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Adobe Flash ActionScript 2.0 User guide

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LEARNING ACTIONSCRIPT
™
2.0
IN FLASH
®
© 2007 Adobe Systems Incorporated. All rights reserved.
Learning ActionScript 2.0 in Adobe® Flash®
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3
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
System requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Updating Flash XML files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
About the documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Additional resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Chapter 1: What’s New in Flash ActionScript . . . . . . . . . . . . . . . . 19
New in ActionScript 2.0 and Flash Player 9.x . . . . . . . . . . . . . . . . . . . . . 19
New in ActionScript 2.0 and
Flash Player 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Changes to security model for locally installed SWF files. . . . . . . . . . 28
Chapter 2: About ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
What is ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
About choosing between ActionScript 1.0 and ActionScript 2.0 . . . 33
Understanding ActionScript and Flash Player . . . . . . . . . . . . . . . . . . . 34
Chapter 3: Data and Data Types. . . . . . . . . . . . . . . . . . . . . . . . . . 35
About data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
About data types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
About variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Organizing data in objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
About casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Chapter 4: Syntax and Language Fundamentals . . . . . . . . . . . . . 77
About syntax, statements, and expressions . . . . . . . . . . . . . . . . . . . . . . .78
About dot syntax and target paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
About language punctuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
About constants and keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
About statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
About arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
About operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
4Contents
Chapter 5: Functions and Methods . . . . . . . . . . . . . . . . . . . . . . . 163
About functions and methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Understanding methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Chapter 6: Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
About object-oriented programming and Flash . . . . . . . . . . . . . . . . . . 188
Writing custom class files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
About working with custom classes in an application . . . . . . . . . . . . . 199
Example: Writing custom classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .223
Example: Using custom class files in Flash . . . . . . . . . . . . . . . . . . . . . .236
Assigning a class to symbols in Flash . . . . . . . . . . . . . . . . . . . . . . . . . . .239
Compiling and exporting classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Understanding classes and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243
About top-level and built-in classes . . . . . . . . . . . . . . . . . . . . . . . . . . . .246
About working with built-in classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .256
Chapter 7: Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
About inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .263
About writing subclasses in Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .265
Using polymorphism in an application . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Chapter 8: Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
About interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .275
Creating interfaces as data types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Understanding inheritance and interfaces . . . . . . . . . . . . . . . . . . . . . . .282
Example: Using interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .283
Example: Creating a complex interface . . . . . . . . . . . . . . . . . . . . . . . . .285
Chapter 9: Handling Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
About ActionScript and events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .292
Using event handler methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .293
Using event listeners. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .296
Using event listeners with components . . . . . . . . . . . . . . . . . . . . . . . . .298
Using button and movie clip event handlers . . . . . . . . . . . . . . . . . . . . 300
Broadcasting events from component instances. . . . . . . . . . . . . . . . 305
Creating movie clips with button states . . . . . . . . . . . . . . . . . . . . . . . . 305
Event handler scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Scope of the this keyword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Using the Delegate class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Contents 5
Chapter 10: Working with Movie Clips . . . . . . . . . . . . . . . . . . . . . 313
About controlling movie clips with ActionScript . . . . . . . . . . . . . . . . . .314
Calling multiple methods on a single movie clip . . . . . . . . . . . . . . . . . .316
Loading and unloading SWF files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .316
Changing movie clip position and appearance . . . . . . . . . . . . . . . . . . .319
Dragging movie clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Creating movie clips at runtime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .321
Adding parameters to dynamically created movie clips. . . . . . . . . . . 325
Managing movie clip depths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
About caching and scrolling movie clips with ActionScript . . . . . . . 330
Using movie clips as masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Handling movie clip events. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Assigning a class to a movie clip symbol. . . . . . . . . . . . . . . . . . . . . . . . 339
Initializing class properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Chapter 11: Working with Text and Strings . . . . . . . . . . . . . . . . 343
About text fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
About loading text and variables into text fields . . . . . . . . . . . . . . . . . 353
Using fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
About font rendering and anti-alias text . . . . . . . . . . . . . . . . . . . . . . . . 367
About text layout and formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
Formatting text with Cascading Style Sheet styles . . . . . . . . . . . . . . 382
Using HTML-formatted text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
Example: Creating scrolling text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .410
About strings and the String class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Chapter 12: Animation, Filters, and Drawings . . . . . . . . . . . . . . 429
Scripting animation with ActionScript 2.0 . . . . . . . . . . . . . . . . . . . . . . 430
About bitmap caching, scrolling, and performance . . . . . . . . . . . . . 440
About the Tween and TransitionManager classes . . . . . . . . . . . . . . .441
Using filter effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456
Working with filters using ActionScript . . . . . . . . . . . . . . . . . . . . . . . . 463
Manipulating filter effects with code . . . . . . . . . . . . . . . . . . . . . . . . . . . 489
Creating bitmaps with the BitmapData class . . . . . . . . . . . . . . . . . . . . 493
About blending modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496
About operation order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498
Drawing with ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499
Understanding scaling and slice guides . . . . . . . . . . . . . . . . . . . . . . . . .514
6Contents
Chapter 13: Creating Interaction with ActionScript . . . . . . . . . . 519
About events and interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520
Controlling SWF file playback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520
Creating interactivity and visual effects . . . . . . . . . . . . . . . . . . . . . . . . 524
Creating runtime data bindings using ActionScript . . . . . . . . . . . . . . .537
Deconstructing a sample script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .546
Chapter 14: Working with Images, Sound, and Video . . . . . . . 549
About loading and working with external media . . . . . . . . . . . . . . . . 550
Loading external SWF and image files. . . . . . . . . . . . . . . . . . . . . . . . . . 551
About loading and using external MP3 files . . . . . . . . . . . . . . . . . . . . 555
Assigning linkage to assets in the library . . . . . . . . . . . . . . . . . . . . . . . 559
About using FLV video. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560
About creating progress animations for media files. . . . . . . . . . . . . . 580
Chapter 15: Working with External Data . . . . . . . . . . . . . . . . . . 589
Sending and loading variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590
Using HTTP to connect to server-side scripts . . . . . . . . . . . . . . . . . . 594
About file uploading and downloading . . . . . . . . . . . . . . . . . . . . . . . . . 600
About XML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 608
Sending messages to and from Flash Player . . . . . . . . . . . . . . . . . . . . 617
About the External API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 621
Chapter 16: Understanding Security . . . . . . . . . . . . . . . . . . . . . . 631
About compatibility with previous Flash Player security models . . . 631
About local file security and Flash Player. . . . . . . . . . . . . . . . . . . . . . . .633
Restricting networking APIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .648
About domains, cross-domain security, and SWF files . . . . . . . . . . 650
Server-side policy files for permitting access to data . . . . . . . . . . . . .657
HTTP to HTTPS protocol access between SWF files . . . . . . . . . . . .662
Chapter 17: Best Practices and Coding Conventions for
ActionScript 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665
Naming conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .666
Using comments in your code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677
ActionScript coding conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .679
ActionScript and Flash Player optimization . . . . . . . . . . . . . . . . . . . . 695
Formatting ActionScript syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .697
Contents 7
Appendix A: Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707
Appendix B: Deprecated Flash 4 operators . . . . . . . . . . . . . . . . 713
Appendix C: Keyboard Keys and Key Code Values . . . . . . . . . . 715
Appendix D: Writing Scripts for Earlier Versions of Flash Player . .
721
About targeting earlier versions of Flash Player . . . . . . . . . . . . . . . . . . 721
Using Flash to create content for Flash Player 4 . . . . . . . . . . . . . . . . 722
Appendix E: Object-Oriented Programming with ActionScript 1.0.
725
About ActionScript 1.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726
Creating a custom object in ActionScript 1.0 . . . . . . . . . . . . . . . . . . . . 728
Assigning methods to a custom object in ActionScript 1.0. . . . . . . . 729
Defining event handler methods in ActionScript 1.0 . . . . . . . . . . . . . 730
Creating inheritance in ActionScript 1.0 . . . . . . . . . . . . . . . . . . . . . . . . 732
Adding getter/setter properties to objects in ActionScript 1.0 . . . . . 734
Using Function object properties in ActionScript 1.0 . . . . . . . . . . . . . 735
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .737
8Contents
9
Introduction
Adobe Flash CS3 Professional is the professional standard authoring tool for producing high-
impact web experiences. ActionScript is the language you use to add interactivity to Flash
applications, whether your applications are simple animated SWF files or more complex rich
Internet applications. You don’t have to use ActionScript to use Flash, but if you want to
provide basic or complex user interactivity, work with objects other than those built into Flash
(such as buttons and movie clips), or otherwise turn a SWF file into a more robust user
experience, you’ll probably want to use ActionScript.
For more information, see the following topics:
Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Updating Flash XML files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
System requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
About the documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Additional resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Intended audience
This manual assumes that you have already installed Flash and know how to use the user
interface.You should know how to place objects on the Stage and manipulate them in the
Flash authoring environment. If you have used a scripting language before, ActionScript will
seem familiar. But if you’re new to programming, ActionScript basics are easy to learn. You
can start with simple commands and build more complexity as you progress. You can add a lot
of interactivity to your files without having to learn (or write) a lot of code.
10 Introduction
System requirements
ActionScript 2.0 does not have any system requirements in addition to Flash.
Flash CS3 Professional introduces ActionScript 3.0. Flash Player 9 and ActionScript 3.0 are
the default publishing settings for Flash. This manual provides information on how to use
ActionScript 2.0 with Flash. You must change the publishing settings for your Flash files to
Flash Player 9 and ActionScript 2.0. If you do not change the default settings, explanations
and code samples in the documentation might not work correctly. If you develop applications
for earlier versions of Flash Player, see Appendix D, “Writing Scripts for Earlier Versions of
Flash Player,” on page 721.
Updating Flash XML files
It is important that you always have the latest Flash XML files installed. Adobe sometimes
introduces features in dot releases (minor releases) of Flash Player. When such a release is
available, you should update your version of Flash to get the latest XML files. Otherwise, the
Flash compiler might generate errors if you use new properties or methods that were
unavailable in the version of Flash Player that came with your Flash installation.
For example, Flash Player 7 (7.0.19.0) contained a new method for the System object,
System.security.loadPolicyFile. To access this method, you must use the Player
Updater installer to update all the Flash players that are installed with Flash. Otherwise, the
Flash compiler displays errors.
Remember that you can install a Player Updater that is one or more major versions ahead of
your version of Flash. By doing this, you will get the XML files that you need but shouldn’t
have any compiler errors when you publish to older versions of Flash Player. Sometimes new
methods or properties are available to older versions, and having the latest XML files
minimizes the compiler errors you get when you try to access older methods or properties.
About the documentation 11
About the documentation
This manual provides an overview of ActionScript syntax and information on how to use
ActionScript when working with different types of objects. For details on the syntax and usage
of every language element, see the ActionScript 2.0 Language Reference.
For more information, see the following topics:
■ “Learning ActionScript 2.0 book overview” on page 11
■ “About the sample files” on page 14
■ “Terms used in this document” on page 13
■ “Copy and paste code” on page 13
Learning ActionScript 2.0 book overview
The following list summarizes the contents of this manual:
■ Chapter 1, “What’s New in Flash ActionScript,” describes features that are new in
ActionScript, changes to the compiler and debugger, and the new programming model for
the ActionScript 2.0 language.
■ Chapter 2, “About ActionScript,” outlines what the ActionScript language is and details
how to choose between which version of ActionScript to use.
■ Chapter 3, “Data and Data Types,” describes the terminology and basic concepts about
data, data types, and variables. You use these concepts throughout the manual.
■ Chapter 4, “Syntax and Language Fundamentals,” describes the terminology and basic
concepts of the ActionScript language. You use these concepts throughout the manual.
■ Chapter 5, “Functions and Methods,” describes how to write different kinds of functions
and methods and how to use them in your application.
■ Chapter 6, “Classes,” describes how to create custom classes and objects in ActionScript.
This chapter also lists the built-in classes in ActionScript and provides a brief overview of
how you use them to access powerful features in ActionScript.
■ Chapter 7, “Inheritance,” describes inheritance in the ActionScript language and describes
how to extend built-in or custom classes.
■ Chapter 8, “Interfaces,” describes how to create and work with interfaces in ActionScript.
■ Chapter 9, “Handling Events,” describes a few different ways to handle events: event
handler methods, event listeners, and button and movie clip event handlers.
■ Chapter 10, “Working with Movie Clips,” describes movie clips and the ActionScript you
can use to control them.
12 Introduction
■ Chapter 11, “Working with Text and Strings,” describes the different ways you can
control text and strings in Flash and includes information on text formatting and
advanced anti-aliasing.
■ Chapter 12, “Animation, Filters, and Drawings,” describes how to create code-based
animation and images, add filters to objects, and draw using ActionScript.
■ Chapter 13, “Creating Interaction with ActionScript,” describes some simple ways in
which you can create more interactive applications, including controlling when SWF files
play, creating custom pointers, and creating sound controls.
■ Chapter 14, “Working with Images, Sound, and Video,” describes how to import external
media files, such as bitmap images, MP3 files, Flash Video (FLV) files, and other SWF
files, in your Flash applications. This chapter also provides an overview of how to work
with video in your applications, and how to create progress bar loading animations.
■ Chapter 15, “Working with External Data,” describes how to process data from external
sources using server- or client-side scripts in your applications. This chapter describes how
to integrate data with your applications.
■ Chapter 16, “Understanding Security,” explains security in Flash Player, as it pertains to
working with SWF files locally on your hard disk. This chapter also explains cross-domain
security issues, and how to load data from servers, or across domains.
■ Chapter 17, “Best Practices and Coding Conventions for ActionScript 2.0,” explains the
best practices for using Flash and writing ActionScript. This chapter also lists standardized
coding conventions, such as naming variables, and other conventions.
■ Appendix A, “Error Messages,” lists the error messages that the Flash compiler can
generate.
■ Appendix B, “Deprecated Flash 4 operators,” lists all the deprecated Flash 4 operators and
their associativity.
■ Appendix C, “Keyboard Keys and Key Code Values,” lists all the keys on a standard
keyboard and the corresponding ASCII key code values that are used to identify the keys
in ActionScript.
■ Appendix D, “Writing Scripts for Earlier Versions of Flash Player,” provides guidelines to
help you write scripts that are syntactically correct for the player version you are targeting.
■ Appendix E, “Object-Oriented Programming with ActionScript 1.0,” provides
information on using the ActionScript 1.0 object model to write scripts.
This manual explains how to use the ActionScript language. For information on the language
elements themselves, see the ActionScript 2.0 Language Reference.
About the documentation 13
Typographical conventions
This manual uses the following typographical conventions:
■ Code font indicates ActionScript code.
■ Bold code font, typically within a procedure, indicates code that you need to modify or
add to code you have already added to your FLA file. In some case, it might be used to
highlight code to look at.
■ Boldface text indicates data you need to type into the user interface, such as a filename or
instance name.
■ Italic text indicates a new term defined in the text that follows. In a file path, it might
indicate a value that should be replaced (for example, with a directory name on your own
hard disk).
Terms used in this document
The following terms are used in this manual:
■ You refers to the developer who is writing a script or application.
■ The user refers to the person who is running your scripts and applications.
■ Compile time is the time at which you publish, export, test, or debug your document.
■ Runtime is the time at which your script is running in Flash Player.
Copy and paste code
When you paste ActionScript from the Help panel into your FLA or ActionScript file, you
have to be careful about special characters. Special characters include special quotation marks
(also called curly quotation marks or smart quotation marks). These characters are not
interpreted by the ActionScript editor, so your code throws an error if you try to compile it
in Flash.
You can determine that your quotation mark characters are special characters if they do not
color-code correctly. That is, if all your strings do not change in color in the code editor, you
need to replace the special characters with regular straight quotation mark characters. If you
type a single or double quotation mark character directly into the ActionScript editor, you
always type a straight quotation mark character. The compiler (when you test or publish a
SWF file) throws an error and lets you know if there are the wrong kind (special quotation
marks or curly quotation marks) of characters in your code.
NOTE
You might also encounter special quotation marks if you paste ActionScript from other
locations, such as a web page or a Microsoft Word document.
14 Introduction
Be cautious of proper line breaks when you copy and paste code. If you paste your code from
some locations, the line of code might break in an improper location. Make sure that the color
coding of your syntax is correct in the ActionScript editor if you think line breaks might be a
problem. You might want to compare your code in the Actions panel to that in the Help panel
to see if it matches. Try turning on Word Wrap in the ActionScript editor to help solve
surplus line breaks in your code (select View > Word Wrap in the Script window, or Word
Wrap from the Actions panel pop-up menu.)
Additional resources
In addition to this manual about ActionScript, there are manuals on other Flash topics, such
as components and Adobe Flash Lite. You can access each manual in the Help panel (Help >
Flash Help), by viewing the default Table of Contents. Click the Clear button to see each
manual that’s available; for more information, see “Where to find documentation on other
subjects” on page 17.
For more information about other available resources, see the following topics:
■ “About the sample files” on page 14
■ “Where to find PDF files or printed documentation” on page 15
■ “About LiveDocs” on page 15
■ “Additional online resources” on page 16
■ “Where to find documentation on other subjects” on page 17
About the sample files
There are numerous ActionScript-based sample files available that install with Flash. These
sample files show you how code works in a FLA file; this is often a useful learning tool. The
chapters in this manual often reference these files, but we recommend that you also check out
the sample files folder on your hard disk.
The sample files include application FLA files that use common Flash functionality installed
with Flash. These applications were designed to introduce new Flash developers to the
capabilities of Flash applications, as well as show advanced developers how Flash features work
in context.
Additional resources 15
For samples of ActionScript-focused sample source files, see the Flash Samples page at
www.adobe.com/go/learn_fl_samples. Download and decompress the Samples zip file and
navigate to the ActionScript2.0 folder to access the samples. For components-focused sample
files, navigate to the ComponentsAS2 folder.
Where to find PDF files or printed documentation
If you prefer to read documentation in printed format, the PDF versions of each Help manual
are available for downloading. Go to www.adobe.com/support/documentation/ and select the
product you’re interested in. You can view or download the PDF or link to the LiveDocs
version of the manual.
Often, you can also purchase printed documentation. For updated information, go to the
Documentation support site.
About LiveDocs
You can access documentation at the LiveDocs website, in addition to accessing it from the
Help panel. The LiveDocs website contains all of the Flash Help pages and might contain
comments that clarify, update, or correct parts of the documentation. Click View Comments
on LiveDocs at the bottom of a page in the Help panel to display the equivalent page on the
LiveDocs website. Go to http://livedocs.macromedia.com to see a list of all of the available
documentation in the LiveDocs format.
Technical writers monitor the LiveDocs website. One of the advantages of LiveDocs is seeing
comments that clarify the documentation or correct any errata or issues that arise after a
software release. LiveDocs is not the place to make help requests, such as asking questions
about your code that doesn’t work, comment on problems with software or installation, or ask
how to create something with Flash. It is the correct place to provide feedback about the
documentation (for example, you notice a sentence or paragraph that could be clarified).
When you click the button to add a comment on LiveDocs, there are several points about the
kinds of comments that are acceptable on the system. Please read these guidelines closely, or
your comment might be removed from the website.
If you have a question about Flash, please ask it on the Adobe web forums: www.adobe.com/
support/forums/. The web forums are the best place to ask questions, because there are many
Adobe employees, Team Adobe volunteers, Adobe user group managers and members, and
even technical writers who monitor these forums.
16 Introduction
Engineers do not monitor the LiveDocs system but do monitor the Flash wish list. If you
think you have found a bug in the software, or you would like to request an enhancement to
Flash, please fill out the wishform at www.adobe.com/go/wish. If you report your bug or
enhancement request on LiveDocs, it will not be officially added to the bug database. You
must use the wishform instead, if you want an engineer to see your bug or request.
Remember to be careful about special characters and line breaks when you paste from the
web, including LiveDocs. Adobe has made every effort to remove all special characters from
code samples, but if you have problems pasting code, see “Copy and paste code” on page 13.
Additional online resources
There are several resources online that offer a wealth of instruction, help, and guidance to help
you learn Flash. Check the following websites often for updates:
The Adobe Developer Center website (www.adobe.com/devnet) is updated regularly with
the latest information on Flash, plus advice from expert users, advanced topics, examples, tips,
tutorials (including multipart tutorials), and other updates. Check the website often for the
latest news on Flash and how to get the most out of the program.
The Adobe Flash Support Center (www.adobe.com/support/flash) provides TechNotes,
documentation updates, and links to additional resources in the Flash community.
The Adobe Weblogs website (http://weblogs.macromedia.com) provides a list of both
Adobe employee and community weblogs (also known as blogs).
The Adobe web forums (http://www.adobe.com/support/forums/) provides numerous
forums for asking specific questions about Flash, your applications, or the ActionScript
language. The forums are monitored by Team Adobe volunteers and often visited by Adobe
employees as well. If you’re not sure where to go, or how to solve a problem, a Flash forum is
a good place to start.
The Adobe Community website (www.adobe.com/community) regularly hosts a series of live
presentations on a variety of topics by Adobe employees or community members. Check the
website often for updates.
Additional resources 17
Where to find documentation on other subjects
The following manuals offer additional information on subjects commonly associated with
ActionScript 2.0:
■ For information about the elements that compose the ActionScript language, see the
ActionScript 2.0 Language Reference.
■ For information about working in the Flash authoring environment, see How to Use Help.
■ For information about working with components, see Using ActionScript 2.0 Components.
18 Introduction
19
1
CHAPTER 1
What’s New in Flash
ActionScript
Adobe Flash CS3 Professional provides several enhancements that make it easy for you to
write robust scripts using the ActionScript language. The new features, which are discussed in
this chapter, include new language elements (see “Additions to the ActionScript language in
Flash Player 8” on page 22), improved editing tools (see “ActionScript editing changes”
on page 27), changes to the security model, and other ActionScript-related improvements to
the authoring tool.
For more information, see the following topics:
New in ActionScript 2.0 and Flash Player 9.x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
New in ActionScript 2.0 and Flash Player 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Changes to security model for locally installed SWF files. . . . . . . . . . . . . . . . . . . . . . 28
New in ActionScript 2.0 and Flash Player
9.x
Flash Player 9.x allows a user to switch the Flash Player into and out of fullscreen mode. The
following items support this new feature:
■ Stage.displayState property
■ Stage.onFullScreen event handler
■ allowFullScreen parameter in the object and embed HTML tags
For more information, see ActionScript 2.0 Language Reference.
Flash Player 9.x also introduces a new FileReference event,
onUploadCompleteData. This
event can be invoked after a server receives a successful upload. For more information on this
new item, see ActionScript 2.0 Language Reference.
20 What’s New in Flash ActionScript
New in ActionScript 2.0 and
Flash Player 8
The ActionScript language has grown and developed since its introduction several years ago.
With each new release of Flash, additional keywords, objects, methods, and other language
elements were added to ActionScript. There are also ActionScript-related improvements to
the Flash 8 authoring environments. Flash Basic 8 and Flash Professional 8 introduced several
new language elements for expressive features, such as filters and blending modes, and
application development, such as JavaScript integration (ExternalInterface) and file input and
output (FileReference and FileReferenceList).
This section provides an overview of the ActionScript language elements and classes that are
new or changed in Flash 8 and ActionScript-related improvements to the authoring tool. For
a list of specific additions to ActionScript 2.0, see “Additions to the ActionScript language in
Flash Player 8” on page 22. To use any of the new language elements in your scripts, you must
target Flash Player 8 when you publish your documents.
The following features were added to both Flash Basic 8 and Flash Professional 8 (unless
noted otherwise):
■ ActionScript editor enhancements let you show hidden characters in your scripts. For
more information, see “Display hidden characters” in Using Flash.
■ Debug options are now available in the Script window, as well as the Actions panel, for
ActionScript files.
■ The Configuration directory that includes XML files and Class files is reorganized. See
“Configuration folders installed with Flash” in Using Flash for details.
■ You can set a preference to reload modified script files when working on an application,
which helps you avoid working with older versions of script files, and overwriting newer
script files. For more information, see “Set ActionScript preferences” in Using Flash.
■ The Script window feature is available in Flash. That means you can now create an
ActionScript file in either program.
■ Script Assist (similar to Normal Mode in earlier editions of Flash) helps you code without
needing to understand syntax. For more information on Script Assist, see “About Script
Assist mode” in Using Flash.
■ You can load new kinds of image files at runtime, which include progressive JPEG images,
and non-animated GIF and PNG files. If you load an animated file, the first frame of the
animation appears.
■ You can assign linkage identifiers to bitmap and sound files stored in the Library, which
means that you can attach images to the Stage or work with these assets in shared libraries.
/