Motif and Common Desktop Environment: Style Guide Reference Migration Version

Motif and CDE 2.1 Style Guide Reference

Input Models (CDE)

Reference

Description

Input models specify the way data is entered or manipulated in a CDE application.

Input devices have different actions depending on which part of the interface the user is interacting with. Usually, mouse users can access windows and controls more easily than keyboard users, due to the inherent flexibility in mouse manipulation. Keyboard users must use specific keys to move the cursor in the application.

Guidelines

Required

Only one window at a time can have keyboard focus. Highlight the window that has focus. Within the window that has keyboard focus, only one component at a time can have focus.

The keyboard focus determines which component on the screen receives keyboard events. This rule prevents confusion about which window and component have focus.

Required

If your application uses an explicit focus policy, when the user presses the SELECT button, do not move focus to a component that is not traversable or does not accept input.

An explicit focus policy requires the user to explicitly select which window or component receives keyboard focus. Generally, the user gives focus to a window or component by pressing the SELECT button over it. However, this policy must not allow the user to give focus to a component that is not traversable or does not accept input.

Required

If your application uses an explicit focus policy, highlight (with a location cursor) the component with the keyboard focus.

The user needs to know the location of the keyboard focus to be able to control an application.

Required

Support methods of interaction for keyboard-only users. All features of your application should be available from the keyboard.

Some users may not have access to a pointing device. These users need to be able to access the full functionality of the application from the keyboard. Also, advanced users may use the keyboard to perform some tasks more quickly than with a pointing device.

Required

Use the following bindings for mouse buttons:

SELECT

Used for selection, activation, and setting the location cursor, SELECT is the leftmost button, except for left-handed users, where it can be the rightmost button.

TRANSFER

Used for moving and copying elements, TRANSFER is the middle mouse button, unless dragging is integrated with selection or the mouse has fewer than three buttons.

MENU

Used for popping up menus, MENU is the rightmost button, except for left-handed users, where it can be the leftmost button, or unless the mouse has fewer than three buttons. If the mouse has one button, bind the MENU button to Alt SELECT.

Required

Do not warp the pointer unless you have given the user a means of disabling the behavior.

The pointer position is intended only as input to applications, not as an output mechanism. An application warps the pointer when it changes the pointer's position. This practice is confusing to users and reduces their sense of control over an application. Warping the pointer can also cause problems for users of absolute location pointing devices (for example, a puck on a graphics tablet).

Required

Components or applications developed for CDE must adhere to Motif key bindings (see Appendix A).

Essential Related Topics

For more information, see the Keyboard (Device) and Mouse (Device) reference pages.

Supplemental Related Topics

For more information, see the Pointer (Predefined) reference page.