From 3944ef4b2e468f38bcc5d1f5631f9cc4218da72e Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Tue, 24 Sep 2019 22:11:44 +0200
Subject: [PATCH] ui: merge package input

Event handling is as fundamental as operations, so move the input
package declarations to package ui.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 ui/app/doc.go                    |  6 ++--
 ui/app/internal/input/key.go     | 17 ++++++-----
 ui/app/internal/input/pointer.go | 19 ++++++-------
 ui/app/internal/input/router.go  | 19 ++++++-------
 ui/app/window.go                 | 32 ++++++++++-----------
 ui/doc.go                        | 27 ++++++++++++++++++
 ui/gesture/gesture.go            |  7 ++---
 ui/input.go                      | 20 +++++++++++++
 ui/input/input.go                | 48 --------------------------------
 ui/key/key.go                    | 12 ++++----
 ui/layout/layout.go              |  5 ++--
 ui/layout/layout_test.go         |  3 +-
 ui/pointer/doc.go                |  7 ++---
 ui/pointer/pointer.go            |  5 ++--
 ui/system/system.go              |  3 +-
 15 files changed, 108 insertions(+), 122 deletions(-)
 create mode 100644 ui/input.go
 delete mode 100644 ui/input/input.go

diff --git a/ui/app/doc.go b/ui/app/doc.go
index 52379bea..a78201c5 100644
--- a/ui/app/doc.go
+++ b/ui/app/doc.go
@@ -57,9 +57,9 @@ For example, to display a blank but otherwise functional window:
 
 Event queue
 
-A Window's Queue method returns an input.Queue implementation that distributes
-incoming events to the input handlers declared in the latest call to Update.
-See the gioui.org/ui/input package for more information about input handlers.
+A Window's Queue method returns an ui.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.
 
 */
 package app
diff --git a/ui/app/internal/input/key.go b/ui/app/internal/input/key.go
index 1db60bf6..d2c95bf1 100644
--- a/ui/app/internal/input/key.go
+++ b/ui/app/internal/input/key.go
@@ -4,7 +4,6 @@ package input
 
 import (
 	"gioui.org/ui"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/opconst"
 	"gioui.org/ui/internal/ops"
 	"gioui.org/ui/key"
@@ -13,8 +12,8 @@ import (
 type TextInputState uint8
 
 type keyQueue struct {
-	focus    input.Key
-	handlers map[input.Key]*keyHandler
+	focus    ui.Key
+	handlers map[ui.Key]*keyHandler
 	reader   ops.Reader
 	state    TextInputState
 }
@@ -46,7 +45,7 @@ func (q *keyQueue) InputState() TextInputState {
 
 func (q *keyQueue) Frame(root *ui.Ops, events *handlerEvents) {
 	if q.handlers == nil {
-		q.handlers = make(map[input.Key]*keyHandler)
+		q.handlers = make(map[ui.Key]*keyHandler)
 	}
 	for _, h := range q.handlers {
 		h.active = false
@@ -83,14 +82,14 @@ func (q *keyQueue) Frame(root *ui.Ops, events *handlerEvents) {
 	}
 }
 
-func (q *keyQueue) Push(e input.Event, events *handlerEvents) {
+func (q *keyQueue) Push(e ui.Event, events *handlerEvents) {
 	if q.focus != nil {
 		events.Add(q.focus, e)
 	}
 }
 
-func (q *keyQueue) resolveFocus(events *handlerEvents) (input.Key, listenerPriority, bool) {
-	var k input.Key
+func (q *keyQueue) resolveFocus(events *handlerEvents) (ui.Key, listenerPriority, bool) {
+	var k ui.Key
 	var pri listenerPriority
 	var hide bool
 loop:
@@ -116,7 +115,7 @@ loop:
 				h = new(keyHandler)
 				q.handlers[op.Key] = h
 				// Reset the handler on (each) first appearance.
-				events.Set(op.Key, []input.Event{key.FocusEvent{Focus: false}})
+				events.Set(op.Key, []ui.Event{key.FocusEvent{Focus: false}})
 			}
 			h.active = true
 		case opconst.TypeHideInput:
@@ -145,6 +144,6 @@ func decodeKeyInputOp(d []byte, refs []interface{}) key.InputOp {
 	}
 	return key.InputOp{
 		Focus: d[1] != 0,
-		Key:   refs[0].(input.Key),
+		Key:   refs[0].(ui.Key),
 	}
 }
diff --git a/ui/app/internal/input/pointer.go b/ui/app/internal/input/pointer.go
index 64c86547..31de1f68 100644
--- a/ui/app/internal/input/pointer.go
+++ b/ui/app/internal/input/pointer.go
@@ -8,7 +8,6 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/f32"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/opconst"
 	"gioui.org/ui/internal/ops"
 	"gioui.org/ui/pointer"
@@ -17,10 +16,10 @@ import (
 type pointerQueue struct {
 	hitTree  []hitNode
 	areas    []areaNode
-	handlers map[input.Key]*pointerHandler
+	handlers map[ui.Key]*pointerHandler
 	pointers []pointerInfo
 	reader   ops.Reader
-	scratch  []input.Key
+	scratch  []ui.Key
 }
 
 type hitNode struct {
@@ -30,13 +29,13 @@ type hitNode struct {
 	pass bool
 
 	// For handler nodes.
-	key input.Key
+	key ui.Key
 }
 
 type pointerInfo struct {
 	id       pointer.ID
 	pressed  bool
-	handlers []input.Key
+	handlers []ui.Key
 }
 
 type pointerHandler struct {
@@ -101,7 +100,7 @@ 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, []input.Event{pointer.Event{Type: pointer.Cancel}})
+				events.Set(op.Key, []ui.Event{pointer.Event{Type: pointer.Cancel}})
 			}
 			h.active = true
 			h.area = area
@@ -111,7 +110,7 @@ func (q *pointerQueue) collectHandlers(r *ops.Reader, events *handlerEvents, t u
 	}
 }
 
-func (q *pointerQueue) opHit(handlers *[]input.Key, pos f32.Point) {
+func (q *pointerQueue) opHit(handlers *[]ui.Key, pos f32.Point) {
 	// Track whether we're passing through hits.
 	pass := true
 	idx := len(q.hitTree) - 1
@@ -154,7 +153,7 @@ func (a *areaNode) hit(p f32.Point) bool {
 
 func (q *pointerQueue) init() {
 	if q.handlers == nil {
-		q.handlers = make(map[input.Key]*pointerHandler)
+		q.handlers = make(map[ui.Key]*pointerHandler)
 	}
 }
 
@@ -176,7 +175,7 @@ func (q *pointerQueue) Frame(root *ui.Ops, events *handlerEvents) {
 	}
 }
 
-func (q *pointerQueue) dropHandler(k input.Key) {
+func (q *pointerQueue) dropHandler(k ui.Key) {
 	for i := range q.pointers {
 		p := &q.pointers[i]
 		for i := len(p.handlers) - 1; i >= 0; i-- {
@@ -320,7 +319,7 @@ func decodePointerInputOp(d []byte, refs []interface{}) pointer.InputOp {
 	}
 	return pointer.InputOp{
 		Grab: d[1] != 0,
-		Key:  refs[0].(input.Key),
+		Key:  refs[0].(ui.Key),
 	}
 }
 
diff --git a/ui/app/internal/input/router.go b/ui/app/internal/input/router.go
index 3f4ef28e..a70cdfa6 100644
--- a/ui/app/internal/input/router.go
+++ b/ui/app/internal/input/router.go
@@ -7,7 +7,6 @@ import (
 	"time"
 
 	"gioui.org/ui"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/opconst"
 	"gioui.org/ui/internal/ops"
 	"gioui.org/ui/key"
@@ -30,15 +29,15 @@ type Router struct {
 	wakeupTime time.Time
 
 	// ProfileOp summary.
-	profHandlers []input.Key
+	profHandlers []ui.Key
 }
 
 type handlerEvents struct {
-	handlers map[input.Key][]input.Event
+	handlers map[ui.Key][]ui.Event
 	updated  bool
 }
 
-func (q *Router) Next(k input.Key) (input.Event, bool) {
+func (q *Router) Next(k ui.Key) (ui.Event, bool) {
 	return q.handlers.Next(k)
 }
 
@@ -57,7 +56,7 @@ func (q *Router) Frame(ops *ui.Ops) {
 	}
 }
 
-func (q *Router) Add(e input.Event) bool {
+func (q *Router) Add(e ui.Event) bool {
 	switch e := e.(type) {
 	case pointer.Event:
 		q.pqueue.Push(e, &q.handlers)
@@ -103,17 +102,17 @@ func (q *Router) WakeupTime() (time.Time, bool) {
 
 func (h *handlerEvents) init() {
 	if h.handlers == nil {
-		h.handlers = make(map[input.Key][]input.Event)
+		h.handlers = make(map[ui.Key][]ui.Event)
 	}
 }
 
-func (h *handlerEvents) Set(k input.Key, evts []input.Event) {
+func (h *handlerEvents) Set(k ui.Key, evts []ui.Event) {
 	h.init()
 	h.handlers[k] = evts
 	h.updated = true
 }
 
-func (h *handlerEvents) Add(k input.Key, e input.Event) {
+func (h *handlerEvents) Add(k ui.Key, e ui.Event) {
 	h.init()
 	h.handlers[k] = append(h.handlers[k], e)
 	h.updated = true
@@ -125,7 +124,7 @@ func (h *handlerEvents) Updated() bool {
 	return u
 }
 
-func (h *handlerEvents) Next(k input.Key) (input.Event, bool) {
+func (h *handlerEvents) Next(k ui.Key) (ui.Event, bool) {
 	events := h.handlers[k]
 	if len(events) == 0 {
 		return nil, false
@@ -146,7 +145,7 @@ func decodeProfileOp(d []byte, refs []interface{}) system.ProfileOp {
 		panic("invalid op")
 	}
 	return system.ProfileOp{
-		Key: refs[0].(input.Key),
+		Key: refs[0].(ui.Key),
 	}
 }
 
diff --git a/ui/app/window.go b/ui/app/window.go
index 0854d400..3f90a7d8 100644
--- a/ui/app/window.go
+++ b/ui/app/window.go
@@ -10,8 +10,7 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/app/internal/gpu"
-	iinput "gioui.org/ui/app/internal/input"
-	"gioui.org/ui/input"
+	"gioui.org/ui/app/internal/input"
 	"gioui.org/ui/system"
 )
 
@@ -32,8 +31,8 @@ type Window struct {
 	drawStart time.Time
 	gpu       *gpu.GPU
 
-	out         chan input.Event
-	in          chan input.Event
+	out         chan ui.Event
+	in          chan ui.Event
 	ack         chan struct{}
 	invalidates chan struct{}
 	frames      chan *ui.Ops
@@ -47,11 +46,10 @@ type Window struct {
 	queue Queue
 }
 
-// Queue is an input.Queue implementation that distributes
-// system input events to the input handlers declared in the
-// most recent call to Update.
+// Queue is an ui.Queue implementation that distributes system events
+// to the input handlers declared in the most recent call to Update.
 type Queue struct {
-	q iinput.Router
+	q input.Router
 }
 
 // driverEvent is sent when a new native driver
@@ -71,7 +69,7 @@ var _ interface {
 } = (*window)(nil)
 
 // Pre-allocate the ack event to avoid garbage.
-var ackEvent input.Event
+var ackEvent ui.Event
 
 // NewWindow creates a new window for a set of window
 // options. The options are hints; the platform is free to
@@ -96,8 +94,8 @@ func NewWindow(options ...WindowOption) *Window {
 	}
 
 	w := &Window{
-		in:          make(chan input.Event),
-		out:         make(chan input.Event),
+		in:          make(chan ui.Event),
+		out:         make(chan ui.Event),
 		ack:         make(chan struct{}),
 		invalidates: make(chan struct{}, 1),
 		frames:      make(chan *ui.Ops),
@@ -107,7 +105,7 @@ func NewWindow(options ...WindowOption) *Window {
 }
 
 // Events returns the channel where events are delivered.
-func (w *Window) Events() <-chan input.Event {
+func (w *Window) Events() <-chan ui.Event {
 	return w.out
 }
 
@@ -135,9 +133,9 @@ func (w *Window) draw(size image.Point, frame *ui.Ops) {
 	w.queue.q.Frame(frame)
 	now := time.Now()
 	switch w.queue.q.TextInputState() {
-	case iinput.TextInputOpen:
+	case input.TextInputOpen:
 		w.driver.showTextInput(true)
-	case iinput.TextInputClose:
+	case input.TextInputClose:
 		w.driver.showTextInput(false)
 	}
 	frameDur := now.Sub(w.lastFrame)
@@ -196,7 +194,7 @@ func (w *Window) setDriver(d *window) {
 	w.event(driverEvent{d})
 }
 
-func (w *Window) event(e input.Event) {
+func (w *Window) event(e ui.Event) {
 	w.in <- e
 	<-w.ack
 }
@@ -313,7 +311,7 @@ func (w *Window) run(opts *windowOptions) {
 				w.out <- e2
 				w.ack <- struct{}{}
 				return
-			case input.Event:
+			case ui.Event:
 				if w.queue.q.Add(e2) {
 					w.setNextFrame(time.Time{})
 					w.updateAnimation()
@@ -325,7 +323,7 @@ func (w *Window) run(opts *windowOptions) {
 	}
 }
 
-func (q *Queue) Next(k input.Key) (input.Event, bool) {
+func (q *Queue) Next(k ui.Key) (ui.Event, bool) {
 	return q.q.Next(k)
 }
 
diff --git a/ui/doc.go b/ui/doc.go
index 65a7c36e..f46d9681 100644
--- a/ui/doc.go
+++ b/ui/doc.go
@@ -80,5 +80,32 @@ size vary between platforms and displays.
 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, ok := queue.Next(h); ok; e, ok = queue.Next(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/ui/key
+
+	ops := new(ui.Ops)
+	var h *Handler = ...
+	key.InputOp{Key: h}.Add(ops)
+
 */
 package ui
diff --git a/ui/gesture/gesture.go b/ui/gesture/gesture.go
index db6dc00a..5e58638c 100644
--- a/ui/gesture/gesture.go
+++ b/ui/gesture/gesture.go
@@ -3,7 +3,7 @@
 /*
 Package gesture implements common pointer gestures.
 
-Gestures accept low level pointer Events from an input
+Gestures accept low level pointer Events from an event
 Queue and detect higher level actions such as clicks
 and scrolling.
 */
@@ -14,7 +14,6 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/f32"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/fling"
 	"gioui.org/ui/pointer"
 )
@@ -106,7 +105,7 @@ func (c *Click) State() ClickState {
 }
 
 // Next returns the next click event, if any.
-func (c *Click) Next(q input.Queue) (ClickEvent, bool) {
+func (c *Click) Next(q ui.Queue) (ClickEvent, bool) {
 	for evt, ok := q.Next(c); ok; evt, ok = q.Next(c) {
 		e, ok := evt.(pointer.Event)
 		if !ok {
@@ -154,7 +153,7 @@ 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 input.Queue, axis Axis) int {
+func (s *Scroll) Scroll(cfg ui.Config, q ui.Queue, axis Axis) int {
 	if s.axis != axis {
 		s.axis = axis
 		return 0
diff --git a/ui/input.go b/ui/input.go
new file mode 100644
index 00000000..9b85a6f7
--- /dev/null
+++ b/ui/input.go
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package ui
+
+// Queue maps an event handler key to the events
+// available to the handler.
+type Queue interface {
+	// Next returns the next available event, or
+	// false if none are available.
+	Next(k Key) (Event, bool)
+}
+
+// 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()
+}
diff --git a/ui/input/input.go b/ui/input/input.go
deleted file mode 100644
index 47905624..00000000
--- a/ui/input/input.go
+++ /dev/null
@@ -1,48 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-/*
-Package input exposes a unified interface for receiving input
-events.
-
-For example:
-
-	var queue input.Queue = ...
-
-	for e, ok := queue.Next(h); ok; e, ok = queue.Next(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 input types.
-
-The following example marks a handler ready for key input:
-
-	import gioui.org/ui/input
-	import gioui.org/ui/key
-
-	ops := new(ui.Ops)
-	var h *Handler = ...
-	key.InputOp{Key: h}.Add(ops)
-
-*/
-package input
-
-// Queue maps an event handler key to the events
-// available to the handler.
-type Queue interface {
-	// Next returns the next available event, or
-	// false if none are available.
-	Next(k Key) (Event, bool)
-}
-
-// 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()
-}
diff --git a/ui/key/key.go b/ui/key/key.go
index cccac527..85683f07 100644
--- a/ui/key/key.go
+++ b/ui/key/key.go
@@ -1,18 +1,16 @@
 // SPDX-License-Identifier: Unlicense OR MIT
 
 /*
-Package key implements key and text events and
-operations.
+Package key implements key and text events and operations.
 
-The InputOp operations is used for declaring key
-input handlers. Use the Queue interface from package
-input to receive events.
+The InputOp operations is used for declaring key input handlers. Use
+an implementation of the Queue interface from package ui to receive
+events.
 */
 package key
 
 import (
 	"gioui.org/ui"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/opconst"
 )
 
@@ -21,7 +19,7 @@ import (
 // focused key handler. Set the Focus flag to request
 // the focus.
 type InputOp struct {
-	Key   input.Key
+	Key   ui.Key
 	Focus bool
 }
 
diff --git a/ui/layout/layout.go b/ui/layout/layout.go
index 802e3853..a9b78e11 100644
--- a/ui/layout/layout.go
+++ b/ui/layout/layout.go
@@ -6,7 +6,6 @@ import (
 	"image"
 
 	"gioui.org/ui"
-	"gioui.org/ui/input"
 )
 
 // Constraints represent a set of acceptable ranges for
@@ -38,7 +37,7 @@ type Alignment uint8
 // space.
 type Direction uint8
 
-// Widget is a function scope for drawing, processing input and
+// Widget is a function scope for drawing, processing events and
 // computing dimensions for a user interface element.
 type Widget func()
 
@@ -52,7 +51,7 @@ type Context struct {
 	Dimensions Dimensions
 
 	ui.Config
-	input.Queue
+	ui.Queue
 	*ui.Ops
 }
 
diff --git a/ui/layout/layout_test.go b/ui/layout/layout_test.go
index 8f9deb81..d95ca747 100644
--- a/ui/layout/layout_test.go
+++ b/ui/layout/layout_test.go
@@ -6,7 +6,6 @@ import (
 	"time"
 
 	"gioui.org/ui"
-	"gioui.org/ui/input"
 	"gioui.org/ui/layout"
 )
 
@@ -150,6 +149,6 @@ func (config) Px(v ui.Value) int {
 	return int(v.V + .5)
 }
 
-func (queue) Next(k input.Key) (input.Event, bool) {
+func (queue) Next(k ui.Key) (ui.Event, bool) {
 	return nil, false
 }
diff --git a/ui/pointer/doc.go b/ui/pointer/doc.go
index b532ef01..94585baf 100644
--- a/ui/pointer/doc.go
+++ b/ui/pointer/doc.go
@@ -5,9 +5,8 @@ Package pointer implements pointer events and operations.
 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 Queue from package input to
-receive events.
+The InputOp operation is used to declare a handler ready for pointer
+events. Use a ui.Queue to receive events.
 
 Areas
 
@@ -72,7 +71,7 @@ drawer handle and the interface below should receive pointer events.
 
 Disambiguation
 
-When more than one handler matches a pointer event, the input queue
+When more than one handler matches a pointer event, the event queue
 follows a set of rules for distributing the event.
 
 As long as the pointer has not received a Press event, all
diff --git a/ui/pointer/pointer.go b/ui/pointer/pointer.go
index 1f73c356..7a9dfea4 100644
--- a/ui/pointer/pointer.go
+++ b/ui/pointer/pointer.go
@@ -9,7 +9,6 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/f32"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/opconst"
 )
 
@@ -64,7 +63,7 @@ type areaOp struct {
 // InputOp declares an input handler ready for pointer
 // events.
 type InputOp struct {
-	Key input.Key
+	Key ui.Key
 	// Grab, if set, request that the handler get
 	// Grabbed priority.
 	Grab bool
@@ -86,7 +85,7 @@ type Priority uint8
 // Source of an Event.
 type Source uint8
 
-// Must match input.areaKind
+// Must match app/internal/input.areaKind
 type areaKind uint8
 
 const (
diff --git a/ui/system/system.go b/ui/system/system.go
index 8f7c0b13..fb4eced6 100644
--- a/ui/system/system.go
+++ b/ui/system/system.go
@@ -6,14 +6,13 @@ package system
 
 import (
 	"gioui.org/ui"
-	"gioui.org/ui/input"
 	"gioui.org/ui/internal/opconst"
 )
 
 // ProfileOp registers a handler for receiving
 // ProfileEvents.
 type ProfileOp struct {
-	Key input.Key
+	Key ui.Key
 }
 
 // ProfileEvent contain profile data from a single