erm/vendor/github.com/lxn/walk/keyevent.go

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2021-07-30 22:29:20 +00:00
// Copyright 2011 The Walk Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build windows
package walk
type keyEventHandlerInfo struct {
handler KeyEventHandler
once bool
}
type KeyEventHandler func(key Key)
type KeyEvent struct {
handlers []keyEventHandlerInfo
}
func (e *KeyEvent) Attach(handler KeyEventHandler) int {
handlerInfo := keyEventHandlerInfo{handler, false}
for i, h := range e.handlers {
if h.handler == nil {
e.handlers[i] = handlerInfo
return i
}
}
e.handlers = append(e.handlers, handlerInfo)
return len(e.handlers) - 1
}
func (e *KeyEvent) Detach(handle int) {
e.handlers[handle].handler = nil
}
func (e *KeyEvent) Once(handler KeyEventHandler) {
i := e.Attach(handler)
e.handlers[i].once = true
}
type KeyEventPublisher struct {
event KeyEvent
}
func (p *KeyEventPublisher) Event() *KeyEvent {
return &p.event
}
func (p *KeyEventPublisher) Publish(key Key) {
for i, h := range p.event.handlers {
if h.handler != nil {
h.handler(key)
if h.once {
p.event.Detach(i)
}
}
}
}