io/input,io/router: [API] rename package io/router to io/input

The input name better matches its purpose, in particular when we
introduce input.Source.

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

io/input/clipboard.go

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package input
+
+import (
+	"gioui.org/io/event"
+)
+
+type clipboardQueue struct {
+	receivers map[event.Tag]struct{}
+	// request avoid read clipboard every frame while waiting.
+	requested bool
+	text      *string
+}
+
+// WriteClipboard returns the most recent text to be copied
+// to the clipboard, if any.
+func (q *clipboardQueue) WriteClipboard() (string, bool) {
+	if q.text == nil {
+		return "", false
+	}
+	text := *q.text
+	q.text = nil
+	return text, true
+}
+
+// ReadClipboard reports if any new handler is waiting
+// to read the clipboard.
+func (q *clipboardQueue) ReadClipboard() bool {
+	if len(q.receivers) == 0 || q.requested {
+		return false
+	}
+	q.requested = true
+	return true
+}
+
+func (q *clipboardQueue) Push(e event.Event, events *handlerEvents) {
+	for r := range q.receivers {
+		events.Add(r, e)
+		delete(q.receivers, r)
+	}
+}
+
+func (q *clipboardQueue) ProcessWriteClipboard(refs []interface{}) {
+	q.text = refs[0].(*string)
+}
+
+func (q *clipboardQueue) ProcessReadClipboard(refs []interface{}) {
+	if q.receivers == nil {
+		q.receivers = make(map[event.Tag]struct{})
+	}
+	tag := refs[0].(event.Tag)
+	if _, ok := q.receivers[tag]; !ok {
+		q.receivers[tag] = struct{}{}
+		q.requested = false
+	}
+}