Memory Management via Garbage Collection [Actionscript 3]

In actionscript you can force garbage collection (GC) to run, but it's a bad idea if you do so.
System.gc();
But we can't predict at what time it'll run even if you force it to run.
GC runs once a while and you can make objects eligible to dispose by using several methods.

• Unregister all listeners
• Stop all timers and intervals
• Stop playheads like sounds,videos.
• Deactivate objects that would become unreachable if the object itself became unreachable. (nullify)

Scenario behind as3 garbage collection is more much similar to java gc.

Lesson 01 - Installing Java

Before starting with anything, we have to set up a java background to work with it in our PC. All you need to do is,

• Download java via http://www.java.com/en/download/
• Install 
• Setting up the path

After downloading and installing java Let's use,

>>>Command prompt to setting up the path<<<

1. First go to java installed folder --> jdkx.x.x_xx -->bin and copy the path
2. Then open command prompt ([Window key+R] then type cmd)
3. Go to the folder you expected to do your java work using cmd.
   (*See the note below)
4. Then type, set path=%path%;your bin path copied
   eg. set path=%path%;C:\Program Files\Java\jdk1.5.0_09\bin
   
    

*Note

• to change the drive, type the drive name: eg. D: 
• to change the folder type cd folderName eg. cd Umesh
• to clear the path and go back to the drive  type cd/ 
  
  
  
                                                               OR

        

>>>>>>Advaced Settings<<<<<<

Windows 8

1. Drag the Mouse pointer to the Right bottom corner of the screen
2. Click on the Search icon and type: Control Panel
3. Click on -> Control Panel -> System -> Advanced
4. Click on Environment Variables, under System Variables, find PATH, and click on it.
5. In the Edit windows, modify PATH by adding the location of the class to the value for PATH. If you do not have the item PATH, you may select to add a new variable and add PATH as the name and the location of the class as the value.
6. Close the window.
7. Reopen Command prompt window, and run your java code.

Windows 7

1. Select Computer from the Start menu
2. Choose System Properties from the context menu
3. Click Advanced system settings > Advanced tab
4. Click on Environment Variables, under System Variables, find PATH, and click on it.
5. In the Edit windows, modify PATH by adding the location of the class to the value for PATH. If you do not have the item PATH, you may select to add a new variable and add PATH as the name and the location of the class as the value.
6. Reopen Command prompt window, and run your java code.

Windows XP

1. Start -> Control Panel -> System -> Advanced
2. Click on Environment Variables, under System Variables, find PATH, and click on it.
3. In the Edit windows, modify PATH by adding the location of the class to the value for PATH. If you do not have the item PATH, you may select to add a new variable and add PATH as the name and the location of the class as the value.
4. Close the window.
5. Reopen Command prompt window, and run your java code.

Windows Vista

1. Right click My Computer icon
2. Choose Properties from the context menu
3. Click Advanced tab (Advanced system settings link in Vista)
4. In the Edit windows, modify PATH by adding the location of the class to the value for PATH. If you do not have the item PATH, you may select to add a new variable and add PATH as the name and the location of the class as the value.
5. Reopen Command prompt window, and run your java code.

Setting Path on Solaris and Linux

To find out if the java executable is in your PATH, execute:
% java -version

This will print the version of the java executable, if it can find it. If you get error java: Command not found. Then path is not properly set.

To find out which java executable the first one found in your PATH, execute:
% which java

Below are the steps to set the PATH permanently,
Note: We are here giving instructions for two most popular Shells on Linux and Solaris.
Please visit link below if you are using any other shells.
Path Setting Tutorial

For bash Shell:

1. Edit the startup file (~/ .bashrc)
2. Modify PATH variable:
   PATH="$PATH":/usr/local/jdk1.6.0/bin
3. export PATH
4. Save and close the file
5. Open new Terminal window
6. Verify the PATH is set properly
   % java -version

For C Shell (csh):

1. Edit startup file (~/ .cshrc)
2. Set Path
   set path="$PATH":/usr/local/jdk1.6.0/bin
3. Save and Close the file
4. Open new Terminal window
5. Verify the PATH is set properly
   % java -version

 

Floating bubbles [Actionscript 3]

• Open Flash new document.
• Create a small ball shape movieclip in the library.
• Give it a AS linkage name "Ball".
  
  

What we are going to do :

• Creating the ball. [Random place, Random Size, Random Color ...].
• Displaying the ball on stage.
• Moving the ball. 

 <code>

//stage size = 926 x534 px
import flash.events.Event;
import flash.utils.Timer;
import flash.events.TimerEvent;
import flash.geom.ColorTransform;

var Bx;
var By;
var Bd;
var Ba;
var red;
var green;
var blue;

/*

  Assigning variables
        ball x position = Bx
        ball y position = By
        ball diameter   = Bd
        ball opacity    = Ba
   
        red   = red color amount of the ball
        green = green color amount of the ball
        blue  = color amount of the ball

*/


function createBall():void{
    Bx = Math.floor(Math.random()*926)+1; 

//Max value = 926 Min value = 1
    By = -Math.floor(Math.random()*534)-54;
//according to the values, ball creates above the stage
    Bd = Math.floor(Math.random()*20)+10;
    Ba = Math.floor(Math.random()*99)+60;
    var ball:Ball = new Ball();
    ball.x = Bx;
    ball.y = By;
    ball.width = Bd;
    ball.height = Bd;
   
   
    red = Math.random();
    green = Math.random();
    blue = Math.random();
    var myColour:ColorTransform = new  
    ColorTransform(red+0.6,green,blue-0.2);
    ball.transform.colorTransform = myColour;
    ball.alpha = Ba/100;
    var xposInf = Math.floor(Math.random()*5)-2;
    var yposInf = Math.floor(Math.random()*5)-2;
    function moveBall(e:Event):void{
        ball.x+=xposInf;
        ball.y+=yposInf;
    }
// Adding the ball on stage   
    stage.addChild(ball);
//Moving the ball according to frame rate.   
    stage.addEventListener(Event.ENTER_FRAME,moveBall);
/*
To save the memory usage
after 60 seconds ball created will be removed
*/
    var timer:Timer = new Timer(60000,1);
    timer.addEventListener(TimerEvent.TIMER,removeBall);
    function removeBall(e:Event):void{
        stage.removeChild(ball);
    }
    timer.start();
}


/*
    A function to create a ball
        Ball x,y,size,opacity values generates randomly as well as color value.
        xposInf is a variable for horizontal(x) speed of the ball (random value)
        yposInf is a variable for vertical (y) speed of the ball (random value)
     
*/

// A function to create 2 balls at a time
function addBalls(e:Event):void{
    createBall();
    createBall();
}
// creating two balls on stage continuously
stage.addEventListener(Event.ENTER_FRAME,addBalls);
//adding a significant amount(100) balls at the start
for(var i=0;i<100;i++){
    createBall();
}







x,y Camera using scrollRect [Actionscript 3]

In this tutorial, we are going to make a 2D camera (moves along x and y axises).

•  First make your backround (Better if it's larger than stage) and give it an instance name "Background"
• According to the press of arrow keys camera gonna move. 

Let's get started...

<code>

import flash.geom.Rectangle;

import flash.events.Event;

import flash.events.KeyboardEvent;

var myCam:Rectangle = new Rectangle(0,0,stage.stageWidth,stage.stageHeight);

/* creating a rectangle which act as a camera to a movieClip which is our Background
     parameters for new rectangle

             Rectangle x position = 0
             Rectangle y position = 0
             Rectangle width       = stage width
             Rectangle height       = stage height

*/

//creating a function in order to move the camera (i.e. our rectangle) using arrow keys

function moveCamera(e:KeyboardEvent):void{

            if(e.keyCode==Keyboard.UP){

                        myCam.y-=2;

            }

            if(e.keyCode==Keyboard.DOWN){

                        myCam.y+=2;

            }

            if(e.keyCode==Keyboard.LEFT){

                        myCam.x-=2;

            }

            if(e.keyCode==Keyboard.RIGHT){

                        myCam.x+=2;

            }

}

//calling the camera move function to the stage

stage.addEventListener(KeyboardEvent.KEY_DOWN,moveCamera);

function updateView(e:Event):void{

            Background.scrollRect = myCam;

}

/*

              assigning viewing area of the Background to the rectangle(our cam)
              so, we can see the area bounded to the rectangle more like a mask
              but you can't use .mask instead of scrollRect :D
              note that myCam position, scale parameters generates in, as myCam is
              inside Background

*/

stage.addEventListener(Event.ENTER_FRAME, updateView);

/*         calling the updateView function on stage. stage gets updated according to the frame
            rate and the function updateView

*/

 </code>

• Note : scrollRect animations are not well smooth.
• Light Blue colour  texts represent variables and functions
• Green texts represent comments