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/linux.yml

@@ -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: |

app/app.go

@@ -61,6 +61,10 @@ type FrameEvent struct {
 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

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/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/metal_macos.go

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

app/os.go

@@ -173,19 +173,13 @@ type context interface {
 	Unlock()
 }
 
-// basicDriver is the subset of [driver] that may be called even after
-// a window is destroyed.
-type basicDriver interface {
+// 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()
-}
-
-// driver is the interface for the platform implementation
-// of a window.
-type driver interface {
-	basicDriver
 	// SetAnimating sets the animation flag. When the window is animating,
 	// FrameEvents are delivered as fast as the display can handle them.
 	SetAnimating(anim bool)

app/os_android.go

@@ -1495,3 +1495,6 @@ func Java_org_gioui_Gio_scheduleMainFuncs(env *C.JNIEnv, cls C.jclass) {
 
 func (AndroidViewEvent) implementsViewEvent() {}
 func (AndroidViewEvent) ImplementsEvent()     {}
+func (a AndroidViewEvent) Valid() bool {
+	return a != (AndroidViewEvent{})
+}

app/os_ios.go

@@ -441,3 +441,6 @@ func gio_runMain() {
 
 func (UIKitViewEvent) implementsViewEvent() {}
 func (UIKitViewEvent) ImplementsEvent()     {}
+func (u UIKitViewEvent) Valid() bool {
+	return u != (UIKitViewEvent{})
+}

app/os_js.go

@@ -822,3 +822,6 @@ func translateKey(k string) (key.Name, bool) {
 
 func (JSViewEvent) implementsViewEvent() {}
 func (JSViewEvent) ImplementsEvent()     {}
+func (j JSViewEvent) Valid() bool {
+	return !(j.Element.IsNull() || j.Element.IsUndefined())
+}

app/os_macos.go

@@ -40,7 +40,7 @@ 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);
 
@@ -925,7 +925,9 @@ func newWindow(win *callbacks, options []Option) {
 		w.loop = newEventLoop(w.w, w.wakeup)
 		win.SetDriver(w)
 		res <- struct{}{}
-		if err := w.init(); err != nil {
+		var cnf Config
+		cnf.apply(unit.Metric{}, options)
+		if err := w.init(cnf.CustomRenderer); err != nil {
 			w.ProcessEvent(DestroyEvent{Err: err})
 			return
 		}
@@ -946,8 +948,12 @@ func newWindow(win *callbacks, options []Option) {
 	<-res
 }
 
-func (w *window) init() 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 errors.New("newOSWindow: failed to create view")
 	}
@@ -1068,3 +1074,6 @@ func convertMods(mods C.NSUInteger) key.Modifiers {
 
 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
@@ -16,6 +16,7 @@ __attribute__ ((visibility ("hidden"))) CALayer *gio_layerFactory(void);
 
 @interface GioView : NSView <CALayerDelegate,NSTextInputClient>
 @property uintptr_t handle;
+@property BOOL presentWithTrans;
 @end
 
 @implementation GioWindowDelegate
@@ -88,7 +89,7 @@ static void handleMouse(GioView *view, NSEvent *event, int typ, CGFloat dx, CGFl
 	gio_onDraw(self.handle);
 }
 - (CALayer *)makeBackingLayer {
-	CALayer *layer = gio_layerFactory();
+	CALayer *layer = gio_layerFactory(self.presentWithTrans);
 	layer.delegate = self;
 	return layer;
 }
@@ -392,10 +393,11 @@ 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;
 

app/os_unix.go

@@ -9,7 +9,6 @@ import (
 	"errors"
 	"unsafe"
 
-	"gioui.org/io/event"
 	"gioui.org/io/pointer"
 )
 
@@ -22,6 +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.
@@ -32,6 +34,9 @@ type WaylandViewEvent struct {
 
 func (WaylandViewEvent) implementsViewEvent() {}
 func (WaylandViewEvent) ImplementsEvent()     {}
+func (w WaylandViewEvent) Valid() bool {
+	return w != (WaylandViewEvent{})
+}
 
 func osMain() {
 	select {}
@@ -57,35 +62,12 @@ func newWindow(window *callbacks, options []Option) {
 			errFirst = err
 		}
 	}
-	window.SetDriver(&dummyDriver{
-		win:     window,
-		wakeups: make(chan event.Event, 1),
-	})
 	if errFirst == nil {
 		errFirst = errors.New("app: no window driver available")
 	}
 	window.ProcessEvent(DestroyEvent{Err: errFirst})
 }
 
-type dummyDriver struct {
-	win     *callbacks
-	wakeups chan event.Event
-}
-
-func (d *dummyDriver) Event() event.Event {
-	if e, ok := d.win.nextEvent(); ok {
-		return e
-	}
-	return <-d.wakeups
-}
-
-func (d *dummyDriver) Invalidate() {
-	select {
-	case d.wakeups <- wakeupEvent{}:
-	default:
-	}
-}
-
 // xCursor contains mapping from pointer.Cursor to XCursor.
 var xCursor = [...]string{
 	pointer.CursorDefault:                  "left_ptr",

app/os_wayland.go

@@ -217,10 +217,6 @@ type window struct {
 	wakeups chan struct{}
 
 	closing bool
-
-	// invMu avoids the race between the destruction of disp and
-	// Invalidate waking it up.
-	invMu sync.Mutex
 }
 
 type poller struct {
@@ -1369,10 +1365,8 @@ func (w *window) close(err error) {
 	w.ProcessEvent(WaylandViewEvent{})
 	w.ProcessEvent(DestroyEvent{Err: err})
 	w.destroy()
-	w.invMu.Lock()
 	w.disp.destroy()
 	w.disp = nil
-	w.invMu.Unlock()
 }
 
 func (w *window) dispatch() {
@@ -1416,11 +1410,7 @@ func (w *window) Invalidate() {
 	default:
 		return
 	}
-	w.invMu.Lock()
-	defer w.invMu.Unlock()
-	if w.disp != nil {
-		w.disp.wakeup()
-	}
+	w.disp.wakeup()
 }
 
 func (w *window) Run(f func()) {
@@ -1643,6 +1633,14 @@ func (w *window) flushScroll() {
 	if total == (f32.Point{}) {
 		return
 	}
+	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,
@@ -1652,12 +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) {

app/os_windows.go

@@ -54,9 +54,6 @@ type window struct {
 	borderSize image.Point
 	config     Config
 	loop       *eventLoop
-
-	// invMu avoids the race between destroying the window and Invalidate.
-	invMu sync.Mutex
 }
 
 const _WM_WAKEUP = windows.WM_USER + iota
@@ -304,10 +301,8 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 			windows.ReleaseDC(w.hdc)
 			w.hdc = 0
 		}
-		w.invMu.Lock()
 		// The system destroys the HWND for us.
 		w.hwnd = 0
-		w.invMu.Unlock()
 		windows.PostQuitMessage(0)
 	case windows.WM_NCCALCSIZE:
 		if w.config.Decorated {
@@ -331,6 +326,12 @@ func windowProc(hwnd syscall.Handle, msg uint32, wParam, lParam uintptr) uintptr
 		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:
@@ -620,13 +621,6 @@ func (w *window) Frame(frame *op.Ops) {
 }
 
 func (w *window) wakeup() {
-	w.invMu.Lock()
-	defer w.invMu.Unlock()
-	if w.hwnd == 0 {
-		w.loop.Wakeup()
-		w.loop.FlushEvents()
-		return
-	}
 	if err := windows.PostMessage(w.hwnd, _WM_WAKEUP, 0, 0); err != nil {
 		panic(err)
 	}
@@ -993,3 +987,6 @@ func configForDPI(dpi int) unit.Metric {
 
 func (Win32ViewEvent) implementsViewEvent() {}
 func (Win32ViewEvent) ImplementsEvent()     {}
+func (w Win32ViewEvent) Valid() bool {
+	return w != (Win32ViewEvent{})
+}

app/os_x11.go

@@ -113,9 +113,6 @@ type x11Window struct {
 	wakeups chan struct{}
 	handler x11EventHandler
 	buf     [100]byte
-
-	// invMy avoids the race between destroy and Invalidate.
-	invMu sync.Mutex
 }
 
 var (
@@ -416,11 +413,6 @@ func (w *x11Window) Invalidate() {
 	case w.wakeups <- struct{}{}:
 	default:
 	}
-	w.invMu.Lock()
-	defer w.invMu.Unlock()
-	if w.x == nil {
-		return
-	}
 	if _, err := syscall.Write(w.notify.write, x11OneByte); err != nil && err != syscall.EAGAIN {
 		panic(fmt.Errorf("failed to write to pipe: %v", err))
 	}
@@ -509,8 +501,6 @@ func (w *x11Window) dispatch() {
 }
 
 func (w *x11Window) destroy() {
-	w.invMu.Lock()
-	defer w.invMu.Unlock()
 	if w.notify.write != 0 {
 		syscall.Close(w.notify.write)
 		w.notify.write = 0

app/window.go

@@ -7,8 +7,8 @@ import (
 	"fmt"
 	"image"
 	"image/color"
-	"reflect"
 	"runtime"
+	"sync"
 	"time"
 	"unicode/utf8"
 
@@ -41,7 +41,8 @@ type Option func(unit.Metric, *Config)
 //
 // More than one Window is not supported on iOS, Android, WebAssembly.
 type Window struct {
-	initialOpts []Option
+	initialOpts    []Option
+	initialActions []system.Action
 
 	ctx context
 	gpu gpu.GPU
@@ -88,8 +89,11 @@ type Window struct {
 	}
 	imeState editorState
 	driver   driver
-	// basic is the driver interface that is needed even after the window is gone.
-	basic basicDriver
+
+	// invMu protects mayInvalidate.
+	invMu         sync.Mutex
+	mayInvalidate bool
+
 	// coalesced tracks the most recent events waiting to be delivered
 	// to the client.
 	coalesced eventSummary
@@ -103,11 +107,12 @@ type Window struct {
 }
 
 type eventSummary struct {
-	wakeup  bool
-	cfg     *ConfigEvent
-	view    *ViewEvent
-	frame   *frameEvent
-	destroy *DestroyEvent
+	wakeup       bool
+	cfg          *ConfigEvent
+	view         *ViewEvent
+	frame        *frameEvent
+	framePending bool
+	destroy      *DestroyEvent
 }
 
 type callbacks struct {
@@ -214,6 +219,7 @@ func (w *Window) frame(frame *op.Ops, viewport image.Point) error {
 }
 
 func (w *Window) processFrame(frame *op.Ops, ack chan<- struct{}) {
+	w.coalesced.framePending = false
 	wrapper := &w.decorations.Ops
 	off := op.Offset(w.lastFrame.off).Push(wrapper)
 	ops.AddCall(&wrapper.Internal, &frame.Internal, ops.PC{}, ops.PCFor(&frame.Internal))
@@ -271,8 +277,11 @@ func (w *Window) updateState() {
 //
 // Invalidate is safe for concurrent use.
 func (w *Window) Invalidate() {
-	if w.basic != nil {
-		w.basic.Invalidate()
+	w.invMu.Lock()
+	defer w.invMu.Unlock()
+	if w.mayInvalidate {
+		w.mayInvalidate = false
+		w.driver.Invalidate()
 	}
 }
 
@@ -282,7 +291,7 @@ func (w *Window) Option(opts ...Option) {
 	if len(opts) == 0 {
 		return
 	}
-	if w.basic == nil {
+	if w.driver == nil {
 		w.initialOpts = append(w.initialOpts, opts...)
 		return
 	}
@@ -377,11 +386,11 @@ func (w *Window) setNextFrame(at time.Time) {
 	}
 }
 
-func (c *callbacks) SetDriver(d basicDriver) {
-	c.w.basic = d
-	if d, ok := d.(driver); ok {
-		c.w.driver = d
+func (c *callbacks) SetDriver(d driver) {
+	if d == nil {
+		panic("nil driver")
 	}
+	c.w.driver = d
 }
 
 func (c *callbacks) ProcessFrame(frame *op.Ops, ack chan<- struct{}) {
@@ -548,10 +557,20 @@ func (c *callbacks) Invalidate() {
 }
 
 func (c *callbacks) nextEvent() (event.Event, bool) {
-	s := &c.w.coalesced
-	// Every event counts as a wakeup.
-	defer func() { s.wakeup = false }()
+	return c.w.nextEvent()
+}
+
+func (w *Window) nextEvent() (event.Event, bool) {
+	s := &w.coalesced
+	defer func() {
+		// Every event counts as a wakeup.
+		s.wakeup = false
+	}()
 	switch {
+	case s.framePending:
+		// If the user didn't call FrameEvent.Event, process
+		// an empty frame.
+		w.processFrame(new(op.Ops), nil)
 	case s.view != nil:
 		e := *s.view
 		s.view = nil
@@ -568,10 +587,14 @@ func (c *callbacks) nextEvent() (event.Event, bool) {
 	case s.frame != nil:
 		e := *s.frame
 		s.frame = nil
+		s.framePending = true
 		return e.FrameEvent, true
 	case s.wakeup:
 		return wakeupEvent{}, true
 	}
+	w.invMu.Lock()
+	defer w.invMu.Unlock()
+	w.mayInvalidate = w.driver != nil
 	return nil, false
 }
 
@@ -615,6 +638,9 @@ func (w *Window) processEvent(e event.Event) bool {
 		w.coalesced.frame = &e2
 	case DestroyEvent:
 		w.destroyGPU()
+		w.invMu.Lock()
+		w.mayInvalidate = false
+		w.invMu.Unlock()
 		w.driver = nil
 		if q := w.timer.quit; q != nil {
 			q <- struct{}{}
@@ -622,7 +648,7 @@ func (w *Window) processEvent(e event.Event) bool {
 		}
 		w.coalesced.destroy = &e2
 	case ViewEvent:
-		if reflect.ValueOf(e2).IsZero() && w.gpu != nil {
+		if !e2.Valid() && w.gpu != nil {
 			w.ctx.Lock()
 			w.gpu.Release()
 			w.gpu = nil
@@ -686,10 +712,17 @@ func (w *Window) processEvent(e event.Event) bool {
 // [FrameEvent], or until [Invalidate] is called. The window is created
 // and shown the first time Event is called.
 func (w *Window) Event() event.Event {
-	if w.basic == nil {
+	if w.driver == nil {
 		w.init()
 	}
-	return w.basic.Event()
+	if w.driver == nil {
+		e, ok := w.nextEvent()
+		if !ok {
+			panic("window initializion failed without a DestroyEvent")
+		}
+		return e
+	}
+	return w.driver.Event()
 }
 
 func (w *Window) init() {
@@ -727,6 +760,10 @@ func (w *Window) init() {
 	w.imeState.compose = key.Range{Start: -1, End: -1}
 	w.semantic.ids = make(map[input.SemanticID]input.SemanticNode)
 	newWindow(&callbacks{w}, options)
+	for _, acts := range w.initialActions {
+		w.Perform(acts)
+	}
+	w.initialActions = nil
 }
 
 func (w *Window) updateCursor() {
@@ -826,6 +863,10 @@ func (w *Window) Perform(actions system.Action) {
 	if acts == 0 {
 		return
 	}
+	if w.driver == nil {
+		w.initialActions = append(w.initialActions, acts)
+		return
+	}
 	w.Run(func() {
 		w.driver.Perform(actions)
 	})

io/input/pointer_test.go

@@ -1086,6 +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

@@ -274,28 +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
 			}
 		}
 	}
@@ -313,15 +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 {