Instance metadata editor

InstanceMetadataEditor.as

package {
import com.bit101.components.PushButton;
import com.bit101.components.TextArea;
import com.codeazur.as3swf.SWF;
import com.codeazur.as3swf.tags.*;//TagPlaceObject;
import flash.display.DisplayObject;
import flash.display.DisplayObjectContainer;
import flash.display.Loader;
import flash.display.Sprite;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.geom.Point;
import flash.net.FileFilter;
import flash.net.FileReference;
import flash.utils.ByteArray;
import flash.utils.describeType;

[SWF(width = 465, height = 465)]
public class InstanceMetadataEditor extends Sprite {
    private var loader:Loader;
    private var file:FileReference;
    private var ta:TextArea;
    private var index:int;

    public function InstanceMetadataEditor() {
        new PushButton(this, 10, 10, "LOAD SWF", onLoadClick);
        (new PushButton(this, 120, 10, "SAVE SWF", onSaveClick)).enabled = false;
        file = new FileReference;
        file.addEventListener (Event.SELECT, onFileSelected);
        file.addEventListener (Event.COMPLETE, onFileLoaded);
        loader = new Loader();
        loader.addEventListener(MouseEvent.CLICK, onClick);
        loader.y = 40;
        addChild(loader);
        ta = new TextArea(this, 230, 10);
        ta.width = 465 - 10 - 230;
        ta.height = 465 - 10 - 10;
        ta.alpha = 0.75;
    }
    private function onLoadClick (...a):void { file.browse ([new FileFilter("Flash files: (*.swf)", "*.swf")]); }
    private function onFileSelected (e:Event):void { file.load (); }
    private function onFileLoaded (e:Event):void {
        loader.unloadAndStop(true);
        loader.loadBytes (file.data);
        (getChildAt(1) as PushButton).enabled = true;
        ta.text = "click on object in loaded swf to read/write its metaData";
    }
    private function onClick (e:MouseEvent):void {
        var objects:Array = loader.getObjectsUnderPoint(new Point(mouseX, mouseY));
        if (objects.length > 0) {
            // how do you pick topmost object? idk, will just grab [0]
            var topmost:DisplayObject = objects[0];
            while (topmost.parent != loader.content) topmost = topmost.parent;

            ta.text = JSON.stringify(topmost.metaData);

            // how do you identify this object in parsed swf? idk, will use its position in display list
            var container:DisplayObjectContainer = loader.content as DisplayObjectContainer;
            for (var i:int = 0, index = -1; i < container.numChildren; i++) {
                if (container.getChildAt(i) == topmost) {
                    index = i; break;
                }
            }
        }
    }
    private function onSaveClick (...a):void {
        var count:int = index;
        var swf:SWF = new SWF(file.data);
        for (var i:int = 0; i < swf.tags.length; i++) {
            if (swf.tags[i] is TagPlaceObject) {
                count--;
                if (count < 0) {
                    var po1:* = swf.tags[i];
                    var po4:TagPlaceObject4 = new TagPlaceObject4();

                    var typeInfo:XML = describeType(po1);
                    for each (var varName:String in typeInfo.variable.@name) {
                        po4[varName] = po1[varName];
                    }

                    // inject metadata
                    if (ta.text.charAt(0) == "{") {
                        po4.metaData = JSON.parse(ta.text);
                    }

                    swf.tags.splice(i, 1, po4);
                    break;
                }
            }
        }

        var bytes:ByteArray = new ByteArray();
        swf.publish(bytes);

        new FileReference().save(bytes, "output.swf");
    }
}
}