AS3: Preventing a parent from getting a Child's mouse clicks

If you have code that is like this:

var parent_sprite:Sprite = new Sprite();

parent_sprite.addEventListener(MouseEvent.CLICK,
     handle_mouse_click);
addChild(parent_sprite);

function handle_mouse_click(event:MouseEvent):void {
     parent_sprite.removeEventListener(MouseEvent.CLICK,
            handle_mouse_click);
     var child_sprite:Sprite = new Sprite();
     draw_button_using_child_sprite(); // Some func to
                                       // draw a button
     child_sprite.addEventListener(MouseEvent.CLICK,
            handle_button_click);

      parent_sprite.addChild(child_sprite);
}

function handle_button_click(event:MouseEvent):void {
    do_my_stuff();
    parent_sprite.removeChild(child_sprite);
    parent_sprite.addEventListener(MouseEvent.CLICK,
            handle_mouse_click);
}

Now one would expect that on clicking on the parent_sprite, the child_sprite would appear. On click on the child_sprite, some stuff would get done and then the child_sprite is removed and the parent_sprite would be the only one on screen.

What I experienced is, that the child_sprite reappeared on the screen. This was because the parent was registering a click as soon as the event for the parent was registered again in handle_button_click() and was doing a addChild(child_sprite). The reason for this is that AS3 has a concept of "bubbling" where a event is passed down to the parent once the child is done with it and it will continue down the chain to the stage.

The solution to this is to use stopPropagation() or stopImmediatePropagation(). stopPropagation() will only prevent parent from receiving the events. While stopImmediatePropagation will prevent everyone listening for the event in the chain from receiving it.

So the code would be:

var parent_sprite:Sprite = new Sprite();
addChild(parent_sprite);
parent_sprite.addEventListener(MouseEvent.CLICK,
         handle_mouse_click);

function handle_mouse_click(event:MouseEvent):void {
          parent_sprite.removeEventListener(MouseEvent.CLICK,
               handle_mouse_click);
          var child_sprite:Sprite = new Sprite();
          draw_button_using_child_sprite(); // Some func
                                           // to draw a button
          child_sprite.addEventListener(MouseEvent.CLICK,
               handle_button_click);
       
           parent_sprite.addChild(child_sprite);
}

function handle_button_click(event:MouseEvent):void {
         do_my_stuff();
         parent_sprite.removeChild(child_sprite);
         parent_sprite.addEventListener(MouseEvent.CLICK,
               handle_mouse_click);
         event.stopPropagation(); // Prevent parent from
                                 // receiving event
}

Got the information for this from:
http://www.kirupa.com/forum/showpost.php?p=1948149&postcount=202

AS3: Using a String to access Object / Class properties and getDefinitionByName

Consider for example you have a wonderful asset library and have a great scheme of describing maps and such in XML. So you get a asset name from XML and now want to add it to stage.

Remember you can access a Object property like so:

import my_assets.graphics;

var grap:graphics = new graphics();

var my_prop:String = "wonderful_img_class"; /* Got from XML :p */

stage.addChild(new graph[my_prop]); /* Now you asset is displayed */

wonderful_img_class in this case could refer to a image you have included using the [Embed(source=)] tag.

I initially spent time trying to use getDefinitionByName and got hit by the "Error #1065: Variable is not defined" before realising I could just do the above.

From my initial googling getDefinitionByName seems pretty unflexible and hence useless.

However if you want to investigate getDefinitionByName this post seems most useful:

http://www.rozengain.com/blog/2009/08/21/getdefinitionbyname-referenceerror-and-the-frame-metadata-tag/

AS3: Runtime loading of images

The steps on this link work: http://www.heaveninteractive.com/weblog/2008/03/28/loading-an-external-jpg-png-or-gif-file-in-actionscript-30/

AS3: Embedding XML files

If you have a XML file called myfile.xml. Code to include this would be:

[Embed(source="mfile.xml", mimeType="application/octet-stream")]
[Bindable]
private var my_file:Class;

function some_func():void {
   var my_xml:XML = XML(new my_file);
}

my_xml now contains valid XML. You can now access stuff it like normal XML variables.

Got this from the comments in this post: http://dispatchevent.org/roger/embed-almost-anything-in-your-swf/

AS3: Adding a Sprite as a child to a Flex Container for example a Canvas

From http://www.sebastiaanholtrop.com/archives/3 use:

import mx.core.*;

var my_canvas:Canvas = new Canvas();
var my_uic:UIComponent = new UIComponent();
var my_sprite:Sprite = new Sprite();

my_canvas.addChild(my_uic);
my_uic.addChild(my_sprite);

Flex 3: Adding you custom component sources in the compiler

Rather then copying custom or external code libraries to your source, it is better to add it using mxmlc compiler option "--source-path=/your/path/here".

AS3: Enabling scaling in AS3 for your games or movies

By default AS3 set scaling to NO_SCALE. If you want to override this so that your games or movies scale properly use:

stage.scaleMode = StageScaleMode.SHOW_ALL;

once your stage has been initialized.