Comments on: A Closer Look: Using MovieClip.addFrameScript()

By: William B. Sanders

William B. Sanders — Sat, 28 Aug 2010 21:46:42 +0000

Hi Otavio,

Yes, you want to clear the code from your timeline. That is the point. It’s bad enough having timeline code all over the place and playing “Where’s Waldo?” with your code. To have a combination of both code in a class (or a design pattern) and on the timeline is a nightmare.

Remember—now there’s no reason to have code on the timeline. Ever.

Kindest regards,
Bill

By: Otavio Silva

Otavio Silva — Thu, 26 Aug 2010 20:31:53 +0000

Nice post, but one thing needs to be said!

Lets say you have some code on your timeline, for example a stop(); function call, and then after discovering this amazing function ( addFrameScript()) you decide to give it a try. Remember that the timeline code will be completely overwritten!

So its one or the other, not both!

By: Jloa

Jloa — Wed, 09 Dec 2009 22:17:34 +0000

Hi, David!
Do you happen 2 know if there are any other undocumented function like the one u described?

By: Barbara Parkman

Barbara Parkman — Thu, 24 Sep 2009 14:34:54 +0000

Hi Bill and Chandima,

Thanks for the tip about the playhead. I figured out how to use addFrameScript() with an event dispatch and thus avoid having a script on the timeline, and it certainly is cool! I made a little app that has 3 colored balls moving across the stage. When the red one gets to the end of its timeline, it triggers the green one etc. Here’s the URL: http://bitsong.com/forPosting/dispatchTest/dispatchTest.html

Here’s some of my code: I include Main.as and one of the colored ball classes, RedBallContainer.as Your blog is a great place to get exciting new ideas! Thanks.

Barbara

^?View Code ACTIONSCRIPT3

package{
	import flash.display.MovieClip;
	import flash.events.Event;
 
	public class Main extends MovieClip{
		public function Main(){
			redBallContainer.stop();
			greenBallContainer.stop();
			blueBallContainer.stop();
 
			redBallContainer.gotoAndPlay(2); // starts everything rolling
 
			stage.addEventListener("startRed", onStartRed); // listener for function called when playhead reaches frame 60
			stage.addEventListener("startGreen", onStartGreen);
			stage.addEventListener("startBlue", onStartBlue);
		}
 
		private function onStartRed(event:Event){
			redBallContainer.gotoAndPlay(2); 
			trace("start red");
		}
		private function onStartGreen(event:Event){
			greenBallContainer.gotoAndPlay(2);
			trace("start green");
		}
		private function onStartBlue(event:Event){
			blueBallContainer.gotoAndPlay(2);
			trace("start blue");
		}
	}
}

^?View Code ACTIONSCRIPT3

package{
	import flash.display.MovieClip;
	import flash.events.Event;
 
	public class RedBallContainer extends MovieClip{
		public function RedBallContainer(){
			this.addFrameScript(59, stopRedStartGreen) // this is instead of having to call stopRedStartGreen() 
													   // from frame 60 of RedBallContainer timeline
		}
		public function stopRedStartGreen(){ // called using addFrameStript above
			this.gotoAndStop(60); // stops red ball movement on frame 60
			dispatchEvent(new Event("startGreen", true)); // dispatches event to start green ball 
		}
	}
}

By: William B. Sanders

William B. Sanders — Wed, 23 Sep 2009 20:54:01 +0000

Hi David & Barbara,

@David–I couldn’t improve on Chandima’s comment except to add when when using variables you’d want to change the constants to variables. Like you, I’ve only recently learned of this method even though it’s been out for a few years.

@Barbara–Essentially, the MC playhead is acting like a trigger. As soon as it hits the frame, the function is going to be called and it doesn’t matter what you put in the function. I can imagine an endless number of scenarios for this method.

Kindest regards,
Bill

By: Chandima Cumaranatunge

Chandima Cumaranatunge — Wed, 23 Sep 2009 18:58:22 +0000

Hi David, You can do the following if you know that certain labels exist in a movie clip.

The following class extends an MC on the stage that has two labels called ’start’ and ‘end’ on the tween.

^?View Code ACTIONSCRIPT

package
{
    import flash.display.MovieClip;
    import flash.display.FrameLabel;
 
    public class MyMovieclip extends MovieClip
    {
        private var labels:Object
 
        public function MyMovieclip()
        {
            labels = this.currentLabels;
 
            for ( var i:uint = 0; i < labels.length; i++ )
            {
                var framelabel:FrameLabel = labels[i];
                labels[ framelabel.name ] = framelabel.frame
            }
 
            addFrameScript( labels['start'], onStartAnim, labels['end'] - 1, onEndAnim );
        }
 
        public function onStartAnim():void 
        {
            trace('starting animation');
        }
 
        public function onEndAnim():void 
        {
            trace('ending animation');
        }
    }
}

Now you can safely modify the tween lengths etc. knowing that the code references the labels and not explicit frame numbers.

By: Barbara Parkman

Barbara Parkman — Wed, 23 Sep 2009 15:59:27 +0000

My own project is going to be very dependent on being able to make things happen like this. I haven’t tried to write the code yet, but I was assuming I could make the code finish playing an animation and then jump to a function using event dispatches. Is this not the case? Thanks.

Barbara

By: David Wilhelm

David Wilhelm — Wed, 23 Sep 2009 13:44:47 +0000

Thanks for explaining this cool feature which I had no idea existed. I can see it being very useful when dealing with animated MovieClip assets … eg. a game where you want to know when the player’s ship has finished blowing up. The one thing that seems awkward is having to reference the exact frame number.. wish there was a way to use a frame label instead.