RxJS:区分单击和拖动

Question

我有一个AngularJS组件,它应该对单击或拖动做出反应(调整区域大小).

我开始在我的应用程序中使用RxJS(ReactiveX),因此我尝试使用它找到解决方案.请求的Angular方面是次要的......

为了简化问题(并训练自己),我根据rx.angular.js拖拽示例制作了一个滑块指令:http: //plnkr.co/edit/UqdyB2请参阅Slide.js文件(其他代码用于其他实验).这个逻辑的代码是:

    function(scope, element, attributes)
    {
      var thumb = element.children(0);
      var sliderPosition = element[0].getBoundingClientRect().left;
      var sliderWidth = element[0].getBoundingClientRect().width;
      var thumbPosition = thumb[0].getBoundingClientRect().left;
      var thumbWidth = thumb[0].getBoundingClientRect().width;

      // Based on drag'n'drop example of rx-angular.js
      // Get the three major events
      var mousedown = rx.Observable.fromEvent(thumb,     'mousedown');
      var mousemove = rx.Observable.fromEvent(element,   'mousemove');
      var mouseup   = rx.Observable.fromEvent($document, 'mouseup');

      // I would like to be able to detect a single click vs. click and drag.
      // I would say if we get mouseup shortly after mousedown, it is a single click;
      // mousedown.delay(200).takeUntil(mouseup)
      //   .subscribe(function() { console.log('Simple click'); }, undefined, function() { console.log('Simple click completed'); });

      var locatedMouseDown = mousedown.map(function (event) 
      {
        event.preventDefault();
        // console.log('Click', event.clientX - sliderPosition);
        // calculate offsets when mouse down
        var initialThumbPosition = thumb[0].getBoundingClientRect().left - sliderPosition;
        return { from: initialThumbPosition, offset: event.clientX - sliderPosition };
      });

      // Combine mouse down with mouse move until mouse up
      var mousedrag = locatedMouseDown.flatMap(function (clickInfo) 
      {
        return mousemove.map(function (event)
        {
          var move = event.clientX - sliderPosition - clickInfo.offset;
          // console.log('Move', clickInfo);
          // calculate offsets from mouse down to mouse moves
          return clickInfo.from + move;
        }).takeUntil(mouseup);
      });

      mousedrag 
        .map(function (position)
        {
          if (position < 0)
            return 0;
          if (position > sliderWidth - thumbWidth)
            return sliderWidth - thumbWidth;
          return position;
        })
        .subscribe(function (position) 
        {
          // console.log('Drag', position);
          // Update position
          thumb.css({ left: position + 'px' });
        });
    }

这主要是D'n'D水平约束到给定范围.

现在,我想听mousedown,如果鼠标在短时间内发生(例如200 ms,调整),我将其视为点击并进行特定处理(例如,将位置重置为零).

我尝试过delay().takeUntil(mouseup),如另一个SO答案所示,没有成功.也许也可能需要switch()(以避免拖动路径).

任何的想法？提前致谢.

Answer 1

您可以使用timeout（timeoutWith如果您使用的是 ReactiveX/RxJS）

var click$ = mousedown.flatMap(function (md) {
  return mouseup.timeoutWith(200, Observable.empty());
});

如果 mouseup 在超时之前没有发生，它只会传播一个空的Observable。如果是，那么下游观察者将收到一个事件。