Began migrating the Windows code away from using container entirely. This is going to be a mess for Tab... hopefully only a short-term one.

container_windows.go

@@ -89,13 +89,13 @@ const (
 	paddingDialogUnits = 4
 )
 
-func (w *window) beginResize() (d *sizing) {
+func beginResize(hwnd C.HWND) (d *sizing) {
 	var baseX, baseY C.int
 	var internalLeading C.LONG
 
 	d = new(sizing)
 
-	C.calculateBaseUnits(w.hwnd, &baseX, &baseY, &internalLeading)
+	C.calculateBaseUnits(hwnd, &baseX, &baseY, &internalLeading)
 	d.baseX = baseX
 	d.baseY = baseY
 	d.internalLeading = internalLeading

tab_windows.c

@@ -10,6 +10,8 @@ static LRESULT CALLBACK tabSubProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM l
 {
 	NMHDR *nmhdr = (NMHDR *) lParam;
 	LRESULT r;
+	RECT resizeRect;
+	WINDOWPOS *wp;
 
 	switch (uMsg) {
 	case msgNOTIFY:
@@ -27,6 +29,17 @@ static LRESULT CALLBACK tabSubProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM l
 		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
 	case msgTabCurrentTabHasChildren:
 		return (LRESULT) tabTabHasChildren((void *) data, SendMessageW(hwnd, TCM_GETCURSEL, 0, 0));
+	case WM_WINDOWPOSCHANGING:
+	case WM_WINDOWPOSCHANGED:
+		wp = (WINDOWPOS *) lParam;
+		resizeRect.left = wp->x;
+		resizeRect.top = wp->y;
+		resizeRect.right = wp->x + wp->cx;
+		resizeRect.bottom = wp->y + wp->cy;
+		tabGetContentRect(hwnd, &resizeRect);
+		tabResized((void *) data, resizeRect);
+		// and chain up
+		return (*fv_DefSubclassProc)(hwnd, uMsg, wParam, lParam);
 	case WM_NCDESTROY:
 		if ((*fv_RemoveWindowSubclass)(hwnd, tabSubProc, id) == FALSE)
 			xpanic("error removing Tab subclass (which was for its own event handler)", GetLastError());

tab_windows.go

@@ -20,6 +20,7 @@ type tab struct {
 	tabs			[]*container
 	children		[]Control
 	chainresize	func(x int, y int, width int, height int, d *sizing)
+	current		int
 }
 
 func newTab() Tab {
@@ -28,6 +29,7 @@ func newTab() Tab {
 		0) // don't set WS_EX_CONTROLPARENT here; see uitask_windows.c
 	t := &tab{
 		controlSingleHWND:		newControlSingleHWND(hwnd),
+		current:				-1,
 	}
 	t.fpreferredSize = t.xpreferredSize
 	t.chainresize = t.fresize
@@ -61,7 +63,9 @@ func tabChanging(data unsafe.Pointer, current C.LRESULT) {
 //export tabChanged
 func tabChanged(data unsafe.Pointer, new C.LRESULT) {
 	t := (*tab)(data)
-	t.tabs[int(new)].show()
+	t.current = int(new)
+	// TODO resize the new tab
+	t.tabs[t.current].show()
 }
 
 //export tabTabHasChildren
@@ -89,27 +93,22 @@ func (t *tab) xpreferredSize(d *sizing) (width, height int) {
 	return width, height + int(C.tabGetTabHeight(t.hwnd))
 }
 
-// a tab control contains other controls; size appropriately
+// no need to resize the other controls; we do that in tabResized() which is called by the tab subclass handler
 func (t *tab) xresize(x int, y int, width int, height int, d *sizing) {
-	// first, chain up to the container base to keep the Z-order correct
+	// just chain up to the container base to keep the Z-order correct
 	t.chainresize(x, y, width, height, d)
-
-	// now resize the children
-	var r C.RECT
-
-	// figure out what the rect for each child is...
-	// the tab contents are children of the tab itself, so ignore x and y, which are relative to the window!
-	r.left = C.LONG(0)
-	r.top = C.LONG(0)
-	r.right = C.LONG(width)
-	r.bottom = C.LONG(height)
-	C.tabGetContentRect(t.hwnd, &r)
-	// and resize tabs
-	// don't resize just the current tab; resize all tabs!
-	for i, _ := range t.tabs {
-		// because each widget is actually a child of the Window, the origin is the one we calculated above
-		t.tabs[i].resize(int(r.left), int(r.top), int(r.right - r.left), int(r.bottom - r.top), d)
-		// TODO get the actual client rect
-		t.children[i].resize(int(0), int(0), int(r.right - r.left), int(r.bottom - r.top), d)
-	}
+}
+
+//export tabResized
+func tabResized(data unsafe.Pointer, r C.RECT) {
+	t := (*tab)(data)
+	if t.current == -1 {		// nothing to do
+		return
+	}
+	d := beginResize(t.hwnd)
+	// only need to resize the current tab; we resize new tabs when the tab changes in tabChanged() above
+	// because each widget is actually a child of the Window, the origin is the one we calculated above
+	t.tabs[t.current].resize(int(r.left), int(r.top), int(r.right - r.left), int(r.bottom - r.top), d)
+	// TODO get the actual client rect
+	t.children[t.current].resize(int(0), int(0), int(r.right - r.left), int(r.bottom - r.top), d)
 }

window_windows.c

@@ -28,7 +28,8 @@ static LRESULT CALLBACK windowWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARA
 		if (FillRect((HDC) wParam, &r, windowBackground) == 0)
 			xpanic("error filling WM_PRINTCLIENT DC with window background color", GetLastError());
 		return lResult;
-	case WM_SIZE:
+	case WM_WINDOWPOSCHANGING:
+	case WM_WINDOWPOSCHANGED:
 		if (GetClientRect(hwnd, &r) == 0)
 			xpanic("error getting client rect for Window in WM_SIZE", GetLastError());
 		windowResize(data, &r);

window_windows.go

@@ -86,7 +86,7 @@ func (w *window) SetMargined(margined bool) {
 //export windowResize
 func windowResize(data unsafe.Pointer, r *C.RECT) {
 	w := (*window)(data)
-	d := w.beginResize()
+	d := beginResize(w.hwnd)
 	if w.margined {
 		marginRectDLU(r, marginDialogUnits, marginDialogUnits, marginDialogUnits, marginDialogUnits, d)
 	}