Actionscript Key Listener Tutorial

August 1, 2008 at 7:23 pm · 348 views · Filed under tutorial

Overview

Allowing users to use the keyboard as well as the mouse is a great way to incite interaction with your flash. This tutorial will show how to code it and what you can do with some keyboard events. This changed with actionscript 3, note this tutorial is AS3.
altKeY (Boolean) Indicates whether the Alt key is active (true) or inactive (false).
charCode (uint) Contains the character code value of the key pressed or released.
ctrlKey (Boolean) Indicates whether the Control key is active (true) or inactive (false).
keyCode (uint) The key code value of the key pressed or released. KeyboardEvent
keyLocation (uint) Indicates the location of the key on the keyboard. KeyboardEvent
shiftKey (Boolean) Indicates whether the Shift key modifier is active (true) or inactive (false).

Steps

1. import KeyboardEvent,

   import flash.events.KeyboardEvent;

2. assign any keycodes

   //keycodes
   var left:uint = 37;
   var up:uint = 38;
   var right:uint = 39;
   var down:uint = 40;

3. add event listener KeyboardEvent.KEY_DOWN

   stage.addEventListener(KeyboardEvent.KEY_DOWN,keyDownListener);

4. respond to keys

   function keyDownListener(e:KeyboardEvent) {
           trace(e.keyCode.toString());
   }

   or

   function keyDownListener(e:KeyboardEvent) {
           if (e.keyCode==left){
   		ship.x-=10;
   		ship.rotation = 90;
   	}
   	if (e.keyCode==up){
   		ship.y-=10;
   		ship.rotation = 180;
   	}
   	if (e.keyCode==right){
   		ship.x+=10;
   		ship.rotation = 270;
   	}
   	if (e.keyCode==down){
   		ship.y+=10;
   		ship.rotation = 0;
   	}
   }

Example

Here we have a swf with the keyboard event listener on the stage, and feedback boxes to give us all we can know about the event. It will tell us about certain keys (alt, ctrl (cmd), and shift) with a Boolean, it will tell us the keyCode and the charCode. The keyCode is the number that is tied to the actual button pressed or key, and the charCode relates to the character represented by the button(s) pressed. So hitting ’s’ and then hitting ’shift + s’ will tell you different charCodes, ’s’ and ‘S’. but you’ll see that the s key has the same keyCode (you’ll also see the ’shift’ keyCode as well). If needed you can use the String.fromCharCode function to determine what the charCode for something is. The location on the keyboard is even reported, this helps distinguish between the left shift and the right shift and even the numbers across the qwerty and the numpad on the right of the screen.

Actionscript

Download

source file download: key-listener.fla

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Google Indexes SWFs and external content | Fleximagically Searchable | Ryan Stewart’s Flex SEO Contest

July 15, 2008 at 6:54 pm · 248 views · Filed under personal

Ryan has announced a contest to investigate how Google is actually crawling swfs. He introduced the term “fleximagically searchable” to be included in external content, which is then loaded into the Flex swf. Hoping that google will read the external source file through the swf. Also testing how this shows up in the search results. Even though I think there a lot more to SEO than just letting Google crawl your site, there’s the pagerank and everything that Google uses in it’s top secret algorithm to determine search result position ranks.

Here’s the official rules:

• It has to be a Flex application
• “Fleximagically Searchable” must be dynamically loaded. It can’t be static text inside of your application. - But I don’t care how you load it, in fact that might make a difference in how Google ranks you.
• The first link must be deep linked directly into where you load “Fleximagically Searchable” into your application. Feel free to use any deep linking methods out there.
• Nothing in your code can dynamically load the phrase automatically. It has to be the result of a user interaction.
• You must provide source code and be willing to talk about exactly what you did.
• Multiple entries are allowed if you want to try different things.

They seem to be a bit vague in places, but we’ll see if Ryan decides to clarify anything.

More information: I’ve found that’s helpful at Peter Elst’s post. And Ryan explains Google and Flash’s relatoinship development here. Here and here is what Google has officially said. Here is the official press release from Adobe about their new

I’ll have a couple entries I’m sure… and I’ll be sure to post about those as well.

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Actionscript to Reference Dynamically created instances Flash Movie Clip | Array notation | Tutorial

July 14, 2008 at 8:02 pm · 531 views · Filed under tutorial

Overview:

Often I’ve had some dynamically created movieclip and then wanted to reference it in my code. This is hard to do if it is named dynamically as well, such as with an incrementing variable. If you use one (or more) variable to name an instance in runtime, you can’t always know what it will be called.
There are two ways (that I know of) to reference these clips, one is the array operator [] and the other is using the eval() function is as2 (but I’ve noticed that as3 has removed the eval function, so I’d recommend getting used to array notation).

Steps:

1. Create the object dynamically (or with a variable) (_root.myClip.duplicateMovieClip (”myClip”+i, i);)
2. Reference it with either array notation or with eval. (thisOne = _root["myClip"+i];) or (eval(”myClip” + i))

Example:

I create some movie clips dynamically using a for loop and name them all incrementally with a variable (myClip+i). But then i want to refer to some of them later, specifically. I don’t know what they are named though. They are all myClip1 myClip2 myClip3 and so on. I can use array notation to reference these (or eval). I’ve found it’s easiest to create a reference to the name once and then use it to refer to the clip I want. I imagined a scenario that when you click a mc you would want a different one to be moved. So clicking myClip3 moves myClip4 and so on. I’ve made it wrap so that 5 moves 1… They change the _y property of the next to match the one that’s clicked. Clicking the refresh button will loop through all the clips and (this time using eval) randomize the y coordinate.

Actionscript:

Download:

Source fla file: download

Reference:

Nuno Mira shows a good example:

this.createEmptyMovieClip("outer_mc", 1); // create a mc called outer_mc
outer_mc.createEmptyMovieClip("inner_mc", 1); // create a mc called inner_mc inside outer_mc
// 3 different ways of targeting inner_mc
trace(outer_mc.inner_mc);
trace(outer_mc["inner_mc"]);
trace(this["outer_mc"]["inner_mc"]);
// all output _level0.outer_mc.inner_mc

TheCanadian@Kirupa states it nicely:
The Problem
How can I reference objects using a variable? This is commonly a problem with dynamically created buttons:

for(i = 0; i < 3; i++) {
button+i.someProp = "Hello World!"; //error
}

The Answer
This is probably the question that gets asked the most. Referencing an object with a variable is done using something called associative array referencing or array notation. The fundamental concept behind this is that:

myObject.prop = "value";
//and
myObject["prop"] = "value";

Are the same thing. Associative array referencing follows the pattern of scope["prop"] where scope is the object which contains the property and prop is the name of the property you wish to reference. Save appearance, array notation works in exactly the same way as dot notation.

Going back to the original, problematic, example, the correct code would look like this:

for(i = 0; i < 3; i++) {
this["button"+i].someProp = "Hello World!";
}

The button string is concatenated (joined) with the i variable, forming a new reference with each iteration of the loop. First button0, then button1, et cetera.

That’s the quick, but some of you may think that that’s the same notation that is used with instances of the Array class. While that is true, the converse is actually more correct: Array instances use that notation.

Arrays are exactly the same as generic Objects, the only difference is that they have a collection of methods to deal with their properties. And because they require a need for organization, they typically only use numerical properties. Given the array myArray = ["a", "b", "c"], you could theoretically reference the indices using myArray.0, myArray.1 and myArray.2. The reason that we must use array notation is because the compiler doesn’t allow the reference of numerical properties with dot notation.

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StomperNet’s Stomper Universe | Interactive Flash Site Map

June 25, 2008 at 10:20 pm · 205 views · Filed under portfolio, work

StomperNet now has a site map. Only it’s much bigger than just a site map, we’re calling it Stomper Universe! It contains all the pieces parts that make up StomperNet. It links to different sites, video series, tools, and more by giving a 3D interactive space to inspect the thumbnails and click through to the sites! It will help visitors navigate easily to all areas of StomperNet, whether they are new to them or old favorites.

So go check out the StomperNet Universe now!

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Brownian Movement in Actionscript | Random Motion Tutorial

June 24, 2008 at 10:34 pm · 843 views · Filed under tutorial

Overview

Having things drift around or move randomly has always interested me. Having an animation that is never going to be the exact same thing is very exciting. The focus turns from key-ing exact animations to programming a feel and letting the animations take car of themselves! One type of seemingly random motion is Brownian motion. This gives the movement a random walk wandering look, it will just drift around with no real direction.

Steps

Step by step this process is very simple. In every random motion you create the random number, and apply it to the property. If you want constant random action (motion) rather than just random placement, you repeat that over and over.

1. Make a random number (random velocity)
2. Apply the random number (apply velocity to property)
3. Repeat (if needed)

To create a random number in actionscript, use Math.random(), which creates a random number between 0 and 1. Usually you’ll want to scale it to a range you want to use. If you want a number between 50 and 100, you’d do Math.random() * 50 + 50. *50 to scale it to 0-50, and + 50 to bring it up to 50 - 100. Also if we want to get a 100 range around 0 (-50 - 50) we would do Math.random() * 100 - 50. In the code below I’ve abstracted this to Math.random() * this.randomRange - this.randomRange/2.

Example

Here I’ve got dots created and placed randomly, with randomly set scale and alpha. On every frame each dot has a random velocity applied to it’s x and y coordinates.
The yellow dot is the simple example (code below) and the rest are included in the complex example below.

Actionscript

Simple Example:

Complex example:

Download

randomMotion.fla

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StomperNet’s Scrutinizer Update v1.0

June 16, 2008 at 6:58 pm · 133 views · Filed under portfolio, work

StomperNet’s Scrutinizer has recieved some updates!

• New help documentation
• Keyboard Shortcut Functionality
  • saving a screenshot
  • bookmarking a page
  • toggling the visualization
  • toggle auto-zoom
• Aesthetic improvements
• Performance optimizations
• Improved auto-update.

If you’re wondering what the heck StomperNet’s Scrutinizer is:

What is it?

The Scrutinizer is a web browser, based upon the Adobe AIR toolkit and the WebKit browser, that offers a simulation of the human visual system. Specifically, it illustrates the distinction between foveal and peripheral vision in visual acuity and color perception. Using this simulation, you can get a better idea of how users interact with your site design. We explain this, and some of the succes we’ve had, in a 30 minute video called Click Fu. It’s also a great tool for observing users interacting with your pages. By slowing them down, the Scrutinizer makes it easier for you to figure out what information the user is consuming and what actions they are considering. Learn about other ways to use the tool at our Top Ten list.

How it Works

The Scrutinizer browser applies a visual filter to where the mouse is located, simulating foveal vision centered around the mouse. For parts of the screen far away from themouse, the display deteriorates into lower resolution, both in detail and color. You can use the browser to get a better understanding of the low level mechanics of how users interact with your site design. Attempting to accomplish a key task on your site using the Scrutinizer can be very enlightening. Watching a user unfamiliar with your site attempt a key task with the Scrutinizer is even better at revealing how your site design affects the way the user extracts meaning from your presentation. Learn more in the Click Fu video, covering practical examples of improved e-commerce, or the 52 second ” Your Vision is an Illusion“, presenting a dramatic illustration of foveal vision. Finally, check out using the Scrutinizer for a findability challenge on Amazon.com.

Top Ten Things You Can Do with the Scrutinizer

1. Simulate eye tracking in a usability task
2. Assess the ease of use of multi-step processes
3. Give your designer a fresh pair of eyes
4. Find out what “pops” in your design
5. Conduct findability challenges
6. Ask: does your visual grid work?
7. Evaluate your site’s contrast levels
8. Insure learnability in your template
9. Avoid button gravity errors
10. Tell the story of how your eyes work

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Style htmlText with CSS in your Actionscript | Flash/CSS Tutorial

June 5, 2008 at 8:03 pm · 2,120 views · Filed under tutorial

Overview

In flash you can have text areas that are rendered as html. You can also apply formatting styles to this html. This will show a simple example on how to apply css to html text in flash. I’ll do a simple anchor tag style to show you the ropes. We’ll style a link to be underlined and then when you hover or mouse over it, we’ll change the color. It’s a design style that is widely used online in html, but flash doesn’t natively do it. As a matter of fact, flash doesn’t even natively underline links.

Steps

1. Import TextField.StyleSheet
2. create a style sheet object: var myCSS:StyleSheet = new StyleSheet();
3. Specify your styles: myCSS.setStyle(”a:link”, {color:’#0000CC’,textDecoration:’underline’});
4. Ensure that the text box is html enabled: myHTML.htmlText = myHTMLText;
5. Apply the style sheet object to your html text box: myHTML.styleSheet = myCSS;

Example

Actionscript

Download

open source flashhtmlcss.zip

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Calling actionscript functions through HTML text | asfunction Tutorial

May 30, 2008 at 7:56 pm · 1,924 views · Filed under tutorial

Add this to the list of things I should have already known!

Story

I’ve got an html enabled text box and was trying to devise a way that I could have a hyperlink anchor tag not link to a webpage but actually do something flash. It didn’t seem possible, and I looked through all the different html css combinations I could think of. I finally resorted to trying to use some component like Deng or FlashML. FlashML had a smaller footprint and seemed to do more what I wanted, so I started investigating it. To my dismay, the support for it was few and far between. I found an older version that came with an example file and then a newer one with some documentation but no example and I found no examples any where else. So Lee, if you ever read this, some new examples could be nice. In the documentation I was reading about a functino called AddASFunction and the example html line was very interesting:

I started looking through the rest of the documentation to find this asfunction use. But all it had was:
The href attribute can include the asfunction string which allows the link provided by the anchor to call a function in Flash. More of this can be found within the addASFunction definition in this help document.
I knew I was on to something, asfunction. So a quick google search and I found the official doc! I was shocked that I had the tool to do this the whole time! Well, shocked and feeling like an idiot for never having heard of it before. I knew it could be done somehow, but had no idea that it was already a feature of htmlText in flash! So now that you know my embarrassing story, I’ll let you in on the secret.

Overview

In flash, you can allow html text within a text area. You either set the text html property as true with actionscript (my_txt.html = true;) or click the ‘Render text as HTML’ button in the properties window of the text area. You cannot enable html text on static text areas however. You can have links and various html elements (but not full html). Usually links have a url in the href attribut of the anchor tag, but flash will read a special value of ‘asfunction’ which specifies that an actionscript function is to be called rather than a url. The correct syntax is asfunction followed by a colon and then the name of the actionscript function to be called, optionally followed by a comma and a possible single argument to be passed to the specified function (href=”asfunction:functionName,argument”).

Steps

1. Enable html in the text box.
2. Have your function (ex: functionName) ready to be called from the html link.
3. Give the href attribute of the anchor tag a property “asfunction:functionName,argument” Notice that the official documentation calls for spaces after punctuation, but any space you put after the colon (:) or comma (,) will be sent to the function in the argument, or will expect a space in the function name and give you a headache.

Example

In this example I’ve got an html enabled text box with 4 links. The first is a standard link (I hope you know what that does). The next link calls an actionscript function with asfunction. The third link sends a single argument to another function. And the last link sends multiple arguments to yet another function. Wait! Multiple arguments? I thought I said only one was supported, well this example shows how to send multiple arguments disguised as a single param and parse them. It’s pretty simple actually.

Actionscript

HTML

Download Source

asfunction.zip

Comments