Question

如果我为鼠标悬停事件设置处理程序，它将看起来像这样。

boxPanel.addDomHandler(new MouseOverHandler() {
            @Override
            public void onMouseOver(MouseOverEvent e) {
               //do something
            }
        }, MouseOverEvent.getType());

请注意最后的MouseOverEvent.getType()，因为它与我的问题有关。

如果我想为所有鼠标事件添加处理程序，如此

spotlightPanel.addDomHandler(new HandlesAllMouseEvents() {
        @Override
        public void onMouseOver(MouseOverEvent event) {
            //do something
        }
        @Override
        public void onMouseOut(MouseOutEvent event) {
            //do something
        }
        @Override
        public void onMouseDown(MouseDownEvent event) {
            //do something
        }
        @Override
        public void onMouseUp(MouseUpEvent event) {
            //do something
        }
        @Override
        public void onMouseMove(MouseMoveEvent event) { 
            //do something
        }
        @Override
        public void onMouseWheel(MouseWheelEvent event) {
            //do something
        }
    }, ???);

什么会???是？我尝试了MouseEvent.getType()之类的东西，但这种方法并不存在。我尝试输入多个事件，如(MouseOverEvent.getType(), MouseOutEvent.getType())，但语法都错了。引用HandlesAllMouseEvents()的所有鼠标事件的正确方法是什么？

Answer 1

由于HandlesAllMouseEvents是多个事件类型的接口，因此您必须将每个事件类型添加到窗口小部件，但重用相同的处理程序。

    Widget spotlightPanel = [...]

    HandlesAllMouseEvents mouseHandler = new HandlesAllMouseEvents(){
        public void onMouseDown(MouseDownEvent event) {}
        public void onMouseUp(MouseUpEvent event) {}
        public void onMouseMove(MouseMoveEvent event) {}
        public void onMouseOut(MouseOutEvent event) {}
        public void onMouseOver(MouseOverEvent event) {}
        public void onMouseWheel(MouseWheelEvent event) {}
    };

    spotlightPanel.addDomHandler(mouseHandler, MouseDownEvent.getType());
    spotlightPanel.addDomHandler(mouseHandler, MouseUpEvent.getType());
    spotlightPanel.addDomHandler(mouseHandler, MouseMoveEvent.getType());
    spotlightPanel.addDomHandler(mouseHandler, MouseOverEvent.getType());
    spotlightPanel.addDomHandler(mouseHandler, MouseWheelEvent.getType());

获取所有鼠标事件类型

1 个答案: