Accessibility Best Practices Overview
Macromedia Flash 8 allows designers and developers to create powerful web applications that are exciting, engaging, and accessible to all. With new features integrated into Macromedia Flash Player 8 and the Macromedia Flash 8 application, users of assistive technologies may now access the best experience on the web.
Designing accessible content requires designers and developers to pay attention to the user experience. Since many Macromedia Flash 8 designers and developers are not familiar with the capabilities of screen readers and other assistive technologies, these design guidelines provide several desirable practices for creating content in Macromedia Flash 8. These hints are intended to provide a helpful starting point for designers and developers striving to create accessible content in Macromedia Flash 8.
The following are some practical suggestions for optimizing the accessibility of your Macromedia Flash content.
Assign Text Equivalents for Visual Elements
Provide text equivalents for graphic elements in Macromedia Flash 8. Provide names for graphic icons. Add text equivalents for gesturing animations that highlight an area of the page. When you use a feature like Break Apart for text, be sure to provide a name or description. When a group of related graphic elements are used to convey a single idea, provide a single text equivalent and make the child objects inaccessible. Learn more about providing text equivalents.
Animation
Make Looping Elements Inaccessible
Movies that never stop moving cause screen readers to refresh frequently. Even in cases where the movies are at the bottom of a page, the screen reader can interpret motion as an update to the page and return to the top and start reading again. For this reason, child objects of movie clips or entire movies should be made inaccessible. Learn more about handling animation.
Allow Users to Control Motion
Try not to present information in your movie that remains on the screen for only a short time. Screen readers may a difficult time keeping up with quick changes in Macromedia Flash movies. You can resolve this type of problem by adding Next buttons that control movement. Learn more about handling animation.
Using Accessible Components
A core set of accessible UI components is provided in Macromedia Flash to help you with accessible application development. These components can automate many of the most common accessibility practices related to labeling, keyboard access, and testing and help to ensure a consistent user experience across rich applications.For each component, the designer or developer need only enable the accessibility object by using the command enableAccessibility(). This includes the accessibility object with the component as the movie is compiled. Learn more about components and accessibility.
Enable Control Over Reading Order
The default reading order of a Macromedia Flash movie may not follow the same order that the designer would expect based on the visual layout. There are at least three means of controlling reading order. First, the designer or developer can limit the physical size of the stage and keep the layout simple. Second, the designer or developer can develop a secondary control that places a linear version of the content offstage. Third, the reading order can be specified using ActionScript. Learn more about controlling reading order in Macromedia Flash
Ensure Keyboard Access to All Controls
When adding buttons and other controls to Macromedia Flash movies, make sure that users can navigate through your movie effectively using only the keyboard. Keep in mind that applications need to be tested both with and without a screen reader. To facilitate keyboard access, try to keep scripts within frames as opposed to attaching them directly to objects. Also, avoid using empty movie clips as buttons. These ‘hit areas’ are not recognized by screen readers. Finally, add keyboard shortcuts to commonly used buttons to facilitate access. Learn more about ensuring keyboard access.
Caption Audio Content
Macromedia Flash makes delivering audio content simple and easy. It is important when delivering narrative audio to provide captions at the same time. Captions can be delivered using one of three primary methods. First, the text objects can be placed on stage by hand. Second, the designer can import video with the captions already included. By far the most flexible method of delivering captions is to stream an XML caption file. One easy and powerful means of delivering captions relies on the use of Hi-Caption SE. With the Hi-Caption Viewer component for Macromedia Flash, designers and developers need only point to a caption file and customize the user interface to deliver professional looking captions. Learn more about captions.
Enable Control Over Audio Playback
Music and audio that plays as the site loads presents a serious challenge to screen reader users. The audio from a Flash movie can interfere with the end users ability to hear the contents of a movie using a screen reader. As a result, it is important to make sure that control over when music is played is provided to the user. The simplest strategy for handling audio playback is simply to allow the end user to control audio with a play and pause button. Learn more about how to enable control over audio.
Expose Structure
Macromedia Flash movies can be complex in terms of layout, structure, and navigation. As a result, it can be very difficult for screen reader users to make sense of a complex Macromedia Flash movie. As sites become more complex, try to add a description for the entire movie to help orient screen reader users to the structure of the site. This can be accomplished using either the root-level description or a separate information screen. The advantage of building a separate information screen is that it allows to user to get to the content without hearing the description at each refresh.
Expose State of Controls
Macromedia Flash allows for an infinite variety of controls. For all controls, it is important to provide the user with feedback on the control as it changes. In the simple example below, notice that once the button is pressed it changes from a play to a pause button. As the state of the button changes, the accessibility information for this button should be updated as well.
Use Color Wisely
Macromedia Flash allows designers to use a wide variety of color combinations. When making color choices for a Macromedia Flash movie, the designer should not rely on color alone to convey information. For example, it would not be appropriate to provide an instruction that reads, “Click the green button to go forward and the red button to go back.” At the same time, it is important to make sure that there is sufficient contrast between foreground and background colors to make content easily readable.
Validate for Accessibility
Accessibility guidelines provide only limited guidance for the design of accessible Macromedia Flash content. Many of the most common issues in accessible Macromedia Flash design are not reflected in accessibility standards such as Section 508 or the W3C guidelines. Macromedia Flash designers and developers should rely on a variety of methods for validation of Macromedia Flash content for accessibility. First, try accessing your content using screen access technologies such as Window-Eyes from GW Micro. This will provide the best insight into the usability of a movie for screen users. Also, be sure to test your site using only the keyboard without a screen reader running. Keyboard access differs when a screen reader is not present. Second, make use of third party repair and validation tools for Macromedia Flash. These tools can help to identify common errors in Macromedia Flash design. Third, be sure to test the site with actual users. It is very important that, before claiming that a site is accessible, it is evaluated either formally or informally by people with disabilities.
