apache flex - Best way to get the color where a mouse was clicked in AS3

Question

I have an image (mx) and i want to get the uint of the pixel that was clicked.

Any ideas?

Answer 1

A few minutes on the BitmapData LiveDoc Page will take you where you need to go. Once you have your image loaded into a Bitmap variable, you can access its BitmapData property. Add a Mouse Click Event Listener to the image and then use BitmapData::getPixel. The example for getPixel shows how to convert the uint response to an rgb hex code.

Here's a modification of the Example given on the BitmapData page that worked for me (using mxmlc - YMMV):

package {
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Loader;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.net.URLRequest;

    public class BitmapDataExample extends Sprite {
        private var url:String = "santa-drunk1.jpg";
        private var size:uint = 200;
        private var image:Bitmap;

        public function BitmapDataExample() {
            configureAssets();
        }

        private function configureAssets():void {
            var loader:Loader = new Loader();
            loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandler);

            var request:URLRequest = new URLRequest(url);
            loader.load(request);
            addChild(loader);
        }

        private function completeHandler(event:Event):void {
            var loader:Loader = Loader(event.target.loader);
            this.image = Bitmap(loader.content);

            this.addEventListener(MouseEvent.CLICK, this.clickListener);
        }

        private function clickListener(event:MouseEvent):void {
            var pixelValue:uint = this.image.bitmapData.getPixel(event.localX, event.localY)
            trace(pixelValue.toString(16));
        }
    }
}