Added Button and Checkbox.

button.go

@@ -0,0 +1,114 @@
+// 12 december 2015
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include "ui.h"
+// extern void doButtonOnClicked(uiButton *, void *);
+// static inline void realuiButtonOnClicked(uiButton *b)
+// {
+// 	uiButtonOnClicked(b, doButtonOnClicked, NULL);
+// }
+import "C"
+
+// no need to lock this; only the GUI thread can access it
+var buttons = make(map[*C.uiButton]*Button)
+
+// Button is a Control that represents a button that the user can
+// click to perform an action. A Button has a text label that should
+// describe what the button does.
+type Button struct {
+	c	*C.uiControl
+	b	*C.uiButton
+
+	onClicked		func(*Button)
+}
+
+// NewButton creates a new Button with the given text as its label.
+func NewButton(text string) *Button {
+	b := new(Button)
+
+	ctext := C.CString(text)
+	b.b = C.uiNewButton(ctext)
+	b.c = (*C.uiControl)(unsafe.Pointer(b.b))
+	freestr(ctext)
+
+	C.realuiButtonOnClicked(b.b)
+	buttons[b.b] = b
+
+	return b
+}
+
+// Destroy destroys the Button.
+func (b *Button) Destroy() {
+	delete(buttons, b.b)
+	C.uiControlDestroy(b.c)
+}
+
+// LibuiControl returns the libui uiControl pointer that backs
+// the Window. This is only used by package ui itself and should
+// not be called by programs.
+func (b *Button) LibuiControl() uintptr {
+	return uintptr(unsafe.Pointer(b.c))
+}
+
+// Handle returns the OS-level handle associated with this Button.
+// 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 GtkButton.
+// On OS X this is a pointer to a NSButton.
+func (b *Button) Handle() uintptr {
+	return uintptr(C.uiControlHandle(b.c))
+}
+
+// Show shows the Button.
+func (b *Button) Show() {
+	C.uiControlShow(b.c)
+}
+
+// Hide hides the Button.
+func (b *Button) Hide() {
+	C.uiControlHide(b.c)
+}
+
+// Enable enables the Button.
+func (b *Button) Enable() {
+	C.uiControlEnable(b.c)
+}
+
+// Disable disables the Button.
+func (b *Button) Disable() {
+	C.uiControlDisable(b.c)
+}
+
+// Text returns the Button's text.
+func (b *Button) Text() string {
+	ctext := C.uiButtonText(b.b)
+	text := C.GoString(ctext)
+	C.uiFreeText(ctext)
+	return text
+}
+
+// SetText sets the Button's text to text.
+func (b *Button) SetText(text string) {
+	ctext := C.CString(text)
+	C.uiButtonSetText(b.b, ctext)
+	freestr(ctext)
+}
+
+// OnClicked registers f to be run when the user clicks the Button.
+// Only one function can be registered at a time.
+func (b *Button) OnClicked(f func(*Button)) {
+	b.onClicked = f
+}
+
+//export doButtonOnClicked
+func doButtonOnClicked(bb *C.uiButton, data unsafe.Pointer) {
+	b := buttons[bb]
+	if b.onClicked != nil {
+		b.onClicked(b)
+	}
+}

checkbox.go

@@ -0,0 +1,124 @@
+// 12 december 2015
+
+package ui
+
+import (
+	"unsafe"
+)
+
+// #include "ui.h"
+// extern void doCheckboxOnToggled(uiCheckbox *, void *);
+// static inline void realuiCheckboxOnToggled(uiCheckbox *c)
+// {
+// 	uiCheckboxOnToggled(c, doCheckboxOnToggled, NULL);
+// }
+import "C"
+
+// no need to lock this; only the GUI thread can access it
+var checkboxes = make(map[*C.uiCheckbox]*Checkbox)
+
+// Checkbox is a Control that represents a box with a text label at its
+// side. When the user clicks the checkbox, a check mark will appear
+// in the box; clicking it again removes the check.
+type Checkbox struct {
+	co	*C.uiControl
+	c	*C.uiCheckbox
+
+	onToggled		func(*Checkbox)
+}
+
+// NewCheckbox creates a new Checkbox with the given text as its label.
+func NewCheckbox(text string) *Checkbox {
+	c := new(Checkbox)
+
+	ctext := C.CString(text)
+	c.c = C.uiNewCheckbox(ctext)
+	c.co = (*C.uiControl)(unsafe.Pointer(c.c))
+	freestr(ctext)
+
+	C.realuiCheckboxOnToggled(c.c)
+	checkboxes[c.c] = c
+
+	return c
+}
+
+// Destroy destroys the Checkbox.
+func (c *Checkbox) Destroy() {
+	delete(checkboxes, c.c)
+	C.uiControlDestroy(c.co)
+}
+
+// LibuiControl returns the libui uiControl pointer that c.coks
+// the Window. This is only used by package ui itself and should
+// not be called by programs.
+func (c *Checkbox) LibuiControl() uintptr {
+	return uintptr(unsafe.Pointer(c.co))
+}
+
+// Handle returns the OS-level handle associated with this Checkbox.
+// 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 GtkCheckButton.
+// On OS X this is a pointer to a NSButton.
+func (c *Checkbox) Handle() uintptr {
+	return uintptr(C.uiControlHandle(c.co))
+}
+
+// Show shows the Checkbox.
+func (c *Checkbox) Show() {
+	C.uiControlShow(c.co)
+}
+
+// Hide hides the Checkbox.
+func (c *Checkbox) Hide() {
+	C.uiControlHide(c.co)
+}
+
+// Enable enables the Checkbox.
+func (c *Checkbox) Enable() {
+	C.uiControlEnable(c.co)
+}
+
+// Disable disables the Checkbox.
+func (c *Checkbox) Disable() {
+	C.uiControlDisable(c.co)
+}
+
+// Text returns the Checkbox's text.
+func (c *Checkbox) Text() string {
+	ctext := C.uiCheckboxText(c.c)
+	text := C.GoString(ctext)
+	C.uiFreeText(ctext)
+	return text
+}
+
+// SetText sets the Checkbox's text to text.
+func (c *Checkbox) SetText(text string) {
+	ctext := C.CString(text)
+	C.uiCheckboxSetText(c.c, ctext)
+	freestr(ctext)
+}
+
+// OnToggled registers f to be run when the user clicks the Checkbox.
+// Only one function can be registered at a time.
+func (c *Checkbox) OnToggled(f func(*Checkbox)) {
+	c.onToggled = f
+}
+
+//export doCheckboxOnToggled
+func doCheckboxOnToggled(cc *C.uiCheckbox, data unsafe.Pointer) {
+	c := checkboxes[cc]
+	if c.onToggled != nil {
+		c.onToggled(c)
+	}
+}
+
+// Checked returns whether the Checkbox is checked.
+func (c *Checkbox) Checked() bool {
+	return tobool(C.uiCheckboxChecked(c.c))
+}
+
+// SetChecked sets whether the Checkbox is checked.
+func (c *Checkbox) SetChecked(checked bool) {
+	C.uiCheckboxSetChecked(c.c, frombool(checked))
+}

control.go

@@ -23,6 +23,11 @@ type Control interface {
 	// then call LibuiControlDestroy.
 	Destroy()
 
+	// LibuiControl returns the libui uiControl pointer that backs
+	// the Control. This is only used by package ui itself and should
+	// not be called by programs.
+	LibuiControl() uintptr
+
 	// Handle returns the OS-level handle that backs the
 	// Control. On OSs that use reference counting for
 	// controls, Handle does not increment the reference

window.go

@@ -63,6 +63,13 @@ func (w *Window) Destroy() {
 	C.uiControlDestroy(w.c)
 }
 
+// LibuiControl returns the libui uiControl pointer that backs
+// the Window. This is only used by package ui itself and should
+// not be called by programs.
+func (w *Window) LibuiControl() uintptr {
+	return uintptr(unsafe.Pointer(w.c))
+}
+
 // Handle returns the OS-level handle associated with this Window.
 // On Windows this is an HWND of a libui-internal class.
 // On GTK+ this is a pointer to a GtkWindow.
@@ -134,7 +141,7 @@ func (w *Window) SetChild(child Control) {
 	w.child = child
 	c := (*C.uiControl)(nil)
 	if w.child != nil {
-		c = touiControl(w.child.Handle())
+		c = touiControl(w.child.LibuiControl())
 	}
 	C.uiWindowSetChild(w.w, c)
 }

zz_test.go

@@ -11,6 +11,11 @@ func TestIt(t *testing.T) {
 			Quit()
 			return true
 		})
+		c := NewCheckbox("Click Me")
+		c.OnToggled(func(c *Checkbox) {
+			w.SetMargined(c.Checked())
+		})
+		w.SetChild(c)
 		w.Show()
 	})
 	if err != nil {