KineticJS Drag event is preventing Double-click event from firing

问题

I have a node in KineticJs that has both a drag handler and double-click handler on it. When a user attempts to double-click on the object and moves slightly during the initial click, the drag handler intercepts what would be the double-click, breaking the experience. I have googled this extensively and have tried many solutions to no avail. This issue is captured in the link below but no update has been made to kinetic.

https://github.com/ericdrowell/KineticJS/issues/243

Example Code:

shape.on("dblclick dbltap", function (pos) {
    ModalWindow(this.parent.data,pos); //Loads a modal window
});

shape.on("mousedown",function(e) {
    this.setDraggable(false);
    var that = this;
    console.log("Drag Off");
    setTimeout(function(){
        that.setDraggable(true);
        console.log("Drag On");
    },1000);
});

回答1:

Determining Drag vs Click is a common problem.

One common way to handle the conflict is:

on dragstart save the starting position of the node
on dragend check if the node has moved less than 10 pixels (or whatever distance)
if <10 pixels, move the node back to its starting position
if <10 pixels, fire the click event

Here's example code and a Demo: http://jsfiddle.net/m1erickson/yh67y/

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Prototype</title>
    <script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
    <script src="http://d3lp1msu2r81bx.cloudfront.net/kjs/js/lib/kinetic-v5.0.1.min.js"></script>
<style>
body{padding:20px;}
#container{
  border:solid 1px #ccc;
  margin-top: 10px;
  width:350px;
  height:350px;
}
</style>        
<script>
$(function(){

    $p=$("#event");

    var stage = new Kinetic.Stage({
        container: 'container',
        width: 350,
        height: 350
    });
    var layer = new Kinetic.Layer();
    stage.add(layer);

    var circle1 = new Kinetic.Circle({
        x:100,
        y:100,
        radius: 30,
        fill: 'red',
        stroke: 'black',
        strokeWidth: 4,
        draggable: true
    });
    circle1.startingPos;
    circle1.referredEvent="";
    circle1.on("dragstart",function(){
        this.startingPos=this.position();
    });
    circle1.on("dragend",function(){
        var endingPos=this.position();
        var dx=Math.abs(endingPos.x-this.startingPos.x);
        var dy=Math.abs(endingPos.y-this.startingPos.y);
        if(dx<10 && dy<10){
            this.position(this.startingPos);
            this.referredEvent="--from drag";
            this.fire("click");
            layer.draw();
        }
    });
    circle1.on("click",function(){
        $p.text("clicked"+this.referredEvent);
        this.referredEvent="";
    });
    layer.add(circle1);
    layer.draw();

}); // end $(function(){});
</script>       
</head>
<body>
    <h4>Drags less than 10 pixels will cause click<br>instead of drag.</h4>
    <p id="event">Drag or Click the circle</p>
    <div id="container"></div>
</body>
</html>

Now for double-tapping:

Since the referred click won't count towards one of the taps of a double-tap, you will have to save the time each click occurs (in the click event handler). If you have 2 clicks within a half-second (or whatever time limit) then trigger the doubletap event--this.fire("doubletap");

And Yes...this all sounds like a hack.

But the fact is a mousedown can equally signal a click or a drag.

This is the best workaround we've got.

来源：https://stackoverflow.com/questions/22210576/kineticjs-drag-event-is-preventing-double-click-event-from-firing

标签

javascript

kineticjs