Flashvars and actionscript 3! Flashvar is a way that in your html embed codes (object tags) you can send variables and values into your swf file. These variables can then be grabbed internally and used your programming! Examples of these could be images that you want to use in your swf but don’t want to import or hardcode them into the flash file or paths to xml or flv files to use as well. Actionscript 3 has a different procedure than as2 did as to how you read these flashvars from the actionscript side. The embed codes and html side of things are still the same, but in case your new to actionscript altogether, I’ll give an example of the html as well.

In actionscript 3 we use the loaderInfo object to access the flashvars. The parameters Object of the loaderInfo will contain all the flashvar variables and values.

As an example of something that is visual I’ve created this little app to read some options from flashvars about colors. An app that will read a list of colors and update a box that is on the stage already to those colors with the specified delay. I always have fun with randomness so I threw in the option for random colors as well. This file looks for certain flashvars: color, loop, delay and random. These are the keys or names of the variables and they are followed by the values you want them to hold. Note that flashvars can be set in any order, so you don’t have to start with color and end with random.

In this example I’m looking for 4 flashvars specifically (in any order):

• colors:String – a comma delimited list of hex colors or simply a string “random” for randomly generated colors (the hex for black #000000 needs to be 0×000000 in flash) (default is random)
• loop:Boolean – whether or not to repeat these colors (default is true)
• delay:Number – the delay between colors (in seconds). (default is 1 second)
• random:Boolean – determines whether to cycle through colors in given order or randomize. selecting random overrides the loop to true. (default is false)

This is much more than is required for this example, but I was having fun playing with random colors and timing and options. I figured it diesn’t hurt to show the effect you can have with a couple different variables on one file. Here is an example using the object tags above:

And here are some more (please don’t have a seizure!)

Here’s the full source if you’re interested:

I’ve written a tutorial which is published over at flash.tutsplus. This tutorial demonstrates how to create a horizontally scrolling image viewer and covers xml parsing, loading and resizing external images, and creating intuitive and responsive scrolling!

So check out the Tutorial to Create a Responsive Image Scroller in ActionScript 3.0 over at flash.tutsplus.com!

You’ll find full source code available for download as well as the demo files and step by step milestones all throughout the tutorial.

Here is a preview of a file I’m writing a tutorial for. It’s nothing groundbreaking, but it deals with many normal tasks and will show my process a bit. This tutorial will show how to create a horizontally scrolling image viewer. It will cover xml loading & parsing, loading & resizing external images to fit into a scrollable container, and creating intuitive and responsive scrolling!

Let me know what you think, and if there’s anything you want specifically mentioned/explained in it I’ll do my best! Or if you have any ideas of how this could be improved.

Update: The article/tutorial has now been published follow the link to theTutorial to Create a Responsive Image Scroller in ActionScript 3.0

One of the best features of the flash player if you’re doing video is the fullscreen functionality. It has been a question I’ve heard repeatedly. There are limits to what you can do in fullscreen. Such as minimal keyboard support while in fullscreen. But it is perfect for a video player! Who doesn’t want to see a video expanded to full screen mode?

There are a couple things to consider when coding fullscreen into your flash. Remember the hard coded “Press Esc to exit full screen mode.” that Adobe has placed into the flash player. This is untouchable by developers, and the function returns to normal stage display state. So we call the function to go fullscreen, but the exit fullscreen has already been written for us. This can pose a problem though, when we need the player to do something when we exit fullscreen, that is when we want it to do something more than the generic black box function adobe includes.

Steps

1. specify stage properties
2. full screen button and listeners
3. stage fullscreenEvent listener
4. (functions for each)
5. allowfullscreen = true

Example

1. Stage properties exist that allow us to specify what type of fullscreen we want.  We can have the swf scale to fit the fullscreen area (StageScaleMode.SHOW_ALL), not scale at all (StageScaleMode.NO_SCALE), skew to fit fullscreen (StageScaleMode.EXACT_FIT), and scale to fill fullscreen area (Stage.ScaleMode.NO_BORDER).  We may also edit the alignment of the stage in the fullscreen area; in this example I’m using TOP, but refer to documentation for more options

2. Adobe has placed restrictions on when a swf can enter fullscreen, and has deemed that it must result from a user interaction, a mouse click or keystroke. So create your buttons (or keyListeners). I prefer to have one button to enter fullscreen and another to exit, and have them both call the same function to toggle fullscreen. It gives a clearer communication to the user. I then control the visibility of these buttons depending on the current display state of the stage.

3. Another listener to watch the stage dispaly state. stage.addEventListener(FullScreenEvent.FULL_SCREEN, onFullscreenChange); This will fire every time the stage display state changes. We need this because as I mentioned earlier, when entering fullscreen we use our own function, but the ‘hit esc to exit fullscreen’ functionality is built into the flash player, we can’t update our stage layout or button visibility without watching to catch when the display state is changed. Using this method we can update our stage layout any and every time.

4. Of course flesh out the fullscreenToggle function to include anything else you need.

5. Lastly, for a SWF file embedded in an HTML page, the HTML code to embed Flash Player must include a ‘param’ tag and ‘embed’ attribute with the name ‘allowFullScreen’ and value ‘true’, like this:

<object>
    ...
    <param name="allowFullScreen" value="true" />
    <embed ... allowfullscreen="true" />
</object>

The allowFullScreen tag enables full-screen mode in the player. If you do everything else right and don’t include this in your embed codes, fullscreen will not work. The default value is false if this attribute is omitted. Note the viewer must at least have Flash Player version 9,0,28,0 installed to use full-screen mode. Also note that  the simple (ctrl + enter) testing your movie in flash will not allow fullscreen either, you must use the debug tester (ctrl + shift + enter) … or go open the published swf in flash player.

Actionscript

Source

Download fullscreen_tut.fla file

I have had feedback that certain random movements I program are a bit “jumpy”. Such as my old brownian movement tutorial and I really noticed it in my last tutorial, the parallax 3d depth effect tutorial. I’ve been thinking about it and looking around at some code and now have this updated brownian movement example! Updated for as3 as well as making it less jumpy.

First I’ll explain what I’ve found to be the reason of the jumpiness. And then explain and show what can be done to make this movement be more smooth.

So to examine the old jumpy code. Jump back to the first version post here. I think my technique was well thought out here, but the application was poor. It was recalculating the velocities every single frame and then incrementing the coordinate positions by the newly calculated velocities… This is where the jumpiness comes in. Even though the random value was named velocity, it didn’t actually affect the dot’s velocity, it was just a variable that stored the random value used to move the current x/y coordinates.
To help the animation be more smooth, the velocity needs to be more smooth. The velocity, rather than calculating it fresh each frame, should be randomly modified each frame. And then the new velocity will calculate the new ‘random’ position. Another addition is to introduce another force to dampen the velocity over time, so things don’t get too crazy…

Steps:

1. Modify velocity randomly
2. With velocity and current position, calculate a new position
3. Dampen the velocity

Example:

Here I have a velocity for the x coordinate as well as the y. I’m also experimenting with a z velocity. This adjusts the alpha and scale for depth perception. It doesn’t actually edit the depth or layer the dot shows up on the stage however… keyword here: experimenting.

Actionscript:

Source:

as3random_brownian_movement.fla