Alright, so I'm trying to figure out when a child is added to a movieclip "x", and handling/detouring this operation from within this "x" movieclip.
I tried overriding addChild and addChildAt at with no prevail. The movieclips that are placed on the stage via flash still don't trigger addChild or addChildAt. However, tracing this.numChildren shows '2' correctly.
Any hints?
You can add an event listener for the "added" event for the x movie clip.
x.addEventListener(Event.ADDED, addHandler);
function addHandler(e:Event){
// your code here
}
This link may explain it better:
AS3.0 – Event.ADDED and Event.ADDED_TO_STAGE
The documentation is also a good resource:
flash.events.Event
You can override the default methods of a movieclip by doing the following:
Create a class to extend a movieclip:
package {
import flash.display.*;
public class SuperMovieClip extends MovieClip {
public function SuperMovieClip() {
// constructor code
super();
}
override public function addChild(child:DisplayObject):DisplayObject {
trace("Hello, I am overriding add child");
// still perform the default behavior but you can do what ever you want.
return super.addChild(child);
}
}
}
Then in Flash create a new movieclip, and make sure it is marked as Enable for ActionScript. The Class should be any name you want, but the base class needs to be SuperMovieClip (or the name you chose for your extended class) See image:
Now when any stage clip is created of this base type (regardless if it's in the IDE or through code) it will be of type SuperMovieClip and anytime addChild is called it will override the original function.
For example, I placed an instance of this mc from library onto the stage at design time and compiled it using the following code on the timeline:
import flash.display.Sprite;
stage_mc.addChild(new Sprite());
And it output Hello, I am overriding add child
Related
In the game that I am making, you choose a shape, and then on the next screen choose a color. The shape selector works fine and loads one of 6 'shape' movie clips into the next stage of the game. On this stage, I have buttons to control color. Im trying to make the buttons change the color of the movieclip by launching a custom event. This would then be detected by a listener within the class for each movieclip.
So far this is my code:
The screen that contains the color change button:
package {
import flash.display.MovieClip;
import flash.events.MouseEvent;
public class ColorSelector extends MovieClip
{
public function ColorSelector()
{
charcoal.addEventListener (MouseEvent.CLICK, onClickCharcoal );
}
public function onClickCharcoal (mouseEvent:MouseEvent): void
{
dispatchEvent (new ColorEvent (ColorEvent.CHARCOAL) );
trace ("click")
}}
The custom event class:
package
{
import flash.events.Event;
public class ColorEvent extends Event
{
public static const CHARCOAL:String = "charcoal";
public function ColorEvent( type: String )
{
super ( type );
}
}}
The movieclip being acted upon:
package {
import flash.display.MovieClip;
public class Gobbert extends MovieClip {
public function Gobbert()
{
this.addEventListener (ColorEvent.CHARCOAL, makeCharcoal)
}
public function makeCharcoal (colorEvent: ColorEvent) :void
{
this.alpha = .5
}
}
It seems to me like the event is not getting through to the class with the listener. I could really use a fresh pair of eyes to help me figure out whats going on. The program doesn't give me any error, just doesn't do much else either. Thanks in advance!
You are missing the bubbles parameter on the constructor. If omitted it defaults to false. The call to super on the custom event should be:
super(type, bubbles, cancelable);
You will want to pass bubbles in as true via addEventListener function call or hard code inside the custom event constructor.
Also make sure the target (instance of Gobbert) movie clip is on the event bubbling path which means the ColorSelector has to be a child of the display list of Gobbert. If your display list is not set up this way you may want to rethink your approach and have the event propagate from the selector to a common parent and then set the color on Gobbert through that common parent.
Note: Yes, I know that similar questions have been asked before. However, after following the answers in such questions I'm still stuck and can't find a solution to my problem.
I'm having a problem which requires adding DisplayObjects to the Flash stage. Since I have to Display elements of several different classes, I decided to create a class to work as an intermediary between the .as files and the addChild function called "Displayer" as shown below:
package
{
import flash.display.DisplayObject;
import flash.display.Sprite;
import flash.display.Stage;
public class Displayer extends Sprite //I read somewhere that DisplayObject
//as an extension can't be used for this, so Sprite will have to do.
{
private var _stage:Stage;
function Displayer()
{
_stage = new Stage;
}
public function displayElement(displayable:DisplayObject)
{
_stage.addChild(displayable);
}
}
}
I compile it and there appears a problem that I don't understand: Error #2012: Can't instantiate Stage class. Evidently, something in this code is either missing or out of place, but since it's so straightforward I fail to see what the problem can be. I'm sure that it's not very complicated, I probably just need an outsider's perspective.
The Stage object is not globally accessible. You need to access it through the stage property of a DisplayObject instance.
refer a following docs.
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/Stage.html
package
{
import flash.display.DisplayObject;
import flash.display.Sprite;
import flash.display.Stage;
public class Displayer extends Sprite
{
var isAddedToStage:Boolean;
public function Displayer()
{
if(stage) init();
else addEventListener(Event.ADDED_TO_STAGE, init);
}
private function init(e:Event=null):void
{
removeEventListener(Event.ADDED_TO_STAGE, init);
isAddedToStage = true;
}
public function displayElement(displayable:DisplayObject):void
{
if(isAddedToStage)
this.stage.addChild(displayable);
}
}
}
You don't instantiate the Stage class, as the error says. Just like you cannot instantiate the DisplayObject class (which is why you have to extend Sprite).
Basically, you have two options here:
1) You add the child from a DisplayObjectContainer instance.
var displayerInstance:Displayer = new Displayer();
this.addChild( displayerInstance );
You would run this from a DisplayObjectContainer object that has already been added to the global stage. There is only a single stage in every project, even if you embed SWFs, the stage property of the SWF is actually the stage property of the top level application. So if you have this Displayer instance nested inside a class which is nested inside another class that is created in your main application, you would have to run "addChild" in each of those classes to get the Displayer to show.
2) You cheat. This is not recommended, at all. Basically, you pass in the stage object of an object when you instantiate the Displayer class.
var displayerInstance:Displayer = new Displayer( this.stage );
public function Displayer( stage:Stage ) {
this.stage = stage;
if ( this.stage ) {
this.stage.addChild( this );
}
}
This is a method that is good for adding Singletons to the stage (except there is not constructor for a Singleton). I created a profiler just before Christmas that was a Singleton (And later found Scout, damnit) that used this method for adding things to the stage when appropriate.
Again, that second option is not recommended for this situation, but it is a possibility.
As an aside, you should never add things directly to Stage, unless there is a clear reason for doing so (such as a popup). You should follow the display list methodology, where a DisplayObjectContainer adds another DisplayObject or DisplayObject container as a child and so on and so forth so that they are all connected to the TopLevelApplication.
Ok, I think instantiating a stage class won't do because as the as3 documentation says: "The Stage object is not globally accessible. You need to access it through the stage property of a DisplayObject instance."
You should instead pass a reference to the Stage object to your Displayer class and you can get a reference to the stage object, as the docs say, via a display object instance.
So the constructor might now look like:
function Displayer( stage:Stage )
{
_stage = stage;
}
Assuming that the object which instantiates your Displayer is a child of the stage you can instantiate the Displayer by
displayer = new Displayer( stage );
If you use this approach there is no need for the Displayer class to extend anything or be added to the stage ( which is required btw in the approach of bitmapdata.com ).
There is always a simple solutions.if you need to add a child element into a stage from your class you can just pass the stage into your class as a object and add the child element into it, i did this for adding an image into my stage like this.
package {
import flash.display.Loader;
import flash.display.Sprite;
import flash.net.URLRequest;
import flash.display.Bitmap;
public class ImageLoader extends Sprite{
private var stageObj:Object; //create local variable to refarance stage
public function loadeimage(StageObject:Object, Url:String){ //StageObject will bring the stage refarance into the class
var reQuest:URLRequest = new URLRequest(Url);
loader.load(reQuest);
stageObj=StageObject; //make local refarance for stage inside the class
var image:Bitmap;
image=Bitmap(loader.content);
image.x = 100;
image.y = 100;
stageObj.addChild(image); // add whatever object into stage refarance and this means the real stage..
}
}
}
only the things with comments are important and you can save this file as ImageLoader.as and import it and use it like this.
import ImageLoader;
var IL:ImageLoader = new ImageLoader();
IL.loadeimage(this,"img.jpg");
its simple as that. i think this is what you have search for... good luck. (you can pass any container or parant container this or this.stage it doesn't matter your child will be a part of it.
I am loading one swf into another using the Loader class, but when the child swf finishes loading and is added to the display list, its Document Class is not instantiated. I have a few trace statements that should execute when the object is created, but nothing is happening when loaded into the parent SWF. When I compile the child SWF on its own, the Document Class runs as expected.
So I'm wondering... how do I associate a child SWF's Document Class with Loader.content?
Code updated with a solution from Kishi below.
public class Preloader extends Sprite {
import flash.net.*;
import flash.display.*;
import flash.events.*;
// code in parent SWF's Document Class (Preloader.as)
private var swfLoader:Loader;
public var mainMovie:MovieClip;
public function Preloader(){
swfLoader = new Loader();
swfLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, loaderDone);
swfLoader.load(new URLRequest("mainmovie.swf"));
}
private function loaderDone(e:Event):void {
// Cast Loader.content to MovieClip
mainMovie = MovieClip(swfLoader.content);
mainMovie.addEventListener(Event.ADDED_TO_STAGE, mainMovieAddedListener);
addChildAt(mainMovie, 0);
}
private function mainMovieAddedListener(e:Event):void {
// init() not necessary
}
}
// MainMovie.as runs after casting swfLoader.content to MovieClip
public class MainMovie extends Sprite {
public function MainMovie(){
trace('MainMovie WHATTUP');
}
public function init():void {
trace('init');
}
}
Cheers!
The problem is how you are trying to access the swf instance.
First, the document class instance is referred by Loader's content property. You'd reference it like this:
var swf:DisplayObject = swfLoader.content;
But, even then you'd have to cast the DisplayObject either to it's real class (MainMovie, in this case) or a dynamic class (such as MovieClip), as you are trying to use a custom property, that's not part of DisplayObject itself. Therefore, you could call MainMovie.init() like so:
var swf:MovieClip = MovieClip(swfLoader.content);
swf.init();
Hope that helps.
You're adding the mainMovie to stage, then you add a listener which inites it. The event is not fired as it's added after the movie is on stage.
What Cristi said is probably right, for the reason your init method isn't firing, but the more strange issue is that your loaded child swf's Constructor, MainMovie, should be firing as soon as that object is created.
Whenever I've done things like this, I've never created a new Sprite object from the contents of the loaded swf. Seems what you're doing there is using the swf like it's BitmapData, to create the Sprite mainMovie.
Try this: remove your statement that says swfLoader = null, and instead say addChild(swfLoader);. If you still want that event listener checking for it being added to the stage, put it before you do the addChild(swfLoader);, and of course put it on the swfLoader not the mainMovie object:
swfLoader.addEventListener(Event.ADDED_TO_STAGE, mainMovieAddedListener);
addChild(swfLoader);
See what you get then. [also can you paste the exact error you got from trying to access init?]
debu
I'd like to access the stage of the main timeline from w/i a class that extends a movieclip. Basically, I have a button in the main timeline that makes a HUD appear. The HUD is an extended MovieClip class. When people click on a button in the HUD, I'd like to remove the object from the stage of the main MovieClip.
#curro: I think your confusion may come from the fact that I am running this code from a class definition file. Clicking on a button w/i this object should remove it from the DisplayList of the MainTimeline. Here's the code from the class definition file:
package classes {
import flash.display.Stage;
import flash.display.MovieClip;
import flash.events.MouseEvent;
public class Answers extends MovieClip {
public function Answers(){
listen();
}//constructor
//initiatlize variables
public var answersArray:Array = new Array();
private function listen():void {
submit_btn.addEventListener(MouseEvent.CLICK, function(e:MouseEvent){
answersArray.push(answer_txt.text);
e.currentTarget.parent.parent.stage.removeChild(this);
});//listen
}//listen
}//class Definition
}//package
trace(e.currentTarget.parent.parent) gets me the MainTimeline, and trace(e.currentTarget.parent.parent.stage) appears to return the main stage, but I cannot use removeChild w/o getting an error that I am trying to coerce the stage to be a DisplayObject (which it ought to be).
What's on the stage of the MainTimeline: A single button that, when clicked, adds an instance of the Answers class to the stage.
What's part of the Answers class that's not in the code?
I first created Answers as a MovieClip object in the main library. It has 3 parts:
a TextField named "answer_txt"
a "clear_btn" that clears the answer_txt
a "submit_btn" that submits the text of answer_txt and then removes the entire Answers object from the MainTimeline (at least, that's what I want it to do).
your class definition is really weird. Looks like a mixture of as2 and as3.
Try with this:
package
{
import flash.display.MovieClip;
import flash.events.MouseEvent;
import flash.text.*;
import fl.controls.Button;
public class Answers extends MovieClip
{
public var answersArray:Array = new Array();
public function Answers()
{
submit_btn.addEventListener(MouseEvent.CLICK, remove);
}
private function remove(e:MouseEvent)
{
answersArray.push(answer_txt.text);
this.parent.removeChild(this);
}
}
}
This works on my computer. Your code doesn't. I think it has something to do with the listen method. The class isn't still instatiated and you are making it work.
Hey, I can't make head or tail from the code. Where does submit_btn come from? Is it a property of the class? What about answer_txt?
You don't need to access e.currentTarget... to remove "this" simply:
this.parent.removeChild(this);
If you add that movieclip to the stage then you can access the stage from that class as simple as in the document class
stage
Otherwise you can't access stage from that class. But you can access it by sending the stage as argument when instantiate the class.
How do I access Stage Class properties in Costum Class?
Class:
package {
import Main;
import flash.events.*;
import flash.display.Sprite;
import flash.display.Stage;
public class Run extends Sprite {
var obj:a1_spr;
public function Run() {
runAssets();
}
private function runAssets():void {
obj = new a1_spr()
addChild(obj);
obj.x = stage.stageWidth/2;
}
}
}
Output:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
To expand on what Joel said, and put it into context:
Every display object has a .stage property, but that property is null until you add you display object onto the display list. So during construction, you will never be able to access it, (because it gets added afterwards)
The event ADDED_TO_STAGE gets fired when you add your object to the stage, ltting you know that the .stage property is now populated. After that happens you can access the stage from anywhere in you object.
Hope that clarifies things for you.
this.addEventListener(Event.ADDED_TO_STAGE, handleAdedToStage)
private function handleAddedToStage(event:Event):void
{
this.runAssets()
}
private function runAssets():void
{
obj = new a1_spr();
addChild(obj);
obj.x = this.stage.stageWidth/2;
}
You aren't going to have access to the stage in the constructor (unless you inject the stage into the class). Sprite has a stage property.
when flash compiles the fla assets with your .as files, there's no stage. so the code is initiated as preparation for your documentclass, you have to listen to if there's a stage so it can be rendered.
that's why you listen to ADDED_TO_STAGE , to check it's actually in the display list.
This problem occurs for all display objects, since they must be added to the display list when there's an actual stage.
get used to add that listener, and check for a stage. specially when working in a team and your doing your own components in a larger project.