message: Use convenience `Rectangle::to` conversion in CheckBox
diff: @@ -87,11 +87,7 @@ void CheckBox::onMouseDown(EventHandler::MouseButton button, int x, int y)
  {
  if (!enabled() || !visible() || !hasFocus()) { return; }
  - if (button == EventHandler::MouseButton::BUTTON_LEFT && isPointInRect(x, y,
  - static_cast<int>(rect().x()),
  - static_cast<int>(rect().y()),
  - static_cast<int>(rect().width()),
  - static_cast<int>(rect().height())))
  + if (button == EventHandler::MouseButton::BUTTON_LEFT && mRect.to<int>().contains(Point{x, y}))
  {
  mChecked = !mChecked;
  mCallback();
  