ActionScript

Dialect of programming language ECMAScript

ActionScript is an object-oriented language originally developed by Macromedia Inc. (now owned by Adobe Systems). It is a dialect of ECMAScript (meaning it has the same syntax and semantics of the more widely known JavaScript), and is used primarily for the development of websites and software targeting the Adobe Flash Player platform, used on Web pages in the form of embedded SWF files. The language itself is open-source in that its specification is offered free of charge and both an open source compiler (as part of Adobe Flex) and open source virtual machine (Mozilla Tamarin) are available.

Links:

Examples:

Hello, World!:

Example for versions Adobe Flex 3.4

While the constructor Main() is called first, it contains a small routine that causes initialization to occurr only if it is created on a stage or when it is added to a stage.

“Hello World” is created via a TextField object. 

package 
{
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.display.MovieClip;
	import flash.text.TextField;
	
	public class Main extends Sprite 
	{
		
		public function Main():void 
		{
			if (stage) init();
			else addEventListener(Event.ADDED_TO_STAGE, init);
		}
		
		private function init(e:Event = null):void 
		{
			removeEventListener(Event.ADDED_TO_STAGE, init);

			// entry point		
			var tf:TextField = new TextField();
			tf.text = "Hello World!";
			tf.x = 200;
			tf.y = 20;
			this.addChild(tf);
		}
	}
}

Quadratic equation:

Example for versions Adobe Flex 3.4

When Main() is called, it contains a small routing to initialize the text fields and display labels.

The example is constructed from four text fields, not counting the clickable button or static text. It takes input from three editable text fields (identified by TextFieldType.INPUT), and places the result in the output text field.

The example may be modified to update the result instantly, but this one requires clicking “Calculate” to get the result. 

package 
{
	import flash.display.SimpleButton;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import flash.text.TextField;
	import flash.text.TextFieldType;
	
	/**
	 * ...
	 * @author Raymond Martineau
	 */
	public class Main extends Sprite 
	{
		var tf_a:TextField;
		var tf_b:TextField;
		var tf_c:TextField;
		var tf_result:TextField;
		
		public function Main():void 
		{
			if (stage) init();
			else addEventListener(Event.ADDED_TO_STAGE, init);
		}

		/**
		 * This function initializes the display elements. 
		 */
		private function init(e:Event = null):void 
		{
			removeEventListener(Event.ADDED_TO_STAGE, init);
			
			// entry point
			tf_a = new TextField();
			tf_a.text = "1";
			tf_a.x = 40;
			tf_a.y = 10;
			tf_a.height = 20;
			tf_a.type = TextFieldType.INPUT;
			tf_a.border = true;
			this.addChild(tf_a);
		
			
			tf_b = new TextField();
			tf_b.text = "1";
			tf_b.x = 40;
			tf_b.y = 30;
			tf_b.height = 20;
			tf_b.type = TextFieldType.INPUT;
			tf_b.border = true;
			this.addChild(tf_b);
			
			tf_c = new TextField();
			tf_c.text = "0";
			tf_c.x = 40;
			tf_c.y = 50;
			tf_c.height = 20;
			tf_c.type = TextFieldType.INPUT;
			tf_c.border = true;
			this.addChild(tf_c);

			/** 
			 * If desired, you could add the following line to update
			 * the calculation whenever the value is changed
			 * 
			 *   tf_a.addEventListener(Event.CHANGE, changed);
			 *   tf_b.addEventListener(Event.CHANGE, changed);
			 *   tf_c.addEventListener(Event.CHANGE, changed);
			 * 
			 * In this example, it's activated by clicking the calculate button.
			 */
			
			var tf:TextField;
			tf = new TextField();
			tf.text = "A = ";
			tf.x = 10;
			tf.y = 10;
			tf.width = 29;
			tf.height = 20;
			tf.borderColor = 255;
			this.addChild(tf);
			
			tf = new TextField();
			tf.text = "B = ";
			tf.x = 10;
			tf.y = 30;
			tf.width = 29;
			tf.height = 20;
			this.addChild(tf);

			tf = new TextField();
			tf.text = "C = ";
			tf.x = 10;
			tf.y = 50;
			tf.width = 29;
			tf.height = 20;
			this.addChild(tf);

			var btn:TextField = new TextField();
			btn.x = 40
			btn.y = 80
			btn.width = 80
			btn.height = 20
			btn.text = "Calculate"
			btn.border = true;
			btn.backgroundColor = 0xcccccc;
			btn.background = true;
			btn.selectable = false;
			this.addChild(btn);			
			
			btn.addEventListener(MouseEvent.CLICK, changed);
			
			tf_result = new TextField();
			tf_result.x = 10;
			tf_result.y = 110;
			tf_result.width = 400;
			this.addChild(tf_result);

			updateResult();
		}

		private function changed(e:Event = null)
		{
			updateResult();
		}
		
		private function updateResult()
		{
			var a:Number, b:Number, c:Number, d:Number;
			a = Number(tf_a.text); b = Number(tf_b.text); c = Number(tf_c.text);
			
			d = b * b - 4 * a * c;
			if (a == 0)
			{
				tf_result.text = "Not a quadratic equation";
			}
			else if (d == 0)
			{
				tf_result.text = "One root: " + ( -b / (2 * a));
			}
			else if (d>0)
			{
				tf_result.text = "Two roots: " + (( -b + Math.sqrt(d)) / (2*a)) + ", " + (( -b - Math.sqrt(d)) / (2*a));
			} else if (d < 0)
			{
				var e:Number = -b / 2 * a;
				var f:Number = Math.sqrt( -d) / 2 * a;
				if (f < 0) f = -f;
				tf_result.text = "Two roots: (" + e + ", " + f + "), (" + e + " - " + f + ")";
			}
			
			return 0; 
		}
		
	}
	
}