我使用jQuery。点击来处理Raphael图形上的鼠标点击事件,同时,我需要处理鼠标拖动事件,鼠标拖动在Raphael中由鼠标下拉,鼠标上拉和鼠标移动组成。

很难区分点击和拖动,因为点击也包含鼠标下拉和鼠标上拉,我怎么能区分鼠标“点击”和鼠标“拖动”然后在Javascript?


当前回答

如果你想使用Rxjs:

var element = document; Rx.Observable .merge( Rx.Observable.fromEvent(element, 'mousedown').mapTo(0), Rx.Observable.fromEvent(element, 'mousemove').mapTo(1) ) .sample(Rx.Observable.fromEvent(element, 'mouseup')) .subscribe(flag => { console.clear(); console.log(flag ? "drag" : "click"); }); <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <script src="https://unpkg.com/@reactivex/rxjs@5.4.1/dist/global/Rx.js"></script>

这是@wong2在他的回答中所做的直接克隆,但转换为RxJs。

样本的使用也很有趣。示例操作符将从源(mousedown和mousemove的合并)中获取最新的值,并在内部观察对象(mouseup)发出时发出它。

其他回答

所有这些解决方案要么在微小的鼠标移动上失效,要么过于复杂。

下面是一个使用两个事件侦听器的简单适应性解决方案。Delta是您必须在上下事件之间水平或垂直移动的距离(以像素为单位),以便代码将其归类为拖拽而不是单击。这是因为有时你会在抬起鼠标或手指之前移动几个像素点。

const delta = 6;
let startX;
let startY;

element.addEventListener('mousedown', function (event) {
  startX = event.pageX;
  startY = event.pageY;
});

element.addEventListener('mouseup', function (event) {
  const diffX = Math.abs(event.pageX - startX);
  const diffY = Math.abs(event.pageY - startY);

  if (diffX < delta && diffY < delta) {
    // Click!
  }
});

如果只是为了过滤掉拖动的情况,这样做:

var moved = false;
$(selector)
  .mousedown(function() {moved = false;})
  .mousemove(function() {moved = true;})
  .mouseup(function(event) {
    if (!moved) {
        // clicked without moving mouse
    }
  });

来自@Przemek的回答,

函数listenClickOnly(元素,回调,阈值=10){ 让拖动= 0; 元素。addEventListener('mousedown', () => drag = 0); 元素。addEventListener('mousemove', () => drag++); 元素。addEventListener('mouseup', e => { 如果(拖动<阈值)回调(e); }); } listenClickOnly ( 文档, () => console.log('click'), 10 );

另一个基于类的香草JS使用距离阈值的解决方案

private initDetectDrag(element) {
    let clickOrigin = { x: 0, y: 0 };
    const dragDistanceThreshhold = 20;

    element.addEventListener('mousedown', (event) => {
        this.isDragged = false
        clickOrigin = { x: event.clientX, y: event.clientY };
    });
    element.addEventListener('mousemove', (event) => {
        if (Math.sqrt(Math.pow(clickOrigin.y - event.clientY, 2) + Math.pow(clickOrigin.x - event.clientX, 2)) > dragDistanceThreshhold) {
            this.isDragged = true
        }
    });
}

在类内部添加(SOMESLIDER_ELEMENT也可以是document为global):

private isDragged: boolean;
constructor() {
    this.initDetectDrag(SOMESLIDER_ELEMENT);
    this.doSomeSlideStuff(SOMESLIDER_ELEMENT);
    element.addEventListener('click', (event) => {
        if (!this.sliderIsDragged) {
            console.log('was clicked');
        } else {
            console.log('was dragged, ignore click or handle this');
        }
    }, false);
}

基于这个答案,我在React组件中这样做:

export default React.memo(() => {
    const containerRef = React.useRef(null);

    React.useEffect(() => {
        document.addEventListener('mousedown', handleMouseMove);

        return () => document.removeEventListener('mousedown', handleMouseMove);
    }, []);

    const handleMouseMove = React.useCallback(() => {
        const drag = (e) => {
            console.log('mouse is moving');
        };

        const lift = (e) => {
            console.log('mouse move ended');
            window.removeEventListener('mousemove', drag);
            window.removeEventListener('mouseup', this);
        };

        window.addEventListener('mousemove', drag);
        window.addEventListener('mouseup', lift);
    }, []);

    return (
        <div style={{ width: '100vw', height: '100vh' }} ref={containerRef} />
    );
})