How to define that a child should only appear in one scene? - actionscript-3

Question

We are making an space impact game. Here are 3 of our classes. Our problem is that when we create our InimigoNoite, they appear all over the game(menus, other levels, etc), instead of only appearing in the Scene that we want. How should we restrict the child to only appear in the CenárioCidade?
We've tried to use gotoandPlay, addChildAt, and also tried to create the Inimigo not in the Main class, but in the Inimigo class itself, but it doesnt appear at all. Please can someone help us? Thank you very much!
KEY.as
package {
import flash.display.Stage;
import flash.events.Event;
import flash.events.KeyboardEvent;
public class Key {
private static var initialized:Boolean = false;
private static var keysDown:Object = new Object();
public static function initialize(stage:Stage) {
if (!initialized) {
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyPressed);
stage.addEventListener(KeyboardEvent.KEY_UP, keyReleased);
stage.addEventListener(Event.DEACTIVATE, clearKeys);
initialized = true;
}
}
public static function isDown(keyCode:uint):Boolean
{
return Boolean(keyCode in keysDown);
}
private static function keyPressed(event:KeyboardEvent):void {
keysDown[event.keyCode] = true;
}
private static function keyReleased(event:KeyboardEvent):void {
if (event.keyCode in keysDown) {
delete keysDown[event.keyCode];
}
}
private static function clearKeys(event:Event):void {
keysDown = new Object();
}
}
}
INIMIGO NOITE.as
package{
import flash.display.MovieClip;
import flash.events.Event;
import flash.utils.Timer;
public class InimigoNoite extends MovieClip{
var speed:Number;
static var list:Array = new Array();
var balaTimer: Timer;
function InimigoNoite(){
list.push(this);
this.x = 1160;
this.y = 150 + (450-150) * Math.random();
speed = Math.random()*5 + 5;
addEventListener("enterFrame", enterFrame);
var intervalo: Number = Math.random()*500 + 1000;
balaTimer = new Timer(intervalo);
balaTimer.addEventListener("timer", bala);
balaTimer.start();
}
function enterFrame (e:Event){
this.x -= speed;
if(this.x < -100){
matar();
return;
}
if(this.hitTestObject(SpaceImpact.navecnoite)){
matar();
}
}
function matar(){
var explosao = new ExplosaoNoite();
stage.addChild(explosao);
explosao.x = this.x;
explosao.y = this.y;
balaTimer.stop();
balaTimer.removeEventListener("timer",bala);
removeEventListener("enterFrame", enterFrame);
stage.removeChild(this);
for(var i in list){
if(list[i] == this){
delete list[i];
}
}
}
function bala(e:Event){
var b = new BalaInimigo();
b.x = this.x -50;
b.y = this.y;
stage.addChild(b);
}
}
}
MAIN.as
package{
import flash.display.MovieClip;
import flash.events.Event;
import flash.utils.Timer;
public class SpaceImpact extends MovieClip{
static var navecnoite:MovieClip;
var inimigoNoiteTimer:Timer;
function SpaceImpact(){
Key.initialize(stage);
inimigoNoiteTimer = new Timer(8000);
inimigoNoiteTimer.addEventListener("timer", criaInimigo);
inimigoNoiteTimer.start();
}
function criaInimigo(e:Event){
var inimigo = new InimigoNoite();
stage.addChild(inimigo);
addChildAt(inimigo, 3);
}
}
}

Answer 1

You never stop the timer. So your inimigo is created and added every 8seconds.
Stop the timer in criaInimigo and/or use the timerComplete Event
function SpaceImpact(){
Key.initialize(stage);
inimigoNoiteTimer = new Timer(8000,1);
inimigoNoiteTimer.addEventListener(TimerEvent.TIMER_COMPLETE, criaInimigo);
inimigoNoiteTimer.start();
}
function criaInimigo(e:Event){
//inimigoNoiteTimer.stop();//only needed if you use the 'timer'-Event
var inimigo = new InimigoNoite();
stage.addChild(inimigo);
addChildAt(inimigo, 3);
}

Answer 2

Right when you application starts, you are creating a new InimigoNoite every 8 seconds. Since you are adding them to the stage, they will appear over top anything you have on your timeline.
The issue (besides creating them when the application starts and never stopping your timer), is that when you through code use addChild, that child will stay on the screen until it's explicitly removed via removeChild (or one of it's parents are - but since the parent is stage that isn't going to happen).
I see that your have a hit test in the InimigoNoite class that can potentially remove it, but I don't see anywhere else where you remove it (so if the hit test never happens, it will never be removed from the stage regardless of scene).
It seem though that the solution to your problem is more advice on how to architect your application.
Don't use scenes.
Your best bet is to create a class file for each distinct state of your game. So something like this as a basic example:
Main Menu State
Game Play State(either 1 game state that encompasses all levels, or one state for each level - or both - depending on how much functionality changes between levels)
Game Over State
Make your game state class files extend Sprite or MovieClip, and if you want you can even create a new MovieClip in flash pro and attach the class to that (thereby being able to drop visual assets on the timeline).
So then your Main class would just be in charge of managing states (and any anything else that is global to the application)
package{
import flash.display.MovieClip;
import flash.events.Event;
public class SpaceImpact extends MovieClip {
private var menu:Menu; //Assumes you have a Menu.as class file
private var game:MainGame; //MainGame.as file
private var gameOver:GameOver; //GameOver.as file
public function SpaceImpact(){
Key.initialize(stage);
goMenu();
}
public function goMenu(e:Event = null):void {
removeAll();
menu = new Menu();
addChild(menu);
menu.addEventListener(Event.COMPLETE, startGame,false,0,true);
}
private function removeMenu():void {
if(menu){
if(menu.parent) removeChild(menu); //remove it from the screen
menu = null;
}
}
public function startGame(e:Event = null):void {
removeAll();
game = new MainGame();
addChild(game);
game.addEventListener(Event.COMPLETE, gameOver,false,0,true);
}
private function removeGame():void {
if(game){
if(game.parent) removeChild(game); //remove it from the screen
game = null;
}
}
public function gameOver(e:Event = null):void {
removeAll();
gameOver = new GameOver();
addChild(gameOver);
gameOver.addEventListener(Event.COMPLETE, goMenu,false,0,true);
}
private function removeGameOver():void {
if(gameOver){
if(gameOver.parent) removeChild(gameOver); //remove it from the screen
gameOver = null;
}
}
private function removeAll():void {
removeGameOver();
removeMenu();
removeGame();
}
}
}
then, your game state for example:
MainGame.as
package{
import flash.display.MovieClip;
import flash.events.Event;
import flash.utils.Timer;
public class MainGame extends MovieClip {
private var inimigoNoiteTimer:Timer;
public function MainGame() {
this.addEventListener(Event.ADDED_TO_STAGE, addedToStage, false, 0, true); //don't do anything until this object has been added to the screen
}
private function addedToStage(e:Event):void {
this.removeEventListener(Event.ADDED_TO_STAGE, addedToStage);
//start spawning
inimigoNoiteTimer = new Timer(8000);
inimigoNoiteTimer.addEventListener("timer", criaInimigo);
inimigoNoiteTimer.start();
}
function criaInimigo(e:Event){
var inimigo = new InimigoNoite();
addChild(inimigo);
}
//when whatever happens that makes your game finished
function gameComplete():void {
dispatchEvent(new Event(addEventListener.COMPLETE));
}
}
}