10)}
+	})
+	if got, exp := dims.Size.X, 25; got != exp {
+		t.Errorf("two children with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Three 10px children with 5px gap: total 40px.
+	l = List{Gap: 5}
+	dims = l.Layout(gtx, 3, func(gtx Context, idx int) Dimensions {
+		return Dimensions{Size: image.Pt(10, 10)}
+	})
+	if got, exp := dims.Size.X, 40; got != exp {
+		t.Errorf("three children with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Single child: no gap.
+	l = List{Gap: 5}
+	dims = l.Layout(gtx, 1, func(gtx Context, idx int) Dimensions {
+		return Dimensions{Size: image.Pt(10, 10)}
+	})
+	if got, exp := dims.Size.X, 10; got != exp {
+		t.Errorf("single child with gap: got width %d, expected %d", got, exp)
+	}
+
+	// Zero children: no gap.
+	l = List{Gap: 5}
+	dims = l.Layout(gtx, 0, nil)
+	if got, exp := dims.Size.X, 0; got != exp {
+		t.Errorf("no children with gap: got width %d, expected %d", got, exp)
+	}
+}
+
+func TestListGapVertical(t *testing.T) {
+	gtx := Context{
+		Ops: new(op.Ops),
+		Constraints: Constraints{
+			Max: image.Pt(20, 100),
+		},
+	}
+
+	l := List{Axis: Vertical, Gap: 10}
+	dims := l.Layout(gtx, 3, func(gtx Context, idx int) Dimensions {
+		return Dimensions{Size: image.Pt(10, 15)}
+	})
+	// 3*15 + 2*10 = 65.
+	if got, exp := dims.Size.Y, 65; got != exp {
+		t.Errorf("vertical list with gap: got height %d, expected %d", got, exp)
+	}
+}
+
+func TestListGapPosition(t *testing.T) {
+	gtx := Context{
+		Ops: new(op.Ops),
+		Constraints: Constraints{
+			Max: image.Pt(30, 20),
+		},
+	}
+
+	// Viewport 30px, 5 children of 10px with 5px gap.
+	// Children fill: 10, 10+5+10=25, 25+5+10=40 >= 30, so 3 visible (last partially).
+	l := List{Gap: 5}
+	l.Layout(gtx, 5, func(gtx Context, idx int) Dimensions {
+		return Dimensions{Size: image.Pt(10, 10)}
+	})
+	if got, exp := l.Position.Count, 3; got != exp {
+		t.Errorf("visible count with gap: got %d, expected %d", got, exp)
+	}
+	if got, exp := l.Position.First, 0; got != exp {
+		t.Errorf("first with gap: got %d, expected %d", got, exp)
+	}
+	// OffsetLast = mainMax - size = 30 - 40 = -10.
+	if got, exp := l.Position.OffsetLast, -10; got != exp {
+		t.Errorf("offset last with gap: got %d, expected %d", got, exp)
+	}
+}
+
 func TestExtraChildren(t *testing.T) {
 	var l List
 	l.Position.First = 1

layout/stack.go

@@ -20,10 +20,6 @@ type Stack struct {
 type StackChild struct {
 	expanded bool
 	widget   Widget
-
-	// Scratch space.
-	call op.CallOp
-	dims Dimensions
 }
 
 // Stacked returns a Stack child that is laid out with no minimum
@@ -52,6 +48,20 @@ func (s Stack) Layout(gtx Context, children ...StackChild) Dimensions {
 	// First lay out Stacked children.
 	cgtx := gtx
 	cgtx.Constraints.Min = image.Point{}
+	// Note: previously the scratch space was inside StackChild.
+	// child.call.Add(gtx.Ops) confused the go escape analysis and caused the
+	// entired children slice to be allocated on the heap, including all widgets
+	// in it. This produced a lot of object allocations. Now the scratch space
+	// is separate from children, and for cases len(children) <= 32, we will
+	// allocate the scratch space on the stack. For cases len(children) > 32,
+	// only the scratch space gets allocated from the heap, during append.
+	type scratchSpace struct {
+		call op.CallOp
+		dims Dimensions
+	}
+	var scratchArray [32]scratchSpace
+	scratch := scratchArray[:0]
+	scratch = append(scratch, make([]scratchSpace, len(children))...)
 	for i, w := range children {
 		if w.expanded {
 			continue
@@ -65,8 +75,8 @@ func (s Stack) Layout(gtx Context, children ...StackChild) Dimensions {
 		if h := dims.Size.Y; h > maxSZ.Y {
 			maxSZ.Y = h
 		}
-		children[i].call = call
+		scratch[i].call = call
-		children[i].dims = dims
+		scratch[i].dims = dims
 	}
 	// Then lay out Expanded children.
 	for i, w := range children {
@@ -83,14 +93,14 @@ func (s Stack) Layout(gtx Context, children ...StackChild) Dimensions {
 		if h := dims.Size.Y; h > maxSZ.Y {
 			maxSZ.Y = h
 		}
-		children[i].call = call
+		scratch[i].call = call
-		children[i].dims = dims
+		scratch[i].dims = dims
 	}
 
 	maxSZ = gtx.Constraints.Constrain(maxSZ)
 	var baseline int
-	for _, ch := range children {
+	for _, scratchChild := range scratch {
-		sz := ch.dims.Size
+		sz := scratchChild.dims.Size
 		var p image.Point
 		switch s.Alignment {
 		case N, S, Center:
@@ -105,10 +115,10 @@ func (s Stack) Layout(gtx Context, children ...StackChild) Dimensions {
 			p.Y = maxSZ.Y - sz.Y
 		}
 		trans := op.Offset(p).Push(gtx.Ops)
-		ch.call.Add(gtx.Ops)
+		scratchChild.call.Add(gtx.Ops)
 		trans.Pop()
 		if baseline == 0 {
-			if b := ch.dims.Baseline; b != 0 {
+			if b := scratchChild.dims.Baseline; b != 0 {
 				baseline = b + maxSZ.Y - sz.Y - p.Y
 			}
 		}