Added Group.

group.go

@@ -0,0 +1,118 @@
+// 12 december 2015
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include "ui.h"
+import "C"
+
+// Group is a Control that holds another Control and wraps it around
+// a labelled box (though some systems make this box invisible).
+// You can use this to group related controls together.
+type Group struct {
+	c	*C.uiControl
+	g	*C.uiGroup
+
+	child		Control
+}
+
+// NewGroup creates a new Group.
+func NewGroup(title string) *Group {
+	g := new(Group)
+
+	ctitle := C.CString(title)
+	g.g = C.uiNewGroup(ctitle)
+	g.c = (*C.uiControl)(unsafe.Pointer(g.g))
+	freestr(ctitle)
+
+	return g
+}
+
+// Destroy destroys the Group. If the Group has a child,
+// Destroy calls Destroy on that as well.
+func (g *Group) Destroy() {
+	if g.child != nil {
+		c := g.child
+		g.SetChild(nil)
+		c.Destroy()
+	}
+	C.uiControlDestroy(g.c)
+}
+
+// LibuiControl returns the libui uiControl pointer that backs
+// the Group. This is only used by package ui itself and should
+// not be called by programs.
+func (g *Group) LibuiControl() uintptr {
+	return uintptr(unsafe.Pointer(g.c))
+}
+
+// Handle returns the OS-level handle associated with this Group.
+// On Windows this is an HWND of a standard Windows API BUTTON
+// class (as provided by Common Controls version 6).
+// On GTK+ this is a pointer to a GtkFrame.
+// On OS X this is a pointer to a NSBox.
+func (g *Group) Handle() uintptr {
+	return uintptr(C.uiControlHandle(g.c))
+}
+
+// Show shows the Group. It uses the OS conception of "presenting"
+// the Group, whatever that may be on a given OS.
+func (g *Group) Show() {
+	C.uiControlShow(g.c)
+}
+
+// Hide hides the Group.
+func (g *Group) Hide() {
+	C.uiControlHide(g.c)
+}
+
+// Enable enables the Group.
+func (g *Group) Enable() {
+	C.uiControlEnable(g.c)
+}
+
+// Disable disables the Group.
+func (g *Group) Disable() {
+	C.uiControlDisable(g.c)
+}
+
+// Title returns the Group's title.
+func (g *Group) Title() string {
+	ctitle := C.uiGroupTitle(g.g)
+	title := C.GoString(ctitle)
+	C.uiFreeText(ctitle)
+	return title
+}
+
+// SetTitle sets the Group's title to title.
+func (g *Group) SetTitle(title string) {
+	ctitle := C.CString(title)
+	C.uiGroupSetTitle(g.g, ctitle)
+	freestr(ctitle)
+}
+
+// SetChild sets the Group's child to child. If child is nil, the Group
+// will not have a child.
+func (g *Group) SetChild(child Control) {
+	g.child = child
+	c := (*C.uiControl)(nil)
+	if g.child != nil {
+		c = touiControl(g.child.LibuiControl())
+	}
+	C.uiGroupSetChild(g.g, c)
+}
+
+// Margined returns whether the Group has margins around its child.
+func (g *Group) Margined() bool {
+	return tobool(C.uiGroupMargined(g.g))
+}
+
+// SetMargined controls whether the Group has margins around its
+// child. The size of the margins are determined by the OS and its
+// best practices.
+func (g *Group) SetMargined(margined bool) {
+	C.uiGroupSetMargined(g.g, frombool(margined))
+}

zz_test.go

@@ -11,9 +11,14 @@ func TestIt(t *testing.T) {
 			Quit()
 			return true
 		})
-		s := NewSlider(0, 100)
+		s := NewGroup("Group")
 		w.SetChild(s)
 		w.SetMargined(true)
+		b := NewButton("Click Me")
+		b.OnClicked(func(*Button) {
+			s.SetMargined(!s.Margined())
+		})
+		s.SetChild(b)
 		w.Show()
 	})
 	if err != nil {