Common Desktop Environment: Programmer's Overview

User Customization Issues

This section presents guidelines to follow when designing your application's user interface.

Color Use

When you design your application's user interface, do not specify color settings that override the default color scheme that the Common Desktop Environment provides for Motif and desktop widgets. For application-defined colors, use the following colors to promote sharing with other desktop applications:

Black
White
Red
Green
Blue
Yellow
Cyan
Magenta
Gray (eight shades: #de, #bd, #ab, #94, #73, #63, #42, and #21)

In most cases, you should not specify colors, so that your application uses the colors chosen by the end user in the desktop Style Manager.

Font Use

For your Motif widgets, use the fonts supplied by the Common Desktop Environment so that your application's windows look like other desktop client windows and so that users can change the size of these fonts using the Style Manager. If you override the supplied fonts by changing the Motif fontList resource specifications, then you must provide additional functionality if you want users to be able to customize the fonts in your application.

Use the fonts from the Common Desktop Environment standard application font names to specify--in your app-defaults file--resources you use within your application (aside from the ones Motif uses for its widgets). This ensures that your application finds the appropriate fonts on all Common Desktop Environment platforms, which makes your application more portable across such platforms. For more information, see "Standard Font Names" .

Note -

The Style Manager only controls fonts for applications written using Motif version 1.2 or later. It will not supply correct fonts for Motif 1.1 (or earlier) applications. These applications must specify their own fonts in the app-defaults file.

Accessibility

This section provides guidelines for making software applications accessible to people with disabilities.

Physical Disabilities

Provide keyboard access to all application features, such as those usually accessible through menus or drag and drop, to enable people with physical disabilities to more easily use your application.

Visual Disabilities

Follow these guidelines to make your application more accessible to people with visual disabilities:

Do not hardcode application colors.
Do not hardcode graphic attributes such as line, border, and shadow thickness. These attributes should scale with font size.
Do not hardcode font sizes and styles.
Provide descriptive names for all widgets. In particular, include descriptive names in your application code for widgets that do not display labels on the screen; for example, palette items or icons. This often enables screen-reading software to provide descriptive information to blind users.

Hearing Disabilities

Follow these guidelines to make your application more accessible to people with hearing disabilities:

Never assume that an end user will hear an audible notification.
Where appropriate, allow end users to choose between audible or visual cues.
Do not overuse or rely exclusively on audible cues.
Enable end users to configure frequency and volume of audible cues.

Language, Cognitive, and Other Disabilities

The access guidelines outlined for visual, hearing, and physical disabilities typically benefit end users with cognitive, language, and other disabilities. In addition to those guidelines, include tear-off menus and user-configurable menus for important application features whenever possible.

Mouse Double-Click Speed

For the end user to experience consistency across applications, you should not hardcode double-click durations into your application or app-defaults files. This way, when the user changes the double-click time in the Style Manager, your application responds along with the other desktop applications.

Demo Programs

The drawing program demo in /usr/dt/examples/template uses the Common Desktop Environment's default colors and fonts. This enables the user to customize the colors and fonts in this program by using the Style Manager. Read the README file for detailed information on this demo.