Tag Archives: howto

FlashSize – simple browser resizing

How to allow SWFs to display at 100% width/height in your browser – but enforce a minimum width and height, in case of a smaller browser window size than you’ve designed for.

Until recently, I’d used other Flash/browser resize managers when I needed to ensure a SWF is embedded in HTML at 100% width and height, but with support for a minimum width and height setting. But I recently needed a solution the didn’t depend on external JavaScript, due to not having control of the page the SWF is embedded in.


 

With my simple FlashSize script, all you need do is call:


 

MouseWheelTrap – how to stop simultaneous Flash / browser scrolling

Update: This project is now hosted at GitHub. There are currently known issues with Chrome’s PPAPI plugin architecture. USE AT YOUR OWN RISK.

I recently stumbled over a new AS3 gotcha that seems to be bugging a lot of the Flash community. Apparently a new ‘feature’ of AS3, whereby using the mousewheel inside an embedded Flash movie still scrolls the surrounding browser window (if it has enough content, that is).

This didn’t happen in AS2. If a Flash movie had focus, mousewheel events weren’t sent to the browser window. It wasn’t a problem in FireFox either, until a recent update and adversely affects any AS3 Flash app embedded in an HTML page where you might want to scroll or zoom with the mousewheel while over the Flash, instead of the scrolling the browser window.

So, I decided to cook up some code to fix this. While it’s early version and isn’t perfect, it suits my purposes, is easy to set up and doesn’t require any external JavaScript – so I’d thought I’d share it with the world, in case Adobe never get around to addressing this ‘feature’.

Introducing MouseWheelTrap. A handy little utility class that traps mousewheel events while the mouse is over the Flash, so your app scrolls how it was intended to. I’ve tested it with SWFObject on PC IE and FireFox, but not with SWFMacMouseWheel on Mac (if someone could tell me if it works). I decided against using jQuery for trapping mouse events, partly out of laziness, partly because many people have no control over the HTML that embeds their Flash app and therefore can’t add custom JavaScript.

Setting up MouseWheelTrap is easy:

  • Download the MouseWheelTrap ZIP package, or just the AS file.
  • Unzip the package and have a look at the demo, or just take the MouseWheelTrap.as file and put it in the com.spikything.utils folder into your own project or classpath.
  • Import the utility and set it up somewhere in your main class like so:

Simple huh? Let me know how you get on…

Local playback security in FlashDevelop and Flash CS3 / CS4

I’ve seen a few people get into a pickle over this one. When you’re developing and testing locally, you need to set the ‘Local Playback Security’ setting (sometimes referred to as the ‘use network services’ option) depending on whether you wish to access local external files (e.g. XML files, or images) or some other server (e.g. your dev backend server). You can’t access both from a locally running SWF anymore, since it’s a security risk. So here’s how to set that option in Flash CS3 / CS4 or from within FlashDevelop.

How to embed fonts in pure AS3

On my travels as a contractor, I’ve seen various methods used for embedding fonts in ActionScript 3 projects (code embedded, creating font SWFs, runtime loading, etc). Each of them has its own merits (and limitations), but generally you’re looking for something that’s easy to do, easy to maintain (for others, not just yourself) and of course that works!

So, here’s the method I use for pure AS3 projects I compile with the Flex SDK. I embed the TTF or OTF file in a ‘Style’ class and include those font files in the CVS/SVN repository too – it does my head in when fonts go missing, because a designer can’t remember which font they used:

Through experience, this seems to be the most robust and maintainable way of dealing with fonts (not to throw out more flexible, but perhaps less robust ways, such as runtime loading), especially when you need control of the unicode ranges you are embedding – which I have included for reference.

How to use ExternalInterface to integrate AS3 with JavaScript

Here’s a quick snippet of code for setting up intercommunication between a SWF and JavaScript, using ExternalInterface:

Attaching a Bitmap – AS2 vs AS3

A common task that has changed drastically in ActionScript 3.0 is loading a library image via its linkageID into a BitmapData object and attaching it to a movieclip. In ActionScript 2.0, this can be done like so:

In ActionScript 3.0 movieclips and bitmaps are not attached or created like this – everything is created with the new keyword. Also, a BitmapData object should be dropped into a new Bitmap, which can be added to the stage with the all-important addChild() method.

Since a library bitmap inherits from BitmapData, you now set the class of the bitmap its Linkage Properties in Flash CS3, instantiate it and wrap it in a Bitmap object that you add to the stage:

Attaching a bitmap in AS3

Where ‘Butterfly’ refers to the bitmap library item you’ve given the class definition ‘Butterfly’. The Base class is generated automatically. These five lines of code can be shortened to one, but is less readable:

Note that in Flex Builder, unlike Flash CS3, you would embed an image using the embed meta tag, associating it with a variable, instead of its Linkage Properties dialog:

Building SWFs in Flex Builder is a whole different topic – so stay tuned!