io/event: move event types from package ui to its own package

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/doc.go

@@ -57,7 +57,7 @@ For example, to display a blank but otherwise functional window:
 
 Event queue
 
-A Window's Queue method returns an ui.Queue implementation that distributes
+A Window's Queue method returns an event.Queue implementation that distributes
 incoming events to the event handlers declared in the latest call to Update.
 See the gioui.org/ui package for more information about event handlers.
 

app/internal/input/key.go

@@ -5,6 +5,7 @@ package input
 import (
 	"gioui.org/internal/opconst"
 	"gioui.org/internal/ops"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/ui"
 )
@@ -12,8 +13,8 @@ import (
 type TextInputState uint8
 
 type keyQueue struct {
-	focus    ui.Key
+	focus    event.Key
-	handlers map[ui.Key]*keyHandler
+	handlers map[event.Key]*keyHandler
 	reader   ops.Reader
 	state    TextInputState
 }
@@ -45,7 +46,7 @@ func (q *keyQueue) InputState() TextInputState {
 
 func (q *keyQueue) Frame(root *ui.Ops, events *handlerEvents) {
 	if q.handlers == nil {
-		q.handlers = make(map[ui.Key]*keyHandler)
+		q.handlers = make(map[event.Key]*keyHandler)
 	}
 	for _, h := range q.handlers {
 		h.active = false
@@ -82,14 +83,14 @@ func (q *keyQueue) Frame(root *ui.Ops, events *handlerEvents) {
 	}
 }
 
-func (q *keyQueue) Push(e ui.Event, events *handlerEvents) {
+func (q *keyQueue) Push(e event.Event, events *handlerEvents) {
 	if q.focus != nil {
 		events.Add(q.focus, e)
 	}
 }
 
-func (q *keyQueue) resolveFocus(events *handlerEvents) (ui.Key, listenerPriority, bool) {
+func (q *keyQueue) resolveFocus(events *handlerEvents) (event.Key, listenerPriority, bool) {
-	var k ui.Key
+	var k event.Key
 	var pri listenerPriority
 	var hide bool
 loop:
@@ -115,7 +116,7 @@ loop:
 				h = new(keyHandler)
 				q.handlers[op.Key] = h
 				// Reset the handler on (each) first appearance.
-				events.Set(op.Key, []ui.Event{key.FocusEvent{Focus: false}})
+				events.Set(op.Key, []event.Event{key.FocusEvent{Focus: false}})
 			}
 			h.active = true
 		case opconst.TypeHideInput:
@@ -144,6 +145,6 @@ func decodeKeyInputOp(d []byte, refs []interface{}) key.InputOp {
 	}
 	return key.InputOp{
 		Focus: d[1] != 0,
-		Key:   refs[0].(ui.Key),
+		Key:   refs[0].(event.Key),
 	}
 }

app/internal/input/pointer.go

@@ -9,6 +9,7 @@ import (
 	"gioui.org/f32"
 	"gioui.org/internal/opconst"
 	"gioui.org/internal/ops"
+	"gioui.org/io/event"
 	"gioui.org/io/pointer"
 	"gioui.org/ui"
 )
@@ -16,10 +17,10 @@ import (
 type pointerQueue struct {
 	hitTree  []hitNode
 	areas    []areaNode
-	handlers map[ui.Key]*pointerHandler
+	handlers map[event.Key]*pointerHandler
 	pointers []pointerInfo
 	reader   ops.Reader
-	scratch  []ui.Key
+	scratch  []event.Key
 }
 
 type hitNode struct {
@@ -29,13 +30,13 @@ type hitNode struct {
 	pass bool
 
 	// For handler nodes.
-	key ui.Key
+	key event.Key
 }
 
 type pointerInfo struct {
 	id       pointer.ID
 	pressed  bool
-	handlers []ui.Key
+	handlers []event.Key
 }
 
 type pointerHandler struct {
@@ -100,7 +101,7 @@ func (q *pointerQueue) collectHandlers(r *ops.Reader, events *handlerEvents, t u
 			if !ok {
 				h = new(pointerHandler)
 				q.handlers[op.Key] = h
-				events.Set(op.Key, []ui.Event{pointer.Event{Type: pointer.Cancel}})
+				events.Set(op.Key, []event.Event{pointer.Event{Type: pointer.Cancel}})
 			}
 			h.active = true
 			h.area = area
@@ -110,7 +111,7 @@ func (q *pointerQueue) collectHandlers(r *ops.Reader, events *handlerEvents, t u
 	}
 }
 
-func (q *pointerQueue) opHit(handlers *[]ui.Key, pos f32.Point) {
+func (q *pointerQueue) opHit(handlers *[]event.Key, pos f32.Point) {
 	// Track whether we're passing through hits.
 	pass := true
 	idx := len(q.hitTree) - 1
@@ -153,7 +154,7 @@ func (a *areaNode) hit(p f32.Point) bool {
 
 func (q *pointerQueue) init() {
 	if q.handlers == nil {
-		q.handlers = make(map[ui.Key]*pointerHandler)
+		q.handlers = make(map[event.Key]*pointerHandler)
 	}
 }
 
@@ -175,7 +176,7 @@ func (q *pointerQueue) Frame(root *ui.Ops, events *handlerEvents) {
 	}
 }
 
-func (q *pointerQueue) dropHandler(k ui.Key) {
+func (q *pointerQueue) dropHandler(k event.Key) {
 	for i := range q.pointers {
 		p := &q.pointers[i]
 		for i := len(p.handlers) - 1; i >= 0; i-- {
@@ -319,7 +320,7 @@ func decodePointerInputOp(d []byte, refs []interface{}) pointer.InputOp {
 	}
 	return pointer.InputOp{
 		Grab: d[1] != 0,
-		Key:  refs[0].(ui.Key),
+		Key:  refs[0].(event.Key),
 	}
 }
 

app/internal/input/router.go

@@ -8,6 +8,7 @@ import (
 
 	"gioui.org/internal/opconst"
 	"gioui.org/internal/ops"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/io/profile"
@@ -38,15 +39,15 @@ type Router struct {
 	wakeupTime time.Time
 
 	// ProfileOp summary.
-	profHandlers []ui.Key
+	profHandlers []event.Key
 }
 
 type handlerEvents struct {
-	handlers  map[ui.Key][]ui.Event
+	handlers  map[event.Key][]event.Event
 	hadEvents bool
 }
 
-func (q *Router) Events(k ui.Key) []ui.Event {
+func (q *Router) Events(k event.Key) []event.Event {
 	events := q.handlers.Events(k)
 	q.deliveredEvents = q.deliveredEvents || len(events) > 0
 	return events
@@ -68,7 +69,7 @@ func (q *Router) Frame(ops *ui.Ops) {
 	}
 }
 
-func (q *Router) Add(e ui.Event) bool {
+func (q *Router) Add(e event.Event) bool {
 	switch e := e.(type) {
 	case pointer.Event:
 		q.pqueue.Push(e, &q.handlers)
@@ -114,17 +115,17 @@ func (q *Router) WakeupTime() (time.Time, bool) {
 
 func (h *handlerEvents) init() {
 	if h.handlers == nil {
-		h.handlers = make(map[ui.Key][]ui.Event)
+		h.handlers = make(map[event.Key][]event.Event)
 	}
 }
 
-func (h *handlerEvents) Set(k ui.Key, evts []ui.Event) {
+func (h *handlerEvents) Set(k event.Key, evts []event.Event) {
 	h.init()
 	h.handlers[k] = evts
 	h.hadEvents = true
 }
 
-func (h *handlerEvents) Add(k ui.Key, e ui.Event) {
+func (h *handlerEvents) Add(k event.Key, e event.Event) {
 	h.init()
 	h.handlers[k] = append(h.handlers[k], e)
 	h.hadEvents = true
@@ -136,7 +137,7 @@ func (h *handlerEvents) HadEvents() bool {
 	return u
 }
 
-func (h *handlerEvents) Events(k ui.Key) []ui.Event {
+func (h *handlerEvents) Events(k event.Key) []event.Event {
 	if events, ok := h.handlers[k]; ok {
 		h.handlers[k] = h.handlers[k][:0]
 		return events
@@ -155,7 +156,7 @@ func decodeProfileOp(d []byte, refs []interface{}) profile.Op {
 		panic("invalid op")
 	}
 	return profile.Op{
-		Key: refs[0].(ui.Key),
+		Key: refs[0].(event.Key),
 	}
 }
 

app/window.go

@@ -10,6 +10,7 @@ import (
 
 	"gioui.org/app/internal/gpu"
 	"gioui.org/app/internal/input"
+	"gioui.org/io/event"
 	"gioui.org/io/profile"
 	"gioui.org/ui"
 )
@@ -31,8 +32,8 @@ type Window struct {
 	drawStart time.Time
 	gpu       *gpu.GPU
 
-	out         chan ui.Event
+	out         chan event.Event
-	in          chan ui.Event
+	in          chan event.Event
 	ack         chan struct{}
 	invalidates chan struct{}
 	frames      chan *ui.Ops
@@ -46,7 +47,7 @@ type Window struct {
 	queue Queue
 }
 
-// Queue is an ui.Queue implementation that distributes system events
+// Queue is an event.Queue implementation that distributes system events
 // to the input handlers declared in the most recent call to Update.
 type Queue struct {
 	q input.Router
@@ -69,7 +70,7 @@ var _ interface {
 } = (*window)(nil)
 
 // Pre-allocate the ack event to avoid garbage.
-var ackEvent ui.Event
+var ackEvent event.Event
 
 // NewWindow creates a new window for a set of window
 // options. The options are hints; the platform is free to
@@ -94,8 +95,8 @@ func NewWindow(options ...WindowOption) *Window {
 	}
 
 	w := &Window{
-		in:          make(chan ui.Event),
+		in:          make(chan event.Event),
-		out:         make(chan ui.Event),
+		out:         make(chan event.Event),
 		ack:         make(chan struct{}),
 		invalidates: make(chan struct{}, 1),
 		frames:      make(chan *ui.Ops),
@@ -105,7 +106,7 @@ func NewWindow(options ...WindowOption) *Window {
 }
 
 // Events returns the channel where events are delivered.
-func (w *Window) Events() <-chan ui.Event {
+func (w *Window) Events() <-chan event.Event {
 	return w.out
 }
 
@@ -194,7 +195,7 @@ func (w *Window) setDriver(d *window) {
 	w.event(driverEvent{d})
 }
 
-func (w *Window) event(e ui.Event) {
+func (w *Window) event(e event.Event) {
 	w.in <- e
 	<-w.ack
 }
@@ -311,7 +312,7 @@ func (w *Window) run(opts *windowOptions) {
 				w.out <- e2
 				w.ack <- struct{}{}
 				return
-			case ui.Event:
+			case event.Event:
 				if w.queue.q.Add(e2) {
 					w.setNextFrame(time.Time{})
 					w.updateAnimation()
@@ -323,7 +324,7 @@ func (w *Window) run(opts *windowOptions) {
 	}
 }
 
-func (q *Queue) Events(k ui.Key) []ui.Event {
+func (q *Queue) Events(k event.Key) []event.Event {
 	return q.q.Events(k)
 }
 

gesture/gesture.go

@@ -14,6 +14,7 @@ import (
 
 	"gioui.org/f32"
 	"gioui.org/internal/fling"
+	"gioui.org/io/event"
 	"gioui.org/io/pointer"
 	"gioui.org/ui"
 )
@@ -105,7 +106,7 @@ func (c *Click) State() ClickState {
 }
 
 // Events returns the next click event, if any.
-func (c *Click) Events(q ui.Queue) []ClickEvent {
+func (c *Click) Events(q event.Queue) []ClickEvent {
 	var events []ClickEvent
 	for _, evt := range q.Events(c) {
 		e, ok := evt.(pointer.Event)
@@ -154,7 +155,7 @@ func (s *Scroll) Stop() {
 
 // Scroll detects the scrolling distance from the available events and
 // ongoing fling gestures.
-func (s *Scroll) Scroll(cfg ui.Config, q ui.Queue, axis Axis) int {
+func (s *Scroll) Scroll(cfg ui.Config, q event.Queue, axis Axis) int {
 	if s.axis != axis {
 		s.axis = axis
 		return 0

io/event/event.go

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+/*
+Package event contains the types for event handling.
+
+The Queue interface is the protocol for receiving external events.
+
+For example:
+
+	var queue event.Queue = ...
+
+	for _, e := range queue.Events(h) {
+		switch e.(type) {
+			...
+		}
+	}
+
+In general, handlers must be declared before events become
+available. Other packages such as pointer and key provide
+the means for declaring handlers for specific event types.
+
+The following example declares a handler ready for key input:
+
+	import gioui.org/io/key
+
+	ops := new(ui.Ops)
+	var h *Handler = ...
+	key.InputOp{Key: h}.Add(ops)
+
+*/
+package event
+
+// Queue maps an event handler key to the events
+// available to the handler.
+type Queue interface {
+	// Events returns the available events for a
+	// Key.
+	Events(k Key) []Event
+}
+
+// Key is the stable identifier for an event handler.
+// For a handler h, the key is typically &h.
+type Key interface{}
+
+// Event is the marker interface for events.
+type Event interface {
+	ImplementsEvent()
+}

io/key/key.go

@@ -10,8 +10,9 @@ events.
 package key
 
 import (
-	"gioui.org/ui"
 	"gioui.org/internal/opconst"
+	"gioui.org/io/event"
+	"gioui.org/ui"
 )
 
 // InputOp declares a handler ready for key events.
@@ -19,7 +20,7 @@ import (
 // focused key handler. Set the Focus flag to request
 // the focus.
 type InputOp struct {
-	Key   ui.Key
+	Key   event.Key
 	Focus bool
 }
 

io/pointer/doc.go

@@ -6,7 +6,7 @@ A pointer is either a mouse controlled cursor or a touch
 object such as a finger.
 
 The InputOp operation is used to declare a handler ready for pointer
-events. Use a ui.Queue to receive events.
+events. Use an event.Queue to receive events.
 
 Areas
 

io/pointer/pointer.go

@@ -7,9 +7,10 @@ import (
 	"image"
 	"time"
 
-	"gioui.org/ui"
 	"gioui.org/f32"
 	"gioui.org/internal/opconst"
+	"gioui.org/io/event"
+	"gioui.org/ui"
 )
 
 // Event is a pointer event.
@@ -63,7 +64,7 @@ type areaOp struct {
 // InputOp declares an input handler ready for pointer
 // events.
 type InputOp struct {
-	Key ui.Key
+	Key event.Key
 	// Grab, if set, request that the handler get
 	// Grabbed priority.
 	Grab bool

io/profile/profile.go

@@ -6,13 +6,14 @@ package profile
 
 import (
 	"gioui.org/internal/opconst"
+	"gioui.org/io/event"
 	"gioui.org/ui"
 )
 
 // Op registers a handler for receiving
 // Events.
 type Op struct {
-	Key ui.Key
+	Key event.Key
 }
 
 // Event contains profile data from a single

layout/layout.go

@@ -5,6 +5,7 @@ package layout
 import (
 	"image"
 
+	"gioui.org/io/event"
 	"gioui.org/ui"
 )
 
@@ -51,7 +52,7 @@ type Context struct {
 	Dimensions Dimensions
 
 	ui.Config
-	ui.Queue
+	event.Queue
 	*ui.Ops
 }
 

layout/layout_test.go

@@ -5,6 +5,7 @@ import (
 	"image"
 	"time"
 
+	"gioui.org/io/event"
 	"gioui.org/layout"
 	"gioui.org/ui"
 )
@@ -149,6 +150,6 @@ func (config) Px(v ui.Value) int {
 	return int(v.V + .5)
 }
 
-func (queue) Events(k ui.Key) []ui.Event {
+func (queue) Events(k event.Key) []event.Event {
 	return nil
 }

text/editor.go

@@ -10,6 +10,7 @@ import (
 	"unicode/utf8"
 
 	"gioui.org/gesture"
+	"gioui.org/io/event"
 	"gioui.org/io/key"
 	"gioui.org/io/pointer"
 	"gioui.org/layout"
@@ -64,7 +65,7 @@ type Editor struct {
 	clicker gesture.Click
 
 	// events is the list of events not yet processed.
-	events []ui.Event
+	events []event.Event
 }
 
 type EditorEvent interface {

ui/doc.go

@@ -81,31 +81,5 @@ To maintain a constant visual size across platforms and displays, always
 use dps or sps to define user interfaces. Only use pixels for derived
 values.
 
-Events
-
-The Queue interface is the protocol for receiving external events.
-
-For example:
-
-	var queue ui.Queue = ...
-
-	for _, e := range queue.Events(h) {
-		switch e.(type) {
-			...
-		}
-	}
-
-In general, handlers must be declared before events become
-available. Other packages such as pointer and key provide
-the means for declaring handlers for specific event types.
-
-The following example declares a handler ready for key input:
-
-	import gioui.org/io/key
-
-	ops := new(ui.Ops)
-	var h *Handler = ...
-	key.InputOp{Key: h}.Add(ops)
-
 */
 package ui

ui/input.go

@@ -1,20 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-package ui
-
-// Queue maps an event handler key to the events
-// available to the handler.
-type Queue interface {
-	// Events returns the available events for a
-	// Key.
-	Events(k Key) []Event
-}
-
-// Key is the stable identifier for an event handler.
-// For a handler h, the key is typically &h.
-type Key interface{}
-
-// Event is the marker interface for events.
-type Event interface {
-	ImplementsEvent()
-}