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

95 lines
1.8 KiB
Go

// 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
import (
"syscall"
"github.com/lxn/win"
)
type dropFilesEventHandlerInfo struct {
handler DropFilesEventHandler
once bool
}
type DropFilesEventHandler func([]string)
type DropFilesEvent struct {
hWnd win.HWND
handlers []dropFilesEventHandlerInfo
}
func (e *DropFilesEvent) Attach(handler DropFilesEventHandler) int {
if len(e.handlers) == 0 {
win.DragAcceptFiles(e.hWnd, true)
}
handlerInfo := dropFilesEventHandlerInfo{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 *DropFilesEvent) Detach(handle int) {
e.handlers[handle].handler = nil
for _, h := range e.handlers {
if h.handler != nil {
return
}
}
win.DragAcceptFiles(e.hWnd, false)
}
func (e *DropFilesEvent) Once(handler DropFilesEventHandler) {
i := e.Attach(handler)
e.handlers[i].once = true
}
type DropFilesEventPublisher struct {
event DropFilesEvent
}
func (p *DropFilesEventPublisher) Event(hWnd win.HWND) *DropFilesEvent {
p.event.hWnd = hWnd
return &p.event
}
func (p *DropFilesEventPublisher) Publish(hDrop win.HDROP) {
var files []string
n := win.DragQueryFile(hDrop, 0xFFFFFFFF, nil, 0)
for i := 0; i < int(n); i++ {
bufSize := uint(512)
buf := make([]uint16, bufSize)
if win.DragQueryFile(hDrop, uint(i), &buf[0], bufSize) > 0 {
files = append(files, syscall.UTF16ToString(buf))
}
}
win.DragFinish(hDrop)
for i, h := range p.event.handlers {
if h.handler != nil {
h.handler(files)
if h.once {
p.event.Detach(i)
}
}
}
}