Learning ActionScript 2.0 in Flash Trademarks 1 Step RoboPDF, ActiveEdit, ActiveTest, Authorware, Blue Sky Software, Blue Sky, Breeze, Breezo, Captivate, Central, ColdFusion, Contribute, Database Explorer, Director, Dreamweaver, Fireworks, Flash, FlashCast, FlashHelp, Flash Lite, FlashPaper, Flash Video Encoder, Flex, Flex Builder, Fontographer, FreeHand, Generator, HomeSite, JRun, MacRecorder, Macromedia, MXML, RoboEngine, RoboHelp, RoboInfo, RoboPDF, Roundtrip, Roundtrip HTML, Shockwave, SoundEdit, Studio MX, UltraDev, and WebHelp 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. Macromedia Flash 8 video is powered by On2 TrueMotion video technology. © 1992-2005 On2 Technologies, Inc. All Rights Reserved. http://www.on2.com. Visual SourceSafe is a registered trademark or trademark of Microsoft Corporation in the United States and/or other countries. Copyright © 2005 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 written approval from Macromedia, Inc. Notwithstanding the foregoing, the owner or authorized user of a valid copy of the software with which this manual was provided may print out one copy of this manual from an electronic version of this manual for the sole purpose of such owner or authorized user learning to use such software, provided that no part of this manual may be printed out, reproduced, distributed, resold, or transmitted for any other purposes, including, without limitation, commercial purposes, such as selling copies of this documentation or providing paid-for support services. Acknowledgments Project Management: Sheila McGinn Writing: Jen deHaan; Peter deHaan, Joey Lott Managing Editor: Rosana Francescato Lead Editor: Lisa Stanziano Editing: Linda Adler, Geta Carlson, Evelyn Eldridge, John Hammett, Mary Kraemer, Noreen Maher, Jessie Wood, Anne Szabla Production Management: Patrice O'Neill, Kristin Conradi, Yuko Yagi Media Design and Production: Adam Barnett, Aaron Begley, Paul Benkman. John Francis, Geeta Karmarkar, Masayo Noda, Paul Rangel, Arena Reed, Mario Reynoso Special thanks to Jody Bleyle, Mary Burger, Lisa Friendly, Stephanie Gowin, Bonnie Loo, Mary Ann Walsh, Erick Vera, the beta testers, and the entire Flash and Flash Player engineering and QA teams. First Edition: September 2005 Macromedia, Inc. 601 Townsend St. San Francisco, CA 94103 Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Intended audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 System requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Updating Flash XML files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 About the documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Additional resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Chapter 1: What's New in Flash 8 ActionScript . . . . . . . . . . . . . . 19 New in ActionScript 2.0 and Flash 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Changes to security model for locally installed SWF files. . . . . . . . . . 28 Chapter 2: Writing and Editing ActionScript 2.0 . . . . . . . . . . . . . 31 About ActionScript and events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Organizing ActionScript code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Using the Actions panel and Script window . . . . . . . . . . . . . . . . . . . . . . 35 About the Actions panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 About the Script window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 About coding in the Actions panel and Script window. . . . . . . . . . . . . 38 About Actions panel features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 About behaviors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 About ActionScript publish settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Chapter 3: About ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 What is ActionScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 About choosing between ActionScript 1.0 and ActionScript 2.0 . . . 69 Understanding ActionScript and Flash Player . . . . . . . . . . . . . . . . . . . .70 Chapter 4: Data and Data Types. . . . . . . . . . . . . . . . . . . . . . . . . . . 71 About data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 About data types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72 About variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Organizing data in objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108 About casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 3 Chapter 5: Syntax and Language Fundamentals . . . . . . . . . . . . 113 About syntax, statements, and expressions . . . . . . . . . . . . . . . . . . . . . .114 About dot syntax and target paths. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 About language punctuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 About constants and keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 About statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141 About arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 About operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Chapter 6: Functions and Methods . . . . . . . . . . . . . . . . . . . . . . . 201 About functions and methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Understanding methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222 Chapter 7: Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 About object-oriented programming and Flash . . . . . . . . . . . . . . . . . .226 Writing custom class files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235 About working with custom classes in an application . . . . . . . . . . . . .238 Example: Writing custom classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .263 Example: Using custom class files in Flash . . . . . . . . . . . . . . . . . . . . . . 276 Assigning a class to symbols in Flash . . . . . . . . . . . . . . . . . . . . . . . . . . .279 Compiling and exporting classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 Understanding classes and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .283 About top-level and built-in classes . . . . . . . . . . . . . . . . . . . . . . . . . . . .286 About working with built-in classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .296 Chapter 8: Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 About inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 About writing subclasses in Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Using polymorphism in an application . . . . . . . . . . . . . . . . . . . . . . . . . 308 Chapter 9: Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 About interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Creating interfaces as data types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Understanding inheritance and interfaces . . . . . . . . . . . . . . . . . . . . . . 320 Example: Using interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Example: Creating a complex interface . . . . . . . . . . . . . . . . . . . . . . . . .323 4 Contents Chapter 10: Handling Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Using event handler methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 Using event listeners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Using event listeners with components . . . . . . . . . . . . . . . . . . . . . . . . . 335 Using button and movie clip event handlers . . . . . . . . . . . . . . . . . . . . . 337 Broadcasting events from component instances . . . . . . . . . . . . . . . . 342 Creating movie clips with button states . . . . . . . . . . . . . . . . . . . . . . . . . 342 Event handler scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Scope of the this keyword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Using the Delegate class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Chapter 11: Working with Movie Clips. . . . . . . . . . . . . . . . . . . . . . 351 About controlling movie clips with ActionScript . . . . . . . . . . . . . . . . . 352 Calling multiple methods on a single movie clip . . . . . . . . . . . . . . . . . 354 Loading and unloading SWF files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 Changing movie clip position and appearance . . . . . . . . . . . . . . . . . . 357 Dragging movie clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Creating movie clips at runtime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 Adding parameters to dynamically created movie clips. . . . . . . . . . . 364 Managing movie clip depths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 About caching and scrolling movie clips with ActionScript . . . . . . . 369 Using movie clips as masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 Handling movie clip events. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378 Assigning a class to a movie clip symbol. . . . . . . . . . . . . . . . . . . . . . . . 378 Initializing class properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379 Chapter 12: Working with Text and Strings . . . . . . . . . . . . . . . . . 381 About text fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 About loading text and variables into text fields . . . . . . . . . . . . . . . . . 392 Using fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 About font rendering and anti-alias text . . . . . . . . . . . . . . . . . . . . . . . . 406 About text layout and formatting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .414 Formatting text with Cascading Style Sheet styles . . . . . . . . . . . . . . .421 Using HTML-formatted text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 Example: Creating scrolling text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 About strings and the String class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 Contents 5 Chapter 13: Animation, Filters, and Drawings. . . . . . . . . . . . . . 469 Scripting animation with ActionScript 2.0 . . . . . . . . . . . . . . . . . . . . . .470 About bitmap ...