Method mousewheel

src/services/focus.rs:130–142

(&self, e: &mut MouseEvent)

    }

    fn mousewheel(&self, e: &mut MouseEvent) {
        if let Some(focused) = self.canvas.focused() {
            if focused.mouse_input() {
                focused.mousewheel(e);
            }
        }

        if self.marked_mouse() {
            if let Some(marked) = self.canvas.marked() {
                marked.mousewheel(e);
            }
        }
    }

    fn marked_mouse(&self) -> bool {
        if let Some(marked) = self.canvas.marked() {