How to select child elements after using groupSVGElements

I am loading an svg into Fabric which has child elements. I'm grouping them using groupSVGElements().

I need to be able select each child element - that is an onclick event that allows me to select a child object.

I've thrown together this fiddle http://jsfiddle.net/AnQW5/2/

Although I can list out the child objects of the group via getObjects, theres no way that I can see to determine which object was clicked. So :

    canvas.observe('object:selected', function(e) {
       console.log(e.target.getObjects());
       // ???
    });

Any ideas?

You can use canvas.add.apply instead groupSVGElements, so you can : have each element to manipulate

var shapesSvg = '<?xml version="1.0" encoding="UTF-8" standalone="no"?><svg version="1.1" xmlns:svg="http://www.w3.org/2000/svg" xmlns="http://www.w3.org/2000/svg" width="320" height="240" viewBox="0 0 320 240"><rect id="rect" x="5" y="50" width="100" height="100" style="fill: rgb(255,0,0);"></rect> <circle id="circle" cx="165" cy="100" r="50" style="fill: rgb(0,255,0);"/></svg>';

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

canvas.setHeight($(window).height());
canvas.setWidth($(window).width());


fabric.loadSVGFromString(shapesSvg, function(objects, options) {
  canvas.add.apply(canvas, objects);
  canvas.renderAll();
});

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.5.0/fabric.min.js"></script>
<canvas id="canvas"></canvas>

Description

The following code detects any object on the screen by it's color, not the best thought.

Code

var $canvas = {
    activePaths: []
};

// Bind to `onMouseDown` event.
function onMouseDown = function (options) {

    var mousePos = canvas.getPointer(options.e);
    mousePos.x = parseInt(mousePos.x);
    mousePos.y = parseInt(mousePos.y);

    var width =  canvas.getWidth();
    var height = canvas.getHeight();

    var pixels = canvas.getContext().getImageData(0, 0, width, height);
    var pixel = (mousePos.x + mousePos.y * pixels.width) * 4;

    var activePathsColor = new fabric['Color']('rgb(' + pixels.data[pixel] + ',' + pixels.data[pixel + 1] + ',' + pixels.data[pixel + 2] + ')');
    var colorHex = '#' + activePathsColor.toHex().toLowerCase();

    var activeObject = canvas.getActiveObject();
    var activePath = [];

    // Check if active objects are type of `group`, if so push the selected path.
    if(activeObject.type == 'group') {

          for (var i = 0; i < activeObject.getObjects().length; i++) {
            var path = activeObject.getObjects()[i];
            if (path.getFill().toLowerCase() == colorHex) {
                $canvas.activePaths.push(path);
            }
        }

    }

}

References

Events: http://fabricjs.com/events/

来源：https://stackoverflow.com/questions/15046602/how-to-select-child-elements-after-using-groupsvgelements

标签

javascript

canvas

fabricjs