Tracking key presses can be useful both form Flash games (i.e. up, down, left, right keys) or even forms and other types of interactivity (enter key, etc.). It’s pretty simple to do in AS3 using the KeyboardEvent object. Here are a couple examples:

The first thing we need to do is set up a listener to track key events:

//Listen for key presses
stage.addEventListener(KeyboardEvent.KEY_DOWN, key_pressed);

So basically we are saying when someone presses down a key we want to run the “key_pressed” function. Let’s create that function now.

There are a couple different ways to track which key is pressed. For the widest range of keys we’ll use the charCode. This is an integer that represents each key on the keyboard. Here’s an example to do that:

//Listen for key presses
stage.addEventListener(KeyboardEvent.KEY_DOWN, key_pressed);

if (event.charCode == 97) {
trace(”a”)
}
}

There is a list of charCodes here.

You’ll notice that the link above only has charCodes for upper case letters. One way to figure out charCodes for a lower case (or any) key is to trace the charCode as you press a key. Uncomment the trace(event.charCode); line in the code above and Flash will trace a charCode each time you press a key.

Now for some keys there is an even easier way to track pressing. It’s called keyCode and it is more readable than the cryptic charCode. Here is some sample code for that:

//Listen for key presses
stage.addEventListener(KeyboardEvent.KEY_DOWN, key_pressed);

}

You can get the keyCodes for that method at the same link as above.

Note - if you see the little AIR logo before the keyCode, it means that particular keyCode only works in the AIR runtime. Or should I say Adobe AIR Runtime… which translates to Adobe Adobe Integrated Runtime Runtime. Sorry … tangent.

So for any keyCodes with that logo in front, you’ll need to use the charCode method I outlined above.

Friends - I hope this helps you accomplish all of your wildest key press tracking dreams! Good luck!

When Actionscript 2 came out, I stopped using buttons and the old Actionscript 1 on(release) methods and starting creating movie clips for my buttons and using instanceName.onRelease functions to make buttons out of those movie clips.

Now with AS3 there is a new way to perform these functions. It’s not much harder than the old way, just different. Here are some examples:

onPress
buttonInstance.addEventListener(MouseEvent.MOUSE_DOWN,function():void {
trace(”down”);
}
);

onRelease
buttonInstance.addEventListener(MouseEvent.MOUSE_UP,function():void {
trace(”up”);
}
);

onRollOver
buttonInstance.addEventListener(MouseEvent.MOUSE_OVER,function():void {
trace(”over”);
}
);

onRollOut
buttonInstance.addEventListener(MouseEvent.MOUSE_OUT,function():void {
trace(”out”);
}
);

Pretty simple right? Not too bad at all.

Click here for some examples of other mouse actions you can track.

E4X may be the best thing about Flash CS3! It stands for ECMAScript for XML and it is the new way to interact with XML in Flash AS3. What is ECMAScript? I don’t know - nor do I care. What I do know is it ROCKS your socks off. If you have used XML in Flash before you’ll will be amazed at how much easier it is.

Remember this?
xmlInstance.firstChild.firstChild.firstChild.firstChild.firstChild.childNodes[5]?

Now you can do this:
xml.nodeName[5]

It is soooo much easier to do. Thank you AS3.

Take a look at the “Chuck Quotes” swf below. Bask in its utter radness. It randomly selects one of 10 Chuck Norris facts and displays it next to the handsome face of none other than Chuck Norris. Here is the actionscript I used to build this beauty:

var xml:XML = new XML();
var loader:URLLoader = new URLLoader();
loader.load(new URLRequest(”http://www.jesseharding.com/blog/files/chuckisms.xml”));
loader.addEventListener(
Event.COMPLETE,
function(evt:Event):void {
xml = XML(evt.target.data);

var randomChuck:String = xml.chuckism[randomNum].@text;
chuckquote.text = randomChuck;
}
);

I’ve got a sample fla file that is very well commented and shows you how to build the “Chuck Quotes” swf below.

Download the fla here

Here is the Chuck Quotes swf:

I recently read on Emmy Huang’s blog that there is a new security update coming out for Flash 9 that may affect existing swf content on the web. This Flash Player update will address some of the vulnerabilities that were discovered in December of last year.

For the most part it looks like there are easy work-arounds to fix any possible problems but if you are using any of the following actionscript items you’ll want to read the Developer Center article about the update.

• Use of sockets or XMLSockets, regardless of the domain the SWF is connecting to
• Use of addRequestHeader or URLRequest.requestHeaders in any network API call when sending or loading data cross-domain OR Provides access to content on remote domains as a web service provider
• Use of SWFs that are exported for Flash Player 7 (SWF7) or below that communicate with the hosting HTML by any means
• Use of ‘”javascript:’” through network APIs to communicate outside a SWF

If you are not sure if your Flash needs to be updated, the Developer Center article goes into detail on each of the issues and gives examples of possible uses.

I’ve been seeing a lot of Flash sites lately that have the background that moves as your mouse moves. It’s a pretty cool effect. The objects in the background move less and the objects in the foreground move more. It almost gives the site a 3D feel.

Anyway - I thought I’d jump into Flash and try to figure out how it’s done. It was actually a LOT easier than I thought it would be (Disclaimer: This is AS2 not AS3).

You can see our finished file here.

The code is explained below, or if you want to jump right to the finished product download the source.

Instructions

The first thing you need to do is start an onEnterFrame function which basically continually checks to see what is going on in your Flash:

this.onEnterFrame = function(){

}

Subtracting the x and y mouse positions from the width and height of the Stage will give us the effect of the background moving opposite from the mouse:

this.onEnterFrame = function(){
cursorX = Stage.width - _xmouse;
cursorY = Stage.height - _ymouse;

}

Now all we need to do is create some movie clips, give them instance names and tie their movement to the cursorX and cursorY variables we created:

this.onEnterFrame = function(){
cursorX = Stage.width - _xmouse;
cursorY = Stage.height - _ymouse;

}

You can play with the math and see how it affects the movement of your movie clips to get that 3D effect. Good luck!