dialog.go
func (d *SelectDialog) OnClose(fn func()) {
	WindowManager().BeginUpdate()
	defer WindowManager().EndUpdate()
	d.onClose = fn
}
func (d *SelectDialog) OnClose(fn func()) {
	WindowManager().BeginUpdate()
	defer WindowManager().EndUpdate()
	d.onClose = fn
}
// OnClose sets the callback that is called when the
// dialog is closed