Add shape on double click

[pmelchior]

Hi Amit. I'd like to give user the ability to mark an object in an image, ideally by double-clicking at its location, which should then draw a circle around it. I've added this event handler to the API after line 250 of webfits-canvas.js:

this.canvas.ondblclick = function(e) {
        var ctx = _this.canvas.getContext('2d');
        ctx.beginPath();
        ctx.arc(_this.xMouseDown, _this.yMouseDown, 80, 0, 2*Math.PI, true);
        ctx.lineWidth=2;
        ctx.strokeStyle='#FF0000';
        ctx.stroke();
        ctx.closePath();
        return _this.draw();
      };

I verified that the double-click event triggers this function, but I don't see any effect on the canvas. I'm aware that's more an issue of my limited canvas knowledge, but if you have an idea to make this work, it might be useful for other webfits applications, too.

[kapadia]

Peter, it might be best to add another canvas as an overlay. This way you keep the image separate from the markings, and don't have to deal with the internals of the webfits library.

In the future I intend to offer methods to facilitate this functionality, but hard to tell you when ...