chore(v2): vendor dependencies for offline/China builds

go mod vendor pins onnxruntime_go v1.12.1, Gio and the rest into v2/vendor so go run/build work without hitting proxy.golang.org (blocked/slow in China). Verified: CGO_ENABLED=1 go build -mod=vendor ./internal/spike and GOOS=windows go build -mod=vendor ./internal/ui both pass. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-23 16:35:01 +08:00
parent 97c1c4a974
commit f58728cddd
972 changed files with 597802 additions and 0 deletions
@@ -0,0 +1,900 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package input
+
+import (
+	"image"
+	"io"
+	"slices"
+	"strings"
+	"time"
+
+	"gioui.org/f32"
+	f32internal "gioui.org/internal/f32"
+	"gioui.org/internal/ops"
+	"gioui.org/io/clipboard"
+	"gioui.org/io/event"
+	"gioui.org/io/key"
+	"gioui.org/io/pointer"
+	"gioui.org/io/semantic"
+	"gioui.org/io/system"
+	"gioui.org/io/transfer"
+	"gioui.org/op"
+)
+
+// Router tracks the [io/event.Tag] identifiers of user interface widgets
+// and routes events to them. [Source] is its interface exposed to widgets.
+type Router struct {
+	savedTrans []f32.Affine2D
+	transStack []f32.Affine2D
+	handlers   map[event.Tag]*handler
+	pointer    struct {
+		queue     pointerQueue
+		collector pointerCollector
+	}
+	key struct {
+		queue keyQueue
+		// The following fields have the same purpose as the fields in
+		// type handler, but for key.Events.
+		filter        keyFilter
+		nextFilter    keyFilter
+		scratchFilter keyFilter
+	}
+	cqueue clipboardQueue
+	// states is the list of pending state changes resulting from
+	// incoming events. The first element, if present, contains the state
+	// and events for the current frame.
+	changes []stateChange
+	reader  ops.Reader
+	// InvalidateCmd summary.
+	wakeup     bool
+	wakeupTime time.Time
+	// Changes queued for next call to Frame.
+	commands []Command
+	// transfers is the pending transfer.DataEvent.Open functions.
+	transfers []io.ReadCloser
+	// deferring is set if command execution and event delivery is deferred
+	// to the next frame.
+	deferring bool
+	// scratchFilters is for garbage-free construction of ephemeral filters.
+	scratchFilters []taggedFilter
+}
+
+// Source implements the interface between a Router and user interface widgets.
+// The zero-value Source is disabled.
+type Source struct {
+	r        *Router
+	disabled bool
+}
+
+// Command represents a request such as moving the focus, or initiating a clipboard read.
+// Commands are queued by calling [Source.Queue].
+type Command interface {
+	ImplementsCommand()
+}
+
+// SemanticNode represents a node in the tree describing the components
+// contained in a frame.
+type SemanticNode struct {
+	ID       SemanticID
+	ParentID SemanticID
+	Children []SemanticNode
+	Desc     SemanticDesc
+
+	areaIdx int
+}
+
+// SemanticDesc provides a semantic description of a UI component.
+type SemanticDesc struct {
+	Class       semantic.ClassOp
+	Description string
+	Label       string
+	Selected    bool
+	Disabled    bool
+	Gestures    SemanticGestures
+	Bounds      image.Rectangle
+}
+
+// SemanticGestures is a bit-set of supported gestures.
+type SemanticGestures int
+
+const (
+	ClickGesture SemanticGestures = 1 << iota
+	ScrollGesture
+)
+
+// SemanticID uniquely identifies a SemanticDescription.
+//
+// By convention, the zero value denotes the non-existent ID.
+type SemanticID uint
+
+// SystemEvent is a marker for events that have platform specific
+// side-effects. SystemEvents are never matched by catch-all filters.
+type SystemEvent struct {
+	Event event.Event
+}
+
+// handler contains the per-handler state tracked by a [Router].
+type handler struct {
+	// active tracks whether the handler was active in the current
+	// frame. Router deletes state belonging to inactive handlers during Frame.
+	active  bool
+	pointer pointerHandler
+	key     keyHandler
+	// filter the handler has asked for through event handling
+	// in the previous frame. It is used for routing events in the
+	// current frame.
+	filter filter
+	// prevFilter is the filter being built in the current frame.
+	nextFilter filter
+	// processedFilter is the filters that have exhausted available events.
+	processedFilter filter
+}
+
+// filter is the union of a set of [io/event.Filters].
+type filter struct {
+	pointer   pointerFilter
+	focusable bool
+}
+
+// taggedFilter is a filter for a particular tag.
+type taggedFilter struct {
+	tag    event.Tag
+	filter filter
+}
+
+// stateChange represents the new state and outgoing events
+// resulting from an incoming event.
+type stateChange struct {
+	// event, if set, is the trigger for the change.
+	event  event.Event
+	state  inputState
+	events []taggedEvent
+}
+
+// inputState represent a immutable snapshot of the state required
+// to route events.
+type inputState struct {
+	clipboardState
+	keyState
+	pointerState
+}
+
+// taggedEvent represents an event and its target handler.
+type taggedEvent struct {
+	event event.Event
+	tag   event.Tag
+}
+
+// Source returns a Source backed by this Router.
+func (q *Router) Source() Source {
+	return Source{r: q}
+}
+
+// Execute a command.
+func (s Source) Execute(c Command) {
+	if !s.Enabled() {
+		return
+	}
+	s.r.execute(c)
+}
+
+// Disabled returns a copy of this source that don't deliver any events.
+func (s Source) Disabled() Source {
+	s2 := s
+	s2.disabled = true
+	return s2
+}
+
+// Enabled reports whether the source is enabled. Only enabled
+// Sources deliver events.
+func (s Source) Enabled() bool {
+	return s.r != nil && !s.disabled
+}
+
+// Focused reports whether tag is focused, according to the most recent
+// [key.FocusEvent] delivered.
+func (s Source) Focused(tag event.Tag) bool {
+	if !s.Enabled() {
+		return false
+	}
+	return s.r.state().keyState.focus == tag
+}
+
+// Event returns the next event that matches at least one of filters.
+// If the source is disabled, no events will be reported.
+func (s Source) Event(filters ...event.Filter) (event.Event, bool) {
+	if !s.Enabled() {
+		return nil, false
+	}
+	return s.r.Event(filters...)
+}
+
+func (q *Router) Event(filters ...event.Filter) (event.Event, bool) {
+	// Merge filters into scratch filters.
+	q.scratchFilters = q.scratchFilters[:0]
+	q.key.scratchFilter = q.key.scratchFilter[:0]
+	for _, f := range filters {
+		var t event.Tag
+		switch f := f.(type) {
+		case key.Filter:
+			q.key.scratchFilter = append(q.key.scratchFilter, f)
+			continue
+		case transfer.SourceFilter:
+			t = f.Target
+		case transfer.TargetFilter:
+			t = f.Target
+		case key.FocusFilter:
+			t = f.Target
+		case pointer.Filter:
+			t = f.Target
+		}
+		if t == nil {
+			continue
+		}
+		var filter *filter
+		for i := range q.scratchFilters {
+			s := &q.scratchFilters[i]
+			if s.tag == t {
+				filter = &s.filter
+				break
+			}
+		}
+		if filter == nil {
+			n := len(q.scratchFilters)
+			if n < cap(q.scratchFilters) {
+				// Re-use previously allocated filter.
+				q.scratchFilters = q.scratchFilters[:n+1]
+				tf := &q.scratchFilters[n]
+				tf.tag = t
+				filter = &tf.filter
+				filter.Reset()
+			} else {
+				q.scratchFilters = append(q.scratchFilters, taggedFilter{tag: t})
+				filter = &q.scratchFilters[n].filter
+			}
+		}
+		filter.Add(f)
+	}
+	for _, tf := range q.scratchFilters {
+		h := q.stateFor(tf.tag)
+		h.filter.Merge(tf.filter)
+		h.nextFilter.Merge(tf.filter)
+	}
+	q.key.filter = append(q.key.filter, q.key.scratchFilter...)
+	q.key.nextFilter = append(q.key.nextFilter, q.key.scratchFilter...)
+	// Deliver reset event, if any.
+	for _, f := range filters {
+		switch f := f.(type) {
+		case key.FocusFilter:
+			if f.Target == nil {
+				break
+			}
+			h := q.stateFor(f.Target)
+			if reset, ok := h.key.ResetEvent(); ok {
+				return reset, true
+			}
+		case pointer.Filter:
+			if f.Target == nil {
+				break
+			}
+			h := q.stateFor(f.Target)
+			if reset, ok := h.pointer.ResetEvent(); ok && h.filter.pointer.Matches(reset) {
+				return reset, true
+			}
+		}
+	}
+	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 = slices.Delete(change.events, j, j+1)
+				// Fast forward state to last matched.
+				q.collapseState(i)
+				return evt.event, true
+			}
+		}
+	}
+	for _, tf := range q.scratchFilters {
+		h := q.stateFor(tf.tag)
+		h.processedFilter.Merge(tf.filter)
+	}
+	return nil, false
+}
+
+// collapseState in the interval [1;idx] into q.changes[0].
+func (q *Router) collapseState(idx int) {
+	if idx == 0 {
+		return
+	}
+	first := &q.changes[0]
+	first.state = q.changes[idx].state
+	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 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 {
+		if q.deferring {
+			// Collect events for replay.
+			for _, ch := range q.changes[1:] {
+				remaining = append(remaining, ch.event)
+			}
+			q.changes = append(q.changes[:0], stateChange{state: q.changes[0].state})
+		} else {
+			// Collapse state.
+			state := q.changes[n-1].state
+			q.changes = append(q.changes[:0], stateChange{state: state})
+		}
+	}
+	for _, rc := range q.transfers {
+		if rc != nil {
+			rc.Close()
+		}
+	}
+	q.transfers = nil
+	q.deferring = false
+	for _, h := range q.handlers {
+		h.filter, h.nextFilter = h.nextFilter, h.filter
+		h.nextFilter.Reset()
+		h.processedFilter.Reset()
+		h.pointer.Reset()
+		h.key.Reset()
+	}
+	q.key.filter, q.key.nextFilter = q.key.nextFilter, q.key.filter
+	q.key.nextFilter = q.key.nextFilter[:0]
+	var ops *ops.Ops
+	if frame != nil {
+		ops = &frame.Internal
+	}
+	q.reader.Reset(ops)
+	q.collect()
+	for k, h := range q.handlers {
+		if !h.active {
+			delete(q.handlers, k)
+		} else {
+			h.active = false
+		}
+	}
+	q.executeCommands()
+	q.Queue(remaining...)
+	st := q.lastState()
+	pst, evts := q.pointer.queue.Frame(q.handlers, st.pointerState)
+	st.pointerState = pst
+	st.keyState = q.key.queue.Frame(q.handlers, q.lastState().keyState)
+	q.changeState(nil, st, evts)
+
+	// Collapse state and events.
+	q.collapseState(len(q.changes) - 1)
+}
+
+// Queue events to be routed.
+func (q *Router) Queue(events ...event.Event) {
+	for _, e := range events {
+		se, system := e.(SystemEvent)
+		if system {
+			e = se.Event
+		}
+		q.processEvent(e, system)
+	}
+}
+
+func (f *filter) Add(flt event.Filter) {
+	switch flt := flt.(type) {
+	case key.FocusFilter:
+		f.focusable = true
+	case pointer.Filter:
+		f.pointer.Add(flt)
+	case transfer.SourceFilter, transfer.TargetFilter:
+		f.pointer.Add(flt)
+	}
+}
+
+// Merge f2 into f.
+func (f *filter) Merge(f2 filter) {
+	f.focusable = f.focusable || f2.focusable
+	f.pointer.Merge(f2.pointer)
+}
+
+func (f *filter) Matches(e event.Event) bool {
+	switch e.(type) {
+	case key.FocusEvent, key.SnippetEvent, key.EditEvent, key.SelectionEvent, key.CompositionEvent:
+		return f.focusable
+	default:
+		return f.pointer.Matches(e)
+	}
+}
+
+func (f *filter) Reset() {
+	*f = filter{
+		pointer: pointerFilter{
+			sourceMimes: f.pointer.sourceMimes[:0],
+			targetMimes: f.pointer.targetMimes[:0],
+		},
+	}
+}
+
+func (q *Router) processEvent(e event.Event, system bool) {
+	state := q.lastState()
+	switch e := e.(type) {
+	case pointer.Event:
+		pstate, evts := q.pointer.queue.Push(q.handlers, state.pointerState, e)
+		state.pointerState = pstate
+		q.changeState(e, state, evts)
+	case key.Event:
+		var evts []taggedEvent
+		if q.key.filter.Matches(state.keyState.focus, e, system) {
+			evts = append(evts, taggedEvent{event: e})
+		}
+		q.changeState(e, state, evts)
+	case key.SnippetEvent:
+		// Expand existing, overlapping snippet.
+		if r := state.content.Snippet.Range; rangeOverlaps(r, key.Range(e)) {
+			if e.Start > r.Start {
+				e.Start = r.Start
+			}
+			if e.End < r.End {
+				e.End = r.End
+			}
+		}
+		var evts []taggedEvent
+		if f := state.focus; f != nil {
+			evts = append(evts, taggedEvent{tag: f, event: e})
+		}
+		q.changeState(e, state, evts)
+	case key.CompositionEvent:
+		e = key.CompositionEvent(rangeNorm(key.Range(e)))
+		var evts []taggedEvent
+		if f := state.focus; f != nil {
+			evts = append(evts, taggedEvent{tag: f, event: e})
+		}
+		q.changeState(e, state, evts)
+	case key.EditEvent, key.FocusEvent, key.SelectionEvent:
+		var evts []taggedEvent
+		if f := state.focus; f != nil {
+			evts = append(evts, taggedEvent{tag: f, event: e})
+		}
+		q.changeState(e, state, evts)
+	case transfer.DataEvent:
+		cstate, evts := q.cqueue.Push(state.clipboardState, e)
+		state.clipboardState = cstate
+		q.changeState(e, state, evts)
+	default:
+		panic("unknown event type")
+	}
+}
+
+func (q *Router) execute(c Command) {
+	// The command can be executed immediately if event delivery is not frozen, and
+	// no event receiver has completed their event handling.
+	if !q.deferring {
+		ch := q.executeCommand(c)
+		immediate := true
+		for _, e := range ch.events {
+			h, ok := q.handlers[e.tag]
+			immediate = immediate && (!ok || !h.processedFilter.Matches(e.event))
+		}
+		if immediate {
+			// Hold on to the remaining events for state replay.
+			var evts []event.Event
+			for _, ch := range q.changes {
+				if ch.event != nil {
+					evts = append(evts, ch.event)
+				}
+			}
+			if len(q.changes) > 1 {
+				q.changes = q.changes[:1]
+			}
+			q.changeState(nil, ch.state, ch.events)
+			q.Queue(evts...)
+			return
+		}
+	}
+	q.deferring = true
+	q.commands = append(q.commands, c)
+}
+
+func (q *Router) state() inputState {
+	if len(q.changes) > 0 {
+		return q.changes[0].state
+	}
+	return inputState{}
+}
+
+func (q *Router) lastState() inputState {
+	if n := len(q.changes); n > 0 {
+		return q.changes[n-1].state
+	}
+	return inputState{}
+}
+
+func (q *Router) executeCommands() {
+	for _, c := range q.commands {
+		ch := q.executeCommand(c)
+		q.changeState(nil, ch.state, ch.events)
+	}
+	q.commands = nil
+}
+
+// executeCommand the command and return the resulting state change along with the
+// tag the state change depended on, if any.
+func (q *Router) executeCommand(c Command) stateChange {
+	state := q.state()
+	var evts []taggedEvent
+	switch req := c.(type) {
+	case key.SelectionCmd:
+		state.keyState = q.key.queue.setSelection(state.keyState, req)
+	case key.FocusCmd:
+		state.keyState, evts = q.key.queue.Focus(q.handlers, state.keyState, req.Tag)
+	case key.SoftKeyboardCmd:
+		state.keyState = state.keyState.softKeyboard(req.Show)
+	case key.SnippetCmd:
+		state.keyState = q.key.queue.setSnippet(state.keyState, req)
+	case transfer.OfferCmd:
+		state.pointerState, evts = q.pointer.queue.offerData(q.handlers, state.pointerState, req)
+	case clipboard.WriteCmd:
+		q.cqueue.ProcessWriteClipboard(req)
+	case clipboard.ReadCmd:
+		state.clipboardState = q.cqueue.ProcessReadClipboard(state.clipboardState, req.Tag)
+	case pointer.GrabCmd:
+		state.pointerState, evts = q.pointer.queue.grab(state.pointerState, req)
+	case op.InvalidateCmd:
+		if !q.wakeup || req.At.Before(q.wakeupTime) {
+			q.wakeup = true
+			q.wakeupTime = req.At
+		}
+	}
+	return stateChange{state: state, events: evts}
+}
+
+func (q *Router) changeState(e event.Event, state inputState, evts []taggedEvent) {
+	// Wrap pointer.DataEvent.Open functions to detect them not being called.
+	for i := range evts {
+		e := &evts[i]
+		if de, ok := e.event.(transfer.DataEvent); ok {
+			transferIdx := len(q.transfers)
+			data := de.Open()
+			q.transfers = append(q.transfers, data)
+			de.Open = func() io.ReadCloser {
+				q.transfers[transferIdx] = nil
+				return data
+			}
+			e.event = de
+		}
+	}
+	// Initialize the first change to contain the current state
+	// and events that are bound for the current frame.
+	if len(q.changes) == 0 {
+		q.changes = append(q.changes, stateChange{})
+	}
+	if e != nil && len(evts) > 0 {
+		// An event triggered events bound for user receivers. Add a state change to be
+		// able to redo the change in case of a command execution.
+		q.changes = append(q.changes, stateChange{event: e, state: state, events: evts})
+	} else {
+		// Otherwise, merge with previous change.
+		prev := &q.changes[len(q.changes)-1]
+		prev.state = state
+		prev.events = append(prev.events, evts...)
+	}
+}
+
+func rangeOverlaps(r1, r2 key.Range) bool {
+	r1 = rangeNorm(r1)
+	r2 = rangeNorm(r2)
+	return r1.Start <= r2.Start && r2.Start < r1.End ||
+		r1.Start <= r2.End && r2.End < r1.End
+}
+
+func rangeNorm(r key.Range) key.Range {
+	if r.End < r.Start {
+		r.End, r.Start = r.Start, r.End
+	}
+	return r
+}
+
+func (q *Router) MoveFocus(dir key.FocusDirection) {
+	state := q.lastState()
+	kstate, evts := q.key.queue.MoveFocus(q.handlers, state.keyState, dir)
+	state.keyState = kstate
+	q.changeState(nil, state, evts)
+}
+
+// RevealFocus scrolls the current focus (if any) into viewport
+// if there are scrollable parent handlers.
+func (q *Router) RevealFocus(viewport image.Rectangle) {
+	state := q.lastState()
+	focus := state.focus
+	if focus == nil {
+		return
+	}
+	kh := &q.handlers[focus].key
+	bounds := q.key.queue.BoundsFor(kh)
+	area := q.key.queue.AreaFor(kh)
+	viewport = q.pointer.queue.ClipFor(area, viewport)
+
+	topleft := bounds.Min.Sub(viewport.Min)
+	topleft = maxPoint(topleft, bounds.Max.Sub(viewport.Max))
+	topleft = minPoint(image.Pt(0, 0), topleft)
+	bottomright := bounds.Max.Sub(viewport.Max)
+	bottomright = minPoint(bottomright, bounds.Min.Sub(viewport.Min))
+	bottomright = maxPoint(image.Pt(0, 0), bottomright)
+	s := topleft
+	if s.X == 0 {
+		s.X = bottomright.X
+	}
+	if s.Y == 0 {
+		s.Y = bottomright.Y
+	}
+	q.ScrollFocus(s)
+}
+
+// ScrollFocus scrolls the focused widget, if any, by dist.
+func (q *Router) ScrollFocus(dist image.Point) {
+	state := q.lastState()
+	focus := state.focus
+	if focus == nil {
+		return
+	}
+	kh := &q.handlers[focus].key
+	area := q.key.queue.AreaFor(kh)
+	q.changeState(nil, q.lastState(), q.pointer.queue.Deliver(q.handlers, area, pointer.Event{
+		Kind:   pointer.Scroll,
+		Source: pointer.Touch,
+		Scroll: f32internal.FPt(dist),
+	}))
+}
+
+func maxPoint(p1, p2 image.Point) image.Point {
+	m := p1
+	if p2.X > m.X {
+		m.X = p2.X
+	}
+	if p2.Y > m.Y {
+		m.Y = p2.Y
+	}
+	return m
+}
+
+func minPoint(p1, p2 image.Point) image.Point {
+	m := p1
+	if p2.X < m.X {
+		m.X = p2.X
+	}
+	if p2.Y < m.Y {
+		m.Y = p2.Y
+	}
+	return m
+}
+
+func (q *Router) ActionAt(p f32.Point) (system.Action, bool) {
+	return q.pointer.queue.ActionAt(p)
+}
+
+func (q *Router) ClickFocus() {
+	focus := q.lastState().focus
+	if focus == nil {
+		return
+	}
+	kh := &q.handlers[focus].key
+	bounds := q.key.queue.BoundsFor(kh)
+	center := bounds.Max.Add(bounds.Min).Div(2)
+	e := pointer.Event{
+		Position: f32.Pt(float32(center.X), float32(center.Y)),
+		Source:   pointer.Touch,
+	}
+	area := q.key.queue.AreaFor(kh)
+	e.Kind = pointer.Press
+	state := q.lastState()
+	q.changeState(nil, state, q.pointer.queue.Deliver(q.handlers, area, e))
+	e.Kind = pointer.Release
+	q.changeState(nil, state, q.pointer.queue.Deliver(q.handlers, area, e))
+}
+
+// TextInputState returns the input state from the most recent
+// call to Frame.
+func (q *Router) TextInputState() TextInputState {
+	state := q.state()
+	kstate, s := state.InputState()
+	state.keyState = kstate
+	q.changeState(nil, state, nil)
+	return s
+}
+
+// TextInputHint returns the input mode from the most recent key.InputOp.
+func (q *Router) TextInputHint() (key.InputHint, bool) {
+	return q.key.queue.InputHint(q.handlers, q.state().keyState)
+}
+
+// WriteClipboard returns the most recent content to be copied
+// to the clipboard, if any.
+func (q *Router) WriteClipboard() (mime string, content []byte, ok bool) {
+	return q.cqueue.WriteClipboard()
+}
+
+// ClipboardRequested reports if any new handler is waiting
+// to read the clipboard.
+func (q *Router) ClipboardRequested() bool {
+	return q.cqueue.ClipboardRequested(q.lastState().clipboardState)
+}
+
+// Cursor returns the last cursor set.
+func (q *Router) Cursor() pointer.Cursor {
+	return q.state().cursor
+}
+
+// SemanticAt returns the first semantic description under pos, if any.
+func (q *Router) SemanticAt(pos f32.Point) (SemanticID, bool) {
+	return q.pointer.queue.SemanticAt(pos)
+}
+
+// AppendSemantics appends the semantic tree to nodes, and returns the result.
+// The root node is the first added.
+func (q *Router) AppendSemantics(nodes []SemanticNode) []SemanticNode {
+	q.pointer.collector.q = &q.pointer.queue
+	q.pointer.collector.ensureRoot()
+	return q.pointer.queue.AppendSemantics(nodes)
+}
+
+// EditorState returns the editor state for the focused handler, or the
+// zero value if there is none.
+func (q *Router) EditorState() EditorState {
+	return q.key.queue.editorState(q.handlers, q.state().keyState)
+}
+
+func (q *Router) stateFor(tag event.Tag) *handler {
+	if tag == nil {
+		panic("internal error: nil tag")
+	}
+	s, ok := q.handlers[tag]
+	if !ok {
+		s = new(handler)
+		if q.handlers == nil {
+			q.handlers = make(map[event.Tag]*handler)
+		}
+		q.handlers[tag] = s
+	}
+	s.active = true
+	return s
+}
+
+func (q *Router) collect() {
+	q.transStack = q.transStack[:0]
+	pc := &q.pointer.collector
+	pc.q = &q.pointer.queue
+	pc.Reset()
+	kq := &q.key.queue
+	q.key.queue.Reset()
+	t := f32.AffineId()
+	for encOp, ok := q.reader.Decode(); ok; encOp, ok = q.reader.Decode() {
+		switch ops.OpType(encOp.Data[0]) {
+		case ops.TypeSave:
+			id := ops.DecodeSave(encOp.Data)
+			if extra := id - len(q.savedTrans) + 1; extra > 0 {
+				for range extra {
+					q.savedTrans = append(q.savedTrans, f32.AffineId())
+				}
+			}
+			q.savedTrans[id] = t
+		case ops.TypeLoad:
+			id := ops.DecodeLoad(encOp.Data)
+			t = q.savedTrans[id]
+			pc.resetState()
+			pc.setTrans(t)
+
+		case ops.TypeClip:
+			var op ops.ClipOp
+			op.Decode(encOp.Data)
+			pc.clip(op)
+		case ops.TypePopClip:
+			pc.popArea()
+		case ops.TypeTransform:
+			t2, push := ops.DecodeTransform(encOp.Data)
+			if push {
+				q.transStack = append(q.transStack, t)
+			}
+			t = t.Mul(t2)
+			pc.setTrans(t)
+		case ops.TypePopTransform:
+			n := len(q.transStack)
+			t = q.transStack[n-1]
+			q.transStack = q.transStack[:n-1]
+			pc.setTrans(t)
+
+		case ops.TypeInput:
+			tag := encOp.Refs[0].(event.Tag)
+			s := q.stateFor(tag)
+			pc.inputOp(tag, &s.pointer)
+			a := pc.currentArea()
+			b := pc.currentAreaBounds()
+			if s.filter.focusable {
+				kq.inputOp(tag, &s.key, t, a, b)
+			}
+
+		// Pointer ops.
+		case ops.TypePass:
+			pc.pass()
+		case ops.TypePopPass:
+			pc.popPass()
+		case ops.TypeCursor:
+			name := pointer.Cursor(encOp.Data[1])
+			pc.cursor(name)
+		case ops.TypeActionInput:
+			act := system.Action(encOp.Data[1])
+			pc.actionInputOp(act)
+		case ops.TypeKeyInputHint:
+			op := key.InputHintOp{
+				Tag:  encOp.Refs[0].(event.Tag),
+				Hint: key.InputHint(encOp.Data[1]),
+			}
+			s := q.stateFor(op.Tag)
+			s.key.inputHint(op.Hint)
+
+		// Semantic ops.
+		case ops.TypeSemanticLabel:
+			lbl := *encOp.Refs[0].(*string)
+			pc.semanticLabel(lbl)
+		case ops.TypeSemanticDesc:
+			desc := *encOp.Refs[0].(*string)
+			pc.semanticDesc(desc)
+		case ops.TypeSemanticClass:
+			class := semantic.ClassOp(encOp.Data[1])
+			pc.semanticClass(class)
+		case ops.TypeSemanticSelected:
+			if encOp.Data[1] != 0 {
+				pc.semanticSelected(true)
+			} else {
+				pc.semanticSelected(false)
+			}
+		case ops.TypeSemanticEnabled:
+			if encOp.Data[1] != 0 {
+				pc.semanticEnabled(true)
+			} else {
+				pc.semanticEnabled(false)
+			}
+		}
+	}
+}
+
+// WakeupTime returns the most recent time for doing another frame,
+// as determined from the last call to Frame.
+func (q *Router) WakeupTime() (time.Time, bool) {
+	t, w := q.wakeupTime, q.wakeup
+	q.wakeup = false
+	// Pending events always trigger wakeups.
+	if len(q.changes) > 1 || len(q.changes) == 1 && len(q.changes[0].events) > 0 {
+		t, w = time.Time{}, true
+	}
+	return t, w
+}
+
+func (s SemanticGestures) String() string {
+	var gestures []string
+	if s&ClickGesture != 0 {
+		gestures = append(gestures, "Click")
+	}
+	return strings.Join(gestures, ",")
+}
+
+func (SystemEvent) ImplementsEvent() {}