Made the sizing recursive chain idempotent and added a -spaced option to the test program to test spacing.

redo/sizing.go

@@ -28,23 +28,17 @@ type controlSizing interface {
 // on Windows, this is only embedded by window, as all other containers cannot have their own children; beginResize() points to an instance method literal (TODO get correct term) from window
 // on GTK+ and Mac OS X, one is embedded by window and all containers; beginResize() points to a global function (TODO NOT GOOD; ideally the sizing data should be passed across size-allocate requests)
 type container struct {
-	child			Control
-	spaced		bool
-	beginResize	func() (d *sizing)	// for the initial call
-	d			*sizing			// for recursive calls
+	child		Control
+	spaced	bool
+	d		*sizing
 }
 
 func (c *container) resize(width, height int) {
 	if c.child == nil {		// no children; nothing to do
 		return
 	}
-	if c.d == nil {			// initial call
-		if c.beginResize == nil {
-			// should be a recursive call, but is not
-			// TODO get rid of this
-			return
-		}
-		c.d = c.beginResize()
+	if c.d == nil {			// not ready (called early or out of the proper recursive call chain (such as by the underlying system when marking an unparented Tab as shown))
+		return
 	}
 	d := c.d
 	allocations := c.child.allocate(0, 0, width, height, d)
@@ -54,6 +48,5 @@ func (c *container) resize(width, height int) {
 		allocations[i].this.commitResize(allocations[i], d)
 	}
 	// always set c.d to nil so it can be garbage-collected
-	// the c.endResize() above won't matter since the c.d there is evaluated then, not when c.endResize() is called
 	c.d = nil
 }

redo/window_darwin.go

@@ -32,7 +32,6 @@ func newWindow(title string, width int, height int, control Control) *window {
 		closing:		newEvent(),
 		container:		new(container),
 	}
-	w.container.beginResize = w.beginResize
 	C.windowSetDelegate(id, unsafe.Pointer(w))
 	w.child = control
 	w.child.setParent(C.windowContentView(w.id))
@@ -78,6 +77,7 @@ func windowClosing(xw unsafe.Pointer) C.BOOL {
 //export windowResized
 func windowResized(xw unsafe.Pointer, width C.uintptr_t, height C.uintptr_t) {
 	w := (*window)(unsafe.Pointer(xw))
+	w.container.d = w.beginResize()
 	w.resize(int(width), int(height))
 	fmt.Printf("new size %d x %d\n", width, height)
 }

redo/window_unix.go

@@ -49,7 +49,6 @@ func newWindow(title string, width int, height int, control Control) *window {
 		closing:		newEvent(),
 		container:		new(container),
 	}
-	w.container.beginResize = w.beginResize
 	C.gtk_window_set_title(w.window, ctitle)
 	g_signal_connect(
 		C.gpointer(unsafe.Pointer(w.window)),
@@ -111,6 +110,7 @@ func windowClosing(wid *C.GtkWidget, e *C.GdkEvent, data C.gpointer) C.gboolean
 //export windowResizing
 func windowResizing(wid *C.GtkWidget, r *C.GdkRectangle, data C.gpointer) {
 	w := (*window)(unsafe.Pointer(data))
+	w.container.d = w.beginResize()
 	w.resize(int(r.width), int(r.height))
 	fmt.Printf("new size %d x %d\n", r.width, r.height)
 }

redo/window_windows.go

@@ -43,7 +43,6 @@ func newWindow(title string, width int, height int, control Control) *window {
 		closing:		newEvent(),
 		container:		new(container),
 	}
-	w.container.beginResize = w.beginResize
 	hwnd := C.newWindow(toUTF16(title), C.int(width), C.int(height), unsafe.Pointer(w))
 	if hwnd != w.hwnd {
 		panic(fmt.Errorf("inconsistency: hwnd returned by CreateWindowEx() (%p) and hwnd stored in window (%p) differ", hwnd, w.hwnd))
@@ -97,6 +96,7 @@ func storeWindowHWND(data unsafe.Pointer, hwnd C.HWND) {
 //export windowResize
 func windowResize(data unsafe.Pointer, r *C.RECT) {
 	w := (*window)(data)
+	w.container.d = w.beginResize()
 	w.resize(int(r.right - r.left), int(r.bottom - r.top))
 }
 

redo/zz_test.go

@@ -11,6 +11,7 @@ import (
 )
 
 var closeOnClick = flag.Bool("close", false, "close on click")
+var spaced = flag.Bool("spaced", false, "enable spacing")
 
 // because Cocoa hates being run off the main thread, even if it's run exclusively off the main thread
 func init() {
@@ -20,6 +21,8 @@ func init() {
 		Do(func() {
 			t := NewTab()
 			w := NewWindow("Hello", 320, 240, t)
+			// TODO use a method here
+			w.(*window).spaced = *spaced
 			w.OnClosing(func() bool {
 				if *closeOnClick {
 					panic("window closed normally in close on click mode (should not happen)")