Method onButton

include/widget/ZoomWidget.hpp:28–32

		Widget::onHover(e2);
	}
	void onButton(const ButtonEvent& e) override {
		ButtonEvent e2 = e;
		e2.pos = e.pos.div(zoom);
		Widget::onButton(e2);
	}
	void onHoverKey(const HoverKeyEvent& e) override {
		HoverKeyEvent e2 = e;
		e2.pos = e.pos.div(zoom);