From time to time, an application needs to present feedback to keep the user informed about the progress of ongoing activities and to alert the user to situations that require intervention. The CDE Motif interface provides many ways to provide such feedback to the user. This section describes the use of error messages, informational messages, and other message dialog boxes.
Use error messages when it is crucial to bring the information to the user's attention because the intended action cannot be carried out without user intervention. Use a Motif error dialog box to present application error messages. Keep in mind the basic three-part structure for error messages. Each error message should tell the user:
It is appropriate to assume that the user knows basic desktop terms, such as files or programs. However, avoid terminology that is typically understood only by an expert or frequent computer user unless the application is specifically targeted at computer professionals.
In many cases, the only user response to an error dialog box is to click the OK button to dismiss the dialog box. However, you should be able to offer resolutions to the problem. If you have buttons for user actions, be sure to also include a Cancel button.
Use informational messages in the window footer to present progress, status, or helpful information to the user. Do not use informational messages to present crucial information because informational messages are deliberately designed to be nonobtrusive and many users may not notice them.
Motif provides a message area at the bottom of the main window, but this is rather clumsy and ugly. A more elegant approach is to provide a wider margin below the data area of the main window where status information can be unobtrusively displayed.
Note: The text Loading earth.gif... is displayed at the start of the load and the text Done is added when the load has completed. The entire message is removed 5 seconds later.
For other examples of using informational messages, see the status message area in the CDE Mailer.
Informational messages in the footer area should be left-justified and displayed in a light font in keeping with their unobtrusive nature. Note that the margin where informational messages are displayed should not accept mouse focus. Progress messages in the footer area are normally displayed only while the operation is in progress. Remove notices and other information that is no longer valid within a few seconds to avoid confusion about whether the information is current.
CDE supports the following dialog boxes: