Added window sizing. I think I'm now ready for the wrapper itself.

main.go

@@ -92,6 +92,11 @@ func wndProc(hwnd HWND, msg uint32, wParam WPARAM, lParam LPARAM) LRESULT {
 		mm.PtMinTrackSize.X = 320
 		mm.PtMinTrackSize.Y = 240
 		return 0
+	case WM_SIZE:
+		if wParam != SIZE_MINIMIZED {
+			resize(hwnd)
+		}
+		return 0
 	case WM_CLOSE:
 		err := DestroyWindow(hwnd)
 		if err != nil {
@@ -119,6 +124,22 @@ func setFontAll(hwnd HWND, lParam LPARAM) (cont bool) {
 	return true
 }
 
+func resize(hwnd HWND) {
+	cr, err := GetClientRect(hwnd)
+	if err != nil {
+		fatalf("error getting window client rect: %v", err)
+	}
+	cr.Bottom -= 80		// Y position of listbox
+	cr.Bottom -= 20		// amount of pixels to leave behind
+	err = SetWindowPos(list,
+		HWND_TOP,
+		20, 80, 100, int(cr.Bottom),
+		0)
+	if err != nil {
+		fatalf("error resizing listbox: %v", err)
+	}
+}
+
 const className = "mainwin"
 
 func main() {
@@ -271,6 +292,7 @@ func main() {
 	if err != nil {
 		fatalf("error setting font on controls: %v", err)
 	}
+	resize(hwnd)
 
 	_, err = ShowWindow(hwnd, nCmdShow)
 	if err != nil {

rectangles.go

@@ -12,3 +12,10 @@ type POINT struct {
 	X	int32
 	Y	int32
 }
+
+type RECT struct {
+	Left		int32
+	Top		int32
+	Right	int32
+	Bottom	int32
+}

windows.go

@@ -114,6 +114,39 @@ const (
 	COLOR_WINDOWTEXT = 8
 )
 
+// SetWindowPos hWndInsertAfter values.
+const (
+	HWND_BOTTOM = HWND(1)
+	HWND_TOP = HWND(0)
+)
+
+// SetWindowPos hWndInsertAfter values that Go won't allow as constants.
+var (
+	_HWND_NOTOPMOST = -2
+	HWND_NOTOPMOST = HWND(_HWND_NOTOPMOST)
+	_HWND_TOPMOST = -1
+	HWND_TOPMOST = HWND(_HWND_TOPMOST)
+)
+
+// SetWindowPos uFlags values.
+const (
+	SWP_DRAWFRAME = 0x0020
+	SWP_FRAMECHANGED = 0x0020
+	SWP_HIDEWINDOW = 0x0080
+	SWP_NOACTIVATE = 0x0010
+	SWP_NOCOPYBITS = 0x0100
+	SWP_NOMOVE = 0x0002
+	SWP_NOOWNERZORDER = 0x0200
+	SWP_NOREDRAW = 0x0008
+	SWP_NOREPOSITION = 0x0200
+	SWP_NOSENDCHANGING = 0x0400
+	SWP_NOSIZE = 0x0001
+	SWP_NOZORDER = 0x0004
+	SWP_SHOWWINDOW = 0x0040
+	SWP_ASYNCWINDOWPOS = 0x4000
+	SWP_DEFERERASE = 0x2000
+)
+
 // ShowWindow settings.
 const (
 	SW_FORCEMINIMIZE = 11
@@ -134,7 +167,9 @@ const (
 var (
 	createWindowEx = user32.NewProc("CreateWindowExW")
 	destroyWindow = user32.NewProc("DestroyWindow")
+	getClientRect = user32.NewProc("GetClientRect")
 	enumChildWindows = user32.NewProc("EnumChildWindows")
+	setWindowPos = user32.NewProc("SetWindowPos")
 	showWindow = user32.NewProc("ShowWindow")
 )
 
@@ -188,6 +223,33 @@ func EnumChildWindows(hWndParent HWND, lpEnumFunc WNDENUMPROC, lParam LPARAM) (e
 	return nil
 }
 
+// TODO return the rect itself?
+func GetClientRect(hWnd HWND) (lpRect *RECT, err error) {
+	lpRect = new(RECT)
+	r1, _, err := getClientRect.Call(
+		uintptr(hWnd),
+		uintptr(unsafe.Pointer(lpRect)))
+	if r1 == 0 {		// failure
+		return nil, err
+	}
+	return lpRect, nil
+}
+
+func SetWindowPos(hWnd HWND, hWndInsertAfter HWND, X int, Y int, cx int, cy int, uFlags uint32) (err error) {
+	r1, _, err := setWindowPos.Call(
+		uintptr(hWnd),
+		uintptr(hWndInsertAfter),
+		uintptr(X),
+		uintptr(Y),
+		uintptr(cx),
+		uintptr(cy),
+		uintptr(uFlags))
+	if r1 == 0 {		// failure
+		return err
+	}
+	return nil
+}
+
 // TODO figure out how to handle errors
 func ShowWindow(hWnd HWND, nCmdShow int) (previouslyVisible bool, err error) {
 	r1, _, _ := showWindow.Call(