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javascriptcanvaskineticjs

KineticJS drag multiple images without grouping them


is it possible to drag all children elements of a layer without grouping them?

I have different layers with image-elements and a path shape. The path draws a bubble around the images. If the user drag the bubble to another place, all images should move there, too.

But it should be also possible to drag a single element. At the moment, it is possible to drag a single element and to drag the bubble, but there is no combination...


Solution

  • Yes, you can drag "related" nodes when a "container" node is dragged:

    • add a class to all children of a bubble (for example, each child's name:"bubble1")

    • on bubble dragstart, save the bubble's starting position

    • on bubble dragmove, calculate how far the bubble has been dragged and reposition all related elements by that same distance

    Example code and a Demo: http://jsfiddle.net/m1erickson/Zr6TE/

    <!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(){
    
        var stage = new Kinetic.Stage({
            container: 'container',
            width: 350,
            height: 350
        });
        var layer = new Kinetic.Layer();
        stage.add(layer);
    
        var bubble=new Kinetic.Circle({
            x:100,
            y:100,
            width:100,
            height:100,
            fill:"blue",
            draggable:true,
        });
        bubble.lastPos;
        bubble.on("dragstart",function(){
            this.lastPos=this.position();
        });
        bubble.on("dragmove",function(){
            var lastPos=bubble.lastPos;
            var pos=bubble.position();
            var deltaX=pos.x-lastPos.x;
            var deltaY=pos.y-lastPos.y;
            layer.find(".bubble1").each(function(child){
                child.position({x:child.x()+deltaX, y:child.y()+deltaY} );
            });
            bubble.lastPos=pos;
            layer.draw();
        });
        layer.add(bubble);
    
        var circle1 = new Kinetic.Circle({
            x:80,
            y:80,
            radius:15,
            fill: 'red',
            stroke: 'black',
            strokeWidth: 4,
            draggable: true,
            name:"bubble1"
        });
        layer.add(circle1);
    
        //
        var circle2 = new Kinetic.Circle({
            x:110,
            y:110,
            radius:15,
            fill: 'green',
            stroke: 'black',
            strokeWidth: 4,
            draggable: true,
            name:"bubble1"
        });
        layer.add(circle2);
    
        //
        layer.draw();
    
    }); // end $(function(){});
    
    </script>       
    </head>
    <body>
        <div id="container"></div>
    </body>
    </html>