app: [Windows] suppress double-click behaviour for custom decorations

Fixes: https://todo.sr.ht/~eliasnaur/gio/600
Signed-off-by: Elias Naur <mail@eliasnaur.com>

.builds/apple.yml

@@ -29,7 +29,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl -s https://dl.google.com/go/go1.19.11.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl -s https://dl.google.com/go/go1.22.2.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/go1.19.11.freebsd-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl https://dl.google.com/go/go1.22.2.freebsd-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - test_gio: |
      cd gio
      go test ./...

.builds/linux.yml

@@ -40,7 +40,7 @@ secrets:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl -s https://dl.google.com/go/go1.19.11.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
+     curl -s https://dl.google.com/go/go1.22.2.linux-amd64.tar.gz | tar -C /home/build/sdk -xzf -
  - check_gofmt: |
      cd gio
      test -z "$(gofmt -s -l .)"
@@ -80,6 +80,8 @@ tasks:
      unzip -q ndk.zip
      rm ndk.zip
      mv android-ndk-* ndk-bundle
+     # sdkmanager needs lots of file descriptors
+     ulimit -n 10000
      yes|sdkmanager --licenses
      sdkmanager "platforms;android-31" "build-tools;32.0.0"
  - test_android: |

.builds/openbsd.yml

@@ -10,7 +10,7 @@ environment:
 tasks:
  - install_go: |
      mkdir -p /home/build/sdk
-     curl https://dl.google.com/go/go1.19.11.src.tar.gz | tar -C /home/build/sdk -xzf -
+     curl https://dl.google.com/go/go1.22.2.src.tar.gz | tar -C /home/build/sdk -xzf -
      cd /home/build/sdk/go/src
      ./make.bash
  - test_gio: |

app/GioView.java

@@ -65,8 +65,8 @@ public final class GioView extends SurfaceView implements Choreographer.FrameCal
 	private final InputMethodManager imm;
 	private final float scrollXScale;
 	private final float scrollYScale;
+	private final AccessibilityManager accessManager;
 	private int keyboardHint;
-	private AccessibilityManager accessManager;
 
 	private long nhandle;
 

app/app.go

@@ -56,6 +56,17 @@ type FrameEvent struct {
 	Source input.Source
 }
 
+// ViewEvent provides handles to the underlying window objects for the
+// current display protocol.
+type ViewEvent interface {
+	implementsViewEvent()
+	ImplementsEvent()
+	// Valid will return true when the ViewEvent does contains valid handles.
+	// If a window receives an invalid ViewEvent, it should deinitialize any
+	// state referring to handles from a previous ViewEvent.
+	Valid() bool
+}
+
 // Insets is the space taken up by
 // system decoration such as translucent
 // system bars and software keyboards.

app/doc.go

@@ -8,18 +8,19 @@ See https://gioui.org for instructions to set up and run Gio programs.
 
 # Windows
 
-Create a new [Window] by calling [NewWindow]. On mobile platforms or when Gio
-is embedded in another project, NewWindow merely connects with a previously
-created window.
+A Window is run by calling its Event method in a loop. The first time a
+method on Window is called, a new GUI window is created and shown. On mobile
+platforms or when Gio is embedded in another project, Window merely connects
+with a previously created GUI window.
 
-A Window is run by calling its NextEvent method in a loop. The most important event is
-[FrameEvent] that prompts an update of the window contents.
+The most important event is [FrameEvent] that prompts an update of the window
+contents.
 
 For example:
 
-	w := app.NewWindow()
+	w := new(app.Window)
 	for {
-		e := w.NextEvent()
+		e := w.Event()
 		if e, ok := e.(app.FrameEvent); ok {
 			ops.Reset()
 			// Add operations to ops.
@@ -49,7 +50,7 @@ For example, to display a blank but otherwise functional window:
 		go func() {
 			w := app.NewWindow()
 			for {
-				w.NextEvent()
+				w.Event()
 			}
 		}()
 		app.Main()

app/egl_android.go

@@ -17,9 +17,8 @@ import (
 )
 
 type androidContext struct {
-	win           *window
-	eglSurf       egl.NativeWindowType
-	width, height int
+	win     *window
+	eglSurf egl.NativeWindowType
 	*egl.Context
 }
 
@@ -45,9 +44,8 @@ func (c *androidContext) Refresh() error {
 	if err := c.win.setVisual(c.Context.VisualID()); err != nil {
 		return err
 	}
-	win, width, height := c.win.nativeWindow()
+	win, _, _ := c.win.nativeWindow()
 	c.eglSurf = egl.NativeWindowType(unsafe.Pointer(win))
-	c.width, c.height = width, height
 	return nil
 }
 
@@ -55,7 +53,7 @@ func (c *androidContext) Lock() error {
 	// The Android emulator creates a broken surface if it is not
 	// created on the same thread as the context is made current.
 	if c.eglSurf != nil {
-		if err := c.Context.CreateSurface(c.eglSurf, c.width, c.height); err != nil {
+		if err := c.Context.CreateSurface(c.eglSurf); err != nil {
 			return err
 		}
 		c.eglSurf = nil

app/egl_wayland.go

@@ -69,7 +69,17 @@ func (c *wlContext) Refresh() error {
 	}
 	c.eglWin = eglWin
 	eglSurf := egl.NativeWindowType(uintptr(unsafe.Pointer(eglWin)))
-	return c.Context.CreateSurface(eglSurf, width, height)
+	if err := c.Context.CreateSurface(eglSurf); err != nil {
+		return err
+	}
+	if err := c.Context.MakeCurrent(); err != nil {
+		return err
+	}
+	defer c.Context.ReleaseCurrent()
+	// We're in charge of the frame callbacks, don't let eglSwapBuffers
+	// wait for callbacks that may never arrive.
+	c.Context.EnableVSync(false)
+	return nil
 }
 
 func (c *wlContext) Lock() error {

app/egl_windows.go

@@ -5,8 +5,6 @@
 package app
 
 import (
-	"golang.org/x/sys/windows"
-
 	"gioui.org/internal/egl"
 )
 
@@ -24,6 +22,18 @@ func init() {
 			if err != nil {
 				return nil, err
 			}
+			win, _, _ := w.HWND()
+			eglSurf := egl.NativeWindowType(win)
+			if err := ctx.CreateSurface(eglSurf); err != nil {
+				ctx.Release()
+				return nil, err
+			}
+			if err := ctx.MakeCurrent(); err != nil {
+				ctx.Release()
+				return nil, err
+			}
+			defer ctx.ReleaseCurrent()
+			ctx.EnableVSync(true)
 			return &glContext{win: w, Context: ctx}, nil
 		},
 	})
@@ -37,21 +47,6 @@ func (c *glContext) Release() {
 }
 
 func (c *glContext) Refresh() error {
-	c.Context.ReleaseSurface()
-	var (
-		win           windows.Handle
-		width, height int
-	)
-	win, width, height = c.win.HWND()
-	eglSurf := egl.NativeWindowType(win)
-	if err := c.Context.CreateSurface(eglSurf, width, height); err != nil {
-		return err
-	}
-	if err := c.Context.MakeCurrent(); err != nil {
-		return err
-	}
-	c.Context.EnableVSync(true)
-	c.Context.ReleaseCurrent()
 	return nil
 }
 

app/egl_x11.go

@@ -25,6 +25,18 @@ func init() {
 		if err != nil {
 			return nil, err
 		}
+		win, _, _ := w.window()
+		eglSurf := egl.NativeWindowType(uintptr(win))
+		if err := ctx.CreateSurface(eglSurf); err != nil {
+			ctx.Release()
+			return nil, err
+		}
+		if err := ctx.MakeCurrent(); err != nil {
+			ctx.Release()
+			return nil, err
+		}
+		defer ctx.ReleaseCurrent()
+		ctx.EnableVSync(true)
 		return &x11Context{win: w, Context: ctx}, nil
 	}
 }
@@ -37,17 +49,6 @@ func (c *x11Context) Release() {
 }
 
 func (c *x11Context) Refresh() error {
-	c.Context.ReleaseSurface()
-	win, width, height := c.win.window()
-	eglSurf := egl.NativeWindowType(uintptr(win))
-	if err := c.Context.CreateSurface(eglSurf, width, height); err != nil {
-		return err
-	}
-	if err := c.Context.MakeCurrent(); err != nil {
-		return err
-	}
-	c.Context.EnableVSync(true)
-	c.Context.ReleaseCurrent()
 	return nil
 }
 

app/gl_macos.m

@@ -7,7 +7,7 @@
 #include <OpenGL/OpenGL.h>
 #include "_cgo_export.h"
 
-CALayer *gio_layerFactory(void) {
+CALayer *gio_layerFactory(BOOL presentWithTrans) {
 	@autoreleasepool {
 		return [CALayer layer];
 	}

app/ime.go

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+package app
+
+import (
+	"unicode"
+	"unicode/utf16"
+
+	"gioui.org/io/input"
+	"gioui.org/io/key"
+)
+
+type editorState struct {
+	input.EditorState
+	compose key.Range
+}
+
+func (e *editorState) Replace(r key.Range, text string) {
+	if r.Start > r.End {
+		r.Start, r.End = r.End, r.Start
+	}
+	runes := []rune(text)
+	newEnd := r.Start + len(runes)
+	adjust := func(pos int) int {
+		switch {
+		case newEnd < pos && pos <= r.End:
+			return newEnd
+		case r.End < pos:
+			diff := newEnd - r.End
+			return pos + diff
+		}
+		return pos
+	}
+	e.Selection.Start = adjust(e.Selection.Start)
+	e.Selection.End = adjust(e.Selection.End)
+	if e.compose.Start != -1 {
+		e.compose.Start = adjust(e.compose.Start)
+		e.compose.End = adjust(e.compose.End)
+	}
+	s := e.Snippet
+	if r.End < s.Start || r.Start > s.End {
+		// Discard snippet if it doesn't overlap with replacement.
+		s = key.Snippet{
+			Range: key.Range{
+				Start: r.Start,
+				End:   r.Start,
+			},
+		}
+	}
+	var newSnippet []rune
+	snippet := []rune(s.Text)
+	// Append first part of existing snippet.
+	if end := r.Start - s.Start; end > 0 {
+		newSnippet = append(newSnippet, snippet[:end]...)
+	}
+	// Append replacement.
+	newSnippet = append(newSnippet, runes...)
+	// Append last part of existing snippet.
+	if start := r.End; start < s.End {
+		newSnippet = append(newSnippet, snippet[start-s.Start:]...)
+	}
+	// Adjust snippet range to include replacement.
+	if r.Start < s.Start {
+		s.Start = r.Start
+	}
+	s.End = s.Start + len(newSnippet)
+	s.Text = string(newSnippet)
+	e.Snippet = s
+}
+
+// UTF16Index converts the given index in runes into an index in utf16 characters.
+func (e *editorState) UTF16Index(runes int) int {
+	if runes == -1 {
+		return -1
+	}
+	if runes < e.Snippet.Start {
+		// Assume runes before sippet are one UTF-16 character each.
+		return runes
+	}
+	chars := e.Snippet.Start
+	runes -= e.Snippet.Start
+	for _, r := range e.Snippet.Text {
+		if runes == 0 {
+			break
+		}
+		runes--
+		chars++
+		if r1, _ := utf16.EncodeRune(r); r1 != unicode.ReplacementChar {
+			chars++
+		}
+	}
+	// Assume runes after snippets are one UTF-16 character each.
+	return chars + runes
+}
+
+// RunesIndex converts the given index in utf16 characters to an index in runes.
+func (e *editorState) RunesIndex(chars int) int {
+	if chars == -1 {
+		return -1
+	}
+	if chars < e.Snippet.Start {
+		// Assume runes before offset are one UTF-16 character each.
+		return chars
+	}
+	runes := e.Snippet.Start
+	chars -= e.Snippet.Start
+	for _, r := range e.Snippet.Text {
+		if chars == 0 {
+			break
+		}
+		chars--
+		runes++
+		if r1, _ := utf16.EncodeRune(r); r1 != unicode.ReplacementChar {
+			chars--
+		}
+	}
+	// Assume runes after snippets are one UTF-16 character each.
+	return runes + chars
+}

app/internal/log/log.go

@@ -1,7 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-// Package points standard output, standard error and the standard
-// library package log to the platform logger.
-package log
-
-var appID = "gio"

app/internal/windows/windows.go

@@ -266,6 +266,7 @@ const (
 	WM_MOUSEWHEEL           = 0x020A
 	WM_MOUSEHWHEEL          = 0x020E
 	WM_NCACTIVATE           = 0x0086
+	WM_NCLBUTTONDBLCLK      = 0x00A3
 	WM_NCHITTEST            = 0x0084
 	WM_NCCALCSIZE           = 0x0083
 	WM_PAINT                = 0x000F

app/log_android.go

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package log
+package app
 
 /*
 #cgo LDFLAGS: -llog
@@ -22,7 +22,7 @@ import (
 // 1024 is the truncation limit from android/log.h, plus a \n.
 const logLineLimit = 1024
 
-var logTag = C.CString(appID)
+var logTag = C.CString(ID)
 
 func init() {
 	// Android's logcat already includes timestamps.

app/log_ios.go

@@ -3,7 +3,7 @@
 //go:build darwin && ios
 // +build darwin,ios
 
-package log
+package app
 
 /*
 #cgo CFLAGS: -Werror -fmodules -fobjc-arc -x objective-c

app/log_windows.go

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
-package log
+package app
 
 import (
 	"log"

app/metal_darwin.go

@@ -60,8 +60,9 @@ static void presentDrawable(CFTypeRef queueRef, CFTypeRef drawableRef) {
 		id<MTLDrawable> drawable = (__bridge id<MTLDrawable>)drawableRef;
 		id<MTLCommandQueue> queue = (__bridge id<MTLCommandQueue>)queueRef;
 		id<MTLCommandBuffer> cmdBuffer = [queue commandBuffer];
-		[cmdBuffer presentDrawable:drawable];
 		[cmdBuffer commit];
+		[cmdBuffer waitUntilScheduled];
+		[drawable present];
 	}
 }
 

app/metal_ios.go

@@ -21,7 +21,10 @@ Class gio_layerClass(void) {
 static CFTypeRef getMetalLayer(CFTypeRef viewRef) {
 	@autoreleasepool {
 		UIView *view = (__bridge UIView *)viewRef;
-		return CFBridgingRetain(view.layer);
+		CAMetalLayer *l = (CAMetalLayer *)view.layer;
+		l.needsDisplayOnBoundsChange = YES;
+		l.presentsWithTransaction = YES;
+		return CFBridgingRetain(l);
 	}
 }
 

app/metal_macos.go

@@ -12,9 +12,13 @@ package app
 #import <QuartzCore/CAMetalLayer.h>
 #include <CoreFoundation/CoreFoundation.h>
 
-CALayer *gio_layerFactory(void) {
+CALayer *gio_layerFactory(BOOL presentWithTrans) {
 	@autoreleasepool {
-		return [CAMetalLayer layer];
+		CAMetalLayer *l = [CAMetalLayer layer];
+		l.autoresizingMask = kCALayerHeightSizable|kCALayerWidthSizable;
+		l.needsDisplayOnBoundsChange = YES;
+		l.presentsWithTransaction = presentWithTrans;
+		return l;
 	}
 }
 

app/os.go

@@ -7,7 +7,9 @@ import (
 	"image"
 	"image/color"
 
+	"gioui.org/io/event"
 	"gioui.org/io/key"
+	"gioui.org/op"
 
 	"gioui.org/gpu"
 	"gioui.org/io/pointer"
@@ -43,6 +45,8 @@ type Config struct {
 	CustomRenderer bool
 	// Decorated reports whether window decorations are provided automatically.
 	Decorated bool
+	// Focused reports whether has the keyboard focus.
+	Focused bool
 	// decoHeight is the height of the fallback decoration for platforms such
 	// as Wayland that may need fallback client-side decorations.
 	decoHeight unit.Dp
@@ -131,6 +135,28 @@ func (o Orientation) String() string {
 	return ""
 }
 
+// eventLoop implements the functionality required for drivers where
+// window event loops must run on a separate thread.
+type eventLoop struct {
+	win *callbacks
+	// wakeup is the callback to wake up the event loop.
+	wakeup func()
+	// driverFuncs is a channel of functions to run the next
+	// time the window loop waits for events.
+	driverFuncs chan func()
+	// invalidates is notified when an invalidate is requested by the client.
+	invalidates chan struct{}
+	// immediateInvalidates is an optimistic invalidates that doesn't require a wakeup.
+	immediateInvalidates chan struct{}
+	// events is where the platform backend delivers events bound for the
+	// user program.
+	events   chan event.Event
+	frames   chan *op.Ops
+	frameAck chan struct{}
+	// delivering avoids re-entrant event delivery.
+	delivering bool
+}
+
 type frameEvent struct {
 	FrameEvent
 
@@ -147,9 +173,13 @@ type context interface {
 	Unlock()
 }
 
-// Driver is the interface for the platform implementation
+// driver is the interface for the platform implementation
 // of a window.
 type driver interface {
+	// Event blocks until an event is available and returns it.
+	Event() event.Event
+	// Invalidate requests a FrameEvent.
+	Invalidate()
 	// SetAnimating sets the animation flag. When the window is animating,
 	// FrameEvents are delivered as fast as the display can handle them.
 	SetAnimating(anim bool)
@@ -166,17 +196,23 @@ type driver interface {
 	// SetCursor updates the current cursor to name.
 	SetCursor(cursor pointer.Cursor)
 	// Wakeup wakes up the event loop and sends a WakeupEvent.
-	Wakeup()
+	// Wakeup()
 	// Perform actions on the window.
 	Perform(system.Action)
 	// EditorStateChanged notifies the driver that the editor state changed.
 	EditorStateChanged(old, new editorState)
+	// Run a function on the window thread.
+	Run(f func())
+	// Frame receives a frame.
+	Frame(frame *op.Ops)
+	// ProcessEvent processes an event.
+	ProcessEvent(e event.Event)
 }
 
 type windowRendezvous struct {
-	in   chan windowAndConfig
-	out  chan windowAndConfig
-	errs chan error
+	in      chan windowAndConfig
+	out     chan windowAndConfig
+	windows chan struct{}
 }
 
 type windowAndConfig struct {
@@ -186,32 +222,137 @@ type windowAndConfig struct {
 
 func newWindowRendezvous() *windowRendezvous {
 	wr := &windowRendezvous{
-		in:   make(chan windowAndConfig),
-		out:  make(chan windowAndConfig),
-		errs: make(chan error),
+		in:      make(chan windowAndConfig),
+		out:     make(chan windowAndConfig),
+		windows: make(chan struct{}),
 	}
 	go func() {
-		var main windowAndConfig
+		in := wr.in
+		var window windowAndConfig
 		var out chan windowAndConfig
 		for {
 			select {
-			case w := <-wr.in:
-				var err error
-				if main.window != nil {
-					err = errors.New("multiple windows are not supported")
-				}
-				wr.errs <- err
-				main = w
+			case w := <-in:
+				window = w
 				out = wr.out
-			case out <- main:
+			case out <- window:
 			}
 		}
 	}()
 	return wr
 }
 
-func (wakeupEvent) ImplementsEvent() {}
-func (ConfigEvent) ImplementsEvent() {}
+func newEventLoop(w *callbacks, wakeup func()) *eventLoop {
+	return &eventLoop{
+		win:                  w,
+		wakeup:               wakeup,
+		events:               make(chan event.Event),
+		invalidates:          make(chan struct{}, 1),
+		immediateInvalidates: make(chan struct{}),
+		frames:               make(chan *op.Ops),
+		frameAck:             make(chan struct{}),
+		driverFuncs:          make(chan func(), 1),
+	}
+}
+
+// Frame receives a frame and waits for its processing. It is called by
+// the client goroutine.
+func (e *eventLoop) Frame(frame *op.Ops) {
+	e.frames <- frame
+	<-e.frameAck
+}
+
+// Event returns the next available event. It is called by the client
+// goroutine.
+func (e *eventLoop) Event() event.Event {
+	for {
+		evt := <-e.events
+		// Receiving a flushEvent indicates to the platform backend that
+		// all previous events have been processed by the user program.
+		if _, ok := evt.(flushEvent); ok {
+			continue
+		}
+		return evt
+	}
+}
+
+// Invalidate requests invalidation of the window. It is called by the client
+// goroutine.
+func (e *eventLoop) Invalidate() {
+	select {
+	case e.immediateInvalidates <- struct{}{}:
+		// The event loop was waiting, no need for a wakeup.
+	case e.invalidates <- struct{}{}:
+		// The event loop is sleeping, wake it up.
+		e.wakeup()
+	default:
+		// A redraw is pending.
+	}
+}
+
+// Run f in the window loop thread. It is called by the client goroutine.
+func (e *eventLoop) Run(f func()) {
+	e.driverFuncs <- f
+	e.wakeup()
+}
+
+// FlushEvents delivers pending events to the client.
+func (e *eventLoop) FlushEvents() {
+	if e.delivering {
+		return
+	}
+	e.delivering = true
+	defer func() { e.delivering = false }()
+	for {
+		evt, ok := e.win.nextEvent()
+		if !ok {
+			break
+		}
+		e.deliverEvent(evt)
+	}
+}
+
+func (e *eventLoop) deliverEvent(evt event.Event) {
+	var frames <-chan *op.Ops
+	for {
+		select {
+		case f := <-e.driverFuncs:
+			f()
+		case frame := <-frames:
+			// The client called FrameEvent.Frame.
+			frames = nil
+			e.win.ProcessFrame(frame, e.frameAck)
+		case e.events <- evt:
+			switch evt.(type) {
+			case flushEvent, DestroyEvent:
+				// DestroyEvents are not flushed.
+				return
+			case FrameEvent:
+				frames = e.frames
+			}
+			evt = theFlushEvent
+		case <-e.invalidates:
+			e.win.Invalidate()
+		case <-e.immediateInvalidates:
+			e.win.Invalidate()
+		}
+	}
+}
+
+func (e *eventLoop) Wakeup() {
+	for {
+		select {
+		case f := <-e.driverFuncs:
+			f()
+		case <-e.invalidates:
+			e.win.Invalidate()
+		case <-e.immediateInvalidates:
+			e.win.Invalidate()
+		default:
+			return
+		}
+	}
+}
 
 func walkActions(actions system.Action, do func(system.Action)) {
 	for a := system.Action(1); actions != 0; a <<= 1 {
@@ -221,3 +362,6 @@ func walkActions(actions system.Action, do func(system.Action)) {
 		}
 	}
 }
+
+func (wakeupEvent) ImplementsEvent() {}
+func (ConfigEvent) ImplementsEvent() {}

app/os_android.go

@@ -137,8 +137,10 @@ import (
 	"unsafe"
 
 	"gioui.org/internal/f32color"
+	"gioui.org/op"
 
 	"gioui.org/f32"
+	"gioui.org/io/event"
 	"gioui.org/io/input"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
@@ -150,6 +152,7 @@ import (
 
 type window struct {
 	callbacks *callbacks
+	loop      *eventLoop
 
 	view   C.jobject
 	handle cgo.Handle
@@ -158,12 +161,13 @@ type window struct {
 	fontScale float32
 	insets    pixelInsets
 
-	stage     Stage
+	visible   bool
 	started   bool
 	animating bool
 
-	win    *C.ANativeWindow
-	config Config
+	win       *C.ANativeWindow
+	config    Config
+	inputHint key.InputHint
 
 	semantic struct {
 		hoverID input.SemanticID
@@ -201,9 +205,9 @@ type pixelInsets struct {
 	top, bottom, left, right int
 }
 
-// ViewEvent is sent whenever the Window's underlying Android view
+// AndroidViewEvent is sent whenever the Window's underlying Android view
 // changes.
-type ViewEvent struct {
+type AndroidViewEvent struct {
 	// View is a JNI global reference to the android.view.View
 	// instance backing the Window. The reference is valid until
 	// the next ViewEvent is received.
@@ -487,24 +491,30 @@ func Java_org_gioui_GioView_onCreateView(env *C.JNIEnv, class C.jclass, view C.j
 	})
 	view = C.jni_NewGlobalRef(env, view)
 	wopts := <-mainWindow.out
+	var cnf Config
 	w, ok := windows[wopts.window]
 	if !ok {
 		w = &window{
 			callbacks: wopts.window,
 		}
+		w.loop = newEventLoop(w.callbacks, w.wakeup)
+		w.callbacks.SetDriver(w)
+		cnf.apply(unit.Metric{}, wopts.options)
 		windows[wopts.window] = w
+	} else {
+		cnf = w.config
 	}
+	mainWindow.windows <- struct{}{}
 	if w.view != 0 {
 		w.detach(env)
 	}
 	w.view = view
+	w.visible = false
 	w.handle = cgo.NewHandle(w)
-	w.callbacks.SetDriver(w)
 	w.loadConfig(env, class)
-	w.Configure(wopts.options)
-	w.SetInputHint(key.HintAny)
-	w.setStage(StagePaused)
-	w.callbacks.Event(ViewEvent{View: uintptr(view)})
+	w.setConfig(env, cnf)
+	w.SetInputHint(w.inputHint)
+	w.processEvent(AndroidViewEvent{View: uintptr(view)})
 	return C.jlong(w.handle)
 }
 
@@ -518,7 +528,7 @@ func Java_org_gioui_GioView_onDestroyView(env *C.JNIEnv, class C.jclass, handle
 func Java_org_gioui_GioView_onStopView(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w := cgo.Handle(handle).Value().(*window)
 	w.started = false
-	w.setStage(StagePaused)
+	w.visible = false
 }
 
 //export Java_org_gioui_GioView_onStartView
@@ -534,7 +544,7 @@ func Java_org_gioui_GioView_onStartView(env *C.JNIEnv, class C.jclass, handle C.
 func Java_org_gioui_GioView_onSurfaceDestroyed(env *C.JNIEnv, class C.jclass, handle C.jlong) {
 	w := cgo.Handle(handle).Value().(*window)
 	w.win = nil
-	w.setStage(StagePaused)
+	w.visible = false
 }
 
 //export Java_org_gioui_GioView_onSurfaceChanged
@@ -556,9 +566,7 @@ func Java_org_gioui_GioView_onLowMemory(env *C.JNIEnv, class C.jclass) {
 func Java_org_gioui_GioView_onConfigurationChanged(env *C.JNIEnv, class C.jclass, view C.jlong) {
 	w := cgo.Handle(view).Value().(*window)
 	w.loadConfig(env, class)
-	if w.stage >= StageInactive {
-		w.draw(env, true)
-	}
+	w.draw(env, true)
 }
 
 //export Java_org_gioui_GioView_onFrameCallback
@@ -567,10 +575,7 @@ func Java_org_gioui_GioView_onFrameCallback(env *C.JNIEnv, class C.jclass, view
 	if !exist {
 		return
 	}
-	if w.stage < StageInactive {
-		return
-	}
-	if w.animating {
+	if w.visible && w.animating {
 		w.draw(env, false)
 		callVoidMethod(env, w.view, gioView.postFrameCallback)
 	}
@@ -579,7 +584,7 @@ func Java_org_gioui_GioView_onFrameCallback(env *C.JNIEnv, class C.jclass, view
 //export Java_org_gioui_GioView_onBack
 func Java_org_gioui_GioView_onBack(env *C.JNIEnv, class C.jclass, view C.jlong) C.jboolean {
 	w := cgo.Handle(view).Value().(*window)
-	if w.callbacks.Event(key.Event{Name: key.NameBack}) {
+	if w.processEvent(key.Event{Name: key.NameBack}) {
 		return C.JNI_TRUE
 	}
 	return C.JNI_FALSE
@@ -588,7 +593,8 @@ func Java_org_gioui_GioView_onBack(env *C.JNIEnv, class C.jclass, view C.jlong)
 //export Java_org_gioui_GioView_onFocusChange
 func Java_org_gioui_GioView_onFocusChange(env *C.JNIEnv, class C.jclass, view C.jlong, focus C.jboolean) {
 	w := cgo.Handle(view).Value().(*window)
-	w.callbacks.Event(key.FocusEvent{Focus: focus == C.JNI_TRUE})
+	w.config.Focused = focus == C.JNI_TRUE
+	w.processEvent(ConfigEvent{Config: w.config})
 }
 
 //export Java_org_gioui_GioView_onWindowInsets
@@ -600,9 +606,7 @@ func Java_org_gioui_GioView_onWindowInsets(env *C.JNIEnv, class C.jclass, view C
 		left:   int(left),
 		right:  int(right),
 	}
-	if w.stage >= StageInactive {
-		w.draw(env, true)
-	}
+	w.draw(env, true)
 }
 
 //export Java_org_gioui_GioView_initializeAccessibilityNodeInfo
@@ -663,6 +667,34 @@ func Java_org_gioui_GioView_onClearA11yFocus(env *C.JNIEnv, class C.jclass, view
 	}
 }
 
+func (w *window) ProcessEvent(e event.Event) {
+	w.processEvent(e)
+}
+
+func (w *window) processEvent(e event.Event) bool {
+	if !w.callbacks.ProcessEvent(e) {
+		return false
+	}
+	w.loop.FlushEvents()
+	return true
+}
+
+func (w *window) Event() event.Event {
+	return w.loop.Event()
+}
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
 func (w *window) initAccessibilityNodeInfo(env *C.JNIEnv, sem input.SemanticNode, off image.Point, info C.jobject) error {
 	for _, ch := range sem.Children {
 		err := callVoidMethod(env, info, android.accessibilityNodeInfo.addChild, jvalue(w.view), jvalue(w.virtualIDFor(ch.ID)))
@@ -767,8 +799,7 @@ func (w *window) semIDFor(virtID C.jint) input.SemanticID {
 
 func (w *window) detach(env *C.JNIEnv) {
 	callVoidMethod(env, w.view, gioView.unregister)
-	w.callbacks.Event(ViewEvent{})
-	w.callbacks.SetDriver(nil)
+	w.processEvent(AndroidViewEvent{})
 	w.handle.Delete()
 	C.jni_DeleteGlobalRef(env, w.view)
 	w.view = 0
@@ -779,18 +810,10 @@ func (w *window) setVisible(env *C.JNIEnv) {
 	if width == 0 || height == 0 {
 		return
 	}
-	w.setStage(StageRunning)
+	w.visible = true
 	w.draw(env, true)
 }
 
-func (w *window) setStage(stage Stage) {
-	if stage == w.stage {
-		return
-	}
-	w.stage = stage
-	w.callbacks.Event(StageEvent{stage})
-}
-
 func (w *window) setVisual(visID int) error {
 	if C.ANativeWindow_setBuffersGeometry(w.win, 0, 0, C.int32_t(visID)) != 0 {
 		return errors.New("ANativeWindow_setBuffersGeometry failed")
@@ -827,10 +850,13 @@ func (w *window) SetAnimating(anim bool) {
 }
 
 func (w *window) draw(env *C.JNIEnv, sync bool) {
+	if !w.visible {
+		return
+	}
 	size := image.Pt(int(C.ANativeWindow_getWidth(w.win)), int(C.ANativeWindow_getHeight(w.win)))
 	if size != w.config.Size {
 		w.config.Size = size
-		w.callbacks.Event(ConfigEvent{Config: w.config})
+		w.processEvent(ConfigEvent{Config: w.config})
 	}
 	if size.X == 0 || size.Y == 0 {
 		return
@@ -844,7 +870,7 @@ func (w *window) draw(env *C.JNIEnv, sync bool) {
 		Left:   unit.Dp(w.insets.left) * dppp,
 		Right:  unit.Dp(w.insets.right) * dppp,
 	}
-	w.callbacks.Event(frameEvent{
+	w.processEvent(frameEvent{
 		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
@@ -944,7 +970,7 @@ func Java_org_gioui_GioView_onKeyEvent(env *C.JNIEnv, class C.jclass, handle C.j
 		if pressed == C.JNI_TRUE {
 			state = key.Press
 		}
-		w.callbacks.Event(key.Event{Name: n, State: state})
+		w.processEvent(key.Event{Name: n, State: state})
 	}
 	if pressed == C.JNI_TRUE && r != 0 && r != '\n' { // Checking for "\n" to prevent duplication with key.NameEnter (gio#224).
 		w.callbacks.EditorInsert(string(rune(r)))
@@ -994,7 +1020,7 @@ func Java_org_gioui_GioView_onTouchEvent(env *C.JNIEnv, class C.jclass, handle C
 	default:
 		return
 	}
-	w.callbacks.Event(pointer.Event{
+	w.processEvent(pointer.Event{
 		Kind:      kind,
 		Source:    src,
 		Buttons:   btns,
@@ -1146,6 +1172,8 @@ func (w *window) ShowTextInput(show bool) {
 }
 
 func (w *window) SetInputHint(mode key.InputHint) {
+	w.inputHint = mode
+
 	// Constants defined at https://developer.android.com/reference/android/text/InputType.
 	const (
 		TYPE_NULL = 0
@@ -1292,9 +1320,9 @@ func findClass(env *C.JNIEnv, name string) C.jclass {
 func osMain() {
 }
 
-func newWindow(window *callbacks, options []Option) error {
+func newWindow(window *callbacks, options []Option) {
 	mainWindow.in <- windowAndConfig{window, options}
-	return <-mainWindow.errs
+	<-mainWindow.windows
 }
 
 func (w *window) WriteClipboard(mime string, s []byte) {
@@ -1313,7 +1341,7 @@ func (w *window) ReadClipboard() {
 			return
 		}
 		content := goString(env, C.jstring(c))
-		w.callbacks.Event(transfer.DataEvent{
+		w.processEvent(transfer.DataEvent{
 			Type: "application/text",
 			Open: func() io.ReadCloser {
 				return io.NopCloser(strings.NewReader(content))
@@ -1323,42 +1351,46 @@ func (w *window) ReadClipboard() {
 }
 
 func (w *window) Configure(options []Option) {
+	cnf := w.config
+	cnf.apply(unit.Metric{}, options)
 	runInJVM(javaVM(), func(env *C.JNIEnv) {
-		prev := w.config
-		cnf := w.config
-		cnf.apply(unit.Metric{}, options)
-		// Decorations are never disabled.
-		cnf.Decorated = true
-
-		if prev.Orientation != cnf.Orientation {
-			w.config.Orientation = cnf.Orientation
-			setOrientation(env, w.view, cnf.Orientation)
-		}
-		if prev.NavigationColor != cnf.NavigationColor {
-			w.config.NavigationColor = cnf.NavigationColor
-			setNavigationColor(env, w.view, cnf.NavigationColor)
-		}
-		if prev.StatusColor != cnf.StatusColor {
-			w.config.StatusColor = cnf.StatusColor
-			setStatusColor(env, w.view, cnf.StatusColor)
-		}
-		if prev.Mode != cnf.Mode {
-			switch cnf.Mode {
-			case Fullscreen:
-				callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_TRUE)
-				w.config.Mode = Fullscreen
-			case Windowed:
-				callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_FALSE)
-				w.config.Mode = Windowed
-			}
-		}
-		if cnf.Decorated != prev.Decorated {
-			w.config.Decorated = cnf.Decorated
-		}
-		w.callbacks.Event(ConfigEvent{Config: w.config})
+		w.setConfig(env, cnf)
 	})
 }
 
+func (w *window) setConfig(env *C.JNIEnv, cnf Config) {
+	prev := w.config
+	// Decorations are never disabled.
+	cnf.Decorated = true
+
+	if prev.Orientation != cnf.Orientation {
+		w.config.Orientation = cnf.Orientation
+		setOrientation(env, w.view, cnf.Orientation)
+	}
+	if prev.NavigationColor != cnf.NavigationColor {
+		w.config.NavigationColor = cnf.NavigationColor
+		setNavigationColor(env, w.view, cnf.NavigationColor)
+	}
+	if prev.StatusColor != cnf.StatusColor {
+		w.config.StatusColor = cnf.StatusColor
+		setStatusColor(env, w.view, cnf.StatusColor)
+	}
+	if prev.Mode != cnf.Mode {
+		switch cnf.Mode {
+		case Fullscreen:
+			callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_TRUE)
+			w.config.Mode = Fullscreen
+		case Windowed:
+			callVoidMethod(env, w.view, gioView.setFullscreen, C.JNI_FALSE)
+			w.config.Mode = Windowed
+		}
+	}
+	if cnf.Decorated != prev.Decorated {
+		w.config.Decorated = cnf.Decorated
+	}
+	w.processEvent(ConfigEvent{Config: w.config})
+}
+
 func (w *window) Perform(system.Action) {}
 
 func (w *window) SetCursor(cursor pointer.Cursor) {
@@ -1367,9 +1399,10 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 	})
 }
 
-func (w *window) Wakeup() {
+func (w *window) wakeup() {
 	runOnMain(func(env *C.JNIEnv) {
-		w.callbacks.Event(wakeupEvent{})
+		w.loop.Wakeup()
+		w.loop.FlushEvents()
 	})
 }
 
@@ -1460,4 +1493,8 @@ func Java_org_gioui_Gio_scheduleMainFuncs(env *C.JNIEnv, cls C.jclass) {
 	}
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (AndroidViewEvent) implementsViewEvent() {}
+func (AndroidViewEvent) ImplementsEvent()     {}
+func (a AndroidViewEvent) Valid() bool {
+	return a != (AndroidViewEvent{})
+}

app/os_darwin.go

@@ -75,9 +75,13 @@ var displayLinks sync.Map
 
 var mainFuncs = make(chan func(), 1)
 
+func isMainThread() bool {
+	return bool(C.isMainThread())
+}
+
 // runOnMain runs the function on the main thread.
 func runOnMain(f func()) {
-	if C.isMainThread() {
+	if isMainThread() {
 		f()
 		return
 	}
@@ -260,8 +264,9 @@ func windowSetCursor(from, to pointer.Cursor) pointer.Cursor {
 	return to
 }
 
-func (w *window) Wakeup() {
+func (w *window) wakeup() {
 	runOnMain(func() {
-		w.w.Event(wakeupEvent{})
+		w.loop.Wakeup()
+		w.loop.FlushEvents()
 	})
 }

app/os_ios.go

@@ -12,6 +12,9 @@ package app
 #include <UIKit/UIKit.h>
 #include <stdint.h>
 
+__attribute__ ((visibility ("hidden"))) int gio_applicationMain(int argc, char *argv[]);
+__attribute__ ((visibility ("hidden"))) void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle);
+
 struct drawParams {
 	CGFloat dpi, sdpi;
 	CGFloat width, height;
@@ -19,6 +22,7 @@ struct drawParams {
 };
 
 static void writeClipboard(unichar *chars, NSUInteger length) {
+#if !TARGET_OS_TV
 	@autoreleasepool {
 		NSString *s = [NSString string];
 		if (length > 0) {
@@ -27,13 +31,18 @@ static void writeClipboard(unichar *chars, NSUInteger length) {
 		UIPasteboard *p = UIPasteboard.generalPasteboard;
 		p.string = s;
 	}
+#endif
 }
 
 static CFTypeRef readClipboard(void) {
+#if !TARGET_OS_TV
 	@autoreleasepool {
 		UIPasteboard *p = UIPasteboard.generalPasteboard;
 		return (__bridge_retained CFTypeRef)p.string;
 	}
+#else
+	return nil;
+#endif
 }
 
 static void showTextInput(CFTypeRef viewRef) {
@@ -73,7 +82,9 @@ import "C"
 import (
 	"image"
 	"io"
+	"os"
 	"runtime"
+	"runtime/cgo"
 	"runtime/debug"
 	"strings"
 	"time"
@@ -81,14 +92,16 @@ import (
 	"unsafe"
 
 	"gioui.org/f32"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
 	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 )
 
-type ViewEvent struct {
+type UIKitViewEvent struct {
 	// ViewController is a CFTypeRef for the UIViewController backing a Window.
 	ViewController uintptr
 }
@@ -97,18 +110,17 @@ type window struct {
 	view        C.CFTypeRef
 	w           *callbacks
 	displayLink *displayLink
+	loop        *eventLoop
 
-	visible bool
-	cursor  pointer.Cursor
-	config  Config
+	hidden bool
+	cursor pointer.Cursor
+	config Config
 
 	pointerMap []C.CFTypeRef
 }
 
 var mainWindow = newWindowRendezvous()
 
-var views = make(map[C.CFTypeRef]*window)
-
 func init() {
 	// Darwin requires UI operations happen on the main thread only.
 	runtime.LockOSThread()
@@ -116,48 +128,52 @@ func init() {
 
 //export onCreate
 func onCreate(view, controller C.CFTypeRef) {
+	wopts := <-mainWindow.out
 	w := &window{
 		view: view,
+		w:    wopts.window,
 	}
+	w.loop = newEventLoop(w.w, w.wakeup)
+	w.w.SetDriver(w)
+	mainWindow.windows <- struct{}{}
 	dl, err := newDisplayLink(func() {
 		w.draw(false)
 	})
 	if err != nil {
-		panic(err)
+		w.w.ProcessEvent(DestroyEvent{Err: err})
+		return
 	}
 	w.displayLink = dl
-	wopts := <-mainWindow.out
-	w.w = wopts.window
-	w.w.SetDriver(w)
-	views[view] = w
+	C.gio_viewSetHandle(view, C.uintptr_t(cgo.NewHandle(w)))
 	w.Configure(wopts.options)
-	w.w.Event(StageEvent{Stage: StagePaused})
-	w.w.Event(ViewEvent{ViewController: uintptr(controller)})
+	w.ProcessEvent(UIKitViewEvent{ViewController: uintptr(controller)})
+}
+
+func viewFor(h C.uintptr_t) *window {
+	return cgo.Handle(h).Value().(*window)
 }
 
 //export gio_onDraw
-func gio_onDraw(view C.CFTypeRef) {
-	w := views[view]
+func gio_onDraw(h C.uintptr_t) {
+	w := viewFor(h)
 	w.draw(true)
 }
 
 func (w *window) draw(sync bool) {
+	if w.hidden {
+		return
+	}
 	params := C.viewDrawParams(w.view)
 	if params.width == 0 || params.height == 0 {
 		return
 	}
-	wasVisible := w.visible
-	w.visible = true
-	if !wasVisible {
-		w.w.Event(StageEvent{Stage: StageRunning})
-	}
 	const inchPrDp = 1.0 / 163
 	m := unit.Metric{
 		PxPerDp: float32(params.dpi) * inchPrDp,
 		PxPerSp: float32(params.sdpi) * inchPrDp,
 	}
 	dppp := unit.Dp(1. / m.PxPerDp)
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
 		FrameEvent: FrameEvent{
 			Now: time.Now(),
 			Size: image.Point{
@@ -177,26 +193,34 @@ func (w *window) draw(sync bool) {
 }
 
 //export onStop
-func onStop(view C.CFTypeRef) {
-	w := views[view]
-	w.visible = false
-	w.w.Event(StageEvent{Stage: StagePaused})
+func onStop(h C.uintptr_t) {
+	w := viewFor(h)
+	w.hidden = true
+}
+
+//export onStart
+func onStart(h C.uintptr_t) {
+	w := viewFor(h)
+	w.hidden = false
+	w.draw(true)
 }
 
 //export onDestroy
-func onDestroy(view C.CFTypeRef) {
-	w := views[view]
-	delete(views, view)
-	w.w.Event(ViewEvent{})
-	w.w.Event(DestroyEvent{})
+func onDestroy(h C.uintptr_t) {
+	w := viewFor(h)
+	w.ProcessEvent(UIKitViewEvent{})
+	w.ProcessEvent(DestroyEvent{})
 	w.displayLink.Close()
+	w.displayLink = nil
+	cgo.Handle(h).Delete()
 	w.view = 0
 }
 
 //export onFocus
-func onFocus(view C.CFTypeRef, focus int) {
-	w := views[view]
-	w.w.Event(key.FocusEvent{Focus: focus != 0})
+func onFocus(h C.uintptr_t, focus int) {
+	w := viewFor(h)
+	w.config.Focused = focus != 0
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export onLowMemory
@@ -206,38 +230,38 @@ func onLowMemory() {
 }
 
 //export onUpArrow
-func onUpArrow(view C.CFTypeRef) {
-	views[view].onKeyCommand(key.NameUpArrow)
+func onUpArrow(h C.uintptr_t) {
+	viewFor(h).onKeyCommand(key.NameUpArrow)
 }
 
 //export onDownArrow
-func onDownArrow(view C.CFTypeRef) {
-	views[view].onKeyCommand(key.NameDownArrow)
+func onDownArrow(h C.uintptr_t) {
+	viewFor(h).onKeyCommand(key.NameDownArrow)
 }
 
 //export onLeftArrow
-func onLeftArrow(view C.CFTypeRef) {
-	views[view].onKeyCommand(key.NameLeftArrow)
+func onLeftArrow(h C.uintptr_t) {
+	viewFor(h).onKeyCommand(key.NameLeftArrow)
 }
 
 //export onRightArrow
-func onRightArrow(view C.CFTypeRef) {
-	views[view].onKeyCommand(key.NameRightArrow)
+func onRightArrow(h C.uintptr_t) {
+	viewFor(h).onKeyCommand(key.NameRightArrow)
 }
 
 //export onDeleteBackward
-func onDeleteBackward(view C.CFTypeRef) {
-	views[view].onKeyCommand(key.NameDeleteBackward)
+func onDeleteBackward(h C.uintptr_t) {
+	viewFor(h).onKeyCommand(key.NameDeleteBackward)
 }
 
 //export onText
-func onText(view, str C.CFTypeRef) {
-	w := views[view]
+func onText(h C.uintptr_t, str C.CFTypeRef) {
+	w := viewFor(h)
 	w.w.EditorInsert(nsstringToString(str))
 }
 
 //export onTouch
-func onTouch(last C.int, view, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.CGFloat, ti C.double) {
+func onTouch(h C.uintptr_t, last C.int, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.CGFloat, ti C.double) {
 	var kind pointer.Kind
 	switch phase {
 	case C.UITouchPhaseBegan:
@@ -251,10 +275,10 @@ func onTouch(last C.int, view, touchRef C.CFTypeRef, phase C.NSInteger, x, y C.C
 	default:
 		return
 	}
-	w := views[view]
+	w := viewFor(h)
 	t := time.Duration(float64(ti) * float64(time.Second))
 	p := f32.Point{X: float32(x), Y: float32(y)}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Touch,
 		PointerID: w.lookupTouch(last != 0, touchRef),
@@ -267,7 +291,7 @@ func (w *window) ReadClipboard() {
 	cstr := C.readClipboard()
 	defer C.CFRelease(cstr)
 	content := nsstringToString(cstr)
-	w.w.Event(transfer.DataEvent{
+	w.ProcessEvent(transfer.DataEvent{
 		Type: "application/text",
 		Open: func() io.ReadCloser {
 			return io.NopCloser(strings.NewReader(content))
@@ -287,7 +311,7 @@ func (w *window) WriteClipboard(mime string, s []byte) {
 func (w *window) Configure([]Option) {
 	// Decorations are never disabled.
 	w.config.Decorated = true
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *window) EditorStateChanged(old, new editorState) {}
@@ -295,10 +319,6 @@ func (w *window) EditorStateChanged(old, new editorState) {}
 func (w *window) Perform(system.Action) {}
 
 func (w *window) SetAnimating(anim bool) {
-	v := w.view
-	if v == 0 {
-		return
-	}
 	if anim {
 		w.displayLink.Start()
 	} else {
@@ -311,7 +331,7 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 }
 
 func (w *window) onKeyCommand(name key.Name) {
-	w.w.Event(key.Event{
+	w.ProcessEvent(key.Event{
 		Name: name,
 	})
 }
@@ -350,17 +370,77 @@ func (w *window) ShowTextInput(show bool) {
 
 func (w *window) SetInputHint(_ key.InputHint) {}
 
-func newWindow(win *callbacks, options []Option) error {
-	mainWindow.in <- windowAndConfig{win, options}
-	return <-mainWindow.errs
+func (w *window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+	w.loop.FlushEvents()
 }
 
+func (w *window) Event() event.Event {
+	return w.loop.Event()
+}
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
+func newWindow(win *callbacks, options []Option) {
+	mainWindow.in <- windowAndConfig{win, options}
+	<-mainWindow.windows
+}
+
+var mainMode = mainModeUndefined
+
+const (
+	mainModeUndefined = iota
+	mainModeExe
+	mainModeLibrary
+)
+
 func osMain() {
+	if !isMainThread() {
+		panic("app.Main must be run on the main goroutine")
+	}
+	switch mainMode {
+	case mainModeUndefined:
+		mainMode = mainModeExe
+		var argv []*C.char
+		for _, arg := range os.Args {
+			a := C.CString(arg)
+			defer C.free(unsafe.Pointer(a))
+			argv = append(argv, a)
+		}
+		C.gio_applicationMain(C.int(len(argv)), unsafe.SliceData(argv))
+	case mainModeExe:
+		panic("app.Main may be called only once")
+	case mainModeLibrary:
+		// Do nothing, we're embedded as a library.
+	}
 }
 
 //export gio_runMain
 func gio_runMain() {
-	runMain()
+	if !isMainThread() {
+		panic("app.Main must be run on the main goroutine")
+	}
+	switch mainMode {
+	case mainModeUndefined:
+		mainMode = mainModeLibrary
+		runMain()
+	case mainModeExe:
+		// Do nothing, main has already been called.
+	}
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (UIKitViewEvent) implementsViewEvent() {}
+func (UIKitViewEvent) ImplementsEvent()     {}
+func (u UIKitViewEvent) Valid() bool {
+	return u != (UIKitViewEvent{})
+}

app/os_ios.m

@@ -11,6 +11,7 @@
 __attribute__ ((visibility ("hidden"))) Class gio_layerClass(void);
 
 @interface GioView: UIView <UIKeyInput>
+@property uintptr_t handle;
 @end
 
 @implementation GioViewController
@@ -25,12 +26,13 @@ CGFloat _keyboardHeight;
 	self.view.layoutMargins = UIEdgeInsetsMake(0, 0, 0, 0);
 	UIView *drawView = [[GioView alloc] initWithFrame:zeroFrame];
 	[self.view addSubview: drawView];
-#ifndef TARGET_OS_TV
+#if !TARGET_OS_TV
 	drawView.multipleTouchEnabled = YES;
 #endif
 	drawView.preservesSuperviewLayoutMargins = YES;
 	drawView.layoutMargins = UIEdgeInsetsMake(0, 0, 0, 0);
 	onCreate((__bridge CFTypeRef)drawView, (__bridge CFTypeRef)self);
+#if !TARGET_OS_TV
 	[[NSNotificationCenter defaultCenter] addObserver:self
 											 selector:@selector(keyboardWillChange:)
 												 name:UIKeyboardWillShowNotification
@@ -43,6 +45,7 @@ CGFloat _keyboardHeight;
 											 selector:@selector(keyboardWillHide:)
 												 name:UIKeyboardWillHideNotification
 											   object:nil];
+#endif
 	[[NSNotificationCenter defaultCenter] addObserver: self
 											 selector: @selector(applicationDidEnterBackground:)
 												 name: UIApplicationDidEnterBackgroundNotification
@@ -54,33 +57,33 @@ CGFloat _keyboardHeight;
 }
 
 - (void)applicationWillEnterForeground:(UIApplication *)application {
-	UIView *drawView = self.view.subviews[0];
-	if (drawView != nil) {
-		gio_onDraw((__bridge CFTypeRef)drawView);
+	GioView *view = (GioView *)self.view.subviews[0];
+	if (view != nil) {
+		onStart(view.handle);
 	}
 }
 
 - (void)applicationDidEnterBackground:(UIApplication *)application {
-	UIView *drawView = self.view.subviews[0];
-	if (drawView != nil) {
-		onStop((__bridge CFTypeRef)drawView);
+	GioView *view = (GioView *)self.view.subviews[0];
+	if (view != nil) {
+		onStop(view.handle);
 	}
 }
 
 - (void)viewDidDisappear:(BOOL)animated {
 	[super viewDidDisappear:animated];
-	CFTypeRef viewRef = (__bridge CFTypeRef)self.view.subviews[0];
-	onDestroy(viewRef);
+	GioView *view = (GioView *)self.view.subviews[0];
+	onDestroy(view.handle);
 }
 
 - (void)viewDidLayoutSubviews {
 	[super viewDidLayoutSubviews];
-	UIView *view = self.view.subviews[0];
+	GioView *view = (GioView *)self.view.subviews[0];
 	CGRect frame = self.view.bounds;
 	// Adjust view bounds to make room for the keyboard.
 	frame.size.height -= _keyboardHeight;
 	view.frame = frame;
-	gio_onDraw((__bridge CFTypeRef)view);
+	gio_onDraw(view.handle);
 }
 
 - (void)didReceiveMemoryWarning {
@@ -88,6 +91,7 @@ CGFloat _keyboardHeight;
 	[super didReceiveMemoryWarning];
 }
 
+#if !TARGET_OS_TV
 - (void)keyboardWillChange:(NSNotification *)note {
 	NSDictionary *userInfo = note.userInfo;
 	CGRect f = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
@@ -99,13 +103,13 @@ CGFloat _keyboardHeight;
 	_keyboardHeight = 0.0;
 	[self.view setNeedsLayout];
 }
+#endif
 @end
 
-static void handleTouches(int last, UIView *view, NSSet<UITouch *> *touches, UIEvent *event) {
+static void handleTouches(int last, GioView *view, NSSet<UITouch *> *touches, UIEvent *event) {
 	CGFloat scale = view.contentScaleFactor;
 	NSUInteger i = 0;
 	NSUInteger n = [touches count];
-	CFTypeRef viewRef = (__bridge CFTypeRef)view;
 	for (UITouch *touch in touches) {
 		CFTypeRef touchRef = (__bridge CFTypeRef)touch;
 		i++;
@@ -116,7 +120,7 @@ static void handleTouches(int last, UIView *view, NSSet<UITouch *> *touches, UIE
 			CGPoint loc = [coalescedTouch locationInView:view];
 			j++;
 			int lastTouch = last && i == n && j == m;
-			onTouch(lastTouch, viewRef, touchRef, touch.phase, loc.x*scale, loc.y*scale, [coalescedTouch timestamp]);
+			onTouch(view.handle, lastTouch, touchRef, touch.phase, loc.x*scale, loc.y*scale, [coalescedTouch timestamp]);
 		}
 	}
 }
@@ -151,13 +155,13 @@ NSArray<UIKeyCommand *> *_keyCommands;
 
 - (void)onWindowDidBecomeKey:(NSNotification *)note {
 	if (self.isFirstResponder) {
-		onFocus((__bridge CFTypeRef)self, YES);
+		onFocus(self.handle, YES);
 	}
 }
 
 - (void)onWindowDidResignKey:(NSNotification *)note {
 	if (self.isFirstResponder) {
-		onFocus((__bridge CFTypeRef)self, NO);
+		onFocus(self.handle, NO);
 	}
 }
 
@@ -178,7 +182,7 @@ NSArray<UIKeyCommand *> *_keyCommands;
 }
 
 - (void)insertText:(NSString *)text {
-	onText((__bridge CFTypeRef)self, (__bridge CFTypeRef)text);
+	onText(self.handle, (__bridge CFTypeRef)text);
 }
 
 - (BOOL)canBecomeFirstResponder {
@@ -190,23 +194,23 @@ NSArray<UIKeyCommand *> *_keyCommands;
 }
 
 - (void)deleteBackward {
-	onDeleteBackward((__bridge CFTypeRef)self);
+	onDeleteBackward(self.handle);
 }
 
 - (void)onUpArrow {
-	onUpArrow((__bridge CFTypeRef)self);
+	onUpArrow(self.handle);
 }
 
 - (void)onDownArrow {
-	onDownArrow((__bridge CFTypeRef)self);
+	onDownArrow(self.handle);
 }
 
 - (void)onLeftArrow {
-	onLeftArrow((__bridge CFTypeRef)self);
+	onLeftArrow(self.handle);
 }
 
 - (void)onRightArrow {
-	onRightArrow((__bridge CFTypeRef)self);
+	onRightArrow(self.handle);
 }
 
 - (NSArray<UIKeyCommand *> *)keyCommands {
@@ -271,3 +275,28 @@ void gio_showCursor() {
 void gio_setCursor(NSUInteger curID) {
 	// Not supported.
 }
+
+void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle) {
+	GioView *v = (__bridge GioView *)viewRef;
+	v.handle = handle;
+}
+
+@interface _gioAppDelegate : UIResponder <UIApplicationDelegate>
+@property (strong, nonatomic) UIWindow *window;
+@end
+
+@implementation _gioAppDelegate
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+	self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
+	GioViewController *controller = [[GioViewController alloc] initWithNibName:nil bundle:nil];
+	self.window.rootViewController = controller;
+	[self.window makeKeyAndVisible];
+	return YES;
+}
+@end
+
+int gio_applicationMain(int argc, char *argv[]) {
+	@autoreleasepool {
+		return UIApplicationMain(argc, argv, nil, NSStringFromClass([_gioAppDelegate class]));
+	}
+}

app/os_js.go

@@ -14,8 +14,10 @@ import (
 	"unicode/utf8"
 
 	"gioui.org/internal/f32color"
+	"gioui.org/op"
 
 	"gioui.org/f32"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
@@ -23,7 +25,7 @@ import (
 	"gioui.org/unit"
 )
 
-type ViewEvent struct {
+type JSViewEvent struct {
 	Element js.Value
 }
 
@@ -54,9 +56,6 @@ type window struct {
 	composing             bool
 	requestFocus          bool
 
-	chanAnimation chan struct{}
-	chanRedraw    chan struct{}
-
 	config    Config
 	inset     f32.Point
 	scale     float32
@@ -69,7 +68,7 @@ type window struct {
 	contextStatus contextStatus
 }
 
-func newWindow(win *callbacks, options []Option) error {
+func newWindow(win *callbacks, options []Option) {
 	doc := js.Global().Get("document")
 	cont := getContainer(doc)
 	cnv := createCanvas(doc)
@@ -84,7 +83,9 @@ func newWindow(win *callbacks, options []Option) error {
 		head:      doc.Get("head"),
 		clipboard: js.Global().Get("navigator").Get("clipboard"),
 		wakeups:   make(chan struct{}, 1),
+		w:         win,
 	}
+	w.w.SetDriver(w)
 	w.requestAnimationFrame = w.window.Get("requestAnimationFrame")
 	w.browserHistory = w.window.Get("history")
 	w.visualViewport = w.window.Get("visualViewport")
@@ -94,15 +95,13 @@ func newWindow(win *callbacks, options []Option) error {
 	if screen := w.window.Get("screen"); screen.Truthy() {
 		w.screenOrientation = screen.Get("orientation")
 	}
-	w.chanAnimation = make(chan struct{}, 1)
-	w.chanRedraw = make(chan struct{}, 1)
 	w.redraw = w.funcOf(func(this js.Value, args []js.Value) interface{} {
-		w.chanAnimation <- struct{}{}
+		w.draw(false)
 		return nil
 	})
 	w.clipboardCallback = w.funcOf(func(this js.Value, args []js.Value) interface{} {
 		content := args[0].String()
-		go win.Event(transfer.DataEvent{
+		w.processEvent(transfer.DataEvent{
 			Type: "application/text",
 			Open: func() io.ReadCloser {
 				return io.NopCloser(strings.NewReader(content))
@@ -112,29 +111,12 @@ func newWindow(win *callbacks, options []Option) error {
 	})
 	w.addEventListeners()
 	w.addHistory()
-	w.w = win
 
-	go func() {
-		defer w.cleanup()
-		w.w.SetDriver(w)
-		w.Configure(options)
-		w.blur()
-		w.w.Event(ViewEvent{Element: cont})
-		w.w.Event(StageEvent{Stage: StageRunning})
-		w.resize()
-		w.draw(true)
-		for {
-			select {
-			case <-w.wakeups:
-				w.w.Event(wakeupEvent{})
-			case <-w.chanAnimation:
-				w.animCallback()
-			case <-w.chanRedraw:
-				w.draw(true)
-			}
-		}
-	}()
-	return nil
+	w.Configure(options)
+	w.blur()
+	w.processEvent(JSViewEvent{Element: cont})
+	w.resize()
+	w.draw(true)
 }
 
 func getContainer(doc js.Value) js.Value {
@@ -194,12 +176,12 @@ func (w *window) addEventListeners() {
 		w.cnv.Set("width", 0)
 		w.cnv.Set("height", 0)
 		w.resize()
-		w.requestRedraw()
+		w.draw(true)
 		return nil
 	})
 	w.addEventListener(w.visualViewport, "resize", func(this js.Value, args []js.Value) interface{} {
 		w.resize()
-		w.requestRedraw()
+		w.draw(true)
 		return nil
 	})
 	w.addEventListener(w.window, "contextmenu", func(this js.Value, args []js.Value) interface{} {
@@ -207,22 +189,11 @@ func (w *window) addEventListeners() {
 		return nil
 	})
 	w.addEventListener(w.window, "popstate", func(this js.Value, args []js.Value) interface{} {
-		if w.w.Event(key.Event{Name: key.NameBack}) {
+		if w.processEvent(key.Event{Name: key.NameBack}) {
 			return w.browserHistory.Call("forward")
 		}
 		return w.browserHistory.Call("back")
 	})
-	w.addEventListener(w.document, "visibilitychange", func(this js.Value, args []js.Value) interface{} {
-		ev := StageEvent{}
-		switch w.document.Get("visibilityState").String() {
-		case "hidden", "prerender", "unloaded":
-			ev.Stage = StagePaused
-		default:
-			ev.Stage = StageRunning
-		}
-		w.w.Event(ev)
-		return nil
-	})
 	w.addEventListener(w.cnv, "mousemove", func(this js.Value, args []js.Value) interface{} {
 		w.pointerEvent(pointer.Move, 0, 0, args[0])
 		return nil
@@ -280,18 +251,20 @@ func (w *window) addEventListeners() {
 			w.touches[i] = js.Null()
 		}
 		w.touches = w.touches[:0]
-		w.w.Event(pointer.Event{
+		w.processEvent(pointer.Event{
 			Kind:   pointer.Cancel,
 			Source: pointer.Touch,
 		})
 		return nil
 	})
 	w.addEventListener(w.tarea, "focus", func(this js.Value, args []js.Value) interface{} {
-		w.w.Event(key.FocusEvent{Focus: true})
+		w.config.Focused = true
+		w.processEvent(ConfigEvent{Config: w.config})
 		return nil
 	})
 	w.addEventListener(w.tarea, "blur", func(this js.Value, args []js.Value) interface{} {
-		w.w.Event(key.FocusEvent{Focus: false})
+		w.config.Focused = false
+		w.processEvent(ConfigEvent{Config: w.config})
 		w.blur()
 		return nil
 	})
@@ -380,10 +353,50 @@ func (w *window) keyEvent(e js.Value, ks key.State) {
 			Modifiers: modifiersFor(e),
 			State:     ks,
 		}
-		w.w.Event(cmd)
+		w.processEvent(cmd)
 	}
 }
 
+func (w *window) ProcessEvent(e event.Event) {
+	w.processEvent(e)
+}
+
+func (w *window) processEvent(e event.Event) bool {
+	if !w.w.ProcessEvent(e) {
+		return false
+	}
+	select {
+	case w.wakeups <- struct{}{}:
+	default:
+	}
+	return true
+}
+
+func (w *window) Event() event.Event {
+	for {
+		evt, ok := w.w.nextEvent()
+		if ok {
+			if _, destroy := evt.(DestroyEvent); destroy {
+				w.cleanup()
+			}
+			return evt
+		}
+		<-w.wakeups
+	}
+}
+
+func (w *window) Invalidate() {
+	w.w.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	f()
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.w.ProcessFrame(frame, nil)
+}
+
 // modifiersFor returns the modifier set for a DOM MouseEvent or
 // KeyEvent.
 func modifiersFor(e js.Value) key.Modifiers {
@@ -431,7 +444,7 @@ func (w *window) touchEvent(kind pointer.Kind, e js.Value) {
 			X: float32(x) * scale,
 			Y: float32(y) * scale,
 		}
-		w.w.Event(pointer.Event{
+		w.processEvent(pointer.Event{
 			Kind:      kind,
 			Source:    pointer.Touch,
 			Position:  pos,
@@ -481,7 +494,7 @@ func (w *window) pointerEvent(kind pointer.Kind, dx, dy float32, e js.Value) {
 	if jbtns&4 != 0 {
 		btns |= pointer.ButtonTertiary
 	}
-	w.w.Event(pointer.Event{
+	w.processEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Mouse,
 		Buttons:   btns,
@@ -508,17 +521,6 @@ func (w *window) funcOf(f func(this js.Value, args []js.Value) interface{}) js.F
 	return jsf
 }
 
-func (w *window) animCallback() {
-	anim := w.animating
-	w.animRequested = anim
-	if anim {
-		w.requestAnimationFrame.Invoke(w.redraw)
-	}
-	if anim {
-		w.draw(false)
-	}
-}
-
 func (w *window) EditorStateChanged(old, new editorState) {}
 
 func (w *window) SetAnimating(anim bool) {
@@ -574,7 +576,7 @@ func (w *window) Configure(options []Option) {
 	if cnf.Decorated != prev.Decorated {
 		w.config.Decorated = cnf.Decorated
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.processEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *window) Perform(system.Action) {}
@@ -613,23 +615,14 @@ func (w *window) SetCursor(cursor pointer.Cursor) {
 	style.Set("cursor", webCursor[cursor])
 }
 
-func (w *window) Wakeup() {
-	select {
-	case w.wakeups <- struct{}{}:
-	default:
-	}
-}
-
 func (w *window) ShowTextInput(show bool) {
 	// Run in a goroutine to avoid a deadlock if the
 	// focus change result in an event.
-	go func() {
-		if show {
-			w.focus()
-		} else {
-			w.blur()
-		}
-	}()
+	if show {
+		w.focus()
+	} else {
+		w.blur()
+	}
 }
 
 func (w *window) SetInputHint(mode key.InputHint) {
@@ -646,7 +639,7 @@ func (w *window) resize() {
 	}
 	if size != w.config.Size {
 		w.config.Size = size
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.processEvent(ConfigEvent{Config: w.config})
 	}
 
 	if vx, vy := w.visualViewport.Get("width"), w.visualViewport.Get("height"); !vx.IsUndefined() && !vy.IsUndefined() {
@@ -666,12 +659,19 @@ func (w *window) draw(sync bool) {
 	if w.contextStatus == contextStatusLost {
 		return
 	}
+	anim := w.animating
+	w.animRequested = anim
+	if anim {
+		w.requestAnimationFrame.Invoke(w.redraw)
+	} else if !sync {
+		return
+	}
 	size, insets, metric := w.getConfig()
 	if metric == (unit.Metric{}) || size.X == 0 || size.Y == 0 {
 		return
 	}
 
-	w.w.Event(frameEvent{
+	w.processEvent(frameEvent{
 		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   size,
@@ -741,13 +741,6 @@ func (w *window) navigationColor(c color.NRGBA) {
 	theme.Set("content", fmt.Sprintf("#%06X", []uint8{rgba.R, rgba.G, rgba.B}))
 }
 
-func (w *window) requestRedraw() {
-	select {
-	case w.chanRedraw <- struct{}{}:
-	default:
-	}
-}
-
 func osMain() {
 	select {}
 }
@@ -827,4 +820,8 @@ func translateKey(k string) (key.Name, bool) {
 	return n, true
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (JSViewEvent) implementsViewEvent() {}
+func (JSViewEvent) ImplementsEvent()     {}
+func (j JSViewEvent) Valid() bool {
+	return !(j.Element.IsNull() || j.Element.IsUndefined())
+}

app/os_macos.go

@@ -10,16 +10,19 @@ import (
 	"image"
 	"io"
 	"runtime"
+	"runtime/cgo"
 	"strings"
 	"time"
 	"unicode"
 	"unicode/utf8"
 
 	"gioui.org/internal/f32"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
 	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 
 	_ "gioui.org/internal/cocoainit"
@@ -37,8 +40,9 @@ import (
 #define MOUSE_SCROLL 4
 
 __attribute__ ((visibility ("hidden"))) void gio_main(void);
-__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createView(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"))) void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle);
 
 static void writeClipboard(CFTypeRef str) {
 	@autoreleasepool {
@@ -58,148 +62,212 @@ static CFTypeRef readClipboard(void) {
 }
 
 static CGFloat viewHeight(CFTypeRef viewRef) {
-	NSView *view = (__bridge NSView *)viewRef;
-	return [view bounds].size.height;
+	@autoreleasepool {
+		NSView *view = (__bridge NSView *)viewRef;
+		return [view bounds].size.height;
+	}
 }
 
 static CGFloat viewWidth(CFTypeRef viewRef) {
-	NSView *view = (__bridge NSView *)viewRef;
-	return [view bounds].size.width;
+	@autoreleasepool {
+		NSView *view = (__bridge NSView *)viewRef;
+		return [view bounds].size.width;
+	}
 }
 
 static CGFloat getScreenBackingScale(void) {
-	return [NSScreen.mainScreen backingScaleFactor];
+	@autoreleasepool {
+		return [NSScreen.mainScreen backingScaleFactor];
+	}
 }
 
 static CGFloat getViewBackingScale(CFTypeRef viewRef) {
-	NSView *view = (__bridge NSView *)viewRef;
-	return [view.window backingScaleFactor];
+	@autoreleasepool {
+		NSView *view = (__bridge NSView *)viewRef;
+		return [view.window backingScaleFactor];
+	}
 }
 
 static void setNeedsDisplay(CFTypeRef viewRef) {
-	NSView *view = (__bridge NSView *)viewRef;
-	[view setNeedsDisplay:YES];
+	@autoreleasepool {
+		NSView *view = (__bridge NSView *)viewRef;
+		[view setNeedsDisplay:YES];
+	}
 }
 
 static NSPoint cascadeTopLeftFromPoint(CFTypeRef windowRef, NSPoint topLeft) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	return [window cascadeTopLeftFromPoint:topLeft];
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		return [window cascadeTopLeftFromPoint:topLeft];
+	}
 }
 
 static void makeKeyAndOrderFront(CFTypeRef windowRef) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	[window makeKeyAndOrderFront:nil];
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		[window makeKeyAndOrderFront:nil];
+	}
 }
 
 static void toggleFullScreen(CFTypeRef windowRef) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	[window toggleFullScreen:nil];
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		[window toggleFullScreen:nil];
+	}
 }
 
 static NSWindowStyleMask getWindowStyleMask(CFTypeRef windowRef) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	return [window styleMask];
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		return [window styleMask];
+	}
 }
 
 static void setWindowStyleMask(CFTypeRef windowRef, NSWindowStyleMask mask) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	window.styleMask = mask;
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		window.styleMask = mask;
+	}
 }
 
 static void setWindowTitleVisibility(CFTypeRef windowRef, NSWindowTitleVisibility state) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	window.titleVisibility = state;
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		window.titleVisibility = state;
+	}
 }
 
 static void setWindowTitlebarAppearsTransparent(CFTypeRef windowRef, int transparent) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	window.titlebarAppearsTransparent = (BOOL)transparent;
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		window.titlebarAppearsTransparent = (BOOL)transparent;
+	}
 }
 
 static void setWindowStandardButtonHidden(CFTypeRef windowRef, NSWindowButton btn, int hide) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	[window standardWindowButton:btn].hidden = (BOOL)hide;
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		[window standardWindowButton:btn].hidden = (BOOL)hide;
+	}
 }
 
 static void performWindowDragWithEvent(CFTypeRef windowRef, CFTypeRef evt) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	[window performWindowDragWithEvent:(__bridge NSEvent*)evt];
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		[window performWindowDragWithEvent:(__bridge NSEvent*)evt];
+	}
 }
 
 static void closeWindow(CFTypeRef windowRef) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	[window performClose:nil];
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		[window performClose:nil];
+	}
 }
 
 static void setSize(CFTypeRef windowRef, CGFloat width, CGFloat height) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	NSSize size = NSMakeSize(width, height);
-	[window setContentSize:size];
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		NSSize size = NSMakeSize(width, height);
+		[window setContentSize:size];
+	}
 }
 
 static void setMinSize(CFTypeRef windowRef, CGFloat width, CGFloat height) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	window.contentMinSize = NSMakeSize(width, height);
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		window.contentMinSize = NSMakeSize(width, height);
+	}
 }
 
 static void setMaxSize(CFTypeRef windowRef, CGFloat width, CGFloat height) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	window.contentMaxSize = NSMakeSize(width, height);
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		window.contentMaxSize = NSMakeSize(width, height);
+	}
 }
 
 static void setScreenFrame(CFTypeRef windowRef, CGFloat x, CGFloat y, CGFloat w, CGFloat h) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	NSRect r = NSMakeRect(x, y, w, h);
-	[window setFrame:r display:YES];
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		NSRect r = NSMakeRect(x, y, w, h);
+		[window setFrame:r display:YES];
+	}
+}
+
+static void resetLayerFrame(CFTypeRef viewRef) {
+	@autoreleasepool {
+		NSView* view = (__bridge NSView *)viewRef;
+		NSRect r = view.frame;
+		view.layer.frame = r;
+	}
 }
 
 static void hideWindow(CFTypeRef windowRef) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	[window miniaturize:window];
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		[window miniaturize:window];
+	}
 }
 
 static void unhideWindow(CFTypeRef windowRef) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	[window deminiaturize:window];
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		[window deminiaturize:window];
+	}
 }
 
 static NSRect getScreenFrame(CFTypeRef windowRef) {
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	return [[window screen] frame];
+	@autoreleasepool {
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		return [[window screen] frame];
+	}
 }
 
 static void setTitle(CFTypeRef windowRef, CFTypeRef titleRef) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	window.title = (__bridge NSString *)titleRef;
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		window.title = (__bridge NSString *)titleRef;
+	}
 }
 
 static int isWindowZoomed(CFTypeRef windowRef) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	return window.zoomed ? 1 : 0;
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		return window.zoomed ? 1 : 0;
+	}
 }
 
 static void zoomWindow(CFTypeRef windowRef) {
-	NSWindow *window = (__bridge NSWindow *)windowRef;
-	[window zoom:nil];
+	@autoreleasepool {
+		NSWindow *window = (__bridge NSWindow *)windowRef;
+		[window zoom:nil];
+	}
 }
 
 static CFTypeRef layerForView(CFTypeRef viewRef) {
-	NSView *view = (__bridge NSView *)viewRef;
-	return (__bridge CFTypeRef)view.layer;
+	@autoreleasepool {
+		NSView *view = (__bridge NSView *)viewRef;
+		return (__bridge CFTypeRef)view.layer;
+	}
 }
 
 static CFTypeRef windowForView(CFTypeRef viewRef) {
-	NSView *view = (__bridge NSView *)viewRef;
-	return (__bridge CFTypeRef)view.window;
+	@autoreleasepool {
+		NSView *view = (__bridge NSView *)viewRef;
+		return (__bridge CFTypeRef)view.window;
+	}
 }
 
 static void raiseWindow(CFTypeRef windowRef) {
-	NSRunningApplication *currentApp = [NSRunningApplication currentApplication];
-	if (![currentApp isActive]) {
-		[currentApp activateWithOptions:(NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps)];
+	@autoreleasepool {
+		NSRunningApplication *currentApp = [NSRunningApplication currentApplication];
+		if (![currentApp isActive]) {
+			[currentApp activateWithOptions:(NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps)];
+		}
+		NSWindow* window = (__bridge NSWindow *)windowRef;
+		[window makeKeyAndOrderFront:nil];
 	}
-	NSWindow* window = (__bridge NSWindow *)windowRef;
-	[window makeKeyAndOrderFront:nil];
 }
 
 static CFTypeRef createInputContext(CFTypeRef clientRef) {
@@ -211,23 +279,23 @@ static CFTypeRef createInputContext(CFTypeRef clientRef) {
 }
 
 static void discardMarkedText(CFTypeRef viewRef) {
-    @autoreleasepool {
+	@autoreleasepool {
 		id<NSTextInputClient> view = (__bridge id<NSTextInputClient>)viewRef;
 		NSTextInputContext *ctx = [NSTextInputContext currentInputContext];
 		if (view == [ctx client]) {
 			[ctx discardMarkedText];
 		}
-    }
+	}
 }
 
 static void invalidateCharacterCoordinates(CFTypeRef viewRef) {
-    @autoreleasepool {
+	@autoreleasepool {
 		id<NSTextInputClient> view = (__bridge id<NSTextInputClient>)viewRef;
 		NSTextInputContext *ctx = [NSTextInputContext currentInputContext];
 		if (view == [ctx client]) {
 			[ctx invalidateCharacterCoordinates];
 		}
-    }
+	}
 }
 */
 import "C"
@@ -237,9 +305,9 @@ func init() {
 	runtime.LockOSThread()
 }
 
-// ViewEvent notified the client of changes to the window AppKit handles.
-// The handles are retained until another ViewEvent is sent.
-type ViewEvent struct {
+// AppKitViewEvent notifies the client of changes to the window AppKit handles.
+// The handles are retained until another AppKitViewEvent is sent.
+type AppKitViewEvent struct {
 	// View is a CFTypeRef for the NSView for the window.
 	View uintptr
 	// Layer is a CFTypeRef of the CALayer of View.
@@ -249,21 +317,20 @@ type ViewEvent struct {
 type window struct {
 	view        C.CFTypeRef
 	w           *callbacks
-	stage       Stage
+	anim        bool
+	visible     bool
 	displayLink *displayLink
 	// redraw is a single entry channel for making sure only one
 	// display link redraw request is in flight.
 	redraw      chan struct{}
 	cursor      pointer.Cursor
 	pointerBtns pointer.Buttons
+	loop        *eventLoop
 
 	scale  float32
 	config Config
 }
 
-// viewMap is the mapping from Cocoa NSViews to Go windows.
-var viewMap = make(map[C.CFTypeRef]*window)
-
 // launched is closed when applicationDidFinishLaunching is called.
 var launched = make(chan struct{})
 
@@ -271,30 +338,8 @@ var launched = make(chan struct{})
 // cascadeTopLeftFromPoint.
 var nextTopLeft C.NSPoint
 
-// mustView is like lookupView, except that it panics
-// if the view isn't mapped.
-func mustView(view C.CFTypeRef) *window {
-	w, ok := lookupView(view)
-	if !ok {
-		panic("no window for view")
-	}
-	return w
-}
-
-func lookupView(view C.CFTypeRef) (*window, bool) {
-	w, exists := viewMap[view]
-	if !exists {
-		return nil, false
-	}
-	return w, true
-}
-
-func deleteView(view C.CFTypeRef) {
-	delete(viewMap, view)
-}
-
-func insertView(view C.CFTypeRef, w *window) {
-	viewMap[view] = w
+func windowFor(h C.uintptr_t) *window {
+	return cgo.Handle(h).Value().(*window)
 }
 
 func (w *window) contextView() C.CFTypeRef {
@@ -307,7 +352,7 @@ func (w *window) ReadClipboard() {
 		defer C.CFRelease(cstr)
 	}
 	content := nsstringToString(cstr)
-	w.w.Event(transfer.DataEvent{
+	w.ProcessEvent(transfer.DataEvent{
 		Type: "application/text",
 		Open: func() io.ReadCloser {
 			return io.NopCloser(strings.NewReader(content))
@@ -419,8 +464,11 @@ func (w *window) Configure(options []Option) {
 		C.setWindowStandardButtonHidden(window, C.NSWindowCloseButton, barTrans)
 		C.setWindowStandardButtonHidden(window, C.NSWindowMiniaturizeButton, barTrans)
 		C.setWindowStandardButtonHidden(window, C.NSWindowZoomButton, barTrans)
+		// When toggling the titlebar, the layer doesn't update its frame
+		// until the next resize. Force it.
+		C.resetLayerFrame(w.view)
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *window) setTitle(prev, cnf Config) {
@@ -471,7 +519,8 @@ func (w *window) ShowTextInput(show bool) {}
 func (w *window) SetInputHint(_ key.InputHint) {}
 
 func (w *window) SetAnimating(anim bool) {
-	if anim {
+	w.anim = anim
+	if w.anim && w.visible {
 		w.displayLink.Start()
 	} else {
 		w.displayLink.Stop()
@@ -488,26 +537,18 @@ func (w *window) runOnMain(f func()) {
 	})
 }
 
-func (w *window) setStage(stage Stage) {
-	if stage == w.stage {
-		return
-	}
-	w.stage = stage
-	w.w.Event(StageEvent{Stage: stage})
-}
-
 //export gio_onKeys
-func gio_onKeys(view, cstr C.CFTypeRef, ti C.double, mods C.NSUInteger, keyDown C.bool) {
+func gio_onKeys(h C.uintptr_t, cstr C.CFTypeRef, ti C.double, mods C.NSUInteger, keyDown C.bool) {
 	str := nsstringToString(cstr)
 	kmods := convertMods(mods)
 	ks := key.Release
 	if keyDown {
 		ks = key.Press
 	}
-	w := mustView(view)
+	w := windowFor(h)
 	for _, k := range str {
 		if n, ok := convertKey(k); ok {
-			w.w.Event(key.Event{
+			w.ProcessEvent(key.Event{
 				Name:      n,
 				Modifiers: kmods,
 				State:     ks,
@@ -517,15 +558,15 @@ func gio_onKeys(view, cstr C.CFTypeRef, ti C.double, mods C.NSUInteger, keyDown
 }
 
 //export gio_onText
-func gio_onText(view, cstr C.CFTypeRef) {
+func gio_onText(h C.uintptr_t, cstr C.CFTypeRef) {
 	str := nsstringToString(cstr)
-	w := mustView(view)
+	w := windowFor(h)
 	w.w.EditorInsert(str)
 }
 
 //export gio_onMouse
-func gio_onMouse(view, evt C.CFTypeRef, cdir C.int, cbtn C.NSInteger, x, y, dx, dy C.CGFloat, ti C.double, mods C.NSUInteger) {
-	w := mustView(view)
+func gio_onMouse(h C.uintptr_t, evt C.CFTypeRef, cdir C.int, cbtn C.NSInteger, x, y, dx, dy C.CGFloat, ti C.double, mods C.NSUInteger) {
+	w := windowFor(h)
 	t := time.Duration(float64(ti)*float64(time.Second) + .5)
 	xf, yf := float32(x)*w.scale, float32(y)*w.scale
 	dxf, dyf := float32(dx)*w.scale, float32(dy)*w.scale
@@ -562,7 +603,7 @@ func gio_onMouse(view, evt C.CFTypeRef, cdir C.int, cbtn C.NSInteger, x, y, dx,
 	default:
 		panic("invalid direction")
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      typ,
 		Source:    pointer.Mouse,
 		Time:      t,
@@ -574,35 +615,29 @@ func gio_onMouse(view, evt C.CFTypeRef, cdir C.int, cbtn C.NSInteger, x, y, dx,
 }
 
 //export gio_onDraw
-func gio_onDraw(view C.CFTypeRef) {
-	w := mustView(view)
+func gio_onDraw(h C.uintptr_t) {
+	w := windowFor(h)
 	w.draw()
 }
 
 //export gio_onFocus
-func gio_onFocus(view C.CFTypeRef, focus C.int) {
-	w := mustView(view)
-	w.w.Event(key.FocusEvent{Focus: focus == 1})
-	if w.stage >= StageInactive {
-		if focus == 0 {
-			w.setStage(StageInactive)
-		} else {
-			w.setStage(StageRunning)
-		}
-	}
+func gio_onFocus(h C.uintptr_t, focus C.int) {
+	w := windowFor(h)
 	w.SetCursor(w.cursor)
+	w.config.Focused = focus == 1
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onChangeScreen
-func gio_onChangeScreen(view C.CFTypeRef, did uint64) {
-	w := mustView(view)
+func gio_onChangeScreen(h C.uintptr_t, did uint64) {
+	w := windowFor(h)
 	w.displayLink.SetDisplayID(did)
 	C.setNeedsDisplay(w.view)
 }
 
 //export gio_hasMarkedText
-func gio_hasMarkedText(view C.CFTypeRef) C.int {
-	w := mustView(view)
+func gio_hasMarkedText(h C.uintptr_t) C.int {
+	w := windowFor(h)
 	state := w.w.EditorState()
 	if state.compose.Start != -1 {
 		return 1
@@ -611,8 +646,8 @@ func gio_hasMarkedText(view C.CFTypeRef) C.int {
 }
 
 //export gio_markedRange
-func gio_markedRange(view C.CFTypeRef) C.NSRange {
-	w := mustView(view)
+func gio_markedRange(h C.uintptr_t) C.NSRange {
+	w := windowFor(h)
 	state := w.w.EditorState()
 	rng := state.compose
 	start, end := rng.Start, rng.End
@@ -627,8 +662,8 @@ func gio_markedRange(view C.CFTypeRef) C.NSRange {
 }
 
 //export gio_selectedRange
-func gio_selectedRange(view C.CFTypeRef) C.NSRange {
-	w := mustView(view)
+func gio_selectedRange(h C.uintptr_t) C.NSRange {
+	w := windowFor(h)
 	state := w.w.EditorState()
 	rng := state.Selection
 	start, end := rng.Start, rng.End
@@ -643,14 +678,14 @@ func gio_selectedRange(view C.CFTypeRef) C.NSRange {
 }
 
 //export gio_unmarkText
-func gio_unmarkText(view C.CFTypeRef) {
-	w := mustView(view)
+func gio_unmarkText(h C.uintptr_t) {
+	w := windowFor(h)
 	w.w.SetComposingRegion(key.Range{Start: -1, End: -1})
 }
 
 //export gio_setMarkedText
-func gio_setMarkedText(view, cstr C.CFTypeRef, selRange C.NSRange, replaceRange C.NSRange) {
-	w := mustView(view)
+func gio_setMarkedText(h C.uintptr_t, cstr C.CFTypeRef, selRange C.NSRange, replaceRange C.NSRange) {
+	w := windowFor(h)
 	str := nsstringToString(cstr)
 	state := w.w.EditorState()
 	rng := state.compose
@@ -689,8 +724,8 @@ func gio_setMarkedText(view, cstr C.CFTypeRef, selRange C.NSRange, replaceRange
 }
 
 //export gio_substringForProposedRange
-func gio_substringForProposedRange(view C.CFTypeRef, crng C.NSRange, actual C.NSRangePointer) C.CFTypeRef {
-	w := mustView(view)
+func gio_substringForProposedRange(h C.uintptr_t, crng C.NSRange, actual C.NSRangePointer) C.CFTypeRef {
+	w := windowFor(h)
 	state := w.w.EditorState()
 	start, end := state.Snippet.Start, state.Snippet.End
 	if start > end {
@@ -710,8 +745,8 @@ func gio_substringForProposedRange(view C.CFTypeRef, crng C.NSRange, actual C.NS
 }
 
 //export gio_insertText
-func gio_insertText(view, cstr C.CFTypeRef, crng C.NSRange) {
-	w := mustView(view)
+func gio_insertText(h C.uintptr_t, cstr C.CFTypeRef, crng C.NSRange) {
+	w := windowFor(h)
 	state := w.w.EditorState()
 	rng := state.compose
 	if rng.Start == -1 {
@@ -735,13 +770,13 @@ func gio_insertText(view, cstr C.CFTypeRef, crng C.NSRange) {
 }
 
 //export gio_characterIndexForPoint
-func gio_characterIndexForPoint(view C.CFTypeRef, p C.NSPoint) C.NSUInteger {
+func gio_characterIndexForPoint(h C.uintptr_t, p C.NSPoint) C.NSUInteger {
 	return C.NSNotFound
 }
 
 //export gio_firstRectForCharacterRange
-func gio_firstRectForCharacterRange(view C.CFTypeRef, crng C.NSRange, actual C.NSRangePointer) C.NSRect {
-	w := mustView(view)
+func gio_firstRectForCharacterRange(h C.uintptr_t, crng C.NSRange, actual C.NSRangePointer) C.NSRect {
+	w := windowFor(h)
 	state := w.w.EditorState()
 	sel := state.Selection
 	u16start := state.UTF16Index(sel.Start)
@@ -768,6 +803,10 @@ func (w *window) draw() {
 	case <-w.redraw:
 	default:
 	}
+	w.visible = true
+	if w.anim {
+		w.SetAnimating(w.anim)
+	}
 	w.scale = float32(C.getViewBackingScale(w.view))
 	wf, hf := float32(C.viewWidth(w.view)), float32(C.viewHeight(w.view))
 	sz := image.Point{
@@ -776,14 +815,13 @@ func (w *window) draw() {
 	}
 	if sz != w.config.Size {
 		w.config.Size = sz
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	}
 	if sz.X == 0 || sz.Y == 0 {
 		return
 	}
 	cfg := configFor(w.scale)
-	w.setStage(StageRunning)
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
 		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
@@ -793,6 +831,27 @@ func (w *window) draw() {
 	})
 }
 
+func (w *window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+	w.loop.FlushEvents()
+}
+
+func (w *window) Event() event.Event {
+	return w.loop.Event()
+}
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
 func configFor(scale float32) unit.Metric {
 	return unit.Metric{
 		PxPerDp: scale,
@@ -800,56 +859,54 @@ func configFor(scale float32) unit.Metric {
 	}
 }
 
-//export gio_onClose
-func gio_onClose(view C.CFTypeRef) {
-	w := mustView(view)
-	w.w.Event(ViewEvent{})
-	w.w.Event(DestroyEvent{})
+//export gio_onAttached
+func gio_onAttached(h C.uintptr_t, attached C.int) {
+	w := windowFor(h)
+	if attached != 0 {
+		layer := C.layerForView(w.view)
+		w.ProcessEvent(AppKitViewEvent{View: uintptr(w.view), Layer: uintptr(layer)})
+	} else {
+		w.ProcessEvent(AppKitViewEvent{})
+		w.visible = false
+		w.SetAnimating(w.anim)
+	}
+}
+
+//export gio_onDestroy
+func gio_onDestroy(h C.uintptr_t) {
+	w := windowFor(h)
+	w.ProcessEvent(DestroyEvent{})
 	w.displayLink.Close()
 	w.displayLink = nil
-	deleteView(view)
-	C.CFRelease(w.view)
+	cgo.Handle(h).Delete()
 	w.view = 0
 }
 
 //export gio_onHide
-func gio_onHide(view C.CFTypeRef) {
-	w := mustView(view)
-	w.setStage(StagePaused)
+func gio_onHide(h C.uintptr_t) {
+	w := windowFor(h)
+	w.visible = false
+	w.SetAnimating(w.anim)
 }
 
 //export gio_onShow
-func gio_onShow(view C.CFTypeRef) {
-	w := mustView(view)
-	w.setStage(StageRunning)
+func gio_onShow(h C.uintptr_t) {
+	w := windowFor(h)
+	w.draw()
 }
 
 //export gio_onFullscreen
-func gio_onFullscreen(view C.CFTypeRef) {
-	w := mustView(view)
+func gio_onFullscreen(h C.uintptr_t) {
+	w := windowFor(h)
 	w.config.Mode = Fullscreen
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onWindowed
-func gio_onWindowed(view C.CFTypeRef) {
-	w := mustView(view)
+func gio_onWindowed(h C.uintptr_t) {
+	w := windowFor(h)
 	w.config.Mode = Windowed
-	w.w.Event(ConfigEvent{Config: w.config})
-}
-
-//export gio_onAppHide
-func gio_onAppHide() {
-	for _, w := range viewMap {
-		w.setStage(StagePaused)
-	}
-}
-
-//export gio_onAppShow
-func gio_onAppShow() {
-	for _, w := range viewMap {
-		w.setStage(StageRunning)
-	}
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onFinishLaunching
@@ -857,20 +914,27 @@ func gio_onFinishLaunching() {
 	close(launched)
 }
 
-func newWindow(win *callbacks, options []Option) error {
+func newWindow(win *callbacks, options []Option) {
 	<-launched
-	errch := make(chan error)
+	res := make(chan struct{})
 	runOnMain(func() {
-		w, err := newOSWindow()
-		if err != nil {
-			errch <- err
+		w := &window{
+			redraw: make(chan struct{}, 1),
+			w:      win,
+		}
+		w.loop = newEventLoop(w.w, w.wakeup)
+		win.SetDriver(w)
+		res <- struct{}{}
+		var cnf Config
+		cnf.apply(unit.Metric{}, options)
+		if err := w.init(cnf.CustomRenderer); err != nil {
+			w.ProcessEvent(DestroyEvent{Err: err})
 			return
 		}
-		errch <- nil
-		w.w = win
 		window := C.gio_createWindow(w.view, 0, 0, 0, 0, 0, 0)
+		// Release our reference now that the NSWindow has it.
+		C.CFRelease(w.view)
 		w.updateWindowMode()
-		win.SetDriver(w)
 		w.Configure(options)
 		if nextTopLeft.x == 0 && nextTopLeft.y == 0 {
 			// cascadeTopLeftFromPoint treats (0, 0) as a no-op,
@@ -880,23 +944,21 @@ func newWindow(win *callbacks, options []Option) error {
 		nextTopLeft = C.cascadeTopLeftFromPoint(window, nextTopLeft)
 		// makeKeyAndOrderFront assumes ownership of our window reference.
 		C.makeKeyAndOrderFront(window)
-		layer := C.layerForView(w.view)
-		w.w.Event(ViewEvent{View: uintptr(w.view), Layer: uintptr(layer)})
 	})
-	return <-errch
+	<-res
 }
 
-func newOSWindow() (*window, error) {
-	view := C.gio_createView()
+func (w *window) init(customRenderer bool) error {
+	presentWithTrans := 1
+	if customRenderer {
+		presentWithTrans = 0
+	}
+	view := C.gio_createView(C.int(presentWithTrans))
 	if view == 0 {
-		return nil, errors.New("newOSWindows: failed to create view")
+		return errors.New("newOSWindow: failed to create view")
 	}
 	scale := float32(C.getViewBackingScale(view))
-	w := &window{
-		view:   view,
-		scale:  scale,
-		redraw: make(chan struct{}, 1),
-	}
+	w.scale = scale
 	dl, err := newDisplayLink(func() {
 		select {
 		case w.redraw <- struct{}{}:
@@ -904,19 +966,25 @@ func newOSWindow() (*window, error) {
 			return
 		}
 		w.runOnMain(func() {
-			C.setNeedsDisplay(w.view)
+			if w.visible {
+				C.setNeedsDisplay(w.view)
+			}
 		})
 	})
 	w.displayLink = dl
 	if err != nil {
 		C.CFRelease(view)
-		return nil, err
+		return err
 	}
-	insertView(view, w)
-	return w, nil
+	C.gio_viewSetHandle(view, C.uintptr_t(cgo.NewHandle(w)))
+	w.view = view
+	return nil
 }
 
 func osMain() {
+	if !isMainThread() {
+		panic("app.Main must run on the main goroutine")
+	}
 	C.gio_main()
 }
 
@@ -1004,4 +1072,8 @@ func convertMods(mods C.NSUInteger) key.Modifiers {
 	return kmods
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (AppKitViewEvent) implementsViewEvent() {}
+func (AppKitViewEvent) ImplementsEvent()     {}
+func (a AppKitViewEvent) Valid() bool {
+	return a != (AppKitViewEvent{})
+}

app/os_macos.m

@@ -6,7 +6,7 @@
 
 #include "_cgo_export.h"
 
-__attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(void);
+__attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(BOOL presentWithTrans);
 
 @interface GioAppDelegate : NSObject<NSApplicationDelegate>
 @end
@@ -14,40 +14,55 @@ __attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(void);
 @interface GioWindowDelegate : NSObject<NSWindowDelegate>
 @end
 
+@interface GioView : NSView <CALayerDelegate,NSTextInputClient>
+@property uintptr_t handle;
+@property BOOL presentWithTrans;
+@end
+
 @implementation GioWindowDelegate
 - (void)windowWillMiniaturize:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onHide((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onHide(view.handle);
 }
 - (void)windowDidDeminiaturize:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onShow((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onShow(view.handle);
 }
 - (void)windowWillEnterFullScreen:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onFullscreen((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onFullscreen(view.handle);
 }
 - (void)windowWillExitFullScreen:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onWindowed((__bridge CFTypeRef)window.contentView);
+  GioView *view = (GioView *)window.contentView;
+	gio_onWindowed(view.handle);
 }
 - (void)windowDidChangeScreen:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
 	CGDirectDisplayID dispID = [[[window screen] deviceDescription][@"NSScreenNumber"] unsignedIntValue];
-	CFTypeRef view = (__bridge CFTypeRef)window.contentView;
-	gio_onChangeScreen(view, dispID);
+  GioView *view = (GioView *)window.contentView;
+	gio_onChangeScreen(view.handle, dispID);
 }
 - (void)windowDidBecomeKey:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onFocus((__bridge CFTypeRef)window.contentView, 1);
+	GioView *view = (GioView *)window.contentView;
+	if ([window firstResponder] == view) {
+		gio_onFocus(view.handle, 1);
+	}
 }
 - (void)windowDidResignKey:(NSNotification *)notification {
 	NSWindow *window = (NSWindow *)[notification object];
-	gio_onFocus((__bridge CFTypeRef)window.contentView, 0);
+	GioView *view = (GioView *)window.contentView;
+	if ([window firstResponder] == view) {
+		gio_onFocus(view.handle, 0);
+	}
 }
 @end
 
-static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFloat dy) {
+static void handleMouse(GioView *view, NSEvent *event, int typ, CGFloat dx, CGFloat dy) {
 	NSPoint p = [view convertPoint:[event locationInWindow] fromView:nil];
 	if (!event.hasPreciseScrollingDeltas) {
 		// dx and dy are in rows and columns.
@@ -56,12 +71,9 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	}
 	// Origin is in the lower left corner. Convert to upper left.
 	CGFloat height = view.bounds.size.height;
-	gio_onMouse((__bridge CFTypeRef)view, (__bridge CFTypeRef)event, typ, event.buttonNumber, p.x, height - p.y, dx, dy, [event timestamp], [event modifierFlags]);
+	gio_onMouse(view.handle, (__bridge CFTypeRef)event, typ, event.buttonNumber, p.x, height - p.y, dx, dy, [event timestamp], [event modifierFlags]);
 }
 
-@interface GioView : NSView <CALayerDelegate,NSTextInputClient>
-@end
-
 @implementation GioView
 - (void)setFrameSize:(NSSize)newSize {
 	[super setFrameSize:newSize];
@@ -70,21 +82,19 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 // drawRect is called when OpenGL is used, displayLayer otherwise.
 // Don't know why.
 - (void)drawRect:(NSRect)r {
-	gio_onDraw((__bridge CFTypeRef)self);
+	gio_onDraw(self.handle);
 }
 - (void)displayLayer:(CALayer *)layer {
 	layer.contentsScale = self.window.backingScaleFactor;
-	gio_onDraw((__bridge CFTypeRef)self);
+	gio_onDraw(self.handle);
 }
 - (CALayer *)makeBackingLayer {
-	CALayer *layer = gio_layerFactory();
+	CALayer *layer = gio_layerFactory(self.presentWithTrans);
 	layer.delegate = self;
 	return layer;
 }
 - (void)viewDidMoveToWindow {
-	if (self.window == nil) {
-		gio_onClose((__bridge CFTypeRef)self);
-	}
+	gio_onAttached(self.handle, self.window != nil ? 1 : 0);
 }
 - (void)mouseDown:(NSEvent *)event {
 	handleMouse(self, event, MOUSE_DOWN, 0, 0);
@@ -124,14 +134,14 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 - (void)keyDown:(NSEvent *)event {
 	[self interpretKeyEvents:[NSArray arrayWithObject:event]];
 	NSString *keys = [event charactersIgnoringModifiers];
-	gio_onKeys((__bridge CFTypeRef)self, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], true);
+	gio_onKeys(self.handle, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], true);
 }
 - (void)keyUp:(NSEvent *)event {
 	NSString *keys = [event charactersIgnoringModifiers];
-	gio_onKeys((__bridge CFTypeRef)self, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], false);
+	gio_onKeys(self.handle, (__bridge CFTypeRef)keys, [event timestamp], [event modifierFlags], false);
 }
 - (void)insertText:(id)string {
-	gio_onText((__bridge CFTypeRef)self, (__bridge CFTypeRef)string);
+	gio_onText(self.handle, (__bridge CFTypeRef)string);
 }
 - (void)doCommandBySelector:(SEL)sel {
 	// Don't pass commands up the responder chain.
@@ -139,17 +149,17 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 }
 
 - (BOOL)hasMarkedText {
-	int res = gio_hasMarkedText((__bridge CFTypeRef)self);
+	int res = gio_hasMarkedText(self.handle);
 	return res ? YES : NO;
 }
 - (NSRange)markedRange {
-	return gio_markedRange((__bridge CFTypeRef)self);
+	return gio_markedRange(self.handle);
 }
 - (NSRange)selectedRange {
-	return gio_selectedRange((__bridge CFTypeRef)self);
+	return gio_selectedRange(self.handle);
 }
 - (void)unmarkText {
-	gio_unmarkText((__bridge CFTypeRef)self);
+	gio_unmarkText(self.handle);
 }
 - (void)setMarkedText:(id)string
         selectedRange:(NSRange)selRange
@@ -161,14 +171,14 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	} else {
 		str = string;
 	}
-	gio_setMarkedText((__bridge CFTypeRef)self, (__bridge CFTypeRef)str, selRange, replaceRange);
+	gio_setMarkedText(self.handle, (__bridge CFTypeRef)str, selRange, replaceRange);
 }
 - (NSArray<NSAttributedStringKey> *)validAttributesForMarkedText {
 	return nil;
 }
 - (NSAttributedString *)attributedSubstringForProposedRange:(NSRange)range
                                                 actualRange:(NSRangePointer)actualRange {
-	NSString *str = CFBridgingRelease(gio_substringForProposedRange((__bridge CFTypeRef)self, range, actualRange));
+	NSString *str = CFBridgingRelease(gio_substringForProposedRange(self.handle, range, actualRange));
 	return [[NSAttributedString alloc] initWithString:str attributes:nil];
 }
 - (void)insertText:(id)string
@@ -180,17 +190,34 @@ static void handleMouse(NSView *view, NSEvent *event, int typ, CGFloat dx, CGFlo
 	} else {
 		str = string;
 	}
-	gio_insertText((__bridge CFTypeRef)self, (__bridge CFTypeRef)str, replaceRange);
+	gio_insertText(self.handle, (__bridge CFTypeRef)str, replaceRange);
 }
 - (NSUInteger)characterIndexForPoint:(NSPoint)p {
-	return gio_characterIndexForPoint((__bridge CFTypeRef)self, p);
+	return gio_characterIndexForPoint(self.handle, p);
 }
 - (NSRect)firstRectForCharacterRange:(NSRange)rng
                          actualRange:(NSRangePointer)actual {
-    NSRect r = gio_firstRectForCharacterRange((__bridge CFTypeRef)self, rng, actual);
+    NSRect r = gio_firstRectForCharacterRange(self.handle, rng, actual);
     r = [self convertRect:r toView:nil];
     return [[self window] convertRectToScreen:r];
 }
+- (void)applicationWillUnhide:(NSNotification *)notification {
+	gio_onShow(self.handle);
+}
+- (void)applicationDidHide:(NSNotification *)notification {
+	gio_onHide(self.handle);
+}
+- (void)dealloc {
+	gio_onDestroy(self.handle);
+}
+- (BOOL) becomeFirstResponder {
+	gio_onFocus(self.handle, 1);
+	return [super becomeFirstResponder];
+ }
+- (BOOL) resignFirstResponder {
+	gio_onFocus(self.handle, 0);
+	return [super resignFirstResponder];
+}
 @end
 
 // Delegates are weakly referenced from their peers. Nothing
@@ -240,7 +267,7 @@ void gio_showCursor() {
 
 // some cursors are not public, this tries to use a private cursor
 // and uses fallback when the use of private cursor fails.
-void gio_trySetPrivateCursor(SEL cursorName, NSCursor* fallback) {
+static void trySetPrivateCursor(SEL cursorName, NSCursor* fallback) {
 	if ([NSCursor respondsToSelector:cursorName]) {
 		id object = [NSCursor performSelector:cursorName];
 		if ([object isKindOfClass:[NSCursor class]]) {
@@ -272,7 +299,7 @@ void gio_setCursor(NSUInteger curID) {
 				break;
 			case 6: // pointer.CursorAllScroll
 				// For some reason, using _moveCursor fails on Monterey.
-				// gio_trySetPrivateCursor(@selector(_moveCursor), NSCursor.arrowCursor);
+				// trySetPrivateCursor(@selector(_moveCursor), NSCursor.arrowCursor);
 				[NSCursor.arrowCursor set];
 				break;
 			case 7: // pointer.CursorColResize
@@ -282,33 +309,31 @@ void gio_setCursor(NSUInteger curID) {
 				[NSCursor.resizeUpDownCursor set];
 				break;
 			case 9: // pointer.CursorGrab
-				// [NSCursor.openHandCursor set];
-				gio_trySetPrivateCursor(@selector(openHandCursor), NSCursor.arrowCursor);
+				[NSCursor.openHandCursor set];
 				break;
 			case 10: // pointer.CursorGrabbing
-				// [NSCursor.closedHandCursor set];
-				gio_trySetPrivateCursor(@selector(closedHandCursor), NSCursor.arrowCursor);
+				[NSCursor.closedHandCursor set];
 				break;
 			case 11: // pointer.CursorNotAllowed
 				[NSCursor.operationNotAllowedCursor set];
 				break;
 			case 12: // pointer.CursorWait
-				gio_trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
+				trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
 				break;
 			case 13: // pointer.CursorProgress
-				gio_trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
+				trySetPrivateCursor(@selector(busyButClickableCursor), NSCursor.arrowCursor);
 				break;
 			case 14: // pointer.CursorNorthWestResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthWestCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthWestCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 15: // pointer.CursorNorthEastResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthEastCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthEastCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 16: // pointer.CursorSouthWestResize
-				gio_trySetPrivateCursor(@selector(_windowResizeSouthWestCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeSouthWestCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 17: // pointer.CursorSouthEastResize
-				gio_trySetPrivateCursor(@selector(_windowResizeSouthEastCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeSouthEastCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 18: // pointer.CursorNorthSouthResize
 				[NSCursor.resizeUpDownCursor set];
@@ -329,10 +354,10 @@ void gio_setCursor(NSUInteger curID) {
 				[NSCursor.resizeDownCursor set];
 				break;
 			case 24: // pointer.CursorNorthEastSouthWestResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthEastSouthWestCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthEastSouthWestCursor), NSCursor.resizeUpDownCursor);
 				break;
 			case 25: // pointer.CursorNorthWestSouthEastResize
-				gio_trySetPrivateCursor(@selector(_windowResizeNorthWestSouthEastCursor), NSCursor.resizeUpDownCursor);
+				trySetPrivateCursor(@selector(_windowResizeNorthWestSouthEastCursor), NSCursor.resizeUpDownCursor);
 				break;
 			default:
 				[NSCursor.arrowCursor set];
@@ -368,28 +393,39 @@ CFTypeRef gio_createWindow(CFTypeRef viewRef, CGFloat width, CGFloat height, CGF
 	}
 }
 
-CFTypeRef gio_createView(void) {
+CFTypeRef gio_createView(int presentWithTrans) {
 	@autoreleasepool {
 		NSRect frame = NSMakeRect(0, 0, 0, 0);
 		GioView* view = [[GioView alloc] initWithFrame:frame];
+		view.presentWithTrans = presentWithTrans ? YES : NO;
 		view.wantsLayer = YES;
 		view.layerContentsRedrawPolicy = NSViewLayerContentsRedrawDuringViewResize;
+
+		[[NSNotificationCenter defaultCenter] addObserver:view
+												 selector:@selector(applicationWillUnhide:)
+													 name:NSApplicationWillUnhideNotification
+												   object:nil];
+		[[NSNotificationCenter defaultCenter] addObserver:view
+												 selector:@selector(applicationDidHide:)
+													 name:NSApplicationDidHideNotification
+												   object:nil];
 		return CFBridgingRetain(view);
 	}
 }
 
+void gio_viewSetHandle(CFTypeRef viewRef, uintptr_t handle) {
+	@autoreleasepool {
+		GioView *v = (__bridge GioView *)viewRef;
+		v.handle = handle;
+	}
+}
+
 @implementation GioAppDelegate
 - (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
 	[NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
 	[NSApp activateIgnoringOtherApps:YES];
 	gio_onFinishLaunching();
 }
-- (void)applicationDidHide:(NSNotification *)aNotification {
-	gio_onAppHide();
-}
-- (void)applicationWillUnhide:(NSNotification *)notification {
-	gio_onAppShow();
-}
 @end
 
 void gio_main() {

app/os_unix.go

@@ -12,13 +12,6 @@ import (
 	"gioui.org/io/pointer"
 )
 
-// ViewEvent provides handles to the underlying window objects for the
-// current display protocol.
-type ViewEvent interface {
-	implementsViewEvent()
-	ImplementsEvent()
-}
-
 type X11ViewEvent struct {
 	// Display is a pointer to the X11 Display created by XOpenDisplay.
 	Display unsafe.Pointer
@@ -28,6 +21,9 @@ type X11ViewEvent struct {
 
 func (X11ViewEvent) implementsViewEvent() {}
 func (X11ViewEvent) ImplementsEvent()     {}
+func (x X11ViewEvent) Valid() bool {
+	return x != (X11ViewEvent{})
+}
 
 type WaylandViewEvent struct {
 	// Display is the *wl_display returned by wl_display_connect.
@@ -38,6 +34,9 @@ type WaylandViewEvent struct {
 
 func (WaylandViewEvent) implementsViewEvent() {}
 func (WaylandViewEvent) ImplementsEvent()     {}
+func (w WaylandViewEvent) Valid() bool {
+	return w != (WaylandViewEvent{})
+}
 
 func osMain() {
 	select {}
@@ -49,7 +48,7 @@ type windowDriver func(*callbacks, []Option) error
 // let each driver initialize these variables with their own version of createWindow.
 var wlDriver, x11Driver windowDriver
 
-func newWindow(window *callbacks, options []Option) error {
+func newWindow(window *callbacks, options []Option) {
 	var errFirst error
 	for _, d := range []windowDriver{wlDriver, x11Driver} {
 		if d == nil {
@@ -57,16 +56,16 @@ func newWindow(window *callbacks, options []Option) error {
 		}
 		err := d(window, options)
 		if err == nil {
-			return nil
+			return
 		}
 		if errFirst == nil {
 			errFirst = err
 		}
 	}
-	if errFirst != nil {
-		return errFirst
+	if errFirst == nil {
+		errFirst = errors.New("app: no window driver available")
 	}
-	return errors.New("app: no window driver available")
+	window.ProcessEvent(DestroyEvent{Err: errFirst})
 }
 
 // xCursor contains mapping from pointer.Cursor to XCursor.

app/os_wayland.go

@@ -15,6 +15,7 @@ import (
 	"math"
 	"os"
 	"os/exec"
+	"runtime"
 	"strconv"
 	"sync"
 	"time"
@@ -25,10 +26,12 @@ import (
 	"gioui.org/app/internal/xkb"
 	"gioui.org/f32"
 	"gioui.org/internal/fling"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
 	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 )
 
@@ -97,7 +100,9 @@ type wlDisplay struct {
 		read, write int
 	}
 
-	repeat repeatState
+	repeat        repeatState
+	poller        poller
+	readClipClose chan struct{}
 }
 
 type wlSeat struct {
@@ -137,7 +142,7 @@ type repeatState struct {
 	delay time.Duration
 
 	key   uint32
-	win   *callbacks
+	win   *window
 	stopC chan struct{}
 
 	start time.Duration
@@ -194,12 +199,10 @@ type window struct {
 		dir            f32.Point
 	}
 
-	stage             Stage
-	dead              bool
+	configured        bool
 	lastFrameCallback *C.struct_wl_callback
 
 	animating bool
-	redraw    bool
 	// The most recent configure serial waiting to be ack'ed.
 	serial C.uint32_t
 	scale  int
@@ -212,6 +215,8 @@ type window struct {
 	clipReads chan transfer.DataEvent
 
 	wakeups chan struct{}
+
+	closing bool
 }
 
 type poller struct {
@@ -260,25 +265,17 @@ func newWLWindow(callbacks *callbacks, options []Option) error {
 		return err
 	}
 	w.w = callbacks
-	go func() {
-		defer d.destroy()
-		defer w.destroy()
+	w.w.SetDriver(w)
 
-		w.w.SetDriver(w)
+	// Finish and commit setup from createNativeWindow.
+	w.Configure(options)
+	w.draw(true)
+	C.wl_surface_commit(w.surf)
 
-		// Finish and commit setup from createNativeWindow.
-		w.Configure(options)
-		C.wl_surface_commit(w.surf)
-
-		w.w.Event(WaylandViewEvent{
-			Display: unsafe.Pointer(w.display()),
-			Surface: unsafe.Pointer(w.surf),
-		})
-
-		err := w.loop()
-		w.w.Event(WaylandViewEvent{})
-		w.w.Event(DestroyEvent{Err: err})
-	}()
+	w.ProcessEvent(WaylandViewEvent{
+		Display: unsafe.Pointer(w.display()),
+		Surface: unsafe.Pointer(w.surf),
+	})
 	return nil
 }
 
@@ -549,15 +546,15 @@ func gio_onSeatName(data unsafe.Pointer, seat *C.struct_wl_seat, name *C.char) {
 func gio_onXdgSurfaceConfigure(data unsafe.Pointer, wmSurf *C.struct_xdg_surface, serial C.uint32_t) {
 	w := callbackLoad(data).(*window)
 	w.serial = serial
-	w.redraw = true
 	C.xdg_surface_ack_configure(wmSurf, serial)
-	w.setStage(StageRunning)
+	w.configured = true
+	w.draw(true)
 }
 
 //export gio_onToplevelClose
 func gio_onToplevelClose(data unsafe.Pointer, topLvl *C.struct_xdg_toplevel) {
 	w := callbackLoad(data).(*window)
-	w.dead = true
+	w.closing = true
 }
 
 //export gio_onToplevelConfigure
@@ -586,8 +583,8 @@ func gio_onToplevelDecorationConfigure(data unsafe.Pointer, deco *C.struct_zxdg_
 		} else {
 			w.size.Y += int(w.config.decoHeight)
 		}
-		w.w.Event(ConfigEvent{Config: w.config})
-		w.redraw = true
+		w.ProcessEvent(ConfigEvent{Config: w.config})
+		w.draw(true)
 	}
 }
 
@@ -645,7 +642,7 @@ func gio_onSurfaceEnter(data unsafe.Pointer, surf *C.struct_wl_surface, output *
 	if w.config.Mode == Minimized {
 		// Minimized window got brought back up: it is no longer so.
 		w.config.Mode = Windowed
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	}
 }
 
@@ -790,7 +787,7 @@ func gio_onTouchDown(data unsafe.Pointer, touch *C.struct_wl_touch, serial, t C.
 		X: fromFixed(x) * float32(w.scale),
 		Y: fromFixed(y) * float32(w.scale),
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Press,
 		Source:    pointer.Touch,
 		Position:  w.lastTouch,
@@ -806,7 +803,7 @@ func gio_onTouchUp(data unsafe.Pointer, touch *C.struct_wl_touch, serial, t C.ui
 	s.serial = serial
 	w := s.touchFoci[id]
 	delete(s.touchFoci, id)
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Release,
 		Source:    pointer.Touch,
 		Position:  w.lastTouch,
@@ -824,7 +821,7 @@ func gio_onTouchMotion(data unsafe.Pointer, touch *C.struct_wl_touch, t C.uint32
 		X: fromFixed(x) * float32(w.scale),
 		Y: fromFixed(y) * float32(w.scale),
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Move,
 		Position:  w.lastTouch,
 		Source:    pointer.Touch,
@@ -843,7 +840,7 @@ func gio_onTouchCancel(data unsafe.Pointer, touch *C.struct_wl_touch) {
 	s := callbackLoad(data).(*wlSeat)
 	for id, w := range s.touchFoci {
 		delete(s.touchFoci, id)
-		w.w.Event(pointer.Event{
+		w.ProcessEvent(pointer.Event{
 			Kind:   pointer.Cancel,
 			Source: pointer.Touch,
 		})
@@ -869,7 +866,7 @@ func gio_onPointerLeave(data unsafe.Pointer, p *C.struct_wl_pointer, serial C.ui
 	s.serial = serial
 	if w.inCompositor {
 		w.inCompositor = false
-		w.w.Event(pointer.Event{Kind: pointer.Cancel})
+		w.ProcessEvent(pointer.Event{Kind: pointer.Cancel})
 	}
 }
 
@@ -930,7 +927,7 @@ func gio_onPointerButton(data unsafe.Pointer, p *C.struct_wl_pointer, serial, t,
 	}
 	w.flushScroll()
 	w.resetFling()
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Mouse,
 		Buttons:   w.pointerBtns,
@@ -1018,8 +1015,11 @@ func gio_onPointerAxisDiscrete(data unsafe.Pointer, p *C.struct_wl_pointer, axis
 }
 
 func (w *window) ReadClipboard() {
+	if w.disp.readClipClose != nil {
+		return
+	}
+	w.disp.readClipClose = make(chan struct{})
 	r, err := w.disp.readClipboard()
-	// Send empty responses on unavailable clipboards or errors.
 	if r == nil || err != nil {
 		return
 	}
@@ -1027,13 +1027,17 @@ func (w *window) ReadClipboard() {
 	go func() {
 		defer r.Close()
 		data, _ := io.ReadAll(r)
-		w.clipReads <- transfer.DataEvent{
+		e := transfer.DataEvent{
 			Type: "application/text",
 			Open: func() io.ReadCloser {
 				return io.NopCloser(bytes.NewReader(data))
 			},
 		}
-		w.Wakeup()
+		select {
+		case w.clipReads <- e:
+			w.disp.wakeup()
+		case <-w.disp.readClipClose:
+		}
 	}()
 }
 
@@ -1096,8 +1100,7 @@ func (w *window) Configure(options []Option) {
 		w.config.MaxSize = cnf.MaxSize
 		w.setWindowConstraints()
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
-	w.redraw = true
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *window) setWindowConstraints() {
@@ -1134,7 +1137,7 @@ func (w *window) Perform(actions system.Action) {
 	walkActions(actions, func(action system.Action) {
 		switch action {
 		case system.ActionClose:
-			w.dead = true
+			w.closing = true
 		}
 	})
 }
@@ -1217,7 +1220,8 @@ func gio_onKeyboardEnter(data unsafe.Pointer, keyboard *C.struct_wl_keyboard, se
 	w := callbackLoad(unsafe.Pointer(surf)).(*window)
 	s.keyboardFocus = w
 	s.disp.repeat.Stop(0)
-	w.w.Event(key.FocusEvent{Focus: true})
+	w.config.Focused = true
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onKeyboardLeave
@@ -1226,7 +1230,8 @@ func gio_onKeyboardLeave(data unsafe.Pointer, keyboard *C.struct_wl_keyboard, se
 	s.serial = serial
 	s.disp.repeat.Stop(0)
 	w := s.keyboardFocus
-	w.w.Event(key.FocusEvent{Focus: false})
+	w.config.Focused = false
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 //export gio_onKeyboardKey
@@ -1244,7 +1249,7 @@ func gio_onKeyboardKey(data unsafe.Pointer, keyboard *C.struct_wl_keyboard, seri
 			// There's no support for IME yet.
 			w.w.EditorInsert(ee.Text)
 		} else {
-			w.w.Event(e)
+			w.ProcessEvent(e)
 		}
 	}
 	if state != C.WL_KEYBOARD_KEY_STATE_PRESSED {
@@ -1279,7 +1284,7 @@ func (r *repeatState) Start(w *window, keyCode uint32, t time.Duration) {
 	r.now = 0
 	r.stopC = stopC
 	r.key = keyCode
-	r.win = w.w
+	r.win = w
 	rate, delay := r.rate, r.delay
 	go func() {
 		timer := time.NewTimer(delay)
@@ -1337,9 +1342,9 @@ func (r *repeatState) Repeat(d *wlDisplay) {
 		for _, e := range d.xkb.DispatchKey(r.key, key.Press) {
 			if ee, ok := e.(key.EditEvent); ok {
 				// There's no support for IME yet.
-				r.win.EditorInsert(ee.Text)
+				r.win.w.EditorInsert(ee.Text)
 			} else {
-				r.win.Event(e)
+				r.win.ProcessEvent(e)
 			}
 		}
 		r.last += delay
@@ -1352,28 +1357,68 @@ func gio_onFrameDone(data unsafe.Pointer, callback *C.struct_wl_callback, t C.ui
 	w := callbackLoad(data).(*window)
 	if w.lastFrameCallback == callback {
 		w.lastFrameCallback = nil
+		w.draw(false)
 	}
 }
 
-func (w *window) loop() error {
-	var p poller
-	for {
-		if err := w.disp.dispatch(&p); err != nil {
-			return err
-		}
-		select {
-		case e := <-w.clipReads:
-			w.w.Event(e)
-		case <-w.wakeups:
-			w.w.Event(wakeupEvent{})
-		default:
-		}
-		if w.dead {
-			break
-		}
-		w.draw()
+func (w *window) close(err error) {
+	w.ProcessEvent(WaylandViewEvent{})
+	w.ProcessEvent(DestroyEvent{Err: err})
+	w.destroy()
+	w.disp.destroy()
+	w.disp = nil
+}
+
+func (w *window) dispatch() {
+	if w.disp == nil {
+		<-w.wakeups
+		w.w.Invalidate()
+		return
 	}
-	return nil
+	if err := w.disp.dispatch(); err != nil || w.closing {
+		w.close(err)
+		return
+	}
+	select {
+	case e := <-w.clipReads:
+		w.disp.readClipClose = nil
+		w.ProcessEvent(e)
+	case <-w.wakeups:
+		w.w.Invalidate()
+	default:
+	}
+}
+
+func (w *window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+}
+
+func (w *window) Event() event.Event {
+	for {
+		evt, ok := w.w.nextEvent()
+		if !ok {
+			w.dispatch()
+			continue
+		}
+		return evt
+	}
+}
+
+func (w *window) Invalidate() {
+	select {
+	case w.wakeups <- struct{}{}:
+	default:
+		return
+	}
+	w.disp.wakeup()
+}
+
+func (w *window) Run(f func()) {
+	f()
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.w.ProcessFrame(frame, nil)
 }
 
 // bindDataDevice initializes the dataDev field if and only if both
@@ -1389,13 +1434,21 @@ func (d *wlDisplay) bindDataDevice() {
 	}
 }
 
-func (d *wlDisplay) dispatch(p *poller) error {
+func (d *wlDisplay) dispatch() error {
+	// wl_display_prepare_read records the current thread for
+	// use in wl_display_read_events or wl_display_cancel_events.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
 	dispfd := C.wl_display_get_fd(d.disp)
 	// Poll for events and notifications.
-	pollfds := append(p.pollfds[:0],
+	pollfds := append(d.poller.pollfds[:0],
 		syscall.PollFd{Fd: int32(dispfd), Events: syscall.POLLIN | syscall.POLLERR},
 		syscall.PollFd{Fd: int32(d.notify.read), Events: syscall.POLLIN | syscall.POLLERR},
 	)
+	for C.wl_display_prepare_read(d.disp) != 0 {
+		C.wl_display_dispatch_pending(d.disp)
+	}
 	dispFd := &pollfds[0]
 	if ret, err := C.wl_display_flush(d.disp); ret < 0 {
 		if err != syscall.EAGAIN {
@@ -1406,11 +1459,25 @@ func (d *wlDisplay) dispatch(p *poller) error {
 		dispFd.Events |= syscall.POLLOUT
 	}
 	if _, err := syscall.Poll(pollfds, -1); err != nil && err != syscall.EINTR {
+		C.wl_display_cancel_read(d.disp)
 		return fmt.Errorf("wayland: poll failed: %v", err)
 	}
+	if dispFd.Revents&(syscall.POLLERR|syscall.POLLHUP) != 0 {
+		C.wl_display_cancel_read(d.disp)
+		return errors.New("wayland: display file descriptor gone")
+	}
+	// Handle events.
+	if dispFd.Revents&syscall.POLLIN != 0 {
+		if ret, err := C.wl_display_read_events(d.disp); ret < 0 {
+			return fmt.Errorf("wayland: wl_display_read_events failed: %v", err)
+		}
+		C.wl_display_dispatch_pending(d.disp)
+	} else {
+		C.wl_display_cancel_read(d.disp)
+	}
 	// Clear notifications.
 	for {
-		_, err := syscall.Read(d.notify.read, p.buf[:])
+		_, err := syscall.Read(d.notify.read, d.poller.buf[:])
 		if err == syscall.EAGAIN {
 			break
 		}
@@ -1418,29 +1485,15 @@ func (d *wlDisplay) dispatch(p *poller) error {
 			return fmt.Errorf("wayland: read from notify pipe failed: %v", err)
 		}
 	}
-	// Handle events
-	switch {
-	case dispFd.Revents&syscall.POLLIN != 0:
-		if ret, err := C.wl_display_dispatch(d.disp); ret < 0 {
-			return fmt.Errorf("wayland: wl_display_dispatch failed: %v", err)
-		}
-	case dispFd.Revents&(syscall.POLLERR|syscall.POLLHUP) != 0:
-		return errors.New("wayland: display file descriptor gone")
-	}
 	d.repeat.Repeat(d)
 	return nil
 }
 
-func (w *window) Wakeup() {
-	select {
-	case w.wakeups <- struct{}{}:
-	default:
-	}
-	w.disp.wakeup()
-}
-
 func (w *window) SetAnimating(anim bool) {
 	w.animating = anim
+	if anim {
+		w.draw(false)
+	}
 }
 
 // Wakeup wakes up the event loop through the notification pipe.
@@ -1452,6 +1505,10 @@ func (d *wlDisplay) wakeup() {
 }
 
 func (w *window) destroy() {
+	if w.lastFrameCallback != nil {
+		C.wl_callback_destroy(w.lastFrameCallback)
+		w.lastFrameCallback = nil
+	}
 	if w.cursor.surf != nil {
 		C.wl_surface_destroy(w.cursor.surf)
 	}
@@ -1576,7 +1633,15 @@ func (w *window) flushScroll() {
 	if total == (f32.Point{}) {
 		return
 	}
-	w.w.Event(pointer.Event{
+	if w.scroll.steps == (image.Point{}) {
+		w.fling.xExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.X)
+		w.fling.yExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.Y)
+	}
+	// Zero scroll distance prior to calling ProcessEvent, otherwise we may recursively
+	// re-process the scroll distance.
+	w.scroll.dist = f32.Point{}
+	w.scroll.steps = image.Point{}
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Scroll,
 		Source:    pointer.Mouse,
 		Buttons:   w.pointerBtns,
@@ -1585,12 +1650,6 @@ func (w *window) flushScroll() {
 		Time:      w.scroll.time,
 		Modifiers: w.disp.xkb.Modifiers(),
 	})
-	if w.scroll.steps == (image.Point{}) {
-		w.fling.xExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.X)
-		w.fling.yExtrapolation.SampleDelta(w.scroll.time, -w.scroll.dist.Y)
-	}
-	w.scroll.dist = f32.Point{}
-	w.scroll.steps = image.Point{}
 }
 
 func (w *window) onPointerMotion(x, y C.wl_fixed_t, t C.uint32_t) {
@@ -1599,7 +1658,7 @@ func (w *window) onPointerMotion(x, y C.wl_fixed_t, t C.uint32_t) {
 		X: fromFixed(x) * float32(w.scale),
 		Y: fromFixed(y) * float32(w.scale),
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Move,
 		Position:  w.lastPos,
 		Buttons:   w.pointerBtns,
@@ -1620,7 +1679,8 @@ func (w *window) systemGesture() (*C.struct_wl_cursor, C.uint32_t) {
 	if w.config.Mode != Windowed || w.config.Decorated {
 		return nil, 0
 	}
-	border := w.w.w.metric.Dp(3)
+	_, cfg := w.getConfig()
+	border := cfg.Dp(3)
 	x, y, size := int(w.lastPos.X), int(w.lastPos.Y), w.config.Size
 	north := y <= border
 	south := y >= size.Y-border
@@ -1674,13 +1734,10 @@ func (w *window) updateOutputs() {
 	if found && scale != w.scale {
 		w.scale = scale
 		C.wl_surface_set_buffer_scale(w.surf, C.int32_t(w.scale))
-		w.redraw = true
+		w.draw(true)
 	}
-	if !found {
-		w.setStage(StagePaused)
-	} else {
-		w.setStage(StageRunning)
-		w.redraw = true
+	if found {
+		w.draw(true)
 	}
 }
 
@@ -1692,7 +1749,10 @@ func (w *window) getConfig() (image.Point, unit.Metric) {
 	}
 }
 
-func (w *window) draw() {
+func (w *window) draw(sync bool) {
+	if !w.configured {
+		return
+	}
 	w.flushScroll()
 	size, cfg := w.getConfig()
 	if cfg == (unit.Metric{}) {
@@ -1700,11 +1760,9 @@ func (w *window) draw() {
 	}
 	if size != w.config.Size {
 		w.config.Size = size
-		w.w.Event(ConfigEvent{Config: w.config})
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	}
 	anim := w.animating || w.fling.anim.Active()
-	sync := w.redraw
-	w.redraw = false
 	// Draw animation only when not waiting for frame callback.
 	redrawAnim := anim && w.lastFrameCallback == nil
 	if !redrawAnim && !sync {
@@ -1715,7 +1773,7 @@ func (w *window) draw() {
 		// Use the surface as listener data for gio_onFrameDone.
 		C.wl_callback_add_listener(w.lastFrameCallback, &C.gio_callback_listener, unsafe.Pointer(w.surf))
 	}
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
 		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
@@ -1725,14 +1783,6 @@ func (w *window) draw() {
 	})
 }
 
-func (w *window) setStage(s Stage) {
-	if s == w.stage {
-		return
-	}
-	w.stage = s
-	w.w.Event(StageEvent{Stage: s})
-}
-
 func (w *window) display() *C.struct_wl_display {
 	return w.disp.disp
 }
@@ -1824,6 +1874,10 @@ func newWLDisplay() (*wlDisplay, error) {
 }
 
 func (d *wlDisplay) destroy() {
+	if d.readClipClose != nil {
+		close(d.readClipClose)
+		d.readClipClose = nil
+	}
 	if d.notify.write != 0 {
 		syscall.Close(d.notify.write)
 		d.notify.write = 0
@@ -1865,6 +1919,7 @@ func (d *wlDisplay) destroy() {
 	if d.disp != nil {
 		C.wl_display_disconnect(d.disp)
 		callbackDelete(unsafe.Pointer(d.disp))
+		d.disp = nil
 	}
 }
 

app/os_windows.go

@@ -19,17 +19,19 @@ import (
 	syscall "golang.org/x/sys/windows"
 
 	"gioui.org/app/internal/windows"
+	"gioui.org/op"
 	"gioui.org/unit"
 	gowindows "golang.org/x/sys/windows"
 
 	"gioui.org/f32"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
 	"gioui.org/io/transfer"
 )
 
-type ViewEvent struct {
+type Win32ViewEvent struct {
 	HWND uintptr
 }
 
@@ -37,7 +39,6 @@ type window struct {
 	hwnd        syscall.Handle
 	hdc         syscall.Handle
 	w           *callbacks
-	stage       Stage
 	pointerBtns pointer.Buttons
 
 	// cursorIn tracks whether the cursor was inside the window according
@@ -49,10 +50,10 @@ type window struct {
 	placement *windows.WindowPlacement
 
 	animating bool
-	focused   bool
 
 	borderSize image.Point
 	config     Config
+	loop       *eventLoop
 }
 
 const _WM_WAKEUP = windows.WM_USER + iota
@@ -85,36 +86,38 @@ func osMain() {
 	select {}
 }
 
-func newWindow(window *callbacks, options []Option) error {
-	cerr := make(chan error)
+func newWindow(win *callbacks, options []Option) {
+	done := make(chan struct{})
 	go func() {
 		// GetMessage and PeekMessage can filter on a window HWND, but
 		// then thread-specific messages such as WM_QUIT are ignored.
 		// Instead lock the thread so window messages arrive through
 		// unfiltered GetMessage calls.
 		runtime.LockOSThread()
-		w, err := createNativeWindow()
+
+		w := &window{
+			w: win,
+		}
+		w.loop = newEventLoop(w.w, w.wakeup)
+		w.w.SetDriver(w)
+		err := w.init()
+		done <- struct{}{}
 		if err != nil {
-			cerr <- err
+			w.ProcessEvent(DestroyEvent{Err: err})
 			return
 		}
-		cerr <- nil
 		winMap.Store(w.hwnd, w)
 		defer winMap.Delete(w.hwnd)
-		w.w = window
-		w.w.SetDriver(w)
-		w.w.Event(ViewEvent{HWND: uintptr(w.hwnd)})
+		w.ProcessEvent(Win32ViewEvent{HWND: uintptr(w.hwnd)})
 		w.Configure(options)
 		windows.SetForegroundWindow(w.hwnd)
 		windows.SetFocus(w.hwnd)
 		// Since the window class for the cursor is null,
 		// set it here to show the cursor.
 		w.SetCursor(pointer.CursorDefault)
-		if err := w.loop(); err != nil {
-			panic(err)
-		}
+		w.runLoop()
 	}()
-	return <-cerr
+	<-done
 }
 
 // initResources initializes the resources global.
@@ -149,13 +152,13 @@ func initResources() error {
 
 const dwExStyle = windows.WS_EX_APPWINDOW | windows.WS_EX_WINDOWEDGE
 
-func createNativeWindow() (*window, error) {
+func (w *window) init() error {
 	var resErr error
 	resources.once.Do(func() {
 		resErr = initResources()
 	})
 	if resErr != nil {
-		return nil, resErr
+		return resErr
 	}
 	const dwStyle = windows.WS_OVERLAPPEDWINDOW
 
@@ -171,16 +174,15 @@ func createNativeWindow() (*window, error) {
 		resources.handle,
 		0)
 	if err != nil {
-		return nil, err
-	}
-	w := &window{
-		hwnd: hwnd,
+		return err
 	}
 	w.hdc, err = windows.GetDC(hwnd)
 	if err != nil {
-		return nil, err
+		windows.DestroyWindow(hwnd)
+		return err
 	}
-	return w, nil
+	w.hwnd = hwnd
+	return nil
 }
 
 // update() handles changes done by the user, and updates the configuration.
@@ -197,7 +199,7 @@ func (w *window) update() {
 		windows.GetSystemMetrics(windows.SM_CXSIZEFRAME),
 		windows.GetSystemMetrics(windows.SM_CYSIZEFRAME),
 	)
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr {
@@ -238,7 +240,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 				e.State = key.Release
 			}
 
-			w.w.Event(e)
+			w.ProcessEvent(e)
 
 			if (wParam == windows.VK_F10) && (msg == windows.WM_SYSKEYDOWN || msg == windows.WM_SYSKEYUP) {
 				// Reserve F10 for ourselves, and don't let it open the system menu. Other Windows programs
@@ -259,23 +261,15 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 	case windows.WM_MBUTTONUP:
 		w.pointerButton(pointer.ButtonTertiary, false, lParam, getModifiers())
 	case windows.WM_CANCELMODE:
-		w.w.Event(pointer.Event{
+		w.ProcessEvent(pointer.Event{
 			Kind: pointer.Cancel,
 		})
 	case windows.WM_SETFOCUS:
-		w.focused = true
-		w.w.Event(key.FocusEvent{Focus: true})
+		w.config.Focused = true
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	case windows.WM_KILLFOCUS:
-		w.focused = false
-		w.w.Event(key.FocusEvent{Focus: false})
-	case windows.WM_NCACTIVATE:
-		if w.stage >= StageInactive {
-			if wParam == windows.TRUE {
-				w.setStage(StageRunning)
-			} else {
-				w.setStage(StageInactive)
-			}
-		}
+		w.config.Focused = false
+		w.ProcessEvent(ConfigEvent{Config: w.config})
 	case windows.WM_NCHITTEST:
 		if w.config.Decorated {
 			// Let the system handle it.
@@ -288,7 +282,7 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 	case windows.WM_MOUSEMOVE:
 		x, y := coordsFromlParam(lParam)
 		p := f32.Point{X: float32(x), Y: float32(y)}
-		w.w.Event(pointer.Event{
+		w.ProcessEvent(pointer.Event{
 			Kind:      pointer.Move,
 			Source:    pointer.Mouse,
 			Position:  p,
@@ -301,8 +295,8 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 	case windows.WM_MOUSEHWHEEL:
 		w.scrollEvent(wParam, lParam, true, getModifiers())
 	case windows.WM_DESTROY:
-		w.w.Event(ViewEvent{})
-		w.w.Event(DestroyEvent{})
+		w.ProcessEvent(Win32ViewEvent{})
+		w.ProcessEvent(DestroyEvent{})
 		if w.hdc != 0 {
 			windows.ReleaseDC(w.hdc)
 			w.hdc = 0
@@ -328,10 +322,16 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		// Adjust window position to avoid the extra padding in maximized
 		// state. See https://devblogs.microsoft.com/oldnewthing/20150304-00/?p=44543.
 		// Note that trying to do the adjustment in WM_GETMINMAXINFO is ignored by Windows.
-		szp := (*windows.NCCalcSizeParams)(unsafe.Pointer(uintptr(lParam)))
+		szp := (*windows.NCCalcSizeParams)(unsafe.Pointer(lParam))
 		mi := windows.GetMonitorInfo(w.hwnd)
 		szp.Rgrc[0] = mi.WorkArea
 		return 0
+	case windows.WM_NCLBUTTONDBLCLK:
+		if !w.config.Decorated {
+			// Override Windows behaviour when we
+			// draw decorations.
+			return 0
+		}
 	case windows.WM_PAINT:
 		w.draw(true)
 	case windows.WM_SIZE:
@@ -339,18 +339,15 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		switch wParam {
 		case windows.SIZE_MINIMIZED:
 			w.config.Mode = Minimized
-			w.setStage(StagePaused)
 		case windows.SIZE_MAXIMIZED:
 			w.config.Mode = Maximized
-			w.setStage(StageRunning)
 		case windows.SIZE_RESTORED:
 			if w.config.Mode != Fullscreen {
 				w.config.Mode = Windowed
 			}
-			w.setStage(StageRunning)
 		}
 	case windows.WM_GETMINMAXINFO:
-		mm := (*windows.MinMaxInfo)(unsafe.Pointer(uintptr(lParam)))
+		mm := (*windows.MinMaxInfo)(unsafe.Pointer(lParam))
 		var bw, bh int32
 		if w.config.Decorated {
 			r := windows.GetWindowRect(w.hwnd)
@@ -378,7 +375,8 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 			return windows.TRUE
 		}
 	case _WM_WAKEUP:
-		w.w.Event(wakeupEvent{})
+		w.loop.Wakeup()
+		w.loop.FlushEvents()
 	case windows.WM_IME_STARTCOMPOSITION:
 		imc := windows.ImmGetContext(w.hwnd)
 		if imc == 0 {
@@ -498,7 +496,7 @@ func (w *window) hitTest(x, y int) uintptr {
 }
 
 func (w *window) pointerButton(btn pointer.Buttons, press bool, lParam uintptr, kmods key.Modifiers) {
-	if !w.focused {
+	if !w.config.Focused {
 		windows.SetFocus(w.hwnd)
 	}
 
@@ -518,7 +516,7 @@ func (w *window) pointerButton(btn pointer.Buttons, press bool, lParam uintptr,
 	}
 	x, y := coordsFromlParam(lParam)
 	p := f32.Point{X: float32(x), Y: float32(y)}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      kind,
 		Source:    pointer.Mouse,
 		Position:  p,
@@ -553,7 +551,7 @@ func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.
 			sp.Y = -dist
 		}
 	}
-	w.w.Event(pointer.Event{
+	w.ProcessEvent(pointer.Event{
 		Kind:      pointer.Scroll,
 		Source:    pointer.Mouse,
 		Position:  p,
@@ -565,7 +563,7 @@ func (w *window) scrollEvent(wParam, lParam uintptr, horizontal bool, kmods key.
 }
 
 // Adapted from https://blogs.msdn.microsoft.com/oldnewthing/20060126-00/?p=32513/
-func (w *window) loop() error {
+func (w *window) runLoop() {
 	msg := new(windows.Msg)
 loop:
 	for {
@@ -576,7 +574,7 @@ loop:
 		}
 		switch ret := windows.GetMessage(msg, 0, 0, 0); ret {
 		case -1:
-			return errors.New("GetMessage failed")
+			panic(errors.New("GetMessage failed"))
 		case 0:
 			// WM_QUIT received.
 			break loop
@@ -584,7 +582,6 @@ loop:
 		windows.TranslateMessage(msg)
 		windows.DispatchMessage(msg)
 	}
-	return nil
 }
 
 func (w *window) EditorStateChanged(old, new editorState) {
@@ -602,16 +599,30 @@ func (w *window) SetAnimating(anim bool) {
 	w.animating = anim
 }
 
-func (w *window) Wakeup() {
-	if err := windows.PostMessage(w.hwnd, _WM_WAKEUP, 0, 0); err != nil {
-		panic(err)
-	}
+func (w *window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+	w.loop.FlushEvents()
 }
 
-func (w *window) setStage(s Stage) {
-	if s != w.stage {
-		w.stage = s
-		w.w.Event(StageEvent{Stage: s})
+func (w *window) Event() event.Event {
+	return w.loop.Event()
+}
+
+func (w *window) Invalidate() {
+	w.loop.Invalidate()
+}
+
+func (w *window) Run(f func()) {
+	w.loop.Run(f)
+}
+
+func (w *window) Frame(frame *op.Ops) {
+	w.loop.Frame(frame)
+}
+
+func (w *window) wakeup() {
+	if err := windows.PostMessage(w.hwnd, _WM_WAKEUP, 0, 0); err != nil {
+		panic(err)
 	}
 }
 
@@ -621,7 +632,7 @@ func (w *window) draw(sync bool) {
 	}
 	dpi := windows.GetWindowDPI(w.hwnd)
 	cfg := configForDPI(dpi)
-	w.w.Event(frameEvent{
+	w.ProcessEvent(frameEvent{
 		FrameEvent: FrameEvent{
 			Now:    time.Now(),
 			Size:   w.config.Size,
@@ -668,7 +679,7 @@ func (w *window) readClipboard() error {
 	}
 	defer windows.GlobalUnlock(mem)
 	content := gowindows.UTF16PtrToString((*uint16)(unsafe.Pointer(ptr)))
-	w.w.Event(transfer.DataEvent{
+	w.ProcessEvent(transfer.DataEvent{
 		Type: "application/text",
 		Open: func() io.ReadCloser {
 			return io.NopCloser(strings.NewReader(content))
@@ -974,4 +985,8 @@ func configForDPI(dpi int) unit.Metric {
 	}
 }
 
-func (_ ViewEvent) ImplementsEvent() {}
+func (Win32ViewEvent) implementsViewEvent() {}
+func (Win32ViewEvent) ImplementsEvent()     {}
+func (w Win32ViewEvent) Valid() bool {
+	return w != (Win32ViewEvent{})
+}

app/os_x11.go

@@ -38,10 +38,12 @@ import (
 	"unsafe"
 
 	"gioui.org/f32"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/system"
 	"gioui.org/io/transfer"
+	"gioui.org/op"
 	"gioui.org/unit"
 
 	syscall "golang.org/x/sys/unix"
@@ -93,12 +95,10 @@ type x11Window struct {
 		// _NET_WM_STATE_MAXIMIZED_VERT
 		wmStateMaximizedVert C.Atom
 	}
-	stage  Stage
 	metric unit.Metric
 	notify struct {
 		read, write int
 	}
-	dead bool
 
 	animating bool
 
@@ -111,6 +111,8 @@ type x11Window struct {
 	config Config
 
 	wakeups chan struct{}
+	handler x11EventHandler
+	buf     [100]byte
 }
 
 var (
@@ -234,7 +236,7 @@ func (w *x11Window) Configure(options []Option) {
 	if cnf.Decorated != prev.Decorated {
 		w.config.Decorated = cnf.Decorated
 	}
-	w.w.Event(ConfigEvent{Config: w.config})
+	w.ProcessEvent(ConfigEvent{Config: w.config})
 }
 
 func (w *x11Window) setTitle(prev, cnf Config) {
@@ -377,7 +379,36 @@ func (w *x11Window) sendWMStateEvent(action C.long, atom1, atom2 C.ulong) {
 
 var x11OneByte = make([]byte, 1)
 
-func (w *x11Window) Wakeup() {
+func (w *x11Window) ProcessEvent(e event.Event) {
+	w.w.ProcessEvent(e)
+}
+
+func (w *x11Window) shutdown(err error) {
+	w.ProcessEvent(X11ViewEvent{})
+	w.ProcessEvent(DestroyEvent{Err: err})
+	w.destroy()
+}
+
+func (w *x11Window) Event() event.Event {
+	for {
+		evt, ok := w.w.nextEvent()
+		if !ok {
+			w.dispatch()
+			continue
+		}
+		return evt
+	}
+}
+
+func (w *x11Window) Run(f func()) {
+	f()
+}
+
+func (w *x11Window) Frame(frame *op.Ops) {
+	w.w.ProcessFrame(frame, nil)
+}
+
+func (w *x11Window) Invalidate() {
 	select {
 	case w.wakeups <- struct{}{}:
 	default:
@@ -395,16 +426,20 @@ func (w *x11Window) window() (C.Window, int, int) {
 	return w.xw, w.config.Size.X, w.config.Size.Y
 }
 
-func (w *x11Window) setStage(s Stage) {
-	if s == w.stage {
+func (w *x11Window) dispatch() {
+	if w.x == nil {
+		// Only Invalidate can wake us up.
+		<-w.wakeups
+		w.w.Invalidate()
 		return
 	}
-	w.stage = s
-	w.w.Event(StageEvent{Stage: s})
-}
 
-func (w *x11Window) loop() {
-	h := x11EventHandler{w: w, xev: new(C.XEvent), text: make([]byte, 4)}
+	select {
+	case <-w.wakeups:
+		w.w.Invalidate()
+	default:
+	}
+
 	xfd := C.XConnectionNumber(w.x)
 
 	// Poll for events and notifications.
@@ -414,61 +449,55 @@ func (w *x11Window) loop() {
 	}
 	xEvents := &pollfds[0].Revents
 	// Plenty of room for a backlog of notifications.
-	buf := make([]byte, 100)
 
-loop:
-	for !w.dead {
-		var syn, anim bool
-		// Check for pending draw events before checking animation or blocking.
-		// This fixes an issue on Xephyr where on startup XPending() > 0 but
-		// poll will still block. This also prevents no-op calls to poll.
-		if syn = h.handleEvents(); !syn {
-			anim = w.animating
-			if !anim {
-				// Clear poll events.
-				*xEvents = 0
-				// Wait for X event or gio notification.
-				if _, err := syscall.Poll(pollfds, -1); err != nil && err != syscall.EINTR {
-					panic(fmt.Errorf("x11 loop: poll failed: %w", err))
-				}
-				switch {
-				case *xEvents&syscall.POLLIN != 0:
-					syn = h.handleEvents()
-					if w.dead {
-						break loop
-					}
-				case *xEvents&(syscall.POLLERR|syscall.POLLHUP) != 0:
-					break loop
+	var syn, anim bool
+	// Check for pending draw events before checking animation or blocking.
+	// This fixes an issue on Xephyr where on startup XPending() > 0 but
+	// poll will still block. This also prevents no-op calls to poll.
+	syn = w.handler.handleEvents()
+	if w.x == nil {
+		// handleEvents received a close request and destroyed the window.
+		return
+	}
+	if !syn {
+		anim = w.animating
+		if !anim {
+			// Clear poll events.
+			*xEvents = 0
+			// Wait for X event or gio notification.
+			if _, err := syscall.Poll(pollfds, -1); err != nil && err != syscall.EINTR {
+				panic(fmt.Errorf("x11 loop: poll failed: %w", err))
+			}
+			switch {
+			case *xEvents&syscall.POLLIN != 0:
+				syn = w.handler.handleEvents()
+				if w.x == nil {
+					return
 				}
+			case *xEvents&(syscall.POLLERR|syscall.POLLHUP) != 0:
 			}
 		}
-		// Clear notifications.
-		for {
-			_, err := syscall.Read(w.notify.read, buf)
-			if err == syscall.EAGAIN {
-				break
-			}
-			if err != nil {
-				panic(fmt.Errorf("x11 loop: read from notify pipe failed: %w", err))
-			}
+	}
+	// Clear notifications.
+	for {
+		_, err := syscall.Read(w.notify.read, w.buf[:])
+		if err == syscall.EAGAIN {
+			break
 		}
-		select {
-		case <-w.wakeups:
-			w.w.Event(wakeupEvent{})
-		default:
-		}
-
-		if (anim || syn) && w.config.Size.X != 0 && w.config.Size.Y != 0 {
-			w.w.Event(frameEvent{
-				FrameEvent: FrameEvent{
-					Now:    time.Now(),
-					Size:   w.config.Size,
-					Metric: w.metric,
-				},
-				Sync: syn,
-			})
+		if err != nil {
+			panic(fmt.Errorf("x11 loop: read from notify pipe failed: %w", err))
 		}
 	}
+	if (anim || syn) && w.config.Size.X != 0 && w.config.Size.Y != 0 {
+		w.ProcessEvent(frameEvent{
+			FrameEvent: FrameEvent{
+				Now:    time.Now(),
+				Size:   w.config.Size,
+				Metric: w.metric,
+			},
+			Sync: syn,
+		})
+	}
 }
 
 func (w *x11Window) destroy() {
@@ -486,6 +515,7 @@ func (w *x11Window) destroy() {
 	}
 	C.XDestroyWindow(w.x, w.xw)
 	C.XCloseDisplay(w.x)
+	w.x = nil
 }
 
 // atom is a wrapper around XInternAtom. Callers should cache the result
@@ -543,7 +573,7 @@ func (h *x11EventHandler) handleEvents() bool {
 					// There's no support for IME yet.
 					w.w.EditorInsert(ee.Text)
 				} else {
-					w.w.Event(e)
+					w.ProcessEvent(e)
 				}
 			}
 		case C.ButtonPress, C.ButtonRelease:
@@ -605,10 +635,10 @@ func (h *x11EventHandler) handleEvents() bool {
 				w.pointerBtns &^= btn
 			}
 			ev.Buttons = w.pointerBtns
-			w.w.Event(ev)
+			w.ProcessEvent(ev)
 		case C.MotionNotify:
 			mevt := (*C.XMotionEvent)(unsafe.Pointer(xev))
-			w.w.Event(pointer.Event{
+			w.ProcessEvent(pointer.Event{
 				Kind:    pointer.Move,
 				Source:  pointer.Mouse,
 				Buttons: w.pointerBtns,
@@ -623,14 +653,16 @@ func (h *x11EventHandler) handleEvents() bool {
 			// redraw only on the last expose event
 			redraw = (*C.XExposeEvent)(unsafe.Pointer(xev)).count == 0
 		case C.FocusIn:
-			w.w.Event(key.FocusEvent{Focus: true})
+			w.config.Focused = true
+			w.ProcessEvent(ConfigEvent{Config: w.config})
 		case C.FocusOut:
-			w.w.Event(key.FocusEvent{Focus: false})
+			w.config.Focused = false
+			w.ProcessEvent(ConfigEvent{Config: w.config})
 		case C.ConfigureNotify: // window configuration change
 			cevt := (*C.XConfigureEvent)(unsafe.Pointer(xev))
 			if sz := image.Pt(int(cevt.width), int(cevt.height)); sz != w.config.Size {
 				w.config.Size = sz
-				w.w.Event(ConfigEvent{Config: w.config})
+				w.ProcessEvent(ConfigEvent{Config: w.config})
 			}
 			// redraw will be done by a later expose event
 		case C.SelectionNotify:
@@ -652,7 +684,7 @@ func (h *x11EventHandler) handleEvents() bool {
 				break
 			}
 			str := C.GoStringN((*C.char)(unsafe.Pointer(text.value)), C.int(text.nitems))
-			w.w.Event(transfer.DataEvent{
+			w.ProcessEvent(transfer.DataEvent{
 				Type: "application/text",
 				Open: func() io.ReadCloser {
 					return io.NopCloser(strings.NewReader(str))
@@ -711,7 +743,7 @@ func (h *x11EventHandler) handleEvents() bool {
 			cevt := (*C.XClientMessageEvent)(unsafe.Pointer(xev))
 			switch *(*C.long)(unsafe.Pointer(&cevt.data)) {
 			case C.long(w.atoms.evDelWindow):
-				w.dead = true
+				w.shutdown(nil)
 				return false
 			}
 		}
@@ -793,8 +825,10 @@ func newX11Window(gioWin *callbacks, options []Option) error {
 		wakeups:      make(chan struct{}, 1),
 		config:       Config{Size: cnf.Size},
 	}
+	w.handler = x11EventHandler{w: w, xev: new(C.XEvent), text: make([]byte, 4)}
 	w.notify.read = pipe[0]
 	w.notify.write = pipe[1]
+	w.w.SetDriver(w)
 
 	if err := w.updateXkbKeymap(); err != nil {
 		w.destroy()
@@ -830,19 +864,10 @@ func newX11Window(gioWin *callbacks, options []Option) error {
 	// extensions
 	C.XSetWMProtocols(dpy, win, &w.atoms.evDelWindow, 1)
 
-	go func() {
-		w.w.SetDriver(w)
-
-		// make the window visible on the screen
-		C.XMapWindow(dpy, win)
-		w.Configure(options)
-		w.w.Event(X11ViewEvent{Display: unsafe.Pointer(dpy), Window: uintptr(win)})
-		w.setStage(StageRunning)
-		w.loop()
-		w.w.Event(X11ViewEvent{})
-		w.w.Event(DestroyEvent{Err: nil})
-		w.destroy()
-	}()
+	// make the window visible on the screen
+	C.XMapWindow(dpy, win)
+	w.Configure(options)
+	w.ProcessEvent(X11ViewEvent{Display: unsafe.Pointer(dpy), Window: uintptr(win)})
 	return nil
 }
 

app/system.go

@@ -10,40 +10,4 @@ type DestroyEvent struct {
 	Err error
 }
 
-// A StageEvent is generated whenever the stage of a
-// Window changes.
-type StageEvent struct {
-	Stage Stage
-}
-
-// Stage of a Window.
-type Stage uint8
-
-const (
-	// StagePaused is the stage for windows that have no on-screen representation.
-	// Paused windows don't receive frames.
-	StagePaused Stage = iota
-	// StageInactive is the stage for windows that are visible, but not active.
-	// Inactive windows receive frames.
-	StageInactive
-	// StageRunning is for active and visible Windows.
-	// Running windows receive frames.
-	StageRunning
-)
-
-// String implements fmt.Stringer.
-func (l Stage) String() string {
-	switch l {
-	case StagePaused:
-		return "StagePaused"
-	case StageInactive:
-		return "StageInactive"
-	case StageRunning:
-		return "StageRunning"
-	default:
-		panic("unexpected Stage value")
-	}
-}
-
-func (StageEvent) ImplementsEvent()   {}
 func (DestroyEvent) ImplementsEvent() {}

gesture/gesture.go

@@ -271,12 +271,13 @@ func (s *Scroll) Stop() {
 }
 
 // Update state and report the scroll distance along axis.
-func (s *Scroll) Update(cfg unit.Metric, q input.Source, t time.Time, axis Axis, bounds image.Rectangle) int {
+func (s *Scroll) Update(cfg unit.Metric, q input.Source, t time.Time, axis Axis, scrollx, scrolly pointer.ScrollRange) int {
 	total := 0
 	f := pointer.Filter{
-		Target:       s,
-		Kinds:        pointer.Press | pointer.Drag | pointer.Release | pointer.Scroll | pointer.Cancel,
-		ScrollBounds: bounds,
+		Target:  s,
+		Kinds:   pointer.Press | pointer.Drag | pointer.Release | pointer.Scroll | pointer.Cancel,
+		ScrollX: scrollx,
+		ScrollY: scrolly,
 	}
 	for {
 		evt, ok := q.Event(f)

go.mod

@@ -1,16 +1,16 @@
 module gioui.org
 
-go 1.19
+go 1.21
 
 require (
 	eliasnaur.com/font v0.0.0-20230308162249-dd43949cb42d
 	gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2
 	gioui.org/shader v1.0.8
-	github.com/go-text/typesetting v0.0.0-20230803102845-24e03d8b5372
+	github.com/go-text/typesetting v0.1.1
 	golang.org/x/exp v0.0.0-20221012211006-4de253d81b95
 	golang.org/x/exp/shiny v0.0.0-20220827204233-334a2380cb91
 	golang.org/x/image v0.5.0
-	golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64
+	golang.org/x/sys v0.5.0
 )
 
-require golang.org/x/text v0.7.0
+require golang.org/x/text v0.9.0

go.sum

@@ -5,9 +5,10 @@ gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2 h1:AGDDxsJE1RpcXTAxPG2B4jrwVUJG
 gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2/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 v0.0.0-20230803102845-24e03d8b5372 h1:FQivqchis6bE2/9uF70M2gmmLpe82esEm2QadL0TEJo=
-github.com/go-text/typesetting v0.0.0-20230803102845-24e03d8b5372/go.mod h1:evDBbvNR/KaVFZ2ZlDSOWWXIUKq0wCOEtzLxRM8SG3k=
-github.com/go-text/typesetting-utils v0.0.0-20230616150549-2a7df14b6a22 h1:LBQTFxP2MfsyEDqSKmUBZaDuDHN1vpqDyOZjcqS7MYI=
+github.com/go-text/typesetting v0.1.1 h1:bGAesCuo85nXnEN5LmFMVGAGpGkCPtHrZLi//qD7EJo=
+github.com/go-text/typesetting v0.1.1/go.mod h1:d22AnmeKq/on0HNv73UFriMKc4Ez6EqZAofLhAzpSzI=
+github.com/go-text/typesetting-utils v0.0.0-20231211103740-d9332ae51f04 h1:zBx+p/W2aQYtNuyZNcTfinWvXBQwYtDfme051PR/lAY=
+github.com/go-text/typesetting-utils v0.0.0-20231211103740-d9332ae51f04/go.mod h1:DDxDdQEnB70R8owOx3LVpEFvpMK9eeH1o2r0yZhFI9o=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
@@ -28,15 +29,16 @@ golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64 h1:UiNENfZ8gDvpiWw7IpOMQ27spWmThO1RwwdQVbJahJM=
-golang.org/x/sys v0.0.0-20220825204002-c680a09ffe64/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.7.0 h1:4BRB4x83lYWy72KwLD/qYDuTu7q9PjSagHvijDw7cLo=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.9.0 h1:2sjJmO8cDvYveuX97RDLsxlyUxLl+GHoLxBiRdHllBE=
+golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

gpu/gpu.go

@@ -261,7 +261,7 @@ type texture struct {
 type blitter struct {
 	ctx                    driver.Device
 	viewport               image.Point
-	pipelines              [3]*pipeline
+	pipelines              [2][3]*pipeline
 	colUniforms            *blitColUniforms
 	texUniforms            *blitTexUniforms
 	linearGradientUniforms *blitLinearGradientUniforms
@@ -560,12 +560,24 @@ func newBlitter(ctx driver.Device) *blitter {
 func (b *blitter) release() {
 	b.quadVerts.Release()
 	for _, p := range b.pipelines {
-		p.Release()
+		for _, p := range p {
+			p.Release()
+		}
 	}
 }
 
-func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.Sources, uniforms [3]interface{}) ([3]*pipeline, error) {
-	var pipelines [3]*pipeline
+func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.Sources, uniforms [3]interface{}) (pipelines [2][3]*pipeline, err error) {
+	defer func() {
+		if err != nil {
+			for _, p := range pipelines {
+				for _, p := range p {
+					if p != nil {
+						p.Release()
+					}
+				}
+			}
+		}
+	}()
 	blend := driver.BlendDesc{
 		Enable:    true,
 		SrcFactor: driver.BlendFactorOne,
@@ -583,86 +595,76 @@ func createColorPrograms(b driver.Device, vsSrc shader.Sources, fsSrc [3]shader.
 		return pipelines, err
 	}
 	defer vsh.Release()
-	{
-		fsh, err := b.NewFragmentShader(fsSrc[materialTexture])
-		if err != nil {
-			return pipelines, err
+	for i, format := range []driver.TextureFormat{driver.TextureFormatOutput, driver.TextureFormatSRGBA} {
+		{
+			fsh, err := b.NewFragmentShader(fsSrc[materialTexture])
+			if err != nil {
+				return pipelines, err
+			}
+			defer fsh.Release()
+			pipe, err := b.NewPipeline(driver.PipelineDesc{
+				VertexShader:   vsh,
+				FragmentShader: fsh,
+				BlendDesc:      blend,
+				VertexLayout:   layout,
+				PixelFormat:    format,
+				Topology:       driver.TopologyTriangleStrip,
+			})
+			if err != nil {
+				return pipelines, err
+			}
+			var vertBuffer *uniformBuffer
+			if u := uniforms[materialTexture]; u != nil {
+				vertBuffer = newUniformBuffer(b, u)
+			}
+			pipelines[i][materialTexture] = &pipeline{pipe, vertBuffer}
 		}
-		defer fsh.Release()
-		pipe, err := b.NewPipeline(driver.PipelineDesc{
-			VertexShader:   vsh,
-			FragmentShader: fsh,
-			BlendDesc:      blend,
-			VertexLayout:   layout,
-			PixelFormat:    driver.TextureFormatOutput,
-			Topology:       driver.TopologyTriangleStrip,
-		})
-		if err != nil {
-			return pipelines, err
+		{
+			var vertBuffer *uniformBuffer
+			fsh, err := b.NewFragmentShader(fsSrc[materialColor])
+			if err != nil {
+				return pipelines, err
+			}
+			defer fsh.Release()
+			pipe, err := b.NewPipeline(driver.PipelineDesc{
+				VertexShader:   vsh,
+				FragmentShader: fsh,
+				BlendDesc:      blend,
+				VertexLayout:   layout,
+				PixelFormat:    format,
+				Topology:       driver.TopologyTriangleStrip,
+			})
+			if err != nil {
+				return pipelines, err
+			}
+			if u := uniforms[materialColor]; u != nil {
+				vertBuffer = newUniformBuffer(b, u)
+			}
+			pipelines[i][materialColor] = &pipeline{pipe, vertBuffer}
 		}
-		var vertBuffer *uniformBuffer
-		if u := uniforms[materialTexture]; u != nil {
-			vertBuffer = newUniformBuffer(b, u)
+		{
+			var vertBuffer *uniformBuffer
+			fsh, err := b.NewFragmentShader(fsSrc[materialLinearGradient])
+			if err != nil {
+				return pipelines, err
+			}
+			defer fsh.Release()
+			pipe, err := b.NewPipeline(driver.PipelineDesc{
+				VertexShader:   vsh,
+				FragmentShader: fsh,
+				BlendDesc:      blend,
+				VertexLayout:   layout,
+				PixelFormat:    format,
+				Topology:       driver.TopologyTriangleStrip,
+			})
+			if err != nil {
+				return pipelines, err
+			}
+			if u := uniforms[materialLinearGradient]; u != nil {
+				vertBuffer = newUniformBuffer(b, u)
+			}
+			pipelines[i][materialLinearGradient] = &pipeline{pipe, vertBuffer}
 		}
-		pipelines[materialTexture] = &pipeline{pipe, vertBuffer}
-	}
-	{
-		var vertBuffer *uniformBuffer
-		fsh, err := b.NewFragmentShader(fsSrc[materialColor])
-		if err != nil {
-			pipelines[materialTexture].Release()
-			return pipelines, err
-		}
-		defer fsh.Release()
-		pipe, err := b.NewPipeline(driver.PipelineDesc{
-			VertexShader:   vsh,
-			FragmentShader: fsh,
-			BlendDesc:      blend,
-			VertexLayout:   layout,
-			PixelFormat:    driver.TextureFormatOutput,
-			Topology:       driver.TopologyTriangleStrip,
-		})
-		if err != nil {
-			pipelines[materialTexture].Release()
-			return pipelines, err
-		}
-		if u := uniforms[materialColor]; u != nil {
-			vertBuffer = newUniformBuffer(b, u)
-		}
-		pipelines[materialColor] = &pipeline{pipe, vertBuffer}
-	}
-	{
-		var vertBuffer *uniformBuffer
-		fsh, err := b.NewFragmentShader(fsSrc[materialLinearGradient])
-		if err != nil {
-			pipelines[materialTexture].Release()
-			pipelines[materialColor].Release()
-			return pipelines, err
-		}
-		defer fsh.Release()
-		pipe, err := b.NewPipeline(driver.PipelineDesc{
-			VertexShader:   vsh,
-			FragmentShader: fsh,
-			BlendDesc:      blend,
-			VertexLayout:   layout,
-			PixelFormat:    driver.TextureFormatOutput,
-			Topology:       driver.TopologyTriangleStrip,
-		})
-		if err != nil {
-			pipelines[materialTexture].Release()
-			pipelines[materialColor].Release()
-			return pipelines, err
-		}
-		if u := uniforms[materialLinearGradient]; u != nil {
-			vertBuffer = newUniformBuffer(b, u)
-		}
-		pipelines[materialLinearGradient] = &pipeline{pipe, vertBuffer}
-	}
-	if err != nil {
-		for _, p := range pipelines {
-			p.Release()
-		}
-		return pipelines, err
 	}
 	return pipelines, nil
 }
@@ -865,7 +867,7 @@ func (r *renderer) drawLayers(layers []opacityLayer, ops []imageOp) {
 			Min: l.place.Pos,
 			Max: l.place.Pos.Add(l.clip.Size()),
 		}
-		r.ctx.Viewport(v.Min.X, v.Min.Y, v.Max.X, v.Max.Y)
+		r.ctx.Viewport(v.Min.X, v.Min.Y, v.Dx(), v.Dy())
 		f := r.layerFBOs.fbos[fbo]
 		r.drawOps(true, l.clip.Min.Mul(-1), l.clip.Size(), ops[l.opStart:l.opEnd])
 		sr := f32.FRect(v)
@@ -930,7 +932,7 @@ func (d *drawOps) newPathOp() *pathOp {
 	return &d.pathOpCache[len(d.pathOpCache)-1]
 }
 
-func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey opKey, bounds f32.Rectangle, off f32.Point, push bool) {
+func (d *drawOps) addClipPath(state *drawState, aux []byte, auxKey opKey, bounds f32.Rectangle, off f32.Point) {
 	npath := d.newPathOp()
 	*npath = pathOp{
 		parent:    state.cpath,
@@ -1055,7 +1057,7 @@ loop:
 				quads.aux, bounds, _ = d.boundsForTransformedRect(bounds, trans)
 				quads.key = opKey{Key: encOp.Key}
 			}
-			d.addClipPath(&state, quads.aux, quads.key, bounds, off, true)
+			d.addClipPath(&state, quads.aux, quads.key, bounds, off)
 			quads = quadsOp{}
 		case ops.TypePopClip:
 			state.cpath = state.cpath.parent
@@ -1100,7 +1102,7 @@ loop:
 				// this transformed rectangle.
 				k := opKey{Key: encOp.Key}
 				k.SetTransform(t) // TODO: This call has no effect.
-				d.addClipPath(&state, clipData, k, bnd, off, false)
+				d.addClipPath(&state, clipData, k, bnd, off)
 			}
 
 			bounds := cl.Round()
@@ -1230,7 +1232,7 @@ func (r *renderer) prepareDrawOps(ops []imageOp) {
 	}
 }
 
-func (r *renderer) drawOps(isFBO bool, opOff image.Point, viewport image.Point, ops []imageOp) {
+func (r *renderer) drawOps(isFBO bool, opOff, viewport image.Point, ops []imageOp) {
 	var coverTex driver.Texture
 	for i := 0; i < len(ops); i++ {
 		img := ops[i]
@@ -1244,9 +1246,13 @@ func (r *renderer) drawOps(isFBO bool, opOff image.Point, viewport image.Point,
 
 		scale, off := clipSpaceTransform(drc, viewport)
 		var fbo FBO
+		fboIdx := 0
+		if isFBO {
+			fboIdx = 1
+		}
 		switch img.clipType {
 		case clipTypeNone:
-			p := r.blitter.pipelines[m.material]
+			p := r.blitter.pipelines[fboIdx][m.material]
 			r.ctx.BindPipeline(p.pipeline)
 			r.ctx.BindVertexBuffer(r.blitter.quadVerts, 0)
 			r.blitter.blit(m.material, isFBO, m.color, m.color1, m.color2, scale, off, m.opacity, m.uvTrans)
@@ -1265,7 +1271,7 @@ func (r *renderer) drawOps(isFBO bool, opOff image.Point, viewport image.Point,
 			Max: img.place.Pos.Add(drc.Size()),
 		}
 		coverScale, coverOff := texSpaceTransform(f32.FRect(uv), fbo.size)
-		p := r.pather.coverer.pipelines[m.material]
+		p := r.pather.coverer.pipelines[fboIdx][m.material]
 		r.ctx.BindPipeline(p.pipeline)
 		r.ctx.BindVertexBuffer(r.blitter.quadVerts, 0)
 		r.pather.cover(m.material, isFBO, m.color, m.color1, m.color2, scale, off, m.uvTrans, coverScale, coverOff)
@@ -1273,7 +1279,11 @@ func (r *renderer) drawOps(isFBO bool, opOff image.Point, viewport image.Point,
 }
 
 func (b *blitter) blit(mat materialType, fbo bool, col f32color.RGBA, col1, col2 f32color.RGBA, scale, off f32.Point, opacity float32, uvTrans f32.Affine2D) {
-	p := b.pipelines[mat]
+	fboIdx := 0
+	if fbo {
+		fboIdx = 1
+	}
+	p := b.pipelines[fboIdx][mat]
 	b.ctx.BindPipeline(p.pipeline)
 	var uniforms *blitUniforms
 	switch mat {

gpu/internal/rendertest/render_test.go

@@ -483,14 +483,14 @@ func TestGapsInPath(t *testing.T) {
 func TestOpacity(t *testing.T) {
 	run(t, func(ops *op.Ops) {
 		opc1 := paint.PushOpacity(ops, .3)
-		// Fill screen to exercize the glClear optimization.
+		// Fill screen to exercise the glClear optimization.
 		paint.FillShape(ops, color.NRGBA{R: 255, A: 255}, clip.Rect{Max: image.Pt(1024, 1024)}.Op())
 		opc2 := paint.PushOpacity(ops, .6)
 		paint.FillShape(ops, color.NRGBA{G: 255, A: 255}, clip.Rect{Min: image.Pt(20, 10), Max: image.Pt(64, 128)}.Op())
 		opc2.Pop()
 		opc1.Pop()
 		opc3 := paint.PushOpacity(ops, .6)
-		paint.FillShape(ops, color.NRGBA{G: 255, A: 255}, clip.Rect{Min: image.Pt(50+20, 10), Max: image.Pt(50+64, 128)}.Op())
+		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) {
 	})

gpu/path.go

@@ -30,7 +30,7 @@ type pather struct {
 
 type coverer struct {
 	ctx                    driver.Device
-	pipelines              [3]*pipeline
+	pipelines              [2][3]*pipeline
 	texUniforms            *coverTexUniforms
 	colUniforms            *coverColUniforms
 	linearGradientUniforms *coverLinearGradientUniforms
@@ -309,7 +309,9 @@ func (p *pather) release() {
 
 func (c *coverer) release() {
 	for _, p := range c.pipelines {
-		p.Release()
+		for _, p := range p {
+			p.Release()
+		}
 	}
 }
 
@@ -405,7 +407,11 @@ func (c *coverer) cover(mat materialType, isFBO bool, col f32color.RGBA, col1, c
 	}
 	uniforms.transform = [4]float32{scale.X, scale.Y, off.X, off.Y}
 	uniforms.uvCoverTransform = [4]float32{coverScale.X, coverScale.Y, coverOff.X, coverOff.Y}
-	c.pipelines[mat].UploadUniforms(c.ctx)
+	fboIdx := 0
+	if isFBO {
+		fboIdx = 1
+	}
+	c.pipelines[fboIdx][mat].UploadUniforms(c.ctx)
 	c.ctx.DrawArrays(0, 4)
 }
 

internal/egl/egl.go

@@ -15,10 +15,9 @@ import (
 )
 
 type Context struct {
-	disp          _EGLDisplay
-	eglCtx        *eglContext
-	eglSurf       _EGLSurface
-	width, height int
+	disp    _EGLDisplay
+	eglCtx  *eglContext
+	eglSurf _EGLSurface
 }
 
 type eglContext struct {
@@ -121,11 +120,9 @@ func (c *Context) VisualID() int {
 	return c.eglCtx.visualID
 }
 
-func (c *Context) CreateSurface(win NativeWindowType, width, height int) error {
+func (c *Context) CreateSurface(win NativeWindowType) error {
 	eglSurf, err := createSurface(c.disp, c.eglCtx, win)
 	c.eglSurf = eglSurf
-	c.width = width
-	c.height = height
 	return err
 }
 

internal/gl/gl_windows.go

@@ -361,6 +361,9 @@ func (c *Functions) GetProgrami(p Program, pname Enum) int {
 }
 func (c *Functions) GetProgramInfoLog(p Program) string {
 	n := c.GetProgrami(p, INFO_LOG_LENGTH)
+	if n == 0 {
+		return ""
+	}
 	buf := make([]byte, n)
 	syscall.Syscall6(_glGetProgramInfoLog.Addr(), 4, uintptr(p.V), uintptr(len(buf)), 0, uintptr(unsafe.Pointer(&buf[0])), 0, 0)
 	return string(buf)

internal/stroke/stroke.go

@@ -327,6 +327,9 @@ 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}
+	}
 	d := math.Hypot(float64(p.X), float64(p.Y))
 	l64 := float64(l)
 	if math.Abs(d-l64) < 1e-10 {

io/input/key_test.go

@@ -251,9 +251,10 @@ func TestFocusScroll(t *testing.T) {
 	filters := []event.Filter{
 		key.FocusFilter{Target: h},
 		pointer.Filter{
-			Target:       h,
-			Kinds:        pointer.Scroll,
-			ScrollBounds: image.Rect(-100, -100, 100, 100),
+			Target:  h,
+			Kinds:   pointer.Scroll,
+			ScrollX: pointer.ScrollRange{Min: -100, Max: +100},
+			ScrollY: pointer.ScrollRange{Min: -100, Max: +100},
 		},
 	}
 	events(r, -1, filters...)

io/input/pointer.go

@@ -72,7 +72,7 @@ type pointerHandler struct {
 type pointerFilter struct {
 	kinds pointer.Kind
 	// min and max horizontal/vertical scroll
-	scrollRange image.Rectangle
+	scrollX, scrollY pointer.ScrollRange
 
 	sourceMimes []string
 	targetMimes []string
@@ -297,7 +297,8 @@ func (p *pointerFilter) Add(f event.Filter) {
 		p.targetMimes = append(p.targetMimes, f.Type)
 	case pointer.Filter:
 		p.kinds = p.kinds | f.Kinds
-		p.scrollRange = p.scrollRange.Union(f.ScrollBounds)
+		p.scrollX = p.scrollX.Union(f.ScrollX)
+		p.scrollY = p.scrollY.Union(f.ScrollY)
 	}
 }
 
@@ -325,7 +326,8 @@ func (p *pointerFilter) Matches(e event.Event) bool {
 
 func (p *pointerFilter) Merge(p2 pointerFilter) {
 	p.kinds = p.kinds | p2.kinds
-	p.scrollRange = p.scrollRange.Union(p2.scrollRange)
+	p.scrollX = p.scrollX.Union(p2.scrollX)
+	p.scrollY = p.scrollY.Union(p2.scrollY)
 	p.sourceMimes = append(p.sourceMimes, p2.sourceMimes...)
 	p.targetMimes = append(p.targetMimes, p2.targetMimes...)
 }
@@ -333,8 +335,8 @@ func (p *pointerFilter) Merge(p2 pointerFilter) {
 // clampScroll splits a scroll distance in the remaining scroll and the
 // scroll accepted by the filter.
 func (p *pointerFilter) clampScroll(scroll f32.Point) (left, scrolled f32.Point) {
-	left.X, scrolled.X = clampSplit(scroll.X, p.scrollRange.Min.X, p.scrollRange.Max.X)
-	left.Y, scrolled.Y = clampSplit(scroll.Y, p.scrollRange.Min.Y, p.scrollRange.Max.Y)
+	left.X, scrolled.X = clampSplit(scroll.X, p.scrollX.Min, p.scrollX.Max)
+	left.Y, scrolled.Y = clampSplit(scroll.Y, p.scrollY.Min, p.scrollY.Max)
 	return
 }
 

io/input/pointer_test.go

@@ -300,9 +300,9 @@ func TestPointerPriority(t *testing.T) {
 	r1 := clip.Rect(image.Rect(0, 0, 100, 100)).Push(&ops)
 	f1 := func(t event.Tag) event.Filter {
 		return pointer.Filter{
-			Target:       t,
-			Kinds:        pointer.Scroll,
-			ScrollBounds: image.Rectangle{Max: image.Point{X: 100}},
+			Target:  t,
+			Kinds:   pointer.Scroll,
+			ScrollX: pointer.ScrollRange{Max: 100},
 		}
 	}
 	events(&r, -1, f1(handler1))
@@ -311,9 +311,9 @@ func TestPointerPriority(t *testing.T) {
 	r2 := clip.Rect(image.Rect(0, 0, 100, 50)).Push(&ops)
 	f2 := func(t event.Tag) event.Filter {
 		return pointer.Filter{
-			Target:       t,
-			Kinds:        pointer.Scroll,
-			ScrollBounds: image.Rectangle{Max: image.Point{X: 20}},
+			Target:  t,
+			Kinds:   pointer.Scroll,
+			ScrollX: pointer.ScrollRange{Max: 20},
 		}
 	}
 	events(&r, -1, f2(handler2))
@@ -324,9 +324,10 @@ func TestPointerPriority(t *testing.T) {
 	r3 := clip.Rect(image.Rect(0, 100, 100, 200)).Push(&ops)
 	f3 := func(t event.Tag) event.Filter {
 		return pointer.Filter{
-			Target:       t,
-			Kinds:        pointer.Scroll,
-			ScrollBounds: image.Rectangle{Min: image.Point{X: -20, Y: -40}},
+			Target:  t,
+			Kinds:   pointer.Scroll,
+			ScrollX: pointer.ScrollRange{Min: -20},
+			ScrollY: pointer.ScrollRange{Min: -40},
 		}
 	}
 	events(&r, -1, f3(handler3))
@@ -1085,6 +1086,33 @@ func TestPassCursor(t *testing.T) {
 	}
 }
 
+func TestPartialEvent(t *testing.T) {
+	var ops op.Ops
+	var r Router
+
+	rect := clip.Rect(image.Rect(0, 0, 100, 100))
+	background := rect.Push(&ops)
+	event.Op(&ops, 1)
+	background.Pop()
+
+	overlayPass := pointer.PassOp{}.Push(&ops)
+	overlay := rect.Push(&ops)
+	event.Op(&ops, 2)
+	overlay.Pop()
+	overlayPass.Pop()
+	assertEventSequence(t, events(&r, -1, pointer.Filter{Target: 1, Kinds: pointer.Press}))
+	assertEventSequence(t, events(&r, -1, pointer.Filter{Target: 2, Kinds: pointer.Press}))
+	r.Frame(&ops)
+	r.Queue(pointer.Event{
+		Kind: pointer.Press,
+	})
+	assertEventSequence(t, events(&r, -1, pointer.Filter{Target: 1, Kinds: pointer.Press}, key.FocusFilter{Target: 1}),
+		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})
+}
+
 // offer satisfies io.ReadCloser for use in data transfers.
 type offer struct {
 	data   string

io/input/router.go

@@ -35,10 +35,9 @@ type Router struct {
 		queue keyQueue
 		// The following fields have the same purpose as the fields in
 		// type handler, but for key.Events.
-		filter          keyFilter
-		nextFilter      keyFilter
-		processedFilter keyFilter
-		scratchFilter   keyFilter
+		filter        keyFilter
+		nextFilter    keyFilter
+		scratchFilter keyFilter
 	}
 	cqueue clipboardQueue
 	// states is the list of pending state changes resulting from
@@ -275,28 +274,29 @@ func (q *Router) Event(filters ...event.Filter) (event.Event, bool) {
 			}
 		}
 	}
-	if !q.deferring {
-		for i := range q.changes {
-			change := &q.changes[i]
-			for j, evt := range change.events {
-				match := false
-				switch e := evt.event.(type) {
-				case key.Event:
-					match = q.key.scratchFilter.Matches(change.state.keyState.focus, e, false)
-				default:
-					for _, tf := range q.scratchFilters {
-						if evt.tag == tf.tag && tf.filter.Matches(evt.event) {
-							match = true
-							break
-						}
+	for i := range q.changes {
+		if q.deferring && i > 0 {
+			break
+		}
+		change := &q.changes[i]
+		for j, evt := range change.events {
+			match := false
+			switch e := evt.event.(type) {
+			case key.Event:
+				match = q.key.scratchFilter.Matches(change.state.keyState.focus, e, false)
+			default:
+				for _, tf := range q.scratchFilters {
+					if evt.tag == tf.tag && tf.filter.Matches(evt.event) {
+						match = true
+						break
 					}
 				}
-				if match {
-					change.events = append(change.events[:j], change.events[j+1:]...)
-					// Fast forward state to last matched.
-					q.collapseState(i)
-					return evt.event, true
-				}
+			}
+			if match {
+				change.events = append(change.events[:j], change.events[j+1:]...)
+				// Fast forward state to last matched.
+				q.collapseState(i)
+				return evt.event, true
 			}
 		}
 	}
@@ -304,7 +304,6 @@ func (q *Router) Event(filters ...event.Filter) (event.Event, bool) {
 		h := q.stateFor(tf.tag)
 		h.processedFilter.Merge(tf.filter)
 	}
-	q.key.processedFilter = append(q.key.processedFilter, q.key.scratchFilter...)
 	return nil, false
 }
 
@@ -315,15 +314,15 @@ func (q *Router) collapseState(idx int) {
 	}
 	first := &q.changes[0]
 	first.state = q.changes[idx].state
-	for i := 1; i <= idx; i++ {
-		first.events = append(first.events, q.changes[i].events...)
+	for _, ch := range q.changes[1 : idx+1] {
+		first.events = append(first.events, ch.events...)
 	}
 	q.changes = append(q.changes[:1], q.changes[idx+1:]...)
 }
 
-// Frame replaces the declared handlers from the supplied
-// operation list. The text input state, wakeup time and whether
-// there are active profile handlers is also saved.
+// Frame completes the current frame and starts a new with the
+// handlers from the frame argument. Remaining events are discarded,
+// unless they were deferred by a command.
 func (q *Router) Frame(frame *op.Ops) {
 	var remaining []event.Event
 	if n := len(q.changes); n > 0 {

io/pointer/doc.go

@@ -37,11 +37,11 @@ For example:
 	var h1, h2 *Handler
 
 	area := clip.Rect(...).Push(ops)
-	event.Op{Tag: h1}.Add(Ops)
+	event.Op(Ops, h1)
 	area.Pop()
 
 	area := clip.Rect(...).Push(ops)
-	event.Op{Tag: h2}.Add(ops)
+	event.Op(Ops, h2)
 	area.Pop()
 
 implies a tree of two inner nodes, each with one pointer handler attached.

io/pointer/pointer.go

@@ -3,7 +3,6 @@
 package pointer
 
 import (
-	"image"
 	"strings"
 	"time"
 
@@ -61,12 +60,19 @@ type Filter struct {
 	Target event.Tag
 	// Kinds is a bitwise-or of event types to match.
 	Kinds Kind
-	// ScrollBounds describe the maximum scrollable distances in both
-	// axes. Specifically, any Event e delivered to Tag will satisfy
+	// ScrollX and ScrollY constrain the range of scrolling events delivered
+	// to Target. Specifically, any Event e delivered to Tag will satisfy
 	//
-	// ScrollBounds.Min.X <= e.Scroll.X <= ScrollBounds.Max.X (horizontal axis)
-	// ScrollBounds.Min.Y <= e.Scroll.Y <= ScrollBounds.Max.Y (vertical axis)
-	ScrollBounds image.Rectangle
+	// ScrollX.Min <= e.Scroll.X <= ScrollX.Max (horizontal axis)
+	// ScrollY.Min <= e.Scroll.Y <= ScrollY.Max (vertical axis)
+	ScrollX ScrollRange
+	ScrollY ScrollRange
+}
+
+// ScrollRange describes the range of scrolling distances in an
+// axis.
+type ScrollRange struct {
+	Min, Max int
 }
 
 // GrabCmd requests a pointer grab on the pointer identified by ID.
@@ -219,6 +225,13 @@ const (
 	ButtonTertiary
 )
 
+func (s ScrollRange) Union(s2 ScrollRange) ScrollRange {
+	return ScrollRange{
+		Min: min(s.Min, s2.Min),
+		Max: max(s.Max, s2.Max),
+	}
+}
+
 // Push the current pass mode to the pass stack and set the pass mode.
 func (p PassOp) Push(o *op.Ops) PassStack {
 	id, mid := ops.PushOp(&o.Internal, ops.PassStack)

layout/list.go

@@ -7,6 +7,7 @@ import (
 	"math"
 
 	"gioui.org/gesture"
+	"gioui.org/io/pointer"
 	"gioui.org/op"
 	"gioui.org/op/clip"
 )
@@ -158,11 +159,12 @@ func (l *List) update(gtx Context) {
 			max = 0
 		}
 	}
-	scrollRange := image.Rectangle{
-		Min: l.Axis.Convert(image.Pt(min, 0)),
-		Max: l.Axis.Convert(image.Pt(max, 0)),
+	xrange := pointer.ScrollRange{Min: min, Max: max}
+	yrange := pointer.ScrollRange{}
+	if l.Axis == Vertical {
+		xrange, yrange = yrange, xrange
 	}
-	d := l.scroll.Update(gtx.Metric, gtx.Source, gtx.Now, gesture.Axis(l.Axis), scrollRange)
+	d := l.scroll.Update(gtx.Metric, gtx.Source, gtx.Now, gesture.Axis(l.Axis), xrange, yrange)
 	l.scrollDelta = d
 	l.Position.Offset += d
 }

op/clip/clip.go

@@ -138,6 +138,9 @@ type Path struct {
 func (p *Path) Pos() f32.Point { return p.pen }
 
 // Begin the path, storing the path data and final Op into ops.
+//
+// Caller must also call End to finish the drawing.
+// Forgetting to call it will result in a "panic: cannot mix multi ops with single ones".
 func (p *Path) Begin(o *op.Ops) {
 	*p = Path{
 		ops:     &o.Internal,

text/gotext.go

@@ -4,6 +4,7 @@ package text
 
 import (
 	"bytes"
+	"fmt"
 	"image"
 	"io"
 	"log"
@@ -276,7 +277,8 @@ func newShaperImpl(systemFonts bool, collection []FontFace) *shaperImpl {
 // It returns whether the face is now available for use. FontFaces are prioritized
 // in the order in which they are loaded, with the first face being the default.
 func (s *shaperImpl) Load(f FontFace) {
-	s.fontMap.AddFace(f.Face.Face(), opentype.FontToDescription(f.Font))
+	desc := opentype.FontToDescription(f.Font)
+	s.fontMap.AddFace(f.Face.Face(), fontscan.Location{File: fmt.Sprint(desc)}, desc)
 	s.addFace(f.Face.Face(), f.Font)
 }
 

widget/editor.go

@@ -228,19 +228,19 @@ func (e *Editor) processPointer(gtx layout.Context) (EditorEvent, bool) {
 		axis = gesture.Vertical
 		smin, smax = sbounds.Min.Y, sbounds.Max.Y
 	}
-	var scrollRange image.Rectangle
+	var scrollX, scrollY pointer.ScrollRange
 	textDims := e.text.FullDimensions()
 	visibleDims := e.text.Dimensions()
 	if e.SingleLine {
 		scrollOffX := e.text.ScrollOff().X
-		scrollRange.Min.X = min(-scrollOffX, 0)
-		scrollRange.Max.X = max(0, textDims.Size.X-(scrollOffX+visibleDims.Size.X))
+		scrollX.Min = min(-scrollOffX, 0)
+		scrollX.Max = max(0, textDims.Size.X-(scrollOffX+visibleDims.Size.X))
 	} else {
 		scrollOffY := e.text.ScrollOff().Y
-		scrollRange.Min.Y = -scrollOffY
-		scrollRange.Max.Y = max(0, textDims.Size.Y-(scrollOffY+visibleDims.Size.Y))
+		scrollY.Min = -scrollOffY
+		scrollY.Max = max(0, textDims.Size.Y-(scrollOffY+visibleDims.Size.Y))
 	}
-	sdist := e.scroller.Update(gtx.Metric, gtx.Source, gtx.Now, axis, scrollRange)
+	sdist := e.scroller.Update(gtx.Metric, gtx.Source, gtx.Now, axis, scrollX, scrollY)
 	var soff int
 	if e.SingleLine {
 		e.text.ScrollRel(sdist, 0)
@@ -289,6 +289,9 @@ func (e *Editor) processPointerEvent(gtx layout.Context, ev event.Event) (Editor
 				Y: int(math.Round(float64(evt.Position.Y))),
 			})
 			gtx.Execute(key.FocusCmd{Tag: e})
+			if !e.ReadOnly {
+				gtx.Execute(key.SoftKeyboardCmd{Show: true})
+			}
 			if e.scroller.State() != gesture.StateFlinging {
 				e.scrollCaret = true
 			}
@@ -312,8 +315,8 @@ func (e *Editor) processPointerEvent(gtx layout.Context, ev event.Event) (Editor
 				e.text.MoveWord(1, selectionExtend)
 				e.dragging = false
 			case evt.NumClicks >= 3:
-				e.text.MoveStart(selectionClear)
-				e.text.MoveEnd(selectionExtend)
+				e.text.MoveLineStart(selectionClear)
+				e.text.MoveLineEnd(selectionExtend)
 				e.dragging = false
 			}
 		}
@@ -374,8 +377,8 @@ func (e *Editor) processKey(gtx layout.Context) (EditorEvent, bool) {
 		key.Filter{Focus: e, Name: key.NameDeleteBackward, Optional: key.ModShortcutAlt | key.ModShift},
 		key.Filter{Focus: e, Name: key.NameDeleteForward, Optional: key.ModShortcutAlt | key.ModShift},
 
-		key.Filter{Focus: e, Name: key.NameHome, Optional: key.ModShift},
-		key.Filter{Focus: e, Name: key.NameEnd, Optional: key.ModShift},
+		key.Filter{Focus: e, Name: key.NameHome, Optional: key.ModShortcut | key.ModShift},
+		key.Filter{Focus: e, Name: key.NameEnd, Optional: key.ModShortcut | key.ModShift},
 		key.Filter{Focus: e, Name: key.NamePageDown, Optional: key.ModShift},
 		key.Filter{Focus: e, Name: key.NamePageUp, Optional: key.ModShift},
 		condFilter(!atBeginning, key.Filter{Focus: e, Name: key.NameLeftArrow, Optional: key.ModShortcutAlt | key.ModShift}),
@@ -395,7 +398,7 @@ func (e *Editor) processKey(gtx layout.Context) (EditorEvent, bool) {
 		case key.FocusEvent:
 			// Reset IME state.
 			e.ime.imeState = imeState{}
-			if ke.Focus {
+			if ke.Focus && !e.ReadOnly {
 				gtx.Execute(key.SoftKeyboardCmd{Show: true})
 			}
 		case key.Event:
@@ -521,6 +524,10 @@ func (e *Editor) command(gtx layout.Context, k key.Event) (EditorEvent, bool) {
 					}
 				}
 			}
+		case key.NameHome:
+			e.text.MoveTextStart(selAct)
+		case key.NameEnd:
+			e.text.MoveTextEnd(selAct)
 		}
 		return nil, false
 	}
@@ -582,9 +589,9 @@ func (e *Editor) command(gtx layout.Context, k key.Event) (EditorEvent, bool) {
 	case key.NamePageDown:
 		e.text.MovePages(+1, selAct)
 	case key.NameHome:
-		e.text.MoveStart(selAct)
+		e.text.MoveLineStart(selAct)
 	case key.NameEnd:
-		e.text.MoveEnd(selAct)
+		e.text.MoveLineEnd(selAct)
 	}
 	return nil, false
 }

widget/editor_test.go

@@ -256,7 +256,7 @@ func TestEditor(t *testing.T) {
 	// Regression test for bad in-cluster rune offset math.
 	e.SetText("æbc")
 	e.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 0, 3, len("æbc"))
 
 	textSample := "æbc\naøå••"
@@ -268,7 +268,7 @@ func TestEditor(t *testing.T) {
 	}
 	e.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
 	assertCaret(t, e, 0, 0, 0)
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 0, 3, len("æbc"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 0, len("æbc\n"))
@@ -276,7 +276,7 @@ func TestEditor(t *testing.T) {
 	assertCaret(t, e, 0, 3, len("æbc"))
 	e.text.MoveLines(+1, selectionClear)
 	assertCaret(t, e, 1, 4, len("æbc\naøå•"))
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 1, 5, len("æbc\naøå••"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 5, len("æbc\naøå••"))
@@ -300,7 +300,7 @@ func TestEditor(t *testing.T) {
 	// Test that moveLine applies x offsets from previous moves.
 	e.SetText("long line\nshort")
 	e.SetCaret(0, 0)
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	e.text.MoveLines(+1, selectionClear)
 	e.text.MoveLines(-1, selectionClear)
 	assertCaret(t, e, 0, utf8.RuneCountInString("long line"), len("long line"))
@@ -342,14 +342,14 @@ func TestEditorRTL(t *testing.T) {
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 0, 3, len("الح"))
 	// Move to the "end" of the line. This moves to the left edge of the line.
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 0, 4, len("الحب"))
 
 	sentence := "الحب سماء لا\nتمط غير الأحلام"
 	e.SetText(sentence)
 	e.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
 	assertCaret(t, e, 0, 0, 0)
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 0, 12, len("الحب سماء لا"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 0, len("الحب سماء لا\n"))
@@ -361,7 +361,7 @@ func TestEditorRTL(t *testing.T) {
 	assertCaret(t, e, 0, 12, len("الحب سماء لا"))
 	e.text.MoveLines(+1, selectionClear)
 	assertCaret(t, e, 1, 14, len("الحب سماء لا\nتمط غير الأحلا"))
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 1, 15, len("الحب سماء لا\nتمط غير الأحلام"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 15, len("الحب سماء لا\nتمط غير الأحلام"))
@@ -417,7 +417,7 @@ func TestEditorLigature(t *testing.T) {
 	assertCaret(t, e, 0, 0, 0)
 	e.SetText("fl") // just a ligature
 	e.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 0, 2, len("fl"))
 	e.MoveCaret(-1, -1)
 	assertCaret(t, e, 0, 1, len("f"))
@@ -428,7 +428,7 @@ func TestEditorLigature(t *testing.T) {
 	e.SetText("flaffl•ffi\n•fflfi") // 3 ligatures on line 0, 2 on line 1
 	e.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
 	assertCaret(t, e, 0, 0, 0)
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	assertCaret(t, e, 0, 10, len("ffaffl•ffi"))
 	e.MoveCaret(+1, +1)
 	assertCaret(t, e, 1, 0, len("ffaffl•ffi\n"))
@@ -481,7 +481,7 @@ func TestEditorLigature(t *testing.T) {
 	e.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
 	// Ensure that all runes in the final cluster of a line are properly
 	// decoded when moving to the end of the line. This is a regression test.
-	e.text.MoveEnd(selectionClear)
+	e.text.MoveLineEnd(selectionClear)
 	// The first line was broken by line wrapping, not a newline character, and has a trailing
 	// whitespace. However, we should never be able to reach the "other side" of such a trailing
 	// whitespace glyph.
@@ -548,8 +548,10 @@ const (
 	moveRune
 	moveLine
 	movePage
-	moveStart
-	moveEnd
+	moveTextStart
+	moveTextEnd
+	moveLineStart
+	moveLineEnd
 	moveCoord
 	moveWord
 	deleteWord
@@ -599,10 +601,14 @@ func TestEditorCaretConsistency(t *testing.T) {
 				e.text.MoveLines(int(distance), selectionClear)
 			case movePage:
 				e.text.MovePages(int(distance), selectionClear)
-			case moveStart:
-				e.text.MoveStart(selectionClear)
-			case moveEnd:
-				e.text.MoveEnd(selectionClear)
+			case moveLineStart:
+				e.text.MoveLineStart(selectionClear)
+			case moveLineEnd:
+				e.text.MoveLineEnd(selectionClear)
+			case moveTextStart:
+				e.text.MoveTextStart(selectionClear)
+			case moveTextEnd:
+				e.text.MoveTextEnd(selectionClear)
 			case moveCoord:
 				e.text.MoveCoord(image.Pt(int(x), int(y)))
 			case moveWord:
@@ -879,7 +885,7 @@ func (editMutation) Generate(rand *rand.Rand, size int) reflect.Value {
 // to make it much narrower (which makes the lines in the editor reflow), and
 // then verifies that the updated (col, line) positions of the selected text
 // are where we expect.
-func TestEditorSelect(t *testing.T) {
+func TestEditorSelectReflow(t *testing.T) {
 	e := new(Editor)
 	e.SetText(`a 2 4 6 8 a
 b 2 4 6 8 b
@@ -982,6 +988,60 @@ g 2 4 6 8 g
 	}
 }
 
+func TestEditorSelectShortcuts(t *testing.T) {
+	tFont := font.Font{}
+	tFontSize := unit.Sp(10)
+	tShaper := text.NewShaper(text.NoSystemFonts(), text.WithCollection(gofont.Collection()))
+	var tEditor = &Editor{
+		SingleLine: false,
+		ReadOnly:   true,
+	}
+	lines := "abc abc abc\ndef def def\nghi ghi ghi"
+	tEditor.SetText(lines)
+	type testCase struct {
+		// Initial text selection.
+		startPos, endPos int
+		// Keyboard shortcut to execute.
+		keyEvent key.Event
+		// Expected text selection.
+		selection string
+	}
+
+	pos1, pos2 := 14, 21
+	for n, tst := range []testCase{
+		{pos1, pos2, key.Event{Name: "A", Modifiers: key.ModShortcut}, lines},
+		{pos2, pos1, key.Event{Name: "A", Modifiers: key.ModShortcut}, lines},
+		{pos1, pos2, key.Event{Name: key.NameHome, Modifiers: key.ModShift}, "def def d"},
+		{pos1, pos2, key.Event{Name: key.NameEnd, Modifiers: key.ModShift}, "ef"},
+		{pos2, pos1, key.Event{Name: key.NameHome, Modifiers: key.ModShift}, "de"},
+		{pos2, pos1, key.Event{Name: key.NameEnd, Modifiers: key.ModShift}, "f def def"},
+		{pos1, pos2, key.Event{Name: key.NameHome, Modifiers: key.ModShortcut | key.ModShift}, "abc abc abc\ndef def d"},
+		{pos1, pos2, key.Event{Name: key.NameEnd, Modifiers: key.ModShortcut | key.ModShift}, "ef\nghi ghi ghi"},
+		{pos2, pos1, key.Event{Name: key.NameHome, Modifiers: key.ModShortcut | key.ModShift}, "abc abc abc\nde"},
+		{pos2, pos1, key.Event{Name: key.NameEnd, Modifiers: key.ModShortcut | key.ModShift}, "f def def\nghi ghi ghi"},
+	} {
+		tRouter := new(input.Router)
+		gtx := layout.Context{
+			Ops:         new(op.Ops),
+			Locale:      english,
+			Constraints: layout.Exact(image.Pt(100, 100)),
+			Source:      tRouter.Source(),
+		}
+		gtx.Execute(key.FocusCmd{Tag: tEditor})
+		tEditor.Layout(gtx, tShaper, tFont, tFontSize, op.CallOp{}, op.CallOp{})
+
+		tEditor.SetCaret(tst.startPos, tst.endPos)
+		if cStart, cEnd := tEditor.Selection(); cStart != tst.startPos || cEnd != tst.endPos {
+			t.Errorf("TestEditorSelect %d: initial selection", n)
+		}
+		tRouter.Queue(tst.keyEvent)
+		tEditor.Update(gtx)
+		if got := tEditor.SelectedText(); got != tst.selection {
+			t.Errorf("TestEditorSelect %d: Expected %q, got %q", n, tst.selection, got)
+		}
+	}
+}
+
 // Verify that an existing selection is dismissed when you press arrow keys.
 func TestSelectMove(t *testing.T) {
 	e := new(Editor)

widget/index_test.go

@@ -284,9 +284,9 @@ func TestIndexPositionBidi(t *testing.T) {
 			name:   "bidi rtl",
 			glyphs: bidiRTLText,
 			expectedXs: []fixed.Int26_6{
-				2665, 3291, 3861, 4431, 4716, 5286, 5856, 6109, 6621, 7133, 2665, 2380, 1577, 985, 687, 266, // Positions on line 0.
+				2646, 3272, 3842, 4412, 4697, 5267, 5837, 6090, 6602, 7114, 2646, 2380, 1577, 985, 687, 266, // Positions on line 0.
 
-				7886, 7118, 6350, 5582, 4814, 4529, 4231, 3933, 3667, 2300, 2585, 3155, 3667, 2300, 2015, 1709, 1117, 266, // Positions on line 1.
+				7867, 7099, 6331, 5563, 4795, 4510, 4212, 3914, 3648, 2281, 2566, 3136, 3648, 2281, 2015, 1709, 1117, 266, // Positions on line 1.
 
 				8794, 8026, 7258, 6490, 5722, 5437, 4922, 4540, 4134, 3868, 0, 290, 860, 1430, 1715, 1989, 2559, 3071, 3583, // Positions on line 2.
 
@@ -402,7 +402,7 @@ func TestIndexPositionLines(t *testing.T) {
 					xOff:    fixed.Int26_6(0),
 					yOff:    22,
 					glyphs:  15,
-					width:   fixed.Int26_6(7133),
+					width:   fixed.Int26_6(7114),
 					ascent:  fixed.Int26_6(1407),
 					descent: fixed.Int26_6(756),
 				},
@@ -410,7 +410,7 @@ func TestIndexPositionLines(t *testing.T) {
 					xOff:    fixed.Int26_6(0),
 					yOff:    41,
 					glyphs:  15,
-					width:   fixed.Int26_6(7886),
+					width:   fixed.Int26_6(7867),
 					ascent:  fixed.Int26_6(1407),
 					descent: fixed.Int26_6(756),
 				},
@@ -477,18 +477,18 @@ func TestIndexPositionLines(t *testing.T) {
 			glyphs: bidiRTLTextOpp,
 			expectedLines: []lineInfo{
 				{
-					xOff:    fixed.Int26_6(3107),
+					xOff:    fixed.Int26_6(3126),
 					yOff:    22,
 					glyphs:  15,
-					width:   fixed.Int26_6(7133),
+					width:   fixed.Int26_6(7114),
 					ascent:  fixed.Int26_6(1407),
 					descent: fixed.Int26_6(756),
 				},
 				{
-					xOff:    fixed.Int26_6(2354),
+					xOff:    fixed.Int26_6(2373),
 					yOff:    41,
 					glyphs:  15,
-					width:   fixed.Int26_6(7886),
+					width:   fixed.Int26_6(7867),
 					ascent:  fixed.Int26_6(1407),
 					descent: fixed.Int26_6(756),
 				},

widget/material/progressbar.go

@@ -54,6 +54,9 @@ func (p ProgressBarStyle) Layout(gtx layout.Context) layout.Dimensions {
 			if !gtx.Enabled() {
 				fillColor = f32color.Disabled(fillColor)
 			}
+			if fillWidth < int(p.Radius*2) {
+				fillWidth = int(p.Radius * 2)
+			}
 			return shader(fillWidth, fillColor)
 		}),
 	)

widget/selectable.go

@@ -247,8 +247,8 @@ func (e *Selectable) processPointer(gtx layout.Context) {
 					e.text.MoveWord(1, selectionExtend)
 					e.dragging = false
 				case evt.NumClicks >= 3:
-					e.text.MoveStart(selectionClear)
-					e.text.MoveEnd(selectionExtend)
+					e.text.MoveLineStart(selectionClear)
+					e.text.MoveLineEnd(selectionExtend)
 					e.dragging = false
 				}
 			}
@@ -378,9 +378,9 @@ func (e *Selectable) command(gtx layout.Context, k key.Event) {
 	case key.NamePageDown:
 		e.text.MovePages(+1, selAct)
 	case key.NameHome:
-		e.text.MoveStart(selAct)
+		e.text.MoveLineStart(selAct)
 	case key.NameEnd:
-		e.text.MoveEnd(selAct)
+		e.text.MoveLineEnd(selAct)
 	}
 }
 

widget/text.go

@@ -639,9 +639,28 @@ func (e *textView) MoveCaret(startDelta, endDelta int) {
 	e.caret.end = e.moveByGraphemes(e.caret.end, endDelta)
 }
 
-// MoveStart moves the caret to the start of the current line, ensuring that the resulting
+// MoveTextStart moves the caret to the start of the text.
+func (e *textView) MoveTextStart(selAct selectionAction) {
+	caret := e.closestToRune(e.caret.end)
+	e.caret.start = 0
+	e.caret.end = caret.runes
+	e.caret.xoff = -caret.x
+	e.updateSelection(selAct)
+	e.clampCursorToGraphemes()
+}
+
+// MoveTextEnd moves the caret to the end of the text.
+func (e *textView) MoveTextEnd(selAct selectionAction) {
+	caret := e.closestToRune(math.MaxInt)
+	e.caret.start = caret.runes
+	e.caret.xoff = fixed.I(e.params.MaxWidth) - caret.x
+	e.updateSelection(selAct)
+	e.clampCursorToGraphemes()
+}
+
+// MoveLineStart moves the caret to the start of the current line, ensuring that the resulting
 // cursor position is on a grapheme cluster boundary.
-func (e *textView) MoveStart(selAct selectionAction) {
+func (e *textView) MoveLineStart(selAct selectionAction) {
 	caret := e.closestToRune(e.caret.start)
 	caret = e.closestToLineCol(caret.lineCol.line, 0)
 	e.caret.start = caret.runes
@@ -650,9 +669,9 @@ func (e *textView) MoveStart(selAct selectionAction) {
 	e.clampCursorToGraphemes()
 }
 
-// MoveEnd moves the caret to the end of the current line, ensuring that the resulting
+// MoveLineEnd moves the caret to the end of the current line, ensuring that the resulting
 // cursor position is on a grapheme cluster boundary.
-func (e *textView) MoveEnd(selAct selectionAction) {
+func (e *textView) MoveLineEnd(selAct selectionAction) {
 	caret := e.closestToRune(e.caret.start)
 	caret = e.closestToLineCol(caret.lineCol.line, math.MaxInt)
 	e.caret.start = caret.runes