ui/input: change Events to return all events at once

Single stepping events only makes sense for widgets with complex
state, e.g. the text.Editor. For the input.Events source, returning
all events in a single Events call is sufficient and more natural
for clients.

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

ui/gesture/gestures.go

@@ -82,11 +82,7 @@ func (c *Click) Add(ops *ui.Ops) {
 }
 
 func (c *Click) Next(q input.Events) (ClickEvent, bool) {
-	for {
-		evt, ok := q.Next(c)
-		if !ok {
-			break
-		}
+	for _, evt := range q.Events(c) {
 		e, ok := evt.(pointer.Event)
 		if !ok {
 			continue
@@ -139,11 +135,7 @@ func (s *Scroll) Scroll(cfg ui.Config, q input.Events, axis Axis) int {
 		return 0
 	}
 	total := 0
-	for {
-		evt, ok := q.Next(s)
-		if !ok {
-			break
-		}
+	for _, evt := range q.Events(s) {
 		e, ok := evt.(pointer.Event)
 		if !ok {
 			continue

ui/input/input.go

@@ -7,7 +7,7 @@ package input
 // Events maps an event handler key to the events
 // available to the handler.
 type Events interface {
-	Next(k Key) (Event, bool)
+	Events(k Key) []Event
 }
 
 // Key is the stable identifier for an event handler. For a handler h, the

ui/input/queue.go

@@ -19,14 +19,10 @@ type Queue struct {
 
 type handlerEvents map[Key][]Event
 
-func (q *Queue) Next(k Key) (Event, bool) {
+func (q *Queue) Events(k Key) []Event {
 	events := q.handlers[k]
-	if len(events) == 0 {
-		return nil, false
-	}
-	e := events[0]
-	q.handlers[k] = events[1:]
-	return e, true
+	delete(q.handlers, k)
+	return events
 }
 
 func (q *Queue) Frame(ops *ui.Ops) {

ui/text/editor.go

@@ -119,11 +119,7 @@ func (e *Editor) Next() (EditorEvent, bool) {
 	if (sdist > 0 && soff >= smax) || (sdist < 0 && soff <= smin) {
 		e.scroller.Stop()
 	}
-	for {
-		ke, ok := e.Inputs.Next(e)
-		if !ok {
-			break
-		}
+	for _, ke := range e.Inputs.Events(e) {
 		e.blinkStart = e.Config.Now()
 		switch ke := ke.(type) {
 		case key.FocusEvent: