Added parenting/unparenting of controls to the GTK+ backend and the test program.

redo/controls.go

@@ -5,7 +5,8 @@ package ui
 // Control represents a control.
 // All Controls have event handlers that take a single argument (the Doer active during the event) and return nothing.
 type Control interface {
-	// TODO reparent (public)
+	unparent()
+	parent(*window)
 	// TODO enable/disable (public)
 	// TODO show/hide (public)
 	// TODO sizing (likely private)

redo/controls_unix.go

@@ -13,6 +13,8 @@ import "C"
 
 type widgetbase struct {
 	widget	*C.GtkWidget
+	parentw	*window
+	floating	bool
 }
 
 func newWidget(w *C.GtkWidget) *widgetbase {
@@ -21,6 +23,29 @@ func newWidget(w *C.GtkWidget) *widgetbase {
 	}
 }
 
+// these few methods are embedded by all the various Controls since they all will do the same thing
+
+func (w *widgetbase) unparent() {
+	if w.parentw != nil {
+		// add another reference so it doesn't get removed by accident
+		C.g_object_ref(C.gpointer(unsafe.Pointer(w.widget)))
+		// we unref this in parent() below
+		w.floating = true
+		C.gtk_container_remove(w.parentw.layoutc, w.widget)
+		w.parentw = nil
+	}
+}
+
+func (w *widgetbase) parent(win *window) {
+	C.gtk_container_add(win.layoutc, w.widget)
+	w.parentw = win
+	// was previously parented; unref our saved ref
+	if w.floating {
+		C.g_object_unref(C.gpointer(unsafe.Pointer(w.widget)))
+		w.floating = false
+	}
+}
+
 type button struct {
 	*widgetbase
 	button		*C.GtkButton

redo/window_unix.go

@@ -23,6 +23,8 @@ type window struct {
 	layoutc	*C.GtkContainer
 	layout	*C.GtkLayout
 
+	child		Control
+
 	closing	*event
 }
 
@@ -66,8 +68,9 @@ func (w *window) SetControl(control Control) *Request {
 	c := make(chan interface{})
 	return &Request{
 		op:		func() {
-			// TODO unparent
-			// TODO reparent
+			control.unparent()
+			control.parent(w)
+			w.child = control
 			c <- struct{}{}
 		},
 		resp:		c,

redo/zz_test.go

@@ -12,6 +12,8 @@ import (
 func init() {
 	go func() {
 		w := GetNewWindow(Do, "Hello", 320, 240)
+		b := GetNewButton(Do, "There")
+		Wait(Do, w.SetControl(b))
 		done := make(chan struct{})
 		Wait(Do, w.OnClosing(func(c Doer) bool {
 			Stop()