Executing Fabric.js animations in sequence using onComplete

Question

What I want is this:

http://jsfiddle.net/gJz6C/3/

But I want each box to pop in in sequence instead of all at once. I know that fabricjs has the onComplete attribute for this. I'm not so great at javascript and the one example I could find, here: http://fabricjs.com/shadows/, was not so transparent to me. I thought I had a clever solution though, to have a function that draws a single box, then calls itself onComplete, and doesn't do anything if it has been called 10 times. Here's the code and a jsfiddle at the end of it:

var canvas = new fabric.Canvas('canvas1')

function drawbox(seq) {
    if (seq<11) {
        var rect=new fabric.Rect({
            left: seq*25+25,
            top: 10,
            fill: 'red',
            width: 0,
            height: 0,
        });

        canvas.add(rect)

        rect.animate('width',20, {
            onChange:canvas.renderAll.bind(canvas),
            duration: 1000,
            easing: fabric.util.ease.easeOutElastic,
        });

        rect.animate('height',20, {
            onChange:canvas.renderAll.bind(canvas),
            duration: 1000,
            easing: fabric.util.ease.easeOutElastic,
            onComplete: drawbox(seq+1)
        });
    }
}

drawbox(1)

http://jsfiddle.net/bszM5/2/

As you can see from the jsfiddle though, this still draws all the boxes at once or, if you put also put an onComplete attribute in the width animation, it basically stalls the whole tab process for a second, then draws them all at once. Am I misunderstanding how onComplete is used?

Answer 1

The problem is that you pass in onComplete not function but its result.

rect.animate('height',20, {
   onChange:canvas.renderAll.bind(canvas),
   duration: 1000,
   easing: fabric.util.ease.easeOutElastic,
   onComplete: function() {
     // Here
     drawbox(seq+1);
   }
});

Answer 2

If i guess, you want to animate box one at a time, then you should use settimeout function.

          var canvas = new fabric.Canvas('canvas1')

          function drawbox(seq) {
           if (seq<11) {
            var rect=new fabric.Rect({
              left: seq*25+25,
              top: 10,
              fill: 'red',
              width: 0,
              height: 0,
        });

        canvas.add(rect)
        setTimeout(function(){
        rect.animate('width',20, {
            onChange:canvas.renderAll.bind(canvas),
            duration: 1000,
            easing: fabric.util.ease.easeOutElastic,
        });

        rect.animate('height',20, {
            onChange:canvas.renderAll.bind(canvas),
            duration: 1000,
            easing: fabric.util.ease.easeOutElastic,
            onComplete: drawbox(seq+1)
        });
       },1000);     
    }
}

drawbox(1)