PhotoHolder - Bitmap/BitmapData Problems

Question

Hello guys, how are you?
I'm trying to create an actionscript 3 class that receives an external image, adds it into a movieclip and adjusts it without corrupting the aspect ratio of the image.
I've tried working with BitmapData and Bitmap only, but can not hit the calculations. Can anyone help me?
Thank you,
package
    import flash.display.Bitmap;
          import flash.display.BitmapData;
          import flash.display.DisplayObject;
          import flash.display.Loader;
          import flash.display.MovieClip;
          import flash.display.PixelSnapping;
          import flash.display.Sprite;
          import flash.events.Event;
          import flash.events.IOErrorEvent;
          import flash.geom.Matrix;
          import flash.geom.Rectangle;
          import flash.net.URLRequest;
          import flash.system.LoaderContext;
          public class PhotoHolder extends MovieClip
                    private var _loader:Loader;
                    public function PhotoHolder()
                    public function loadPhoto(urlImg:String):void
                              _loader = new Loader();
                              _loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
                              _loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, onError);
                              _loader.load(new URLRequest(urlImg));
                    private function onError(e:IOErrorEvent):void
                              trace("ERROR!");
                    private function onComplete(e:Event):void
                              var loadedImage:Bitmap = Bitmap(_loader.content);
                              var bmd:BitmapData = new BitmapData(_loader.content.width, _loader.content.height, true);
                              bmd.draw(loadedImage, null);
                              this.holder.addChild(createBitmap(bmd));
                    private function createBitmap(bmd:BitmapData):Bitmap
            var bitmap:Bitmap = new Bitmap(bmd);
            bitmap.smoothing = true;
            setSize(bitmap, bmd.width, bmd.height, this.holder.x, this.holder.y);
            return bitmap;
        private function setSize(target:DisplayObject, contentWidth:Number, contentHeight:Number, targetWidth:Number, targetHeight:Number):void
            var w:Number = targetWidth;
            var h:Number = targetHeight;
            // maintain aspect ratio
            var containerRatio:Number = targetWidth / targetHeight;
            var imageRatio:Number = contentWidth / contentHeight;
            if (containerRatio < imageRatio) h = w / imageRatio;
            else                             w = h * imageRatio;
            target.width = w;
            target.height = h;
            //centre content - this might change based on your setup
            target.x = (targetWidth - w) * .5;
            target.y = (targetHeight -h) * .5;

Answer 1

You´re right! It´s happening, the case is my movieclip. I will think about it. I made fell changes in the class, it´s more easy to read. Now, that is the principal methods:
private function onComplete(e:Event):void
                              var w:Number = this.width;
                              var h:Number = this.height;
                              var loadedImage:Bitmap = Bitmap(_loader.content);
                              _ratio = _loader.content.height / _loader.content.width;
                              this.addChild(resizeIt(loadedImage, w, h));
                    private function resizeIt(bitmap:Bitmap, maxW:Number, maxH:Number):Bitmap
                             if (bitmap.width > maxW)
                                   bitmap.width = maxW;
                                   bitmap.height = bitmap.width * _ratio;
                          if (bitmap.height > maxH)
                                 bitmap.height = maxH;
                                bitmap.width = bitmap.height / _ratio;
                          bitmap.smoothing = true;
                           return bitmap;
But I have one more question:
I'm reducing the size of the image to place it in the container. I'm not using scaleX and scaleY. How do I fill the container without losing image quality?