Before you attempt to construct interactive projects in Flash, you should be familiar with the structure of the authoring environment. Even if you already know a previous version of Flash, learning this is advisable. That's because with the release of Flash CS3, Adobe has reorganized existing features to the interface and has either moved or improved other features and functionalities. So, to get a firm footing in the new interface, we strongly suggest that you work your way through this book — from the beginning.

Moreover, you need to proactively plan your interactive projects before you attempt to author them in Flash. An ounce of preplanning goes a long way during the production process. Don't fool yourself — the better your plan looks on paper, the better it performs when it comes to the final execution.

We consolidated the overview of interactive planning in the early chapters of the book. In later chapters, we included step-by-step descriptions of real-world projects that allow you to see how all the theory and planning suggestions apply to the development of specific projects.

There are two primary files that you create during Flash development: Flash document files (.fla) and Flash movie files (.swf). We discuss both of these formats next.

Flash document files (.fla) are architected to provide an efficient authoring environment for projects of all sizes. Within this environment, content can be organized into scenes, and the ordering of scenes can be rearranged throughout the production cycle. Layers provide easy separation of graphics within each scene, and, as Guide or Mask layers, they can also aid drawing or even provide special effects. The Timeline shows keyframes, motion and shape tweens, labels, and comments. The Library (which can be shared amongst movies at author-time or at runtime) stores all the symbols in your project, such as graphics, fonts, animated elements, sounds or video, and components.

Flash documents

Tip

Flash CS3 allows you to resave your Flash CS3 document file (.fla) as a Flash 8 document file (.fla). Choose File

In Flash CS3, you have the option to create two different types of Flash files: Flash file (ActionScript 2.0) and Flash file (ActionScript 3.0). If you are targeting Flash Player 8 or earlier, you should always choose ActionScript 2.0. If you are targeting Flash Player 9 or higher, and you want to use the advanced coding style of ActionScript 3.0, you should choose Flash file (ActionScript 3.0). You can change your target version of ActionScript and the Flash Player at any time by clicking the Flash tab in the File

Figure 1.1 shows how Flash documents are composed of individual scenes that contain keyframes to describe changes on the Stage. What you can't see in this figure is the efficiency of sharing libraries among several Flash documents, loading other Flash movies into a parent, or "master," Flash movie using the loadMovie() action, or creating interactive elements with scripting methods.

Flash movies

Warning

The Protect from import option in the Publish Settings does not prevent third-party utilities from stripping artwork, symbols, sounds, and ActionScript code from your Flash movies. For more information, read Chapter 21, "Publishing Flash Movies."

Much of the information contained originally within a Flash document file (.fla) is discarded in the attempt to make the smallest file possible when exporting a Flash movie file (.swf). When your movie is exported, all original elements remain but layers are essentially flattened and run on one timeline, in the order that was established in the Flash document. Practically all information originally in the file will be optimized somehow, and any unused Library elements are not exported with the Flash movie. Library assets are loaded into and stored in the first frame they are used in. For optimization, reused assets are only saved to the file once and are referenced throughout the movie from this one area. Bitmap images and sounds can be compressed with a variety of quality settings as well.

Tip

Flash Player 6 and higher movies can be optimized with a specialized Compress Movie option that is available in the Flash tab of the Publish Settings dialog box (File

Note

We discuss Flash Player detection in detail in Chapter 22, "Integrating Flash Content with Web Pages."

There are several other ways in which Flash movies, or their parts, can be played back or displayed. Since Flash 4, the Publish feature has offered provisions for the export of movies or sections of movies to either the QuickTime digital video format, the QuickTime Flash layer vector format, or the Animated GIF format. Parts of movies can also be exported as a series of individual bitmaps or as vector files. Single frames can also be exported to these formats.

Figure 1.1. Elements of a Flash document (.fla) in the authoring environment

Refer to Figure 1.2 for a graphic explanation of the characteristics of the Flash movie file (.swf ) format.

Figure 1.2. Overview of the Flash movie (.swf) format

Flash ActionScript files

Flash Video files

Using Flash Player terminology

The difference between the naming conventions of the Flash Player plug-in and the Flash authoring software is potentially confusing. Adobe refers to its latest release of the player as Flash Player 9, tagging the version number at the end of the name instead of following in the naming convention of its predecessors (that is, "Flash 5 Player"). One probable reason the Flash Player is numbered, rather than dubbed "MX" like the authoring software, is because a standard sequential number is required for plug-in detection.

When you publish Flash content to a Web site, don't be tempted to instruct visitors to download and install the "Flash CS3 Player." In versions past, you might have seen sites that required the "Flash MX Player." This terminology is confusing and misleading, as there is no "Flash CS3 Player" for users to download. Always refer to the version number of the Flash Player, not the authoring tool.

Flash Debug files

Note

You learn more about the debugging process in Chapter 33, "Managing and Troubleshooting Flash Movies."

Note

Flash CS3 does not create SWD files when you debug an ActionScript 3.0 Flash Player 9 movie. Debugging capabilities are now directly accessed from the Flash movie (SWF file) by the Debug version of Flash Player 9.

Flash Component files

C:Documents and Settings[Your User Name]Local SettingsApplication ;
DataAdobeFlash 8enConfigurationComponents

On the Mac, you can copy to this location:

[Startup disk]: Users: [Your User Name]: Library: Application Support: ;
Adobe: Flash CS3: en: Configuration: Components

These locations are only used to store additional components; the default components for Flash CS3 are stored in the Flash CS3 application folder.

Flash Project files

In truth, Flash has limited capabilities as an image-editing program. It is more accurate to describe this part of the Flash application as a bitmap handler. Bitmap images are composed of dots on a grid of individual pixels. The location (and color) of each dot must be stored in memory, which makes this a memory-intensive format and leads to larger file sizes. Another characteristic of bitmap images is that they cannot be scaled without compromising quality (clarity and sharpness). The adverse effects of scaling an image up are more pronounced than when scaling down. Because of these two drawbacks — file sizes and scaling limitations — bitmap images are not ideal for Web use. However, for photographic-quality images, bitmap formats are indispensable and often produce better image quality and lower file sizes than vector images of equivalent complexity.

The heart of the Flash application is a vector-based drawing program, with capabilities similar to Adobe Illustrator. A vector-based drawing program doesn't rely upon individual pixels to compose an image. Instead, it draws shapes by defining points that are described by coordinates. Lines that connect these points are called paths, and vectors at each point describe the curvature of the path. Because this scheme is mathematical, there are two distinct advantages: Vector content is significantly more compact, and it's thoroughly scalable without image degradation. These advantages are especially significant for Web use.

The vector animation component of the Flash application is unlike any other program that preceded it. Although Flash is capable of handling bitmaps, its native file format is vector-based. So, unlike many other animation and media programs, Flash relies on the slim and trim vector format for transmission of your final work. Instead of storing megabytes of pixel information for each frame, Flash stores compact vector descriptions of each frame. Whereas a bitmap-based animation file format struggles to display each bitmap in rapid succession, the Flash Player quickly renders the vector descriptions as needed and with far less strain on either the bandwidth or the recipient's machine. This is a huge advantage when transmitting animations and other graphic content over the Web.

Flash Player 6 and higher include a built-in video engine — the Sorenson Spark codec — which means that the Flash Player plug-in can be considered one of the world's smallest video plug-ins. Flash Player 8 and higher feature an additional video codec, the On2 VP6 codec, which has superior compression and image quality. You can import source video files directly into Flash CS3 document files (.fla), or create separate Flash Video files (.flv) that load into your Flash movies. Users do not need to have Apple QuickTime, Real Network's RealPlayer, or Microsoft Windows Media Player installed in order to view video in a Flash movie. Flash Player 6 and higher provide a seamless solution.

Since Flash Player 6, Flash movie files (.swf) have had the capability to load MP3 files during runtime. You can also import other audio file formats into a Flash document file (.fla ) during author-time. Sounds can be attached to keyframes or buttons, for background tracks or sound effects. A sound file's bytes can be distributed evenly across a timeline, so that the .swf file can be progressively downloaded into the Flash Player, enabling a movie to start playing before the entire sound file has been downloaded.

If the heart of Flash is a vector-based drawing program, then the body of Flash is a multimedia-authoring program (or authoring environment). Flash document files (.fla) can contain multiple media assets, including sound, still graphics, animation, and video. Moreover, Flash is a powerful tool for creating truly interactive content because it enables you to add (ActionScript) commands to dynamically control movie file (.swf) playback. Whether you are designing simple menu systems or customized and intuitive experimental interfaces, Flash content can be authored to recognize and respond to user input.

Most multimedia-authoring programs have a component for sequencing content as animation, and Flash is no exception. But in Flash, the animation sequencer is the core of the author-time application. The Timeline window controls the display of all content — static or animated — within your Flash project. Within the Timeline window, there are two areas that enable you to organize content in visual space and in linear time.

Layers and layer folders enable you to keep track of content that has been placed into your Flash document. The visibility of each layer can be controlled independently, making it easier to isolate specific elements as you are authoring. Layers are viewed from front to back within each frame of the Timeline — items on upper layers overlay other items on lower layers. Any number of items can be placed on a single layer, but you have less control over the stacking order within a layer. Within the same layer, ungrouped vector lines and shapes will always be on the bottom level, whereas bitmaps, text, grouped items, and symbol instances will be on the upper level.

The structure that creates the illusion of movement in a Flash movie is a series of frames. Each frame represents a still moment in time. By controlling how the Playhead moves through these frames, you can control the speed, duration, and order of an animated sequence.

By changing the content in your layers on each frame, you can manually create frame-by-frame animation. However, one of the things that makes Flash such a popular animation machine is its ability to auto-interpolate or tween animation. By defining the content on a beginning and an end keyframe and applying a Motion tween or a Shape tween, you can quickly create or modify animated shape transformations and the movement of elements on the Stage.

Within one Flash document, you can also set up a series of separate scenes; each scene is a continuation of the same Main Timeline, but scenes can be named and reordered at any time. Scenes play through from first to last without interruption unless Flash's interactive commands ("actions") dictate otherwise.

The past few versions of Flash brought a vast expansion of the possibilities for integrating Flash interfaces with server-side technology and dynamic loading of content using XML and server technologies such as Adobe ColdFusion, PHP, Microsoft .NET, JSP, Flash Remoting, and Adobe Flash Media Server. These improvements largely came out of the development and maturity of ActionScript as a viable programming language. Flash has developed into an alternative front end for large databases, which means it can serve as an online store, MP3 player, or multiuser game and chat room — an amazing feat for an "animation program"!

With Flash CS3 there are virtually infinite possibilities at your fingertips. Using the components that ship with Flash CS3, you can tap advanced data structures and display them in a Flash movie. You can load JPEGs, GIFs, PNGs, MP3s, and Flash Video files into Flash at run time (or "on the fly"), without having to use a special server technology. You can use a wide range of data formats, from XML to Web Services (SOAP) to Flash Remoting.

There are many other enhancements to the programming environment and functionality of Flash that experienced users will appreciate and new users will come to value. ActionScript 3.0 continues the evolution of Flash's scripting language to a mature format, more closely adhering to ECMAScript 4. These changes support ActionScript's move toward acceptance as a standard, object-oriented programming (OOP) language on its own.