This entry I’ll be showcasing a simple MP3 player written in Adobe Flex. Full source code is available here.

Also included in this project is a wonderful Flex visualizer written by Ben Stucki. The player loads an MP3, either local or remote. An event listener then calls a function when loading is complete that will pull ID3 tag information. In this project I’m only pulling the Title, Artist, and Album tags, but you can pull any associated tag you need. We also create a visualizer component and link it to a playing sound channel, which produces the lovely visualizer.

You can also load remote MP3s just as easily (the default MP3 is local). Simply paste the URL for an mp3 into the text box and then hit the play button.

In addition I’ve incorporated a rather hackish Flex ProgressBar as a “seek” bar. The percentage of play progress is calculated and then applied to the progress bar regularly, and a MouseListener is placed on the progress bar that allows the user to click at various points along the bar. The coordinates of the mouse click are then translated into a percentage of the song length. The song is then stopped and play is started from the new location.

The music sample used is from Wired’s Creative Commons CD. Tracks from this album can also be used to test the remote playing functionality.

Ever wanted to use a custom animated cursor in your Flash project? This video tutorial will show you how to do so via Actionscript. Click here for the source code.

Here’s another Flash video tutorial. This time we’ll be focusing on a “Whack-a-mole” type Flash game. Click here to download the accompanying source code.

I’ve created a video tutorial breaking down in 10 minutes how to make a Flash defender game. If you’d like to check out the game and source, they are also available.

Play the game: http://forum.internaldrive.com/files/vlog/Yadder.swf
Download the source: http://forum.internaldrive.com/files/vlog/VLog1Yadder_src.zip

Most people fluent in Flash Actionscript are familiar with unary and binary operators, but there is also a ternary operator that can be quite useful. First, a refresh on operators:

Unary: count++;

Binary: count = count * 2;

Ternary: var result:String = (count == 0) ? “Empty” : “Not Empty”);

So what does this mean? You can use the ternary form of the if statement as a shorthand. Let’s look at the equivalent full if-else statement:

var result:String;
if (count == 0) result = “Empty”;
else result = “Not Empty”;

Of course, using the ternary operator cuts down on code readability, but three lines can effectively be cut down to one. Remember, the form is this:

(condition) ? ifTrueDoThis : ifFalseDoThis;

For those of you moving from Actionscript 2 to 3 (with a heavier focus on proper object-oriented principles), you may find that accessing your Main class and Stage isn’t as straight-forward. In this post we’ll highlight organizing your classes to properly reference your main class. First, let’s take a look at our Main class:

package {

    import flash.display.Stage;

    import flash.display.MovieClip;

    public class Main extends MovieClip {

        private static var _instance:Main = null;

        public function Main() {

            _instance = this;

        }

        public static function getInstance():Main { return _instance; }

        public static function getStage():Stage { return getInstance().stage; }

    }

}

First we define a static variable, _instance, to hold a static reference to Main. We are assuming throughout this that we will use Main statically. In other words, there will only be a single instance of our Main class. Next, in our constructor, we use the line _instance = this; to set our static version of Main to the one that is created when the constructor is called.

We will use two methods to get access to Main and the main stage. First, getInstace() is a static function that always returns a copy of _instance. If you want the stage instead, use getStage(). All getStage() does differently from getInstance() is return the stage property of _instance rather than the object itself. Using this format simplifies your code in other classes.

Now let’s say you want to use these functions in other classes to add something to the stage. Let’s pretend we have a Tree class that needs to add itself to the main stage when it is created. You could use this code:

package {
    import flash.display.Sprite;</code>

    public class Tree extends Sprite {
        Main.getStage().addChild(this);

        x = Math.random() * Main.getStage().stageWidth;
        y = Math.random() * Main.getStage().stageWidth;
    }
}

You can see that we can easily get properties of the stage (stageWidth and stageHeight) simply by statically referencing Main. Note that we could have used the following lines instead:

x = Math.random() * Main.getInstance().stage.stageWidth;
y = Math.random() * Main.getInstance().stage.stageWidth;

It really just depends on which example you find more elegant. One additional benefit of using the techniques described here is that you can use the getInstance() to determine if Main has loaded. Simply do:

if (Main.getInstance() != null) { /* some function */ }

Hope that gives you an easy framework for accessing your stage and Main class in AS3!