[AS 3] Actionscript Image Crop Project – Part I – Drawing Rectangle

Update: Please visit the revision: Part II – Actionscript 3 Image Cropping

Actionscript 3 offers a method to copy pixels / Bitmap Data from a Bitmap Object. I was thinking of just setting up a little demo of this by first creating a tool that will draw out a rectangle to highlight an area of an image to be copied.

If you press and drag your mouse over the movie below it will draw out the area to crop, if you use this code remember to drop in the Button component to you library.

Here is my Document Class:

package
{
	import flash.display.Sprite;
	import flash.display.Shape;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import fl.controls.Button;

	public class BitmapDataCrop extends Sprite
	{
		private var myRectangle:Shape;
		private var myRectSp:Sprite;
		private var ltx:Number; // top left x position
		private var lty:Number; // top left y position
		private var rtx:Number; // bottom right x position
		private var rty:Number; // bottom right y position
		private var button:Button;
		private var buttonDrag:Button;

		public function BitmapDataCrop()
		{
			stage.addEventListener(MouseEvent.MOUSE_DOWN, rectStartingPoint);
		}

		private function rectStartingPoint(m:MouseEvent):void
		{

			ltx = mouseX;
			lty = mouseY;
			stage.removeEventListener(MouseEvent.MOUSE_DOWN, rectStartingPoint);
			stage.addEventListener(MouseEvent.MOUSE_MOVE, rectDraw);
		}

		private function rectDraw(m:MouseEvent):void
		{
			rtx = mouseX;
			rty = mouseY;

			var myRectangle:Shape = new Shape();
			myRectangle.graphics.beginFill(0xffffff);
            myRectangle.graphics.lineStyle(1, 0x000000);
            myRectangle.graphics.drawRect(ltx, lty, rtx - ltx, rty - lty);
            myRectangle.graphics.endFill();

			var myRectSp:Sprite = new Sprite();
			myRectSp.addChild(myRectangle);
			addChild (myRectSp);

			stage.addEventListener(MouseEvent.MOUSE_UP, stopRectDraw);
		}

		private function stopRectDraw(m:MouseEvent):void
		{
			stage.removeEventListener(MouseEvent.MOUSE_MOVE, rectDraw);
			stage.removeEventListener(MouseEvent.MOUSE_UP, stopRectDraw);

			addButtons();
		}

		private function addButtons():void
		{
			button = new Button();
            button.width = 100;
            button.height = 30;
            button.move ( rtx - button.width - 10,rty - button.height - 10 );
            button.label = "Copy Area";
            addChild(button);

			button.addEventListener(MouseEvent.CLICK, copyImage);

		}

		private function copyImage(m:Event):void
		{
			trace ("begin copy image code");
		}
	}
}