*
* The button's appearance could be modified by Button::SetUnselectedImage, Button::SetBackgroundImage,
* Button::SetSelectedImage, Button::SetSelectedBackgroundImage, Button::SetDisabledBackgroundImage,
*
* The button's appearance could be modified by Button::SetUnselectedImage, Button::SetBackgroundImage,
* Button::SetSelectedImage, Button::SetSelectedBackgroundImage, Button::SetDisabledBackgroundImage,