Started the work for margins; implemented for Window.

newctrl/container_windows.go

@@ -85,7 +85,7 @@ func fromdlgunitsY(du int, d *sizing) int {
 }
 
 const (
-	// TODO figure out how to sort this more nicely
+	// shared by multiple containers
 	marginDialogUnits  = 7
 	paddingDialogUnits = 4
 
@@ -106,9 +106,6 @@ func (w *window) beginResize() (d *sizing) {
 	d.baseY = baseY
 	d.internalLeading = internalLeading
 
-	d.xmargin = fromdlgunitsX(marginDialogUnits, d)
-	d.ymargintop = fromdlgunitsY(marginDialogUnits, d)
-	d.ymarginbottom = d.ymargintop
 	d.xpadding = fromdlgunitsX(paddingDialogUnits, d)
 	d.ypadding = fromdlgunitsY(paddingDialogUnits, d)
 
@@ -126,3 +123,10 @@ func (w *window) beginResize() (d *sizing) {
 
 	return d
 }
+
+func marginRectDLU(r *C.RECT, top int, bottom int, left int, right int, d *sizing) {
+	r.left += fromdlgunitsX(left, d)
+	r.top += fromdlgunitsY(top, d)
+	r.right -= fromdlgunitsX(right, d)
+	r.bottom -= fromdlgunitsY(bottom, d)
+}

newctrl/window.go

@@ -0,0 +1,40 @@
+// 7 july 2014
+
+package ui
+
+// Window represents a top-level window on screen that contains other Controls.
+// Windows in package ui can only contain one control; the Stack, Grid, and SimpleGrid layout Controls allow you to pack multiple Controls in a Window.
+// Note that a Window is not itself a Control.
+type Window interface {
+	// Title and SetTitle get and set the Window's title, respectively.
+	Title() string
+	SetTitle(title string)
+
+	// Show and Hide bring the Window on-screen and off-screen, respectively.
+	Show()
+	Hide()
+
+	// Close closes the Window.
+	// Any Controls within the Window are destroyed, and the Window itself is also destroyed.
+	// Attempting to use a Window after it has been closed results in undefined behavior.
+	// Close unconditionally closes the Window; it neither raises OnClosing nor checks for a return from OnClosing.
+	Close()
+
+	// OnClosing registers an event handler that is triggered when the user clicks the Window's close button.
+	// On systems where whole applications own windows, OnClosing is also triggered when the user asks to close the application.
+	// If this handler returns true, the Window is closed as defined by Close above.
+	// If this handler returns false, the Window is not closed.
+	OnClosing(func() bool)
+
+	// Margined and SetMargined get and set whether the contents of the Window have a margin around them.
+	// The size of the margin is platform-dependent.
+	Margined() bool
+	SetMargined(margined bool)
+
+	windowDialog
+}
+
+// NewWindow creates a new Window with the given title text, size, and control.
+func NewWindow(title string, width int, height int, control Control) Window {
+	return newWindow(title, width, height, control)
+}

newctrl/window_windows.go

@@ -18,6 +18,7 @@ type window struct {
 	closing *event
 
 	child			Control
+	margined		bool
 }
 
 func makeWindowWindowClass() error {
@@ -78,6 +79,14 @@ func (w *window) OnClosing(e func() bool) {
 	w.closing.setbool(e)
 }
 
+func (w *window) Margined() bool {
+	return w.margined
+}
+
+func (w *window) SetMargined(margined bool) {
+	w.margined = margined
+}
+
 //export storeWindowHWND
 func storeWindowHWND(data unsafe.Pointer, hwnd C.HWND) {
 	w := (*window)(data)
@@ -87,7 +96,10 @@ func storeWindowHWND(data unsafe.Pointer, hwnd C.HWND) {
 //export windowResize
 func windowResize(data unsafe.Pointer, r *C.RECT) {
 	w := (*window)(data)
-	TODO := &sizing{}
+	d := w.beginResize()
+	if w.margined {
+		marginRectDLU(r, marginDialogUnits, marginDialogUnits, marginDialogUnits, marginDialogUnits, d)
+	}
 	w.child.resize(int(r.left), int (r.top), int(r.right - r.left), int(r.bottom - r.top), TODO)
 }