AS3 || Using same function with different variables - actionscript-3

I'm very new to AS3 and I'm trying to learn by experimenting in flash, by making a simple 2D farming game with very simple code.
I've made one crop field out of 6 that works, which is a movieclip with different frames for each fruit growing. For example, frame 1-5 is a strawberry growing where frame 5 is when it's ready to be picked, and then 6-10 is of carrots, etc
Is there a way for me to make it so that I don't have to write the exact same code for the next crop field, and instead change the variables in this code depending on which crop field you click on?
Here's an example of the code
if (field1.currentFrame == 1)
{
field1.nextFrame();
infoText.text = "You've watered the crop. Let's wait and see how it turns out!";
function plantStrawberry():void
{
field1.nextFrame();
if (field1.currentFrame == 5)
{
clearInterval(strawberryInterval);
}
}
var strawberryInterval = setInterval(plantStrawberry,5000);
}
pls no judgerino, as said, I'm very new to AS3, lol.

There are a few ways to go about being DRY (don't repeat yourself) with your code in this scenario. The best way, would be to learn to use classes. Classes are blueprints, and are made for these very scenarios.
Here is an example of a simple class to do what you'd like. In Flash/Animate, go to file, then new, then 'ActionScript 3.0 Class' - give it a name of Crop.
In the document that comes up, there should be some basic boilerplate code. Everything should wrapped in a package. The package tells flash where to find this class - so this example, leave it as is (just package {) and save this file in the same folder as your .fla. All functions need to be wrapped in a class declaration, this should be generated for you based off the name you put in (Crop). Next you'll see one function, that has the same name as the class. This is called a constructor, and this function runs whenever you create a new instance of this class. Since classes are blueprints, you create instances of them that are objects - those objects then get all the code you put in this class.
So, to start, you should have this:
package {
public class Crop {
public function Crop() {
// constructor code
}
}
}
Let's go ahead and put your code in. See the code comments for details:
package {
//imports should go here
import flash.display.MovieClip;
import flash.events.Event;
import flash.events.TimerEvent;
import flash.utils.Timer;
//lets make this class extend MovieClip - that means it will be a MovieClip in addition to everything else you add below
public class Crop extends MovieClip {
//instead of setInterval, use a timer - it's easier to manage and cleanup
//in class files, variables and functions have access modifiers, that's what the public and private words are about
//private means only this class can ever use the var/function
private var timer:Timer;
public function Crop() {
//initialize the timer - have it tick every 5 seconds, and repeat 4 times (to move you from frame 1 - 5)
timer = new Timer(5000, 4);
//listen for the TIMER event (which is the tick) and call the function 'grow' when the timer ticks
timer.addEventListener(TimerEvent.TIMER, grow);
}
//a function that starts the timer ticking
public function startGrowing():void {
timer.start();
}
//this function is called every timer tick.
private function grow(e:Event):void {
this.nextFrame(); //go to the next frame of your crop
}
}
}
Save the file. Now that you have this class, you need to attach it to your library assets so they all get this functionality.
In the library panel, for each of your crop objects, right click (or ctrl+click on Mac) and go to properties. In the properties, click advanced, and give it a unique class name (for instance Strawberry). Then in the base class field, put Crop (the class we just made). Repeat for the others.
Now on your timeline, when you want a crop to start growing, you can do:
field1.startGrowing(); //assuming your instance `field1` is one of the crops that you assigned the base class `Crop` to
Hopefully this gives an entry point into the power of classes. You can add more functionality into this one and it automatically apply to all the crops you attached it to.

Although BFAT's tutorial is absolutely correct, it is not the only way to do things, moreover, if you ever move from Flash and AS3 to something else, or even try Starling (a framework that allows to build fast and non-laggy mobile applications in Flash/AS3), you'll find that concept not applicable. It is very Flash-y and I applause to it though.
Instead of making each field subclass the abstract (means, it is never instantiated by itself) Crop class, you can make the Crop class take 1 of these 6 fields as an argument on creation (or later). Basically, you tell "I want to make crop field with wheat graphics". So, let me redo that class a bit.
package
{
// Imports.
import flash.display.Sprite;
import flash.display.MovieClip;
import flash.utils.Timer;
import flash.events.Event;
import flash.events.TimerEvent;
public class Crop extends Sprite
{
// I agree with the use of Timer.
private var timer:Timer;
// Visuals go here.
private var field:MovieClip;
// Class constructor.
public function Crop(FieldClass:Class)
{
// With "new" keyword you can omit ()
// if there are no mandatory arguments.
field = new FieldClass;
field.stop();
addChild(field);
}
// A function that starts the timer ticking.
public function startGrowing():void
{
timer = new Timer(5000, 4);
timer.addEventListener(TimerEvent.TIMER, grow);
timer.start();
}
// This function is called every timer tick.
private function grow(e:Event):void
{
// Command the graphics to go to the next frame.
field.nextFrame();
}
}
}
Then, the usage. When you create fields, you need to set AS3 classes to them to have access, leaving base class as is, Flash will automatically set it to non-specific MovieClip. Lessay, you have crops.Wheat field and crops.Barley field.
import Crop;
import crops.Wheat;
import crops.Barley;
var W:Crop = new Crop(Wheat);
var B:Crop = new Crop(Barley);
addChild(W);
addChild(B);
B.x = 100;
W.startGrowing();
B.startGrowing();

Related

Making a simple tamagoci game getting no compiler errors but receiving no output

Kind of new Actionscript and I'm just trying to make a simple tamagoci game. I've wrote all the code out but and receiving no compiler errors but for some reason I'm also not receiving any output messages for my mouse event listeners. Here is all my code, I really can't find the problem and any help would be greatly appreciated. Thanks.
package{
import flash.display.MovieClip;
import flash.events.MouseEvent;
public class Main extends MovieClip{
public var feedButton:MovieClip;
public var tamagoci:MovieClip;
public var disButton:MovieClip;
public var dietButton:MovieClip;
public function Main() {
this.init();
}
private function init():void {
this.feedButton.addEventListener(MouseEvent.MOUSE_DOWN, onfeedMouseDownHandler);
this.disButton.addEventListener(MouseEvent.MOUSE_DOWN, ondisMouseDownHandler);
this.dietButton.addEventListener(MouseEvent.MOUSE_DOWN, ondietMouseDownHandler);
}
private function onfeedMouseDownHandler(event:MouseEvent)void{
this.tamagoci.scaleX += 0.1;
this.tamagoci.scaleY += 0.1;
}
private function ondisMouseDownHandler(event:MouseEvent)void{
this.tamagoci.gotoAndPlay(5);
}
private function ondietMouseDownHandler(event:MouseEvent)void{
this.tamagoci.scaleX -= 0.1;
this.tamagoci.scaleY -= 0.1;
}
Are you using Flash Professional?
You're declaring your variable types in your class here;
public var feedButton:MovieClip;
public var tamagoci:MovieClip;
public var disButton:MovieClip;
public var dietButton:MovieClip;
But then in your constructor, all you are doing is running init();
public function Main() {
this.init();
}
So, this could one of a few things. The most likely is that you have declared your variables, but you haven't initialised them. You've created the variables to hold your objects, but according to your code, they're empty. More specifically, a variable or class property that doesn't assign an object to a variable of an object type will contain a default value of null.
You could prove this in your code by simply putting a condition inside your init(); method;
if(tamagoci == null){
trace("I haven't been assigned an object of type class yet!")
}
So it could be 1 of these 3 things:
1: If you have written your own classes for these class properties/variables, then you need to instantiate them with the new keyword. The general syntax is;
variable_name = new ClassName(parameter_1, parameter_2);
If you are using classes you have written yourself, you have to create an instance of the object, assign it to a variable, and then add it to the stage using addChild();. For example, lets say you've written your own Tamagoci class;
tamagoci = new Tamagoci();
tamagoci.x = 100; // set the x location
tamagoci.y = 200; // set the y location
addChild(tamagoci);
Notice the use of Tamagoci. This is just an example, but this is the class name, which shouldn't be confused with variable/property name. It could just have easily been;
tamagoci = new MovieClip();
But then, this is just an empty MovieClip. It needs a property to display on the screen. A Shape, A Bitmap, or another container class object like MovieClip or Sprite (container classes allow you to nest display objects inside them). But on a basic level, it must contain a visual component to appear on the stage.
2:
Have you made Main your document class? This is the class which will get automatically called when your Flash movie plays. To set this, click on your stage, and in the properties dialogue box on the right, under PUBLISH, type in the name of your class, which is "Main".
3:
If you have created MovieClips in your library in Flash Professional, then you need to go to your library, right click the MovieClips, and select properties. From there, you need to make sure Export for Actionscript is ticked.
Now, if you click on your MovieClips on the stage, then open the Properties tab in the top right of Flash Professional's default layout, then right at the top should be a text field, and if you hover over it, Instance name will pop up as a tool tip. This is where you name your stage objects. Once that is done, you have access to them in your timeline.
If this is how you've done this, then you don't need to declare the variables in your main class, as they are already declared on your stage by Flash Professional and instantiated automatically.

AS3 Setup Buttons for All Frames in Document Class

I'm making a simple interface with Flash. Let's say we've got:
frame 1: 1 button that advances to frame 10 (goto10)
frame 10: 2 buttons, one advances to frame 20 (goto20), one opens a URL (openURL)
frame 20: 3 buttons, one goes back to frame 1 (goto1), one goes to frame 10 (goto10), and one opens a URL (openURL)
package {
import flash.display.MovieClip
import flash.events.Event;
import flash.net.URLRequest;
import flash.net.URLLoader;
import flash.display.SimpleButton;
public class NKE_DocumentClass extends MovieClip {
public var goto1:SimpleButton = new SimpleButton();
public var goto10:SimpleButton = new SimpleButton();
public var goto20:SimpleButton = new SimpleButton();
public var openURL:SimpleButton = new SimpleButton();
public function NKE_DocumentClass() {
goto1.addEventListener(MouseEvent.CLICK,function(self:MouseEvent):void{clickGo(self,1)});
goto10.addEventListener(MouseEvent.CLICK,function(self:MouseEvent):void{clickGo(self,10)});
goto20.addEventListener(MouseEvent.CLICK,function(self:MouseEvent):void{clickGo(self,20)});
openURL.addEventListener(MouseEvent.CLICK,function(self:MouseEvent):void{urlGo(self,"http://google.com")});
}
public function clickGo(event:MouseEvent, nextCue:int):void {
gotoAndStop(nextCue);
trace("Advanced to: " + nextCue);
}
public function urlGo(event:MouseEvent, goURL:String):void {
var request:URLRequest = new URLRequest(goURL);
new URLLoader(request);
trace("Executed URL: " + goURL);
}
}
}
Problem is, once I leave frame 1, none of the buttons work... they're simply unresponsive. It seems like the code doesn't stay loaded once it leaves frame 1.
Thoughts?
I'm pressuming the problem is because when this code is first executed (as a Document Class) the only button that exists is the button on frame 1? This is under the assumption than you've created buttons in the Flash IDE then added them to the stage from the library on the specific keyframes.
I see you've created the SimpleButtons programmatically but since they haven't been added to the stage in the code you've shown, the presumption is that you've just called them the same names as the buttons you've placed on stage? Correct me if I'm wrong and I'll try to offer some other advice if the below doesn't help.
One solution would be to create them all on the first frame then switch their visibility on and off depending on when you need them.
If you're not sure how:
goto10.visible = false;
etc etc
I can't remember now without testing but if you have placed them all on the stage on different keyframes this may cause a problem.
Back in the days of putting code on the timeline if you put code on frame 1 but it referenced objects that weren't on frame 1 then the code would fail (this is probably what's happening with your document class - it's running when not all objects exist).
I would make sure they're all on one layer without any keyframes, from frame 1, and you just switch their visibility on and off. Alternatively, let your classes add and remove the buttons and other interface elements and don't use the timeline at all.

MovieClip button In Class

Tried this,
package {
import flash.display.MovieClip;
import flash.events.*;
public class test extends MovieClip {
public function test() {
addEventListener(Event.ADDED_TO_STAGE, registerBtn);
}
private function registerBtn(e:Event):void {
this.parent["Homebtn"].addEventListener(MouseEvent.CLICK, myButtonClick);
}
private function myButtonClick(e:MouseEvent):void {
trace("CLICKED");
}
}
}
Image
And the same code on frame 1, And there's a MovieClip Button on stage having Instance name "Homebtn".
Imports
import flash.events.*;
Importing all classes from a package that originates in flash has zero impact on compile size because they're already present in the Flash Player runtime environment. It's pure monotony that you're required to explicitly declare these imports, but good practice when dealing with third party packages.
Stage Relationship
Document code (i.e., code in the Flash IDE timelines) have a direct relationship to MainTimeline, whereas class files do not. If you want to add button1.addEventListener(MouseEvent.CLICK, myButtonClick); to your class, you're not going to be able to do so unless you:
A: Pass a pointer to the button/stage/root to the class when instantiating your test class:
var myObj:test = new test(root)
B: Wait to add the event listener until after you've given the test object a parent relationship to the stage from which to traverse to the button:
addChild(test);
inside your class...
public function test() {
// constructor code
addEventListener(Event.ADDED_TO_STAGE, registerBtn)
}
private function registerBtn():void {
this.parent.button1.addEventListener(MouseEvent.CLICK, myButtonClick);
}
Turn on Debugging
To find the cause of your bugs, you need to debug your code. If you're using Flash IDE CS6, then you can enable this by going to your publish settings and enabling "Permit Debugging". This will take your ambiguous error...
null object reference at myDocument/doSomething()
...to a much clearer...
null object reference at myDocument/doSomething() package\myClass.as:20
...which now denotes which line in your code to look for your issue.
Use the Debug Console
Use the debugging compile mode to bring up the Debug Console. This will provide you with an immediate look at the line of code in question, as well as the Call Stack, and the state of all available Variables. No programmer should be without it.
Run by going to the menu "Debug > Debug Movie > Debug", or use the keyboard combo CONTROL+SHIFT+ENTER.
Now that you're armed with the know-how to do this on your own, I'll cover what you'd encounter, and how you'd fix it (since you're new).
First, it's flash.events with an "s". So we'll change that.
Next, compiling it we get the following errors:
So we see on line 7 of our test.as class: you've placed the timeline code into the class.
var myObj:test = new test(root);
addChild(test);
You don't want to instantiate you class from within itself as it'll never get instantiated. Think of your code as a railroad. The train starts with your timeline code, and only runs on the rails set before it. Your class is floating off to the side, ready with all its interesting turns and zigzags, but you have to add it to the rails for it to be actually run. That's instantiation; we're copying that path onto the current track, and the train runs on it.
So, we get rid of lines 6 & 7, and we're left with Access of possibly undefined property Homebtn. Calling this.parent is actually a getter function, and it returns a DisplayObjectContainer. Because AS3 is a strongly datatyped language, the compiler will know that there is no such property "Homebtn" on DisplayObjectContainers (silly compiler). But of course, you know it's there (or at least it will be by the time this code runs). A simple way of getting around that is by making it evaluate the reference at run-time.
this.parent["Homebtn"].addEventListener(MouseEvent.CLICK, myButtonClick);
By encapsulating the button name as a string and within brackets, we've done that.
Now we recompile again, and get the following:
This is because all event listeners receive one argument: an event object. You may not use it, but not having a variable to hold it is a no-no.
private function registerBtn(e:Event):void {
As a final point. All class functions need to be denoted as to what namespace they exist in. myButtonClick needs one, so we'll add it as private since no external (ie., non-class based) functions need access to it.
Here's your revised code:
test.as
package {
import flash.display.MovieClip;
import flash.events.*;
public class test extends MovieClip {
public function test() {
addEventListener(Event.ADDED_TO_STAGE, registerBtn);
}
private function registerBtn(e:Event):void {
this.parent["Homebtn"].addEventListener(MouseEvent.CLICK, myButtonClick);
}
private function myButtonClick(e:MouseEvent):void {
trace("CLICKED");
}
}
}
test.fla (timeline code on frame 1)
import test;
var Homebtn:MovieClip = new MovieClip();
Homebtn.graphics.beginFill(0xFF0000, 1);
Homebtn.graphics.drawRect(0, 0, 150, 25);
Homebtn.graphics.endFill();
addChild(Homebtn);
var testObj:test = new test();
addChild(testObj);

Actionscript 3.0: Help Linking Document Class To And Audio Slider Class

so I've been going at actionscript 3 for a couple weeks now but I'm still a complete newb. The most difficulty I've had is linking classes to my document class. For example, I'll have a nice great class that does things wonderfully (I could just insert it as the document class of another FLA and it would provide all the functionality I need for that specific function), but now when I have to insert it as a regular class...I guess "subclassing" the document class, all goes to hell.
I know you have to change variables and instantiate things to get it to work and I sort of understand that, but it sometimes it just gets way over my head and I feel like their should be a simple solution if I ALREADY HAVE a full working class. Seems that all too often there's a billion things I need to switch around.
Anyways, I have a specific example I'm hoping someone could help explain and walk me through a bit. I went online and found some code for a slider, then spent the last few hours editing it to contain the mp3 I want, loop it, etc. etc. Now it works great on a designated FLA...I just run it as the document class and up pops a designed audio slider that changes the volume, loops and everything. Now I want to add this slider into a simple game I've been working on, but just have NO idea where to start or what to do. For now I'll keep it simple though.
Say I just have my blank document class and my audio slider class. Now when I run my game, it runs the document class of course, and from there, I want it to run my audio slider class directly. I think if I just solve this I will be able to implement it into my game. So here is my blank document class and my audio slider class! Thanks for the help!
WHAT I'VE TRIED
I attempted to create public variables in the document class for the sprite and the slider, then create a new sprite/slider once the document class runs. I thought that to be on the right track, but then it started looking like I was going to have to do that for almost all the variables in the audio slider class. I also thought...well why can't I just run Volume() in the Document Class? Still confusing me a little why that doesn't work, but it doesn't.
Blank Document Class
package {
import flash.display.MovieClip;
import flash.display.Sprite;
public class ASDocumentClass extends MovieClip {
public function ASDocumentClass() {
}
}
}
and here is the audio slider class
package {
import flash.display.Sprite;
import flash.display.Graphics;
import flash.events.MouseEvent;
import flash.events.Event;
import flash.net.URLRequest;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.media.SoundTransform;
import flash.geom.Rectangle;
public class Volume extends Sprite {
public var snd:Sound = new Sound();
public var channel:SoundChannel = new SoundChannel();
//URLRequest=new URLRequest("solitude.wav");
//Make sure you pass URLRequest an audio file on your computer.
public var req:BackgroundMusic = new BackgroundMusic();
public var boundary:Rectangle;
public var sprite:Sprite;
public var slider:Sprite;
public var xPos:Number=stage.stageWidth/2;
public var yPos:Number=stage.stageHeight/2;
public var vol:Number;
/*
Our request is loaded into the sound object and plays through
our channel. Volume is initially set at 50% and passed as a
transformation to our our channels soundTransform property
(a fancy way of saying volume). The init() function is called.
*/
public function Volume() {
channel=req.play();
channel.addEventListener( Event.SOUND_COMPLETE, onBackgroundMusicFinished,false,0,true );
vol=.5;
channel.soundTransform=new SoundTransform(vol);
init();
}
/*
The init function creates and draws a rectangle and circle
to the stage and centers them based on the height and
width of the stage. In addition, a rectangle object is
created to 'contain' the sliding circle, like an imaginary box.
We pass -100 as the x value because it is added relative
to our sprite. If we set its x value at 0, or the sprites default x
value,the boundary would stop and start at the slider sprite. Change
-100 to 0 in the rectangle object to get a better idea of its use.
*/
public function init():void {
sprite = new Sprite();
sprite.graphics.beginFill(0x999999);
sprite.graphics.drawRect(xPos,yPos,200,5);
sprite.graphics.endFill();
addChild(sprite);
sprite.x-=sprite.width/2;
slider = new Sprite();
slider.graphics.beginFill(0xFF0000);
slider.graphics.drawCircle(xPos,yPos, 20);
slider.graphics.endFill();
addChild(slider);
slider.addEventListener(MouseEvent.MOUSE_DOWN, dragSlider);
stage.addEventListener(MouseEvent.MOUSE_UP, stopSlider);
boundary=new Rectangle(-100,0,200,0);
}
/*
dragSlider runs when the use holds the mouse button down. A
startDrag method is used on our sprite where we specify boundary
as our dragging limits. A new event handler designed
to change the mouse volume is subsequenlty called per frame, where
the slider.x property determines volume.
*/
public function dragSlider(event:MouseEvent):void {
slider.startDrag(false,boundary);
slider.removeEventListener(MouseEvent.CLICK, dragSlider);
slider.addEventListener(Event.ENTER_FRAME, changeVolume);
}
/*
Stops dragging and removes the event listener to save on space. Again,
volume will be based on the sliders current x position, which is
constantly being recalculated per frame because we used an
ENTER_FRAME event.
*/
public function stopSlider(event:MouseEvent):void {
slider.stopDrag();
slider.removeEventListener(MouseEvent.MOUSE_UP, stopSlider);
}
/*
This function is constantly recalculating the vol variable
based on the sliders x position, relative to the length of
our rectangle. Creates a decimal range from 0 to 1, where 1
represents 100% volume and 0 represents mute. Anything exceeding
100% causes distortion.
*/
public function changeVolume(event:Event):void {
vol=.5+Math.round(slider.x)/200;
channel.soundTransform=new SoundTransform(vol);
}
public function onBackgroundMusicFinished(event:Event):void
{
channel = req.play();
channel.addEventListener( Event.SOUND_COMPLETE, onBackgroundMusicFinished );
}
}
}
It looks as though your Volume class is as you said, mostly complete and self-contained. This is good, as it will make instantiating a new instance of it within your document class easier.
Within the document, class, to instantiate a new class, you can do the following:
var new_volume:Volume = new Volume();
addChild(new_volume);
It's important to note that the stage does not come into scope within your Volume class until you have added it to the stage from within it's parent class (in this case, it's parent class is the document class).
So these two lines:
public var xPos:Number=stage.stageWidth/2;
public var yPos:Number=stage.stageHeight/2;
don't work, as the stage is undefined there. To wait until you get know stage is defined, you can use an Event.ADDED_TO_STAGE event listener. So you can re-write your Volume class a bit to look more like this:
package {
/* Imports here */
public class Volume extends Sprite {
/* Other vars here */
public var xPos:Number;
public var yPos:Number;
public function Volume(){
/* Other assignments that are not stage-dependant can go here */
this.addEventListener(Event.ADDED_TO_STAGE, onStage);
}
private function onStage(e:Event):void{
//We remove it immediately so that it doesn't get called multiple times
//As the instance is added to the display list tree
this.removeEventListener(Event.ADDED_TO_STAGE, onStage);
xPos = stage.stageWidth/2;
yPos = stage.stageHeight/2;
/* Now that we have a reference to the stage, let's go ahead and create our slider */
init();
}
from there you can go on with business as usual, and just alter your variable values as needed to get the class to work within the confines of your player environment/document class.

How to change the value of a certain variable in the document class through another class?

here is my problem. In my document class TowerDefenseGame.as, I defined a variable Turrent1Flag:
package
{
import flash.display.MovieClip;
import flash.events.*;
import flash.display.Sprite;
import flash.display.Shape;
import flash.text.TextField;
import flash.text.TextFormat;
import flash.text.TextFieldType;
public class TowerDefenseGame extends MovieClip
{
public var Turrent1Flag==0;
}
public function TowerDefenseGame()
{
......
}
Now, in another class Turrent1Button.as, I need to create a mouse click event, by which the Turrent1Flag is set to 1:
package
{
import flash.display.MovieClip;
import flash.events.*;
import flash.display.Sprite;
import TowerDefenseGame;
public class TurretButton1 extends MovieClip
{
public var ButtonBase:Sprite=new Sprite();
public var TurretBase:Sprite=new Sprite();
public var Gun:Sprite=new Sprite();
public function TurretButton1()
{
......
this.addEventListener(MouseEvent.CLICK, MouseClick);
}
public function MouseClick(event:MouseEvent):void
{
MovieClip(root).Turret1Flag = 1;
}
Well, this does not work. I am using Adobe flash cs6 and it says the value cannot be accessed. Someone know how to do this?
try this:
private static var _instance:TowerDefenseGame;
public static function get instance():TowerDefenseGame { return _instance; }
public function TowerDefenseGame()
{
_instance = this;
}
public function MouseClick(event:MouseEvent):void
{
TowerDefenseGame.instance.Turret1Flag = 1;
}
So, to start out, AS3 makes it difficult to so what you've been used to doing in AS2 on purpose, to allow for better Object Oriented practices. When you maintain high and tight walls between Classes, it becomes easier to change Class A without having any effect whatsoever on Class B. Class B only knows about the doors and windows that are the "official" ways into the house of Class A, so it doesn't matter if you move the couch. You also make it extremely easy to replace Class A with Class C that has similar doors and windows.
When you reach through the walls by introducing global state, you can't replace Class B with Class C without changing Class A, because Class A has a direct reference to Class B and knows exactly where the couch is.
One way to handle this is through Inversion of Control (IoC). So, for our house, the couch might be supplied from outside and whatever component supplied it might keep a reference to it, so it would be able to access the couch no matter where in the house it went. So, you might choose to create your TurretButton and pass that into whoever owns that, while your TowerDefenseGame keeps a reference to it and listens directly to it, changing its own flag in response to the click.
Looking at your code, you probably don't need to go that far, because I don't see any sign that your TurretButton is actually nested. In that case, you can listen directly to it, whether you're creating it on the stage or creating it through code (which I'm not a fan of). If you're using the stage in the IDE and it exists on the stage, then just create a public variable of type TurretButton (or you could probably use SimpleButton since you no longer have need for a special Class here based on the code you've shown). That instance will be available in the constructor of your TowerDefenseGame. Just add your event listener to it, and then the listener and the variable you want to change are in the same scope. Ergo, the problem you were trying to solve never existed--you were simply looking at the problem from a perspective that overcomplicated things.
If, in fact, your code is nested in a way that's not shown, you can use ActionScript 3's event system, which is fabulous, to handle the issue without introducing direct coupling and without having to create the button through code and push it down to where it's used. One way is to just listen for any mouse click (since that is a bubbling event) and look to see what was clicked. Another solution is to generate a custom event from the button that you can then listen to from the top level to change the flag. That would look something like:
package view.button {
public class TurretButton extends MovieClip {
public function TurretButton() {
super();
mouseChildren = false;
addEventListener(MouseEvent.CLICK, broadcastTurretEvent);
}
protected function broadcastTurretEvent(e:Event):void {
dispatchEvent(new Event('turretClicked', true));//the true parameter makes it bubble
}
}
}
Then your tower Class would look like
package {
public class TowerDefenseGame extends MovieClip {
//the fact that you're calling it Turret1Flag suggests you're going to have more than 1
protected var turretFlags:Array /*of Boolean*/ = [false, false];
//your turret button instances
//doesn't show nesting, this is just to indicate that
//these are named instances so you know how what they're called
//they could be nested at any level
public var turret1:TurretButton;
public var turret2:TurretButton;
//...etc.
public function TowerDefenseGame() {
super();
addEventListener('turretClicked', onTurretClicked);
}
protected function onTurretClicked(e:Event):void {
//you can also just extract the number and do the math
//to get the correct array index
switch(e.target.name) {
case 'turret1':
turretFlags[0] = !turretFlags[0];
break;
case 'turret2':
turretFlags[1] = !turretFlags[1];
break;
}
}
}
}
Note how well this scales. You don't have to have a different Class for each button to change each separate flag. It's also easy to add more buttons without a whole lot of code changes. You could take this solution further and create a custom event that has a property that says which button was clicked, and you could supply the value to use to that for the button through dependency injection, etc.
I also made the assumption in my code that flags should be boolean and that they're turning on with the first click and off with the second click, etc. You could take the same idea and change it to, for example, increment with every click. I suspect you don't actually want to do what your code was showing and just turn it on with the first click and just leave it on forever.
Another note is that if you think you might want to code in AS3 over the longer term, you should probably learn the coding conventions that are used in AS3. One of these is that Class names start with a capital letter, but properties and methods do not.
It's probably not a great habit to get into for everything, but a static variable looks like it would work here.
public class TowerDefenseGame extends MovieClip
{
public static var Turrent1Flag = 0;
}
In Turrent1Button.as:
public function MouseClick(event:MouseEvent):void
{
TowerDefenseGame.Turret1Flag = 1;
}