/
clipboard.go
143 lines (123 loc) · 3.46 KB
/
clipboard.go
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//go:build windows
/*
* Based on code originally from https://github.com/atotto/clipboard. Copyright (c) 2013 Ato Araki. All rights reserved.
*/
package w32
import (
"runtime"
"syscall"
"time"
"unsafe"
)
const (
cfUnicodetext = 13
gmemMoveable = 0x0002
)
// waitOpenClipboard opens the clipboard, waiting for up to a second to do so.
func waitOpenClipboard() error {
started := time.Now()
limit := started.Add(time.Second)
var r uintptr
var err error
for time.Now().Before(limit) {
r, _, err = procOpenClipboard.Call(0)
if r != 0 {
return nil
}
time.Sleep(time.Millisecond)
}
return err
}
func GetClipboardText() (string, error) {
// LockOSThread ensure that the whole method will keep executing on the same thread from begin to end (it actually locks the goroutine thread attribution).
// Otherwise if the goroutine switch thread during execution (which is a common practice), the OpenClipboard and CloseClipboard will happen on two different threads, and it will result in a clipboard deadlock.
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if formatAvailable, _, err := procIsClipboardFormatAvailable.Call(cfUnicodetext); formatAvailable == 0 {
return "", err
}
err := waitOpenClipboard()
if err != nil {
return "", err
}
h, _, err := procGetClipboardData.Call(cfUnicodetext)
if h == 0 {
_, _, _ = procCloseClipboard.Call()
return "", err
}
l, _, err := kernelGlobalLock.Call(h)
if l == 0 {
_, _, _ = procCloseClipboard.Call()
return "", err
}
text := syscall.UTF16ToString((*[1 << 20]uint16)(unsafe.Pointer(l))[:])
r, _, err := kernelGlobalUnlock.Call(h)
if r == 0 {
_, _, _ = procCloseClipboard.Call()
return "", err
}
closed, _, err := procCloseClipboard.Call()
if closed == 0 {
return "", err
}
return text, nil
}
func SetClipboardText(text string) error {
// LockOSThread ensure that the whole method will keep executing on the same thread from begin to end (it actually locks the goroutine thread attribution).
// Otherwise if the goroutine switch thread during execution (which is a common practice), the OpenClipboard and CloseClipboard will happen on two different threads, and it will result in a clipboard deadlock.
runtime.LockOSThread()
defer runtime.UnlockOSThread()
err := waitOpenClipboard()
if err != nil {
return err
}
r, _, err := procEmptyClipboard.Call(0)
if r == 0 {
_, _, _ = procCloseClipboard.Call()
return err
}
data, err := syscall.UTF16FromString(text)
if err != nil {
return err
}
// "If the hMem parameter identifies a memory object, the object must have
// been allocated using the function with the GMEM_MOVEABLE flag."
h, _, err := kernelGlobalAlloc.Call(gmemMoveable, uintptr(len(data)*int(unsafe.Sizeof(data[0]))))
if h == 0 {
_, _, _ = procCloseClipboard.Call()
return err
}
defer func() {
if h != 0 {
kernelGlobalFree.Call(h)
}
}()
l, _, err := kernelGlobalLock.Call(h)
if l == 0 {
_, _, _ = procCloseClipboard.Call()
return err
}
r, _, err = kernelLstrcpy.Call(l, uintptr(unsafe.Pointer(&data[0])))
if r == 0 {
_, _, _ = procCloseClipboard.Call()
return err
}
r, _, err = kernelGlobalUnlock.Call(h)
if r == 0 {
if err.(syscall.Errno) != 0 {
_, _, _ = procCloseClipboard.Call()
return err
}
}
r, _, err = procSetClipboardData.Call(cfUnicodetext, h)
if r == 0 {
_, _, _ = procCloseClipboard.Call()
return err
}
h = 0 // suppress deferred cleanup
closed, _, err := procCloseClipboard.Call()
if closed == 0 {
return err
}
return nil
}