app: [Windows] avoid default IME composition window

Mark WM_IME_STARTCOMPOSITION as handled after positioning the IME
composition and candidate windows.

Passing the message on to DefWindowProc can let Windows create its default
composition window, which shows the first composing character below Gio's
caret.

Fixes: https://todo.sr.ht/~eliasnaur/gio/687
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
-// have completed.
+// BUG: On Android, DataDir panics if called before main.
 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))
-	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)
+	C.wl_egl_window_resize(c.eglWin, C.int(width), C.int(height), 0, 0)
 	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
 
@@ -244,45 +318,52 @@ const (
 
 	UNICODE_NOCHAR = 65535
 
-	WM_CANCELMODE           = 0x001F
-	WM_CHAR                 = 0x0102
-	WM_CLOSE                = 0x0010
-	WM_CREATE               = 0x0001
-	WM_DPICHANGED           = 0x02E0
-	WM_DESTROY              = 0x0002
-	WM_ERASEBKGND           = 0x0014
-	WM_GETMINMAXINFO        = 0x0024
-	WM_IME_COMPOSITION      = 0x010F
-	WM_IME_ENDCOMPOSITION   = 0x010E
-	WM_IME_STARTCOMPOSITION = 0x010D
-	WM_KEYDOWN              = 0x0100
-	WM_KEYUP                = 0x0101
-	WM_KILLFOCUS            = 0x0008
-	WM_LBUTTONDOWN          = 0x0201
-	WM_LBUTTONUP            = 0x0202
-	WM_MBUTTONDOWN          = 0x0207
-	WM_MBUTTONUP            = 0x0208
-	WM_MOUSEMOVE            = 0x0200
-	WM_MOUSEWHEEL           = 0x020A
-	WM_MOUSEHWHEEL          = 0x020E
-	WM_NCACTIVATE           = 0x0086
-	WM_NCHITTEST            = 0x0084
-	WM_NCCALCSIZE           = 0x0083
-	WM_PAINT                = 0x000F
-	WM_QUIT                 = 0x0012
-	WM_SETCURSOR            = 0x0020
-	WM_SETFOCUS             = 0x0007
-	WM_SHOWWINDOW           = 0x0018
-	WM_SIZE                 = 0x0005
-	WM_STYLECHANGED         = 0x007D
-	WM_SYSKEYDOWN           = 0x0104
-	WM_SYSKEYUP             = 0x0105
-	WM_RBUTTONDOWN          = 0x0204
-	WM_RBUTTONUP            = 0x0205
-	WM_TIMER                = 0x0113
-	WM_UNICHAR              = 0x0109
-	WM_USER                 = 0x0400
-	WM_WINDOWPOSCHANGED     = 0x0047
+	WM_CANCELMODE            = 0x001F
+	WM_CHAR                  = 0x0102
+	WM_CLOSE                 = 0x0010
+	WM_COPYDATA              = 0x004A
+	WM_CREATE                = 0x0001
+	WM_DPICHANGED            = 0x02E0
+	WM_DESTROY               = 0x0002
+	WM_ERASEBKGND            = 0x0014
+	WM_GETMINMAXINFO         = 0x0024
+	WM_IME_COMPOSITION       = 0x010F
+	WM_IME_ENDCOMPOSITION    = 0x010E
+	WM_IME_STARTCOMPOSITION  = 0x010D
+	WM_KEYDOWN               = 0x0100
+	WM_KEYUP                 = 0x0101
+	WM_KILLFOCUS             = 0x0008
+	WM_LBUTTONDOWN           = 0x0201
+	WM_LBUTTONUP             = 0x0202
+	WM_MBUTTONDOWN           = 0x0207
+	WM_MBUTTONUP             = 0x0208
+	WM_MOUSEMOVE             = 0x0200
+	WM_MOUSEWHEEL            = 0x020A
+	WM_MOUSEHWHEEL           = 0x020E
+	WM_NCACTIVATE            = 0x0086
+	WM_NCHITTEST             = 0x0084
+	WM_NCCALCSIZE            = 0x0083
+	WM_PAINT                 = 0x000F
+	WM_POINTERCAPTURECHANGED = 0x024C
+	WM_POINTERDOWN           = 0x0246
+	WM_POINTERUP             = 0x0247
+	WM_POINTERUPDATE         = 0x0245
+	WM_POINTERWHEEL          = 0x024E
+	WM_POINTERHWHEEL         = 0x024F
+	WM_QUIT                  = 0x0012
+	WM_RBUTTONDOWN           = 0x0204
+	WM_RBUTTONUP             = 0x0205
+	WM_SETCURSOR             = 0x0020
+	WM_SETFOCUS              = 0x0007
+	WM_SHOWWINDOW            = 0x0018
+	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 +426,9 @@ 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 +438,7 @@ 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 +456,11 @@ 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 +513,10 @@ 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 +534,31 @@ 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 +588,18 @@ 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)))
@@ -665,7 +791,10 @@ 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 +910,14 @@ 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() {
-		dataPath = <-dataDirChan
-	})
+	if dataPath == "" {
+		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() {
-		mainFuncs <- f
-		C.gio_wakeupMainThread()
-	}()
+	C.gio_runOnMain(C.uintptr_t(cgo.NewHandle(f)))
 }
 
-//export gio_dispatchMainFuncs
-func gio_dispatchMainFuncs() {
-	for {
-		select {
-		case f := <-mainFuncs:
-			f()
-		default:
-			return
-		}
-	}
+//export gio_runFunc
+func gio_runFunc(h C.uintptr_t) {
+	handle := cgo.Handle(h)
+	defer handle.Delete()
+	f := handle.Value().(func())
+	f()
 }
 
 // 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
-													  object:self.window];
+											  name:UIWindowDidBecomeKeyNotification
+										      object:self.window];
 		[[NSNotificationCenter defaultCenter] removeObserver:self
-														name:UIWindowDidResignKeyNotification
-													  object:self.window];
+											  name:UIWindowDidResignKeyNotification
+											  object:self.window];
 	}
-	self.contentScaleFactor = newWindow.screen.nativeScale;
 	[[NSNotificationCenter defaultCenter] addObserver:self
-											 selector:@selector(onWindowDidBecomeKey:)
-												 name:UIWindowDidBecomeKeyNotification
-											   object:newWindow];
+										  selector:@selector(onWindowDidBecomeKey:)
+										  name:UIWindowDidBecomeKeyNotification
+										  object:newWindow];
 	[[NSNotificationCenter defaultCenter] addObserver:self
-											 selector:@selector(onWindowDidResignKey:)
-												 name:UIWindowDidResignKeyNotification
-											   object:newWindow];
+										  selector:@selector(onWindowDidResignKey:)
+										  name:UIWindowDidResignKeyNotification
+										  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
-		w.flushInput()
+		finalText := w.tarea.Get("value").String()
+
+		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 {
-			return nil
+		e := args[0]
+		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() {
-		return
+	if w.clipboard.Get("readText").Truthy() {
+		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
-	if !w.inCompositor && s != nil {
-		w.inCompositor = true
-		C.xdg_toplevel_move(w.topLvl, s.seat, serial)
+	s := w.disp.seat
+	if w.inCompositor || s.pointerFocus != w {
+		return
 	}
+	w.inCompositor = true
+	C.xdg_toplevel_move(w.topLvl, s.seat, serial)
 }
 
 func (w *window) resize(serial, edge C.uint32_t) {
-	s := w.seat
-	if w.inCompositor || s == nil {
+	s := w.disp.seat
+	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
-	if ptr == nil {
+	s := w.disp.seat
+	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
-	hdc         syscall.Handle
-	w           *callbacks
-	pointerBtns pointer.Buttons
+	hwnd syscall.Handle
+	hdc  syscall.Handle
+	w    *callbacks
 
 	// 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:
-		w.pointerButton(pointer.ButtonPrimary, true, lParam, getModifiers())
-	case windows.WM_LBUTTONUP:
-		w.pointerButton(pointer.ButtonPrimary, false, lParam, getModifiers())
-	case windows.WM_RBUTTONDOWN:
-		w.pointerButton(pointer.ButtonSecondary, true, lParam, getModifiers())
-	case windows.WM_RBUTTONUP:
-		w.pointerButton(pointer.ButtonSecondary, false, lParam, getModifiers())
-	case windows.WM_MBUTTONDOWN:
-		w.pointerButton(pointer.ButtonTertiary, true, lParam, getModifiers())
-	case windows.WM_MBUTTONUP:
-		w.pointerButton(pointer.ButtonTertiary, false, lParam, getModifiers())
+	case windows.WM_POINTERDOWN, windows.WM_POINTERUP, windows.WM_POINTERUPDATE, windows.WM_POINTERCAPTURECHANGED:
+		pid := getPointerIDwParam(wParam)
+		pi, err := windows.GetPointerInfo(uint32(pid))
+		if err != nil {
+			panic(err)
+		}
+		switch msg {
+		case windows.WM_POINTERDOWN:
+			windows.SetCapture(w.hwnd)
+		case windows.WM_POINTERUP:
+			windows.ReleaseCapture()
+		}
+
+		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:
-		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:
+	case windows.WM_POINTERWHEEL:
 		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:
-		w.update()
+		return 0
 	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 {
-		// Only windowed mode should allow resizing.
-		return windows.HTCLIENT
-	}
-	// Check for resize handle before system actions; otherwise it can be impossible to
-	// resize a custom-decorations window when the system move area is flush with the
-	// edge of the window.
-	top := y <= w.borderSize.Y
-	bottom := y >= w.config.Size.Y-w.borderSize.Y
-	left := x <= w.borderSize.X
-	right := x >= w.config.Size.X-w.borderSize.X
-	switch {
-	case top && left:
-		return windows.HTTOPLEFT
-	case top && right:
-		return windows.HTTOPRIGHT
-	case bottom && left:
-		return windows.HTBOTTOMLEFT
-	case bottom && right:
-		return windows.HTBOTTOMRIGHT
-	case top:
-		return windows.HTTOP
-	case bottom:
-		return windows.HTBOTTOM
-	case left:
-		return windows.HTLEFT
-	case right:
-		return windows.HTRIGHT
+	if w.config.Mode == Windowed {
+		// Check for resize handle before system actions; otherwise it can be impossible to
+		// resize a custom-decorations window when the system move area is flush with the
+		// edge of the window.
+		top := y <= w.borderSize.Y
+		bottom := y >= w.config.Size.Y-w.borderSize.Y
+		left := x <= w.borderSize.X
+		right := x >= w.config.Size.X-w.borderSize.X
+		switch {
+		case top && left:
+			return windows.HTTOPLEFT
+		case top && right:
+			return windows.HTTOPRIGHT
+		case bottom && left:
+			return windows.HTBOTTOMLEFT
+		case bottom && right:
+			return windows.HTBOTTOMRIGHT
+		case top:
+			return windows.HTTOP
+		case bottom:
+			return windows.HTBOTTOM
+		case left:
+			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
-	if press {
-		kind = pointer.Press
-		if w.pointerBtns == 0 {
-			windows.SetCapture(w.hwnd)
-		}
-		w.pointerBtns |= btn
-	} else {
-		kind = pointer.Release
-		w.pointerBtns &^= btn
-		if w.pointerBtns == 0 {
-			windows.ReleaseCapture()
-		}
+	src := pointer.Touch
+	if pi.PointerType == windows.PT_MOUSE {
+		src = pointer.Mouse
 	}
+
 	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(),
@@ -750,8 +780,17 @@ func (w *window) Configure(options []Option) {
 		swpStyle |= windows.SWP_NOMOVE | windows.SWP_NOSIZE
 		showMode = windows.SW_SHOWMAXIMIZED
 	}
-	windows.SetWindowLong(w.hwnd, windows.GWL_STYLE, style)
+
+	// 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, 0, x, y, width, height, swpStyle)
+	windows.SetWindowLong(w.hwnd, windows.GWL_STYLE, style)
 	windows.ShowWindow(w.hwnd, showMode)
 }
 
@@ -993,3 +1032,257 @@ 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 (
-	x11Threads sync.Once
-)
+var 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

@@ -444,10 +444,7 @@ func (c *callbacks) SetComposingRegion(r key.Range) {
 func (c *callbacks) EditorInsert(text string) {
 	sel := c.w.imeState.Selection.Range
 	c.EditorReplace(sel, text)
-	start := sel.Start
-	if sel.End < start {
-		start = sel.End
-	}
+	start := min(sel.End, sel.Start)
 	sel.Start = start + utf8.RuneCountInString(text)
 	sel.End = sel.Start
 	c.SetEditorSelection(sel)
@@ -972,6 +969,15 @@ func Decorated(enabled bool) Option {
 	}
 }
 
+// TopMost windows will be rendered above all other non-top-most windows.
+//
+// TopMost windows are only supported on MacOS currently.
+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))
-	B := Affine2D{}.Scale(Point{}, Pt(2, 2))
+	A := AffineId().Offset(Pt(100, 100))
+	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)
-	for i := 0; i < b.N; i++ {
+	aff := AffineId().Scale(Point{}, s)
+	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)
-	for i := 0; i < b.N; i++ {
+	aff := AffineId().Rotate(Point{}, a)
+	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)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5})
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	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)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5}).Scale(Point{}, Point{X: 0.4, Y: -0.5})
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	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)
-	t := Affine2D{}.Offset(Point{X: 0.5, Y: 0.5}).Rotate(Point{}, math.Pi/7)
+	a := AffineId().Offset(Point{X: 1, Y: 1}).Rotate(Point{}, math.Pi/3)
+	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,
-        "narHash": "sha256-eq51hyiaIwtWo19fPEeE0Zr2s83DYMKJoukNLgGGpek=",
+        "lastModified": 1747953325,
+        "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";
-    android.url = "github:tadfisher/android-nixpkgs";
-    android.inputs.nixpkgs.follows = "nixpkgs";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    utils.url = "github:numtide/flake-utils";
   };
 
-  outputs = { self, nixpkgs, android }:
-    let
-      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-darwin" ];
-      forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f system);
-    in
-    {
-      devShells = forAllSystems
-        (system:
-          let
-            pkgs = import nixpkgs {
-              inherit system;
+  outputs = { self, nixpkgs, utils }:
+    utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+
+          # allow unfree Android packages.
+          config.allowUnfree = true;
+          # accept the Android SDK license.
+          config.android_sdk.accept_license = true; 
+        };
+      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.${system} (sdkPkgs: with sdkPkgs;
-              [
-                build-tools-31-0-0
-                cmdline-tools-latest
-                platform-tools
-                platforms-android-31
-                ndk-bundle
-              ]);
-          in
-          {
-            default = with pkgs; mkShell
-              ({
-                ANDROID_SDK_ROOT = "${android-sdk}/share/android-sdk";
-                JAVA_HOME = jdk17.home;
-                packages = [
-                  android-sdk
-                  jdk17
-                  clang
-                ] ++ (if stdenv.isLinux then [
+          in androidComposition.androidsdk;
+        in {
+          default = with pkgs;
+            mkShell (rec {
+              ANDROID_HOME = "${android-sdk}/libexec/android-sdk";
+              packages = [ android-sdk jdk clang ]
+                ++ (if stdenv.isLinux then [
                   vulkan-headers
                   libxkbcommon
                   wayland
@@ -47,11 +43,12 @@
                   xorg.libXfixes
                   libGL
                   pkg-config
-                ] else [ ]);
-              } // (if stdenv.isLinux then {
-                LD_LIBRARY_PATH = "${vulkan-loader}/lib";
-              } else { }));
-          }
-        );
-    };
+                ] else
+                  [ ]);
+            } // (if stdenv.isLinux then {
+              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
-			}
-			if h.pid == e.PointerID {
-				h.entered = true
-			}
+			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
-			}
-			if c.pid != e.PointerID {
-				break
-			}
+			c.pid = e.PointerID
 			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
-	golang.org/x/exp v0.0.0-20240707233637-46b078467d37
-	golang.org/x/exp/shiny v0.0.0-20240707233637-46b078467d37
-	golang.org/x/image v0.18.0
-	golang.org/x/sys v0.22.0
-	golang.org/x/text v0.16.0
+	github.com/go-text/typesetting v0.3.4
+	golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0
+	golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0
+	golang.org/x/image v0.26.0
+	golang.org/x/sys v0.39.0
+	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 v0.2.1/go.mod h1:mTOxEwasOFpAMBjEQDhdWRckoLLeI/+qrQeBCTGEt6M=
-github.com/go-text/typesetting-utils v0.0.0-20241103174707-87a29e9e6066 h1:qCuYC+94v2xrb1PoS4NIDe7DGYtLnU2wWiQe9a1B1c0=
-github.com/go-text/typesetting-utils v0.0.0-20241103174707-87a29e9e6066/go.mod h1:DDxDdQEnB70R8owOx3LVpEFvpMK9eeH1o2r0yZhFI9o=
-golang.org/x/exp v0.0.0-20240707233637-46b078467d37 h1:uLDX+AfeFCct3a2C7uIWBKMJIR3CJMhcgfrUAqjRK6w=
-golang.org/x/exp v0.0.0-20240707233637-46b078467d37/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
-golang.org/x/exp/shiny v0.0.0-20240707233637-46b078467d37 h1:SOSg7+sueresE4IbmmGM60GmlIys+zNX63d6/J4CMtU=
-golang.org/x/exp/shiny v0.0.0-20240707233637-46b078467d37/go.mod h1:3F+MieQB7dRYLTmnncoFbb1crS5lfQoTfDgQy6K4N0o=
-golang.org/x/image v0.18.0 h1:jGzIakQa/ZXI1I0Fxvaa9W7yP25TqT6cHIHn+6CqvSQ=
-golang.org/x/image v0.18.0/go.mod h1:4yyo5vMFQjVjUcVk4jEQcU9MGy/rulF5WvUILseCM2E=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
-golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+github.com/go-text/typesetting v0.3.4 h1:YYurUOtEb9kGSOz4uE3k4OpBGsp1dDL8+fjCeaFamAU=
+github.com/go-text/typesetting v0.3.4/go.mod h1:4qZCQphq4KSgGTAeI0uMEkVbROgfah8BuyF5LRYr7XY=
+github.com/go-text/typesetting-utils v0.0.0-20260223113751-2d88ac90dae3 h1:drBZzMgdYPbmyXqOto4YhhJGrFIQCX94FpR4MzTCsos=
+github.com/go-text/typesetting-utils v0.0.0-20260223113751-2d88ac90dae3/go.mod h1:3/62I4La/HBRX9TcTpBj4eipLiwzf+vhI+7whTc9V7o=
+golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0 h1:R84qjqJb5nVJMxqWYb3np9L5ZsaDtB+a39EqjV0JSUM=
+golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0/go.mod h1:S9Xr4PYopiDyqSyp5NjCrhFrqg6A5zA2E/iPHPhqnS8=
+golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0 h1:tMSqXTK+AQdW3LpCbfatHSRPHeW6+2WuxaVQuHftn80=
+golang.org/x/exp/shiny v0.0.0-20250408133849-7e4ce0ab07d0/go.mod h1:ygj7T6vSGhhm/9yTpOQQNvuAUFziTH7RUiH74EoE2C8=
+golang.org/x/image v0.26.0 h1:4XjIFEZWQmCZi6Wv8BoxsDhRU3RVnLX04dToTDAEPlY=
+golang.org/x/image v0.26.0/go.mod h1:lcxbMFAovzpnJxzXS3nyL83K27tmqtKzIJpctK8YO5c=
+golang.org/x/net v0.48.0 h1:zyQRTTrjc33Lhh0fBgT/H3oZq9WuvRR5gPC70xpDiQU=
+golang.org/x/net v0.48.0/go.mod h1:+ndRgGjkh8FGtu1w1FGbEC31if4VrNVMuKTgcAAnQRY=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
+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
-	neCorner = 1*0.25 + 1*0.5
-	swCorner = 0*0.25 + 0*0.5
-	seCorner = 0*0.25 + 1*0.5
+	nwCorner = 1*0.5 + 0*0.25
+	neCorner = 1*0.5 + 1*0.25
+	swCorner = 0*0.5 + 0*0.25
+	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 (
-		quads quadsOp
-		state drawState
-	)
+	var quads quadsOp
+	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) {
-		// fast-path to allow blitting of pure rectangles
-		_, _, ox, _, _, oy := tr.Elems()
-		off := f32.Pt(ox, oy)
-		bnd.Min = r.Min.Add(off)
-		bnd.Max = r.Max.Add(off)
+	ptr = f32.AffineId()
+	if tr == f32.AffineId() {
+		// fast-path to allow blitting of pure rectangles.
+		bnd = r
 		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 {
-	a, b, _, d, e, _ := t.Elems()
-	return a == 1 && b == 0 && d == 0 && e == 1
+// transformOffset a transform into two parts, one which is pure integer offset
+// and the other representing the scaling, shearing and rotation and fractional
+// 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 clearColExpect = f32color.NRGBAToRGBA(clearCol)
+var (
+	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 (
-		renderTarget *d3d11.RenderTargetView
-	)
+	var 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
-		if height > dim {
-			dim = height
-		}
+		dim := max(height, width)
 		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 TextureFormat uint8
+type (
+	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
-			if height > dim {
-				dim = height
-			}
+			dim := max(height, width)
 			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 {
-		if ext == e {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(exts, ext)
 }
 
 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 y := 0; y < 20; y++ {
+		for x := range 20 {
+			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),
-		NW: 20, NE: 20, SW: 20, SE: 20}.Op(innerOps)
+	return clip.RRect{
+		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 c := 0; c < 4; c++ {
+	for r := range 4 {
+		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 {
-		if ext == e {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(exts, ext)
 }
 
 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
-	loadOnce.Do(func() {
-		err = loadDLLs()
-	})
-	return err
+	return loadOnce()
 }
 
 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 col := 0; col < m.cols; col++ {
+	for row := range m.rows {
+		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 j := 0; j < m.cols; j++ {
+	for i := range m.rows {
+		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 j := 0; j < mm.cols; j++ {
+	for i := range mm.rows {
+		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 j := 0; j < m.cols; j++ {
+	for i := range m.rows {
+		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) {
-		return f32.Point{X: p.X, Y: p.Y}
+	if (p.X == 0 && p.Y == 0) || l == 0 {
+		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)
-		ref f32.Affine2D // transform from absolute frame to ellipse-based one
-		rot f32.Affine2D // rotation matrix for each segment
-		inv f32.Affine2D // transform from ellipse-based frame to absolute one
-	)
+	θ := angle / float32(segments)
+	ref := f32.AffineId() // transform from absolute frame to ellipse-based one
+	rot := f32.AffineId() // rotation matrix for each segment
+	inv := f32.AffineId() // 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 k == tag {
-			return state
-		}
+	if slices.Contains(state.receivers, tag) {
+		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 f == f2 {
-			return
-		}
+	if slices.Contains(*k, f) {
+		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 m == f.Type {
-				return
-			}
+		if slices.Contains(p.sourceMimes, f.Type) {
+			return
 		}
 		p.sourceMimes = append(p.sourceMimes, f.Type)
 	case transfer.TargetFilter:
-		for _, m := range p.targetMimes {
-			if m == f.Type {
-				return
-			}
+		if slices.Contains(p.targetMimes, f.Type) {
+			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 t == e.Type {
-				return true
-			}
+		if slices.Contains(p.sourceMimes, e.Type) {
+			return true
 		}
 	case transfer.DataEvent:
-		for _, t := range p.targetMimes {
-			if t == e.Type {
-				return true
-			}
+		if slices.Contains(p.targetMimes, e.Type) {
+			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 t == tag {
-			return tags
-		}
+	if slices.Contains(tags, tag) {
+		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 m1 == m2 {
-				return m1, true
-			}
+		if slices.Contains(src.sourceMimes, m1) {
+			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, hev2, pointer.Foremost)
-	assertEventPriorities(t, hev3, pointer.Foremost)
+	assertEventPriorities(t, hev1, pointer.Shared, pointer.Shared)
+	assertEventPriorities(t, hev2, pointer.Shared)
+	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
-// Sources deliver events and respond to commands.
-func (s Source) enabled() bool {
-	return s.r != nil
+// Disabled returns a copy of this source that don't deliver any events.
+func (s Source) Disabled() Source {
+	s2 := s
+	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
@@ -618,11 +628,11 @@ 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 = min(image.Pt(0, 0), topleft)
+	topleft = maxPoint(topleft, bounds.Max.Sub(viewport.Max))
+	topleft = minPoint(image.Pt(0, 0), topleft)
 	bottomright := bounds.Max.Sub(viewport.Max)
-	bottomright = min(bottomright, bounds.Min.Sub(viewport.Min))
-	bottomright = max(image.Pt(0, 0), bottomright)
+	bottomright = minPoint(bottomright, bounds.Min.Sub(viewport.Min))
+	bottomright = maxPoint(image.Pt(0, 0), bottomright)
 	s := topleft
 	if s.X == 0 {
 		s.X = bottomright.X
@@ -649,7 +659,7 @@ 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 +670,7 @@ 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 +779,15 @@ 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/mod.go

@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-//go:build !darwin
-// +build !darwin
+//go:build !darwin && !js
 
 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
-		children[i].dims = dims
+		scratch[i].call = c
+		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
-		children[i].dims = dims
+		scratch[i].call = c
+		scratch[i].dims = dims
 	}
 	maxCross := crossMin
 	var maxBaseline int
-	for _, child := range children {
-		if c := f.Axis.Convert(child.dims.Size).Y; c > maxCross {
+	for _, scratchChild := range scratch {
+		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 {
-		dims := child.dims
+	for i, scratchChild := range scratch {
+		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
-		children[i].dims = dims
+		scratch[i].call = call
+		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
-		children[i].dims = dims
+		scratch[i].call = call
+		scratch[i].dims = dims
 	}
 
 	maxSZ = gtx.Constraints.Constrain(maxSZ)
 	var baseline int
-	for _, ch := range children {
-		sz := ch.dims.Size
+	for _, scratchChild := range scratch {
+		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
 			}
 		}

layout/stack_test.go

@@ -17,9 +17,8 @@ func BenchmarkStack(b *testing.B) {
 		},
 	}
 	b.ReportAllocs()
-	b.ResetTimer()
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		gtx.Ops.Reset()
 
 		Stack{}.Layout(gtx,
@@ -41,9 +40,8 @@ func BenchmarkBackground(b *testing.B) {
 		},
 	}
 	b.ReportAllocs()
-	b.ResetTimer()
 
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		gtx.Ops.Reset()
 
 		Background{}.Layout(gtx,