app/internal/window,app/internal/windows: implement Windows clipboard access

Update gio#31

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

app/internal/windows/windows.go

@@ -171,20 +171,31 @@ const (
 
 	PM_REMOVE   = 0x0001
 	PM_NOREMOVE = 0x0000
+
+	GHND = 0x0042
+
+	CF_UNICODETEXT = 13
 )
 
 var (
 	kernel32          = syscall.NewLazySystemDLL("kernel32.dll")
 	_GetModuleHandleW = kernel32.NewProc("GetModuleHandleW")
+	_GlobalAlloc      = kernel32.NewProc("GlobalAlloc")
+	_GlobalFree       = kernel32.NewProc("GlobalFree")
+	_GlobalLock       = kernel32.NewProc("GlobalLock")
+	_GlobalUnlock     = kernel32.NewProc("GlobalUnlock")
 
 	user32                       = syscall.NewLazySystemDLL("user32.dll")
 	_AdjustWindowRectEx          = user32.NewProc("AdjustWindowRectEx")
 	_CallMsgFilter               = user32.NewProc("CallMsgFilterW")
+	_CloseClipboard              = user32.NewProc("CloseClipboard")
 	_CreateWindowEx              = user32.NewProc("CreateWindowExW")
 	_DefWindowProc               = user32.NewProc("DefWindowProcW")
 	_DestroyWindow               = user32.NewProc("DestroyWindow")
 	_DispatchMessage             = user32.NewProc("DispatchMessageW")
+	_EmptyClipboard              = user32.NewProc("EmptyClipboard")
 	_GetClientRect               = user32.NewProc("GetClientRect")
+	_GetClipboardData            = user32.NewProc("GetClipboardData")
 	_GetDC                       = user32.NewProc("GetDC")
 	_GetKeyState                 = user32.NewProc("GetKeyState")
 	_GetMessage                  = user32.NewProc("GetMessageW")
@@ -193,6 +204,7 @@ var (
 	_LoadCursor                  = user32.NewProc("LoadCursorW")
 	_MonitorFromPoint            = user32.NewProc("MonitorFromPoint")
 	_MsgWaitForMultipleObjectsEx = user32.NewProc("MsgWaitForMultipleObjectsEx")
+	_OpenClipboard               = user32.NewProc("OpenClipboard")
 	_PeekMessage                 = user32.NewProc("PeekMessageW")
 	_PostMessage                 = user32.NewProc("PostMessageW")
 	_PostQuitMessage             = user32.NewProc("PostQuitMessage")
@@ -202,6 +214,7 @@ var (
 	_ScreenToClient              = user32.NewProc("ScreenToClient")
 	_ShowWindow                  = user32.NewProc("ShowWindow")
 	_SetCapture                  = user32.NewProc("SetCapture")
+	_SetClipboardData            = user32.NewProc("SetClipboardData")
 	_SetForegroundWindow         = user32.NewProc("SetForegroundWindow")
 	_SetFocus                    = user32.NewProc("SetFocus")
 	_SetProcessDPIAware          = user32.NewProc("SetProcessDPIAware")
@@ -217,14 +230,6 @@ var (
 	_GetDeviceCaps = gdi32.NewProc("GetDeviceCaps")
 )
 
-func GetModuleHandle() (syscall.Handle, error) {
-	h, _, err := _GetModuleHandleW.Call(uintptr(0))
-	if h == 0 {
-		return 0, fmt.Errorf("GetModuleHandleW failed: %v", err)
-	}
-	return syscall.Handle(h), nil
-}
-
 func AdjustWindowRectEx(r *Rect, dwStyle uint32, bMenu int, dwExStyle uint32) {
 	_AdjustWindowRectEx.Call(uintptr(unsafe.Pointer(r)), uintptr(dwStyle), uintptr(bMenu), uintptr(dwExStyle))
 	issue34474KeepAlive(r)
@@ -236,6 +241,14 @@ func CallMsgFilter(m *Msg, nCode uintptr) bool {
 	return r != 0
 }
 
+func CloseClipboard() error {
+	r, _, err := _CloseClipboard.Call()
+	if r == 0 {
+		return fmt.Errorf("CloseClipboard: %v", err)
+	}
+	return nil
+}
+
 func CreateWindowEx(dwExStyle uint32, lpClassName uint16, lpWindowName string, dwStyle uint32, x, y, w, h int32, hWndParent, hMenu, hInstance syscall.Handle, lpParam uintptr) (syscall.Handle, error) {
 	wname := syscall.StringToUTF16Ptr(lpWindowName)
 	hwnd, _, err := _CreateWindowEx.Call(
@@ -270,11 +283,27 @@ func DispatchMessage(m *Msg) {
 	issue34474KeepAlive(m)
 }
 
+func EmptyClipboard() error {
+	r, _, err := _EmptyClipboard.Call()
+	if r == 0 {
+		return fmt.Errorf("EmptyClipboard: %v", err)
+	}
+	return nil
+}
+
 func GetClientRect(hwnd syscall.Handle, r *Rect) {
 	_GetClientRect.Call(uintptr(hwnd), uintptr(unsafe.Pointer(r)))
 	issue34474KeepAlive(r)
 }
 
+func GetClipboardData(format uint32) (syscall.Handle, error) {
+	r, _, err := _GetClipboardData.Call(uintptr(format))
+	if r == 0 {
+		return 0, fmt.Errorf("GetClipboardData: %v", err)
+	}
+	return syscall.Handle(r), nil
+}
+
 func GetDC(hwnd syscall.Handle) (syscall.Handle, error) {
 	hdc, _, err := _GetDC.Call(uintptr(hwnd))
 	if hdc == 0 {
@@ -283,6 +312,14 @@ func GetDC(hwnd syscall.Handle) (syscall.Handle, error) {
 	return syscall.Handle(hdc), nil
 }
 
+func GetModuleHandle() (syscall.Handle, error) {
+	h, _, err := _GetModuleHandleW.Call(uintptr(0))
+	if h == 0 {
+		return 0, fmt.Errorf("GetModuleHandleW failed: %v", err)
+	}
+	return syscall.Handle(h), nil
+}
+
 func getDeviceCaps(hdc syscall.Handle, index int32) int {
 	c, _, _ := _GetDeviceCaps.Call(uintptr(hdc), uintptr(index))
 	return int(c)
@@ -330,6 +367,30 @@ func GetMessageTime() time.Duration {
 	return time.Duration(r) * time.Millisecond
 }
 
+func GlobalAlloc(size int) (syscall.Handle, error) {
+	r, _, err := _GlobalAlloc.Call(GHND, uintptr(size))
+	if r == 0 {
+		return 0, fmt.Errorf("GlobalAlloc: %v", err)
+	}
+	return syscall.Handle(r), nil
+}
+
+func GlobalFree(h syscall.Handle) {
+	_GlobalFree.Call(uintptr(h))
+}
+
+func GlobalLock(h syscall.Handle) (uintptr, error) {
+	r, _, err := _GlobalLock.Call(uintptr(h))
+	if r == 0 {
+		return 0, fmt.Errorf("GlobalLock: %v", err)
+	}
+	return r, nil
+}
+
+func GlobalUnlock(h syscall.Handle) {
+	_GlobalUnlock.Call(uintptr(h))
+}
+
 func KillTimer(hwnd syscall.Handle, nIDEvent uintptr) error {
 	r, _, err := _SetTimer.Call(uintptr(hwnd), uintptr(nIDEvent), 0, 0)
 	if r == 0 {
@@ -360,6 +421,14 @@ func MsgWaitForMultipleObjectsEx(nCount uint32, pHandles uintptr, millis, mask,
 	return res, nil
 }
 
+func OpenClipboard(hwnd syscall.Handle) error {
+	r, _, err := _OpenClipboard.Call(uintptr(hwnd))
+	if r == 0 {
+		return fmt.Errorf("OpenClipboard: %v", err)
+	}
+	return nil
+}
+
 func PeekMessage(m *Msg, hwnd syscall.Handle, wMsgFilterMin, wMsgFilterMax, wRemoveMsg uint32) bool {
 	r, _, _ := _PeekMessage.Call(uintptr(unsafe.Pointer(m)), uintptr(hwnd), uintptr(wMsgFilterMin), uintptr(wMsgFilterMax), uintptr(wRemoveMsg))
 	issue34474KeepAlive(m)
@@ -413,6 +482,14 @@ func SetCapture(hwnd syscall.Handle) syscall.Handle {
 	return syscall.Handle(r)
 }
 
+func SetClipboardData(format uint32, mem syscall.Handle) error {
+	r, _, err := _SetClipboardData.Call(uintptr(format), uintptr(mem))
+	if r == 0 {
+		return fmt.Errorf("SetClipboardData: %v", err)
+	}
+	return nil
+}
+
 func SetTimer(hwnd syscall.Handle, nIDEvent uintptr, uElapse uint32, timerProc uintptr) error {
 	r, _, err := _SetTimer.Call(uintptr(hwnd), uintptr(nIDEvent), uintptr(uElapse), timerProc)
 	if r == 0 {