63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
// Copyright 2011 The Walk Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build windows
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package walk
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type cancelEventHandlerInfo struct {
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handler CancelEventHandler
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once bool
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}
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type CancelEventHandler func(canceled *bool)
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type CancelEvent struct {
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handlers []cancelEventHandlerInfo
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}
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func (e *CancelEvent) Attach(handler CancelEventHandler) int {
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handlerInfo := cancelEventHandlerInfo{handler, false}
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for i, h := range e.handlers {
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if h.handler == nil {
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e.handlers[i] = handlerInfo
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return i
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}
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}
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e.handlers = append(e.handlers, handlerInfo)
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return len(e.handlers) - 1
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}
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func (e *CancelEvent) Detach(handle int) {
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e.handlers[handle].handler = nil
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}
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func (e *CancelEvent) Once(handler CancelEventHandler) {
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i := e.Attach(handler)
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e.handlers[i].once = true
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}
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type CancelEventPublisher struct {
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event CancelEvent
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}
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func (p *CancelEventPublisher) Event() *CancelEvent {
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return &p.event
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}
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func (p *CancelEventPublisher) Publish(canceled *bool) {
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for i, h := range p.event.handlers {
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if h.handler != nil {
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h.handler(canceled)
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if h.once {
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p.event.Detach(i)
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}
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}
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}
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}
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