AS3 Avoider Game Tutorial, Part 3: Game Over

by Michael James Williams on October 9, 2008 · 223 comments

in Avoider Game Base,Tutorial

(This tutorial is also available in Spanish)

Introduction

In this part of my AS3 conversion of Frozen Haddock‘s avoiding game tutorial, I’ll show you how to add a game over screen. Click the image below to see how the game will play by the end of this post.

screenshot

Now, I already said in the first part of this tutorial that we’d be using just one frame of the timeline. This means that we can’t just stick a sign saying “game over” on frame 2 and then run a nextFrame() command when our character dies, so what can we do?

The answer’s pretty simple: we just slap a big “Game Over” sign on top of everything else when we need it, like pulling a curtain down at the end of a play.

Making an Overlay

Let’s get started. If you’ve been following the earlier parts of the tutorial, make a copy of your game folder and open the FLA in this new copy. Otherwise, download the zip file from Part 2, extract it somewhere, and open AvoiderGame-MJW.fla.

Create a new Movie Clip (Insert > New Symbol) called GameOverText, and draw something that will indicate to the player that their game is indeed over. Here’s mine:

screenshot

That font is Arial Black, and I’ve coloured it a dark red to make it stand out against the grey background. Note that I’ve centred the text around the registration point — see Part 1 for a reminder on how to do this.

If you’re using text, Flash might decide that it should be dynamic — that is, that it can be changed using code. Until we add scores, we don’t need this functionality, so click on your text and in the Properties panel, make sure to change the drop-down list from Dynamic Text or Input Text to Static Text. Otherwise, you’ll get an error:

1046: Type was not found or was not a compile-time constant: TextField.

Next we need to make this symbol available to our code. Find it in the Library, right-click it, and select Properties. In the Linkage panel, check the Export for ActionScript box, make a note of the class name (should be GameOverText) and click OK.

Open your document class file, either by directly opening the AS file in the Classes folder (mine’s called AvoiderGame.as), or by finding the document properties (click on an empty space, and selectWindow > Properties if you can’t see them) and clicking the little pencil icon next to the Document class text box. Find the onTick function, and then the piece of code that determines what happens if an enemy hits the player’s avatar:

?View Code ACTIONSCRIPT3
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if ( avatar.hitTestObject( enemy ) ) 
{
	gameTimer.stop();
}

So at the minute, this just stops the whole game if the avatar collides with an enemy. Nothing wrong with that, but it looks like the game has just crashed. Let’s make our Game Over text appear as well:

?View Code ACTIONSCRIPT3
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if ( avatar.hitTestObject( enemy ) ) 
{
	gameTimer.stop();
	var gameOverText:GameOverText = new GameOverText();
	gameOverText.x = 200;
	gameOverText.y = 150;
	addChild( gameOverText );
}

This code should be pretty familiar to you after reading Parts 1 and 2. Remember you can change the values 200 and 150 to alter where on the screen the Game Over text will appear.

Save everything and run it (Control > Test Movie) and when you hit an enemy, you should get something like this:

screenshot

Excellent.

Really Rubbing It In

An “overlay” game over notice like this is fine — it worked for Sonic — but what about a whole game over screen, like in Frozen Haddock’s game?

We can start by doing the same thing that we’re doing now, but making the symbol fill the whole game screen. Create another new Movie Clip, this time called GameOverScreen, and draw a big black rectangle, of any size. Click the rectangle, and change its size to match the dimensions of your stage. (You can change the size of the rectangle by altering its W and H — Width and Height — values in its Properties or Info panel, and you can see the dimensions of the stage by clicking Modify > Document.)

This time, we want the registration point of the symbol to be in the top-left corner. Why? Because then we can align it to the stage by setting its location to (0, 0), rather than having to worry about where the centre of the stage is. You can change the registration point by using the Align panel again:

screenshot

Alternatively, you can change the X and Y properties of the rectangle to 0.0, just as you changed the Width and Height.

Let’s add some text:

screenshot

That’ll do. You can pretty it up if you like. When you’re ready, Export GameOverScreen for ActionScript, just as we did with GameOverText.

Open the document class again, and find the code we modified before:

?View Code ACTIONSCRIPT3
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if ( avatar.hitTestObject( enemy ) ) 
{
	gameTimer.stop();
	var gameOverText:GameOverText = new GameOverText();
	gameOverText.x = 200;
	gameOverText.y = 150;
	addChild( gameOverText );
}

It’s pretty simple to make this work with our new screen. Have a go yourself if you like. My code’s here:

?View Code ACTIONSCRIPT3
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if ( avatar.hitTestObject( enemy ) ) 
{
	gameTimer.stop();
	var gameOverScreen:GameOverScreen = new GameOverScreen();
	gameOverScreen.x = 0;
	gameOverScreen.y = 0;
	addChild( gameOverScreen );
}

Note that I changed the x and y coordinates to zero. If you save and run the game and hit an enemy, you’ll see something like the following:

screenshot

But we can go further with this. We can put the actual game inside its own symbol. This way, rather than dropping a curtain down in front of the stage and leaving all the actors standing around behind it, we can have all the actors in their own glass box, and remove this box from the stage when we drop the game over curtain. This makes the stage much less cluttered, and the actors easier to manage. The only question is, have I gone too far with this analogy?

Adding a Game Screen

Let me clarify this a little. At the minute, our game is set out like this:

screenshot

The document class is controlling pretty much everything. If we continue making it do so, then if we want to add a title screen, a menu screen, a few more levels, a character selection screen, and so on, then the document class is going to get very very bloated.

Let’s separate things a little bit. Here’s what I’m proposing:

screenshot

Much neater! The document class duties only consist of making sure the player is seeing the right screen. Each individual screen manages its relevant parts. Later we might break this down even further, but this is absolutely fine for now.

How do we implement this? Well, you probably won’t be surprised if I tell you that we need to make a new Movie Clip — this time, call it PlayScreen.

This new screen is going to do roughly the same thing as our entire game was doing by the end of the last part. That is, it’s going to contain the avatar, and it’s going to generate the enemies and make them move within it. One important difference between using a Movie Clip to contain everything versus using a document (as we were doing before) is that a document has a default background already set up (ours is grey), but a Movie Clip doesn’t — we have to add one ourselves.

Let’s do that now! Edit your PlayScreen Movie Clip and draw a filled rectangle. Just as with GameOverScreen, make this rectangle the same size as the stage, and set its registration point to the top-left corner. I’ve made mine a very light blue, so as to stand out against the editor’s background:

screenshot

We’re not restricted to using a plain background this time. Because I’m so vain, I’ll demonstrate this by sticking my initials all over the place:

screenshot

Alright great. Obviously you don’t have to use my initials. Or any initials at all, for that matter. You could draw a cave, or a black hole, or a chat window (since the game is about smilies! get it?) or whatever.

Now for the code. I already said that this screen is going to do the same thing as our game already was doing, so you can imagine that it’ll require almost exactly the same code. We could rewrite all this code from scratch. We could copy and paste it, renaming bits as required. Or… we could take advantage of our marvellous object-oriented design.

Remember that the entire game, the entire document, is basically a Movie Clip. When we assign it a document class, this is essentially the same as selecting a Movie Clip from the library and assigning it a Class when we “Export it for ActionScript”. So, there’s no reason that we couldn’t assign PlayScreen the same class that has, up till now, been the document class.

Right-click PlayScreen in the library, select Properties, and check Export for ActionScript. This time, instead of accepting the default value, enter the name of your document class. Click OK.

screenshot

Oh, right. First we’ll have to make a new document class, since no two different objects can share the same class. Cancel the Properties box.

A New Class of Document

Hit File > New and select ActionScript File. Enter the (by now familiar) code:

?View Code ACTIONSCRIPT3
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package 
{
	import flash.display.MovieClip;
	public class DocumentClass extends MovieClip 
	{
		public function DocumentClass() 
		{
 
		}
	}
}

Save this in the Classes directory as DocumentClass.as. (There’ll be no confusing the purpose of this file!) Now, back in your FLA, change the document class to DocumentClass.

screenshot

Check everything’s fine by clicking that pencil icon — if it’s all OK, that should bring up the AS file that you just created.

Now you can set the PlayScreen‘s class to AvoiderGame. So do so!

If you save and run the game now, nothing will happen — that’s because the document class isn’t pulling in the PlayScreen. Head back to the DocumentClass AS file and modify it like so (lines 5, 7, and 8):

?View Code ACTIONSCRIPT3
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package 
{
	import flash.display.MovieClip;
	public class DocumentClass extends MovieClip 
	{
		public var playScreen:AvoiderGame;
 
		public function DocumentClass() 
		{
			playScreen = new AvoiderGame();
			addChild( playScreen );
		}
	}
}

This is pretty much exactly the same code as the AvoiderGame AS file uses to create a new Avatar, though here we’re using it to create a whole game. Save it and run:

screenshot

Awesome.

AvoiderGame Once Removed

Actually we’re not quite done yet. Here’s the sketch of my proposed new setup:

screenshot

And here’s our current setup:

screenshot

We’ve got the same problem as before — a bloated class file — only now it’s not the document class. We want the document class to be pulling in the Game Over screen when the player dies. How can we do this?

If we were using AS2, we might use _root or _stage to tell the document to do something. We’re not going to do that.

In previous versions of this tutorial, I let the playScreen run a function in the document class directly. That’s probably the simplest way of handling things, but it gets very messy very quickly. Even with a game as simple as this, I got a few emails letting me know of problems this quick fix had caused. So we’re not going to do that, either.

Back in Part 1, when we were adding the game timer, I said:

An event listener is like a robot that’s constantly checking to see if a particular “event” has occurred, and which runs another function if so.

The line we used for this was:

?View Code ACTIONSCRIPT3
gameTimer.addEventListener( TimerEvent.TIMER, onTick );

(If you’ll recall, that line ran a function called onTick whenever the Timer “ticked”.)

What I’d like to do now is place a similar event listener on playScreen (line 11):

?View Code ACTIONSCRIPT3
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public function DocumentClass() 
{
	playScreen = new AvoiderGame();
	playScreen.addEventListener( AvatarEvent.DEAD, onAvatarDeath );
	addChild( playScreen );
}

AvatarEvent.DEAD isn’t a built-in Flash event, of course, but we’ll get to that later. Right now let’s write the onAvatarDeath function into the document class:

?View Code ACTIONSCRIPT3
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public function onAvatarDeath( avatarEvent:AvatarEvent ):void
{
 
}

This is just like the onTick function from AvoiderGame.as. Just as then, we need to give it some code to run:

?View Code ACTIONSCRIPT3
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public function onAvatarDeath( avatarEvent:AvatarEvent ):void
{
	var gameOverScreen:GameOverScreen = new GameOverScreen();
	gameOverScreen.x = 0;
	gameOverScreen.y = 0;
	addChild( gameOverScreen );
 
	playScreen = null;
}

Lines 17-20 are copied straight from AvoiderGame.as. Line 22 introduces a new keyword: null. By setting an object equal to null you are essentially resetting it. All event listeners are removed, all contained objects are erased, all functions cease to exist. After being set to null, playScreen is in exactly the same state as before the line playScreen = new PlayScreen(); — this means that the next time we want to use it, we need to run that line again. Nullifying the playScreen will also remove it from view.

Now we need to actually trigger this event.

A Grand Event

You know how our Avatar, Enemy and AvoiderGame classes extend MovieClip so that they can do everything a MovieClip can do? Well, TimerEvent extends a class called Event in the same way. This means that we can make our own kind of event (the AvatarEvent I’ve been talking about) by extending Event, too.

So, let’s try that out, in the same way that we extended MovieClip all those times. Start a new AS file, AvatarEvent.as:

?View Code ACTIONSCRIPT3
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package  
{
	import flash.events.Event;
	public class AvatarEvent extends Event 
	{
		public function AvatarEvent()
		{
 
		}
	}
}

This looks about right, but actually, there’s a problem. When you create an Event of any kind, it expects you to pass through the type of event in the same way that our Enemy class expects you to pass through an x- and y-coordinate — for example, an Event to tell an object to scroll is created like this:

new Event( Event.SCROLL )

We’ve not provided a way to specify the type of event like that in our code, so let’s add that in:

?View Code ACTIONSCRIPT3
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package  
{
	import flash.events.Event;
	public class AvatarEvent extends Event 
	{
		public function AvatarEvent( type:String )
		{
 
		}
	}
}

Now we need to add a type of event for us to use. We can use a public const for this; it’s like a public var except it can’t be changed after you’ve hit Test Movie:

?View Code ACTIONSCRIPT3
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package  
{
	import flash.events.Event;
	public class AvatarEvent extends Event 
	{
		public static const DEAD:String = "dead";
 
		public function AvatarEvent( type:String )
		{
 
		}
	}
}

Great, now we’ll be able to write:

new AvatarEvent( AvatarEvent.DEAD )

…because static consts belong to the class AvatarEvent, not to any specific instance of AvatarEvent.

It’s nearly ready to use, but we need to figure out what to do with this type that gets passed in to the new AvatarEvent. Well, actually… we don’t! Events already know what to do with a type that’s passed in to them, so we just need to “borrow” their code.

We can do this using the super() function, like so:

?View Code ACTIONSCRIPT3
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package  
{
	import flash.events.Event;
	public class AvatarEvent extends Event 
	{
		public static const DEAD:String = "dead";
 
		public function AvatarEvent( type:String )
		{
			super( type );
		}
	}
}

What super( type ) does is, it runs the code from inside the constructor function of the Event class, and passes type through to that. That means we let the existing code (which we can’t see) inside the Event class deal with everything. Fine by me :)

(We’ll look at super in more detail in Part 5. In the meantime, feel free to check out my post about extends, override, and super.)

Now that we have the event listener and the event class, all that remains is to fire off the event when the avatar dies (i.e., when it hits an enemy). Head back to AvoiderGame.as and change this:

?View Code ACTIONSCRIPT3
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if ( avatar.hitTestObject( enemy ) ) 
{
	gameTimer.stop();
	var gameOverScreen:GameOverScreen = new GameOverScreen();
	gameOverScreen.x = 0;
	gameOverScreen.y = 0;
	addChild( gameOverScreen );
}

to this:

?View Code ACTIONSCRIPT3
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if ( avatar.hitTestObject( enemy ) ) 
{
	gameTimer.stop();
	dispatchEvent( new AvatarEvent( AvatarEvent.DEAD ) );
}

Line 49 fires off an AvatarEvent of type DEAD. That’s all there is to it. I removed all the code about the Game Over screen because we’re dealing with that in the document class now.

Save it and run, and hey, what do you know, it all works as it should.

I realise that this last big change didn’t change the game in a way that the player could notice, but reorganising the internal structure like this will certainly make it a lot easier to add new features in the future. I’ll prove this in the next part, where we’ll add a title screen and a reset button with minimal effort — available here.

Also, if you like, you can grab the zip with all the files I’ve been using so far from here.

{ 220 comments… read them below or add one }

davidp October 27, 2011 at 1:47 pm

wow, that fix didn’t fix anything, the hell. anyway, make sure you’re not having any functions outside the class parenthesis.

Mikey December 2, 2011 at 3:43 pm

Hey Iäm having problem with the whole dispatchEvent thing. When the game runs and hits an enemy the gameover page doesnt show.

   public function onTick(timerEvent:TimerEvent):void
        {
            if(Math.random() < 0.1)
            {
            var randomX:Number = Math.random() * 400;
            var newEnemy:Enemy = new Enemy(randomX, -15);
            army.push(newEnemy);
            addChild(newEnemy);
            }

        avatar.x = mouseX;
        avatar.y = mouseY;

    for each(var enemy:Enemy in army)
    {
        enemy.moveDownABit();
        if(avatar.hitTestObject(enemy))
        {
            gameTimer.stop();
            dispatchEvent(new AvatarEvent(AvatarEvent.DEAD));
        }
    }               
}

package
{
    import flash.display.MovieClip;

public class DocumentClass extends MovieClip
{
    public var playScreen:AvioderGame;

public function DocumentClass()
{
    playScreen = new AvioderGame();
    playScreen.addEventListener(AvatarEvent.DEAD, onAvatarDeath);
    addChild(playScreen);
}

public function onAvatarDeath(avatarEvent:AvatarEvent):void
{
    var gameOverScreen:GameOverScreen = new GameOverScreen();
    gameOverScreen.x = 0;
    gameOverScreen.y = 0;
    addChild(gameOverScreen);

    //resetting playScreen
    playScreen = null;
}

}

}

package
{
    import flash.events.Event;

public class AvatarEvent extends Event
{
    public static const DEAD:String = "dead";

public function AvatarEvent(type:String, bubbles:Boolean=false, cancelable:Boolean=false)
{
    super(type, bubbles, cancelable);
}

public override function clone():Event
{
    return new AvatarEvent(type, bubbles, cancelable);
}

public override function toString():String
{
    return formatToString("AvatarEvent", "type", "bubbles", "cancelable", "eventPhase");
}

}

}

Im not sure if this site is very active anymore but if anyone has a solution i would be sooo glad!

C_J__ December 22, 2011 at 7:50 pm

Hi, Thanks for the amazing tutorial, it helped me a lot. I am making a game of my own that is based off this but i have ran into several problems. In the game there are enemies coming from all directions, and you can shoot by pressing the W,A,S,D keys. if i use for loops to continuously shoot the laser, the lasers continue on forever and slow the game down. But when i use your method to removeChild() in a while loop the laser does get removed, but when the shoot key is released and the lasers are removed, all enemies stop moving and start when the shoot key is pressed again.

Here is my key press:

public function onAddToStage( event:Event ):void
        {
            stage.addEventListener( KeyboardEvent.KEY_DOWN, onKeyPress, false, 0, true  );
            stage.addEventListener( KeyboardEvent.KEY_UP, onKeyRelease, false, 0, true  );
        }

    public function onKeyPress( Event:KeyboardEvent ):void
    {
        if ( Event.keyCode == Keyboard.W )
        {
            shootKeyIsBeingPressed = true;
        }
        if ( Event.keyCode == Keyboard.S )
        {
            shootDownPressed = true;
        }
        if ( Event.keyCode == Keyboard.A )
        {
            shootLeftPressed = true;
        }
        if ( Event.keyCode == Keyboard.D )
        {
            shootRightPressed = true;
        }
    }</pre>

Here is my Timer tick with one of the lasers

public function onTick( timerEvent:TimerEvent ):void 
        {
            cursor.x = mouseX;
            cursor.y = mouseY;
            if (SPowered == true){
                sheild.x = mouseX;
                sheild.y = mouseY;
                STime = STime - 1;
                SheildPowerLeft.addToValue(-1);
            }
            if (STime == 0){
                SPowered = false;
                sheild.x = -60;
                sheild.y = -60;
            }
            if (shootKeyIsBeingPressed == true){     //SHOOT FUNCTION

            xx = mouseX;
            yy = mouseY;

        if ( Math.random() &lt; 0.25 )
        {
            var newLaser:Laser = new Laser( xx, yy );
            lasers.push( newLaser );
            addChild( newLaser );
        }   

    } 
    if (shootKeyIsBeingPressed == false){

    }&lt;/pre&gt;

Here is the lasers while loop as well as my old for loop that didnt remove them.

var t:int = lasers.length - 1;
            var laser:Laser;
            while ( t > -1 )
            {

            laser = lasers[t];
            laser.Shoot();

        if ( laser.y &lt; -15 )
        {
            removeChild( laser );
            lasers.splice( t, 1 );
        }
        t = t - 1;
    }
    /*for each ( var laser:Laser in lasers ) 
    {
        laser.Shoot();
    }*/&lt;/pre&gt;

Any help you could give me would be much appreciated, thanks.

                                         -CJ

Noob123 December 25, 2011 at 3:45 pm

package
{
import flash.display.MovieClip;
public class DocumentClass extends MovieClip
{
public var playScreen:AvoiderGame;

    public function DocumentClass() 
    {
        playScreen = new AvoiderGame();
        addChild( playScreen );
    }
}

}

I created this code but the symbol i created doesnt make the screen apear and the game plays as normal without background what should i do?

pedodleche January 19, 2012 at 4:09 am

I am learning AS3 with this tutorial and it has been really helpful…but the question I have is that…whenever I test the game nothing happens…I thought it might be an error I did while writing the code….so then I downloaded yours and I test it but it does not work either…can anyone tell why this is?

Michael James Williams January 20, 2012 at 12:38 am

No idea. What version of Flash are you using?

pedodleche January 26, 2012 at 8:35 pm

I am using cs5….it works on another computer though, so I am writing code on this one, testing it in the other one after advancing quite a bit since I don’t have much access to the other computer

tibbi February 21, 2012 at 7:23 pm

something is wrong at cleaning up :/ at those

removeChild( gameOverScreen );
gameOverScreen = null;

I have tried your version of the game, without any of my custom changes in flashdevelop, with swf profiler. Everytime i restart the game, the amount of playscreens and gameoverscreens is increasing. Only menuscreen stays at 1 instance. memory usage increases too.

tibbi February 21, 2012 at 7:27 pm

just realised that of course the amount of menu screens doesnt increase, its not displayed just as i start the game. Then its always either playscreen(avoidergame) or gameoverscreen..

Jonathan March 18, 2012 at 5:09 pm

This entire tut series up to this point has been great. You just lost me on the dispatchEvent part. I don’t feel you explained it in the tutorial at all. I’m new to flash so I’d really appreciate it if you could just clarify what exactly is going on from the point that we make the AvatarEvent thing.

Sketchist March 31, 2012 at 7:21 pm

I am getting an error D:
C:\Users\user\Desktop\Current Project\Classes\DocumentClass.as, Line 1 5006: An ActionScript file can not have more than one externally visible definition: DocumentClass, AvatarDeath

HELP! please asap I need this FAST!!! PLEASE!

Klaas August 20, 2012 at 9:45 pm

please help me, im getting an error called: C:\Users\user\Desktop\School\Space Run\Classes\DocumentClass.as, Line 1 5006: An ActionScript file can not have more than one externally visible definition: DocumentClass, onAvatarDeath

i followed every step and cant see what i did wrong!

please help me out!

rafeef September 9, 2012 at 10:44 am

Hi MICHAEL ,
Thanks a lot for this Tutorial :) ,

I have a problem like this :
“1046: Type was not found or was not a compile-time constant: TextField.”

Although I do like your solution, Ihave the error :( !! :

If you’re using text, Flash might decide that it should be dynamic — that is, that it can be changed using code. Until we add scores, we don’t need this functionality, so click on your text and in the Properties panel, make sure to change the drop-down list from Dynamic Text or Input Text to Static Text. “

Lucas Horta November 22, 2012 at 6:55 pm

I have the same 1046 error, change to Static Text does not fix the problem.
Could it be my flash version? i’m using cs5.

raco November 26, 2012 at 1:40 am

If somebody has problem with blank preview (when u hit test movie nothing shows) and there is no errors:

I was stuck at the end of game screen. Like i said blank preview and no errors. After a while i figured it out. Although i wrote DocumentClass the flash didn’t recognize it. So after i’ve tried with rerouthing, adding cordinates… i’ve clicked in class file (FLA), so at that pencil next to DocumentClass and i found this:

package {
public class DocumentClass {
public function DocumentClass() {
// constructor code
}
}
}

so just write DocumentClass again. Hope it helps someone

y i know that my writing sucks (:

Canvas December 22, 2012 at 4:05 am

Mikey,

make sure in your document class you have this line

playScreen.addEventListener( PlayerEvent.DEAD, onPlayerDeath );

Richie January 17, 2013 at 4:23 pm

Hey im having an issue with my event. when i lose the game over menu comes up but i get this error

“TypeError: Error #1009: Cannot access a property or method of a null object reference.
at DocumentClass/onAvatarDeath()
at flash.events::EventDispatcher/flash.events:EventDispatcher::dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at MethodInfo-31()”

what does this mean… and how would i fix it?

Félix Moreno January 19, 2013 at 8:59 pm

Hello,
I’m making a game based on this tutorial and I’m getting an error when trying to setup the document class
TypeError: Error #1009: No se puede acceder a una propiedad o a un método de una referencia a un objeto nulo.
at Game()
at DocumentClass()
(I use spanish Flash Pro)
My DocumentClass code:

package 
{
    import flash.display.MovieClip;
    public class DocumentClass extends MovieClip 
    {
        public var playScreen:Game;

    public function DocumentClass() 
    {
        playScreen = new Game();

    addChild( playScreen );
}

}

}

My Game class code:

ackage 
{
    import flash.display.MovieClip;
    import flash.utils.Timer;
    import flash.events.*
    import flash.ui.*
    public class Game extends MovieClip 
    {
        public var downKeyIsBeingPressed:Boolean;
        public var upKeyIsBeingPressed:Boolean;
        public var leftKeyIsBeingPressed:Boolean;
        public var rightKeyIsBeingPressed:Boolean;
        public var player:Player;
        public var gameTimer:Timer;
        public var platforms:Array;
        public var platformDelay:int;
        public var hitting:Boolean;
        public function Game() 
        {
            stage.addEventListener( KeyboardEvent.KEY_DOWN, onKeyPress );
            stage.addEventListener( KeyboardEvent.KEY_UP, onKeyRelease );
            player= new Player();
            addChild(player);
            platforms = new Array();
            platformDelay = 0;
            hitting = false;
            gameTimer = new Timer( 30 );
            gameTimer.addEventListener( TimerEvent.TIMER, onTick );
            gameTimer.start()
        }
        public function onTick(te:TimerEvent) {
            if (!hitting) {
            player.moveABit(0, 1);
            }

        if (rightKeyIsBeingPressed) {
            player.moveABit( 2, 0);
        }
        if (leftKeyIsBeingPressed) {
            player.moveABit( -2, 0);
        }
        if (downKeyIsBeingPressed && !hitting) {
            player.moveABit( 0, 2);
        }
        platformDelay--
        trace (hitting)
        for each ( var platform:Platform in platforms ) 
        {
            platform.y = platform.y - 5
            if ( player.hitTestObject( platform ) ) 
            {
                hitting = true;
                player.y= platform.y- player.height / 2 - platform.height / 2
            }
            else {
                hitting = false;
            }

    }

    if (Math.random()&lt;0.1 &amp;&amp; platformDelay&lt;1){
    var randomX:Number = Math.random() * 200 + 50;
    var newPlatform = new Platform(randomX, 510);
    platforms.push(newPlatform);
    addChild(newPlatform); 
    platformDelay = 60;
    }
    if (player.y &lt; 0 - player.height / 2 || player.y &gt; 500 + player.height / 2) {
        gameTimer.stop();

    }



}
public function onKeyPress(ke:KeyboardEvent) {
    if (ke.keyCode == Keyboard.DOWN) {
        downKeyIsBeingPressed=true
    }
    if (ke.keyCode == Keyboard.UP) {
        upKeyIsBeingPressed=true
    }
    if (ke.keyCode == Keyboard.RIGHT)  {
        rightKeyIsBeingPressed=true
    }
    if (ke.keyCode == Keyboard.LEFT)  {
        leftKeyIsBeingPressed=true
    }
}
public function onKeyRelease(ke:KeyboardEvent) {
    if (ke.keyCode == Keyboard.DOWN) {
        downKeyIsBeingPressed=false
    }
    if (ke.keyCode == Keyboard.UP) {
        upKeyIsBeingPressed=false
    }
    if (ke.keyCode == Keyboard.RIGHT)  {
        rightKeyIsBeingPressed=false
    }
    if (ke.keyCode == Keyboard.LEFT)  {
        leftKeyIsBeingPressed=false
    }
}

}

}

I can’t find anything wrong on it. I assigned the Game Class to the PlayScreen symbol.

kmlgd February 7, 2013 at 8:03 pm

anyone having a problem in this chapter it could be because an .as file with name GameOverScreen needs to be added, it has been skipped in this tutorial. Copy the code from other file like Avatar.as just change the code public class and public function to GameOverScreen, and dont forget to add the info of the file in the GameOverScreen Properties/class.

Meg May 5, 2013 at 8:26 am

Okay…I have no idea what’s going wrong here. I’m getting the 1114 error (The public attribute can only be used inside a package)

Here’s my Document Class code:

package 
{
    import flash.display.MovieClip;
    public class DocumentClass extends MovieClip 
    {
        public var playScreen:AvoiderGame;

    public function DocumentClass() 
    {
        playScreen = new AvoiderGame();
        playScreen.addEventListener( AvatarEvent.DEAD, onAvatarDeath );
        addChild( playScreen );
    }

public function onAvatarDeath( avatarEvent:AvatarEvent ):void
{
    var gameOverScreen:GameOverScreen = new GameOverScreen();
    gameOverScreen.x = 0;
    gameOverScreen.y = 0;
    addChild( gameOverScreen );

    playScreen = null;
}

}

}

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