Using ActionScript in Flash Trademarks Add Life to the Web, Afterburner, Aftershock, Andromedia, Allaire, Animation PowerPack, Aria, Attain, Authorware, Authorware Star, Backstage, Bright Tiger, Clustercats, ColdFusion, Contribute, Design In Motion, Director, Dream Templates, Dreamweaver, Drumbeat 2000, EDJE, EJIPT, Extreme 3D, Fireworks, Flash, Flash Lite, Flex, Fontographer, FreeHand, Generator, HomeSite, JFusion, JRun, Kawa, Know Your Site, Knowledge Objects, Knowledge Stream, Knowledge Track, LikeMinds, Lingo, Live Effects, MacRecorder Logo and Design, Macromedia, Macromedia Action!, Macromedia Breeze, Macromedia Flash, Macromedia M Logo and Design, Macromedia Spectra, Macromedia xRes Logo and Design, MacroModel, Made with Macromedia, Made with Macromedia Logo and Design, MAGIC Logo and Design, Mediamaker, Movie Critic, Open Sesame!, Roundtrip, Roundtrip HTML, Shockwave, Sitespring, SoundEdit, Titlemaker, UltraDev, Web Design 101, what the web can be, and Xtra are either registered trademarks or trademarks of Macromedia, Inc. and may be registered in the United States or in other jurisdictions including internationally. Other product names, logos, designs, titles, words, or phrases mentioned within this publication may be trademarks, service marks, or trade names of Macromedia, Inc. or other entities and may be registered in certain jurisdictions including internationally. Third-Party Information This guide contains links to third-party websites that are not under the control of Macromedia, and Macromedia is not responsible for the content on any linked site. If you access a third-party website mentioned in this guide, then you do so at your own risk. Macromedia provides these links only as a convenience, and the inclusion of the link does not imply that Macromedia endorses or accepts any responsibility for the content on those third-party sites. Speech compression and decompression technology licensed from Nellymoser, Inc. (www.nellymoser.com). SorensonTM SparkTM video compression and decompression technology licensed from Sorenson Media, Inc. Opera ® browser Copyright © 1995-2002 Opera Software ASA and its suppliers. All rights reserved. Apple Disclaimer APPLE COMPUTER, INC. MAKES NO WARRANTIES, EITHER EXPRESS OR IMPLIED, REGARDING THE ENCLOSED COMPUTER SOFTWARE PACKAGE, ITS MERCHANTABILITY OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. THE EXCLUSION OF IMPLIED WARRANTIES IS NOT PERMITTED BY SOME STATES. THE ABOVE EXCLUSION MAY NOT APPLY TO YOU. THIS WARRANTY PROVIDES YOU WITH SPECIFIC LEGAL RIGHTS. THERE MAY BE OTHER RIGHTS THAT YOU MAY HAVE WHICH VARY FROM STATE TO STATE. Copyright © 2004 Macromedia, Inc. All rights reserved. This manual may not be copied, photocopied, reproduced, translated, or converted to any electronic or machine-readable form in whole or in part without prior written approval of Macromedia, Inc. Acknowledgments Director: Erick Vera Project Management: Julee Burdekin, Erick Vera Writing: Jay Armstrong, Jody Bleyle, Mary Burger, Francis Cheng, Jen deHaan, Stephanie Gowin, Phillip Heinz, Shimul Rahim, Samuel R. Neff Managing Editor: Rosana Francescato Editing: Linda Adler, Mary Ferguson, Mary Kraemer, Noreen Maher, Antonio Padial, Lisa Stanziano, Anne Szabla Production Management: Patrice O'Neill Media Design and Production: Adam Barnett, Christopher Basmajian, Aaron Begley, John Francis Second Edition: June 2004 Macromedia, Inc. 600 Townsend St. San Francisco, CA 94103 CONTENTS INTRODUCTION: Getting Started with ActionScript ....................... 7 7 7 7 9 9 9 Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using the documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typographical conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terms used in this document. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHAPTER 1: What's New in Flash MX 2004 ActionScript. . . . . . . . . . . . . . . . . . 11 11 12 13 13 20 21 21 Updating Flash XML files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New and changed language elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New security model and legacy SWF files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Porting existing scripts to Flash Player 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ActionScript editor changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Debugging changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . New object-oriented programming model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHAPTER 2: ActionScript Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 24 24 28 34 39 44 49 57 58 60 61 Differences between ActionScript and JavaScript . . . . . . . . . . . . . . . . . . . . . . . . . Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . About data types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assigning data types to elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . About variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using operators to manipulate values in expressions . . . . . . . . . . . . . . . . . . . . . . . Specifying an object's path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using condition statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using built-in functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Creating functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHAPTER 3: Using Best Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 66 69 82 99 Working with FLA files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General coding conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ActionScript coding standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using classes and ActionScript 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Behaviors conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Screens conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Video conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Performance and Flash Player . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Guidelines for Flash applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Projects and version control guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Guidelines for accessibility in Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Advertising with Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 CHAPTER 4: Writing and Debugging Scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Controlling when ActionScript runs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Using the Actions panel and Script window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Using the ActionScript editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Unicode support for ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Debugging your scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Using the Output panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Updating Flash Player for testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 CHAPTER 5: Handling Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Using event handler methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Using event listeners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Using button and movie clip event handlers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Broadcasting events from component instances . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Creating movie clips with button states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Event handler scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 Scope of the this keyword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 CHAPTER 6: Creating Interaction with ActionScript . . . . . . . . . . . . . . . . . . . . . 179 About events and interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Controlling SWF file playback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Creating interactivity and visual effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Deconstructing a sample script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 CHAPTER 7: Using the Built-In Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 About classes and instances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Overview of built-in classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 CHAPTER 8: Working with Movie Clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 About controlling movie clips with ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . 205 Calling multiple methods on a single movie clip . . . . . . . . . . . . . . . . . . . . . . . . . 206 Loading and unloading additional SWF files . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Specifying a root Timeline for loaded SWF files . . . . . . . . . . . . . . . . . . . . . . . . . 208 Loading JPEG files into movie clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Changing movie clip position and appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Dragging movie clips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Creating movie clips at runtime. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 4 Contents Adding parameters to dynamically created movie clips . . . . . . . . . . . . . . . . . . . . Managing movie clip depths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Drawing shapes with ActionScript. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using movie clips as masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . About masking device fonts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Handling movie clip events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assigning a class to a movie clip symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Initializing class properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHAPTER 9: Working with Text 213 215 216 217 218 218 218 219 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 221 223 224 226 236 244 Using the TextField class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Creating text fields at runtime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using the TextFormat class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Formatting text with Cascading Style Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using HTML-f ...