checkbox.go
func (c *CheckBox) OnChange(fn func(int)) {
	c.mtx.Lock()
	defer c.mtx.Unlock()

	c.onChange = fn
}
func (c *CheckBox) OnChange(fn func(int)) {
	c.mtx.Lock()
	defer c.mtx.Unlock()

	c.onChange = fn
}
func ( c * CheckBox ) OnChange ( fn func ( int ) ) { c . mtx . Lock ( ) defer c . mtx . Unlock ( ) c . onChange = fn }
// OnChange sets the callback that is called whenever the state
// of the CheckBox is changed. Argument of callback is the current
// CheckBox state: 0 - off, 1 - on, 2 - third state
OnChange sets the callback that is called whenever the state of the CheckBox is changed . Argument of callback is the current CheckBox state : 0 - off 1 - on 2 - third state