app: replace Config.center with Perform(ActionCenter)

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

app/os.go

@@ -41,8 +41,6 @@ type Config struct {
 	// CustomRenderer is true when the window content is rendered by the
 	// client.
 	CustomRenderer bool
-	// center is a flag used to center the window. Set by option.
-	center bool
 	// Decorated reports whether window decorations are provided automatically.
 	Decorated bool
 }

app/os_macos.go

@@ -344,13 +344,6 @@ func (w *window) Configure(options []Option) {
 			cnf.MaxSize = cnf.MaxSize.Div(int(screenScale))
 			C.setMaxSize(w.window, C.CGFloat(cnf.MaxSize.X), C.CGFloat(cnf.MaxSize.Y))
 		}
-		if cnf.center {
-			r := C.getScreenFrame(w.window) // the screen size of the window
-			sz := w.config.Size
-			x := (int(r.size.width) - sz.X) / 2
-			y := (int(r.size.height) - sz.Y) / 2
-			C.setScreenFrame(w.window, C.CGFloat(x), C.CGFloat(y), C.CGFloat(sz.X), C.CGFloat(sz.Y))
-		}
 	}
 	if cnf.Decorated != prev.Decorated {
 		w.config.Decorated = cnf.Decorated
@@ -372,6 +365,12 @@ func (w *window) setTitle(prev, cnf Config) {
 func (w *window) Perform(acts system.Action) {
 	walkActions(acts, func(a system.Action) {
 		switch a {
+		case system.ActionCenter:
+			r := C.getScreenFrame(w.window) // the screen size of the window
+			sz := w.config.Size
+			x := (int(r.size.width) - sz.X) / 2
+			y := (int(r.size.height) - sz.Y) / 2
+			C.setScreenFrame(w.window, C.CGFloat(x), C.CGFloat(y), C.CGFloat(sz.X), C.CGFloat(sz.Y))
 		case system.ActionRaise:
 			C.raiseWindow(w.window)
 		}

app/os_windows.go

@@ -631,14 +631,6 @@ func (w *window) Configure(options []Option) {
 		y := wr.Top
 		dx := r.Right - r.Left
 		dy := r.Bottom - r.Top
-		if w.config.center {
-			// Calculate center position on current monitor.
-			mi := windows.GetMonitorInfo(w.hwnd).Monitor
-			x = (mi.Right - mi.Left - dx) / 2
-			y = (mi.Bottom - mi.Top - dy) / 2
-			// Centering is done only once.
-			w.config.center = false
-		}
 		windows.SetWindowPos(w.hwnd, 0, x, y, dx, dy, windows.SWP_NOOWNERZORDER|windows.SWP_FRAMECHANGED)
 		windows.ShowWindow(w.hwnd, windows.SW_SHOWNORMAL)
 
@@ -768,6 +760,18 @@ func (w *window) Close() {
 func (w *window) Perform(acts system.Action) {
 	walkActions(acts, func(a system.Action) {
 		switch a {
+		case system.ActionCenter:
+			if w.config.Mode != Windowed {
+				break
+			}
+			r := windows.GetWindowRect(w.hwnd)
+			dx := r.Right - r.Left
+			dy := r.Bottom - r.Top
+			// Calculate center position on current monitor.
+			mi := windows.GetMonitorInfo(w.hwnd).Monitor
+			x := (mi.Right - mi.Left - dx) / 2
+			y := (mi.Bottom - mi.Top - dy) / 2
+			windows.SetWindowPos(w.hwnd, 0, x, y, dx, dy, windows.SWP_NOOWNERZORDER|windows.SWP_FRAMECHANGED)
 		case system.ActionRaise:
 			w.raise()
 		}

app/os_x11.go

@@ -230,22 +230,6 @@ func (w *x11Window) Configure(options []Option) {
 		if shints.flags != 0 {
 			C.XSetWMNormalHints(w.x, w.xw, &shints)
 		}
-		if cnf.center {
-			screen := C.XDefaultScreen(w.x)
-			width := C.XDisplayWidth(w.x, screen)
-			height := C.XDisplayHeight(w.x, screen)
-
-			var attrs C.XWindowAttributes
-			C.XGetWindowAttributes(w.x, w.xw, &attrs)
-			width -= attrs.border_width
-			height -= attrs.border_width
-
-			sz := w.config.Size
-			x := (int(width) - sz.X) / 2
-			y := (int(height) - sz.Y) / 2
-
-			C.XMoveResizeWindow(w.x, w.xw, C.int(x), C.int(y), C.uint(sz.X), C.uint(sz.Y))
-		}
 	}
 	if cnf.Decorated != prev.Decorated {
 		w.config.Decorated = cnf.Decorated
@@ -276,12 +260,31 @@ func (w *x11Window) setTitle(prev, cnf Config) {
 func (w *x11Window) Perform(acts system.Action) {
 	walkActions(acts, func(a system.Action) {
 		switch a {
+		case system.ActionCenter:
+			w.center()
 		case system.ActionRaise:
 			w.raise()
 		}
 	})
 }
 
+func (w *x11Window) center() {
+	screen := C.XDefaultScreen(w.x)
+	width := C.XDisplayWidth(w.x, screen)
+	height := C.XDisplayHeight(w.x, screen)
+
+	var attrs C.XWindowAttributes
+	C.XGetWindowAttributes(w.x, w.xw, &attrs)
+	width -= attrs.border_width
+	height -= attrs.border_width
+
+	sz := w.config.Size
+	x := (int(width) - sz.X) / 2
+	y := (int(height) - sz.Y) / 2
+
+	C.XMoveResizeWindow(w.x, w.xw, C.int(x), C.int(y), C.uint(sz.X), C.uint(sz.Y))
+}
+
 func (w *x11Window) raise() {
 	var xev C.XEvent
 	ev := (*C.XClientMessageEvent)(unsafe.Pointer(&xev))

app/window.go

@@ -989,12 +989,6 @@ func (w *Window) Perform(actions system.Action) {
 			options = append(options, Maximized.Option())
 		case system.ActionUnmaximize:
 			options = append(options, Windowed.Option())
-		case system.ActionCenter:
-			options = append(options,
-				func(m unit.Metric, cnf *Config) {
-					// Set the flag so the driver can later do the actual centering.
-					cnf.center = true
-				})
 		case system.ActionClose:
 			w.closing = true
 		default: