app: add Window.Raise to bring a window to the front

Fixes gio#252

Signed-off-by: Pierre Curto <pierre.curto@gmail.com>

app/internal/windows/windows.go

@@ -113,6 +113,7 @@ const (
 	SWP_NOOWNERZORDER = 0x0200
 	SWP_NOSIZE        = 0x0001
 	SWP_NOZORDER      = 0x0004
+	SWP_SHOWWINDOW    = 0x0040
 
 	USER_TIMER_MINIMUM = 0x0000000A
 

app/os.go

@@ -141,6 +141,9 @@ type driver interface {
 	// SetCursor updates the current cursor to name.
 	SetCursor(name pointer.CursorName)
 
+	// Raise the window at the top.
+	Raise()
+
 	// Close the window.
 	Close()
 	// Wakeup wakes up the event loop and sends a WakeupEvent.

app/os_android.go

@@ -822,6 +822,8 @@ func (w *window) Config() Config {
 	return w.config
 }
 
+func (w *window) Raise() {}
+
 func (w *window) SetCursor(name pointer.CursorName) {
 	runInJVM(javaVM(), func(env *C.JNIEnv) {
 		setCursor(env, w.view, name)

app/os_ios.go

@@ -275,6 +275,8 @@ func (w *window) Config() Config {
 	return w.config
 }
 
+func (w *window) Raise() {}
+
 func (w *window) SetAnimating(anim bool) {
 	v := w.view
 	if v == 0 {

app/os_js.go

@@ -534,6 +534,8 @@ func (w *window) Config() Config {
 	return w.config
 }
 
+func (w *window) Raise() {}
+
 func (w *window) SetCursor(name pointer.CursorName) {
 	style := w.cnv.Get("style")
 	style.Set("cursor", string(name))

app/os_macos.go

@@ -127,6 +127,12 @@ static CFTypeRef layerForView(CFTypeRef viewRef) {
 	NSView *view = (__bridge NSView *)viewRef;
 	return (__bridge CFTypeRef)view.layer;
 }
+
+static void raiseWindow(CFTypeRef windowRef) {
+	NSWindow* window = (__bridge NSWindow *)windowRef;
+	[window makeKeyAndOrderFront:nil];
+}
+
 */
 import "C"
 
@@ -268,6 +274,10 @@ func (w *window) SetAnimating(anim bool) {
 	}
 }
 
+func (w *window) Raise() {
+	C.raiseWindow(w.window)
+}
+
 func (w *window) runOnMain(f func()) {
 	runOnMain(func() {
 		// Make sure the view is still valid. The window might've been closed

app/os_wayland.go

@@ -927,6 +927,8 @@ func (w *window) Config() Config {
 	return w.config
 }
 
+func (w *window) Raise() {}
+
 func (w *window) SetCursor(name pointer.CursorName) {
 	if name == pointer.CursorNone {
 		C.wl_pointer_set_cursor(w.disp.seat.pointer, w.serial, nil, 0, 0)

app/os_windows.go

@@ -663,6 +663,12 @@ func (w *window) Close() {
 	windows.PostMessage(w.hwnd, windows.WM_CLOSE, 0, 0)
 }
 
+func (w *window) Raise() {
+	windows.SetForegroundWindow(w.hwnd)
+	windows.SetWindowPos(w.hwnd, windows.HWND_TOPMOST, 0, 0, 0, 0,
+		windows.SWP_NOMOVE|windows.SWP_NOSIZE|windows.SWP_SHOWWINDOW)
+}
+
 func convertKeyCode(code uintptr) (string, bool) {
 	if '0' <= code && code <= '9' || 'A' <= code && code <= 'Z' {
 		return string(rune(code)), true

app/os_x11.go

@@ -79,6 +79,8 @@ type x11Window struct {
 		wmState C.Atom
 		// "_NET_WM_STATE_FULLSCREEN"
 		wmStateFullscreen C.Atom
+		// "_NET_ACTIVE_WINDOW"
+		wmActiveWindow C.Atom
 	}
 	stage  system.Stage
 	metric unit.Metric
@@ -165,6 +167,26 @@ func (w *x11Window) Config() Config {
 	return w.config
 }
 
+func (w *x11Window) Raise() {
+	var xev C.XEvent
+	ev := (*C.XClientMessageEvent)(unsafe.Pointer(&xev))
+	*ev = C.XClientMessageEvent{
+		_type:        C.ClientMessage,
+		display:      w.x,
+		window:       w.xw,
+		message_type: w.atoms.wmActiveWindow,
+		format:       32,
+	}
+	C.XSendEvent(
+		w.x,
+		C.XDefaultRootWindow(w.x), // MUST be the root window
+		C.False,
+		C.SubstructureNotifyMask|C.SubstructureRedirectMask,
+		&xev,
+	)
+	C.XMapRaised(w.display(), w.xw)
+}
+
 func (w *x11Window) SetCursor(name pointer.CursorName) {
 	switch name {
 	case pointer.CursorNone:
@@ -680,6 +702,7 @@ func newX11Window(gioWin *callbacks, options []Option) error {
 	w.atoms.wmName = w.atom("_NET_WM_NAME", false)
 	w.atoms.wmState = w.atom("_NET_WM_STATE", false)
 	w.atoms.wmStateFullscreen = w.atom("_NET_WM_STATE_FULLSCREEN", false)
+	w.atoms.wmActiveWindow = w.atom("_NET_ACTIVE_WINDOW", false)
 
 	// extensions
 	C.XSetWMProtocols(dpy, win, &w.atoms.evDelWindow, 1)

app/window.go

@@ -604,6 +604,16 @@ func (w *Window) updateCursor() {
 	}
 }
 
+// Raise requests that the platform bring this window to the top of all open windows.
+// Some platforms do not allow this except under certain circumstances, such as when
+// a window from the same application already has focus. If the platform does not
+// support it, this method will do nothing.
+func (w *Window) Raise() {
+	w.driverDefer(func(d driver) {
+		d.Raise()
+	})
+}
+
 func (q *queue) Events(k event.Tag) []event.Event {
 	return q.q.Events(k)
 }