Wrote up a Bin for the Windows backend. Minor changes in uiBox too.

new/box.c

@@ -38,7 +38,7 @@ static void boxDestroy(uiControl *c)
 	}
 	uiFree(b->controls);
 	// NOW we can chain up to base
-	(*(b->baseDestroy))(c);
+	(*(b->baseDestroy))(uiControl(b));
 	uiFree(b);
 }
 

new/uipriv.h

@@ -10,5 +10,9 @@ extern void uiFree(void *);
 
 extern void complain(const char *, ...);
 
+extern uiContainer *newBin(void);
+extern void binSetMainControl(uiContainer *, uiControl *);
+extern void binSetMargins(uiContainer *, intmax_t, intmax_t, intmax_t, intmax_t);
+
 // lifetimes.c
 extern void properlyDestroyControl(uiControl *);

new/windows/OLDcontainer.c

@@ -50,25 +50,6 @@ static void paintControlBackground(HWND hwnd, HDC dc)
 		logLastError("error resetting window origin in paintControlBackground()");
 }
 
-static void resize(uiControl *control, HWND parent, RECT r, RECT margin)
-{
-	r.left += uiDlgUnitsToX(margin.left, sys.baseX);
-	r.top += uiDlgUnitsToY(margin.top, sys.baseY);
-	r.right -= uiDlgUnitsToX(margin.right, sys.baseX);
-	r.bottom -= uiDlgUnitsToY(margin.bottom, sys.baseY);
-}
-
-// TODO make this a uiOSContainer directly
-struct parent {
-	HWND hwnd;
-	uiControl *mainControl;
-	intmax_t marginLeft;
-	intmax_t marginTop;
-	intmax_t marginRight;
-	intmax_t marginBottom;
-	BOOL canDestroy;
-};
-
 static LRESULT CALLBACK parentWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
 	uiOSContainer *p;

new/windows/bin.c

@@ -0,0 +1,101 @@
+// 27 april 2015
+#include "uipriv_windows.h"
+
+struct bin {
+	uiContainer c;
+	void (*baseDestroy)(uiControl *);
+	uiControl *mainControl;
+	intmax_t marginLeft;
+	intmax_t marginTop;
+	intmax_t marginRight;
+	intmax_t marginBottom;
+};
+
+void binDestroy(uiControl *c)
+{
+	struct bin *b = (struct bin *) c;
+
+	// TODO find a way to move the parented check here
+	// don't chain up to base here; we need to destroy children ourselves first
+	if (b->mainControl != NULL) {
+		uiControlSetParent(b->mainControl, NULL);
+		uiControlDestroy(b->mainControl);
+	}
+	// NOW we can chain up to base
+	(*(b->baseDestroy))(uiControl(b));
+	uiFree(b);
+}
+
+void binPreferredSize(uiControl *c, uiSizing *d, intmax_t *width, intmax_t *height)
+{
+	struct bin *b = (struct bin *) c;
+	intmax_t marginX, marginY;
+
+	// TODO have the margins count even if no control?
+	if (b->mainControl == NULL) {
+		*width = 0;
+		*height = 0;
+		return;
+	}
+	uiControlPreferredSize(b->mainControl, d, width, height);
+	marginX = uiDlgUnitsToX(b->marginLeft, d->sys->baseX) + uiDlgUnitsToX(b->marginRight, d->sys->baseX);
+	marginY = uiDlgUnitsToY(b->marginTop, d->sys->baseY) + uiDlgUnitsToY(b->marginBottom, d->sys->baseY);
+	*width += marginX;
+	*height += marginY;
+}
+
+void binResizeChildren(uiContainer *c, intmax_t x, intmax_t y, intmax_t width, intmax_t height, uiSizing *d)
+{
+	struct bin *b = (struct bin *) c;
+	intmax_t marginLeft, marginTop;
+
+	if (b->mainControl == NULL)
+		return;
+	marginLeft = uiDlgUnitsToX(b->marginLeft, d->sys->baseX);
+	marginTop = uiDlgUnitsToY(b->marginTop, d->sys->baseY);
+	x += marginLeft;
+	y += marginTop;
+	width -= marginLeft + uiDlgUnitsToX(b->marginRight, d->sys->baseX);
+	height -= marginTop + uiDlgUnitsToY(b->marginBottom, d->sys->baseY);
+	uiControlResize(b->mainControl, x, y, width, height, d);
+}
+
+uiContainer *newBin(void)
+{
+	struct bin *b;
+
+	b = uiNew(struct bin);
+
+	uiMakeContainer(uiContainer(b));
+
+	b->baseDestroy = uiControl(b)->Destroy;
+	uiControl(b)->Destroy = binDestroy;
+	uiControl(b)->PreferredSize = binPreferredSize;
+
+	uiContainer(b)->ControlResize = binControlResize;
+
+	return uiContainer(b);
+}
+
+void binSetMainControl(uiContainer *c, uiControl *mainControl)
+{
+	struct bin *b = (struct bin *) c;
+
+	if (b->mainControl != NULL)
+		uiControlSetParent(b->mainControl, NULL);
+	b->mainControl = mainControl;
+	if (b->mainControl != NULL)
+		uiControlSetParent(b->mainControl, uiContainer(b));
+	uiContainerUpdate(uiContainer(b));
+}
+
+void binSetMargins(uiContainer *c, intmax_t left, intmax_t top, intmax_t right, intmax_t bottom)
+{
+	struct bin *b = (struct bin *) c;
+
+	b->marginLeft = left;
+	b->marginRight = right;
+	b->marginTop = top;
+	b->marginBottom = bottom;
+	uiContainerUpdate(uiContainer(b));
+}