View Operations

Following are some of the common operations associated with viewing objects. Although these operations may not always be used with all objects, when supported, they should follow similar conventions.

When the user opens a new window, you should display it at the top of the Z order of its peer windows and activate it. Primary windows are typically peers with each other. Display supplemental or secondary windows belonging to a particular application at the top of their local Z order — that is, the Z order of the windows of that application, not the Z order of other primary windows.

Note
For more information about opening windows, property sheets, and Help windows, see Chapter 6, "Windows," Chapter 8, "Secondary Windows," and Chapter 12, "User Assistance," respectively.

If the user interacts with another window before the new window opens, the new window does not appear on top; instead, it appears where it would usually be displayed if the user activated another window. For example, if the user opens window A, then opens window B, window B appears on top of window A. If the user clicks back in window A before window B is displayed, however, window A remains active and at the top of the Z order; window B appears behind window A.

Whether opening a window allows the user to also edit the information in that window's view depends on a number of factors. These factors can include who the user is, the type of view being used, and the content being viewed.

After the user opens a window, re-executing the command that opened the window should activate the existing window instead of opening another instance of the window. For example, if the user chooses the Properties command for a selected object whose property sheet is already open, the existing property sheet is activated, rather than a second window opened.

Note
This guideline applies per user desktop. Two users opening a window for the same object on a network can each see separate windows for the object from their individual desktops.

Closing a window does not necessarily mean quitting the processes associated with the object being viewed. For example, closing a printer's window does not cancel the printing of documents in its queue. Quitting an application closes its windows, but closing a window does not necessarily quit an application. Similarly, you can use other commands in secondary windows which result in closing the window — for example, OK and Cancel. However, the effect of closing the window with a Close command depends on the context of the window. Avoid assuming that the Close command is the equivalent of the Cancel command.

If there are changes transacted in a window that have not yet been applied and the user chooses the Close command, and those changes will be lost if not applied, display a message asking whether the user wishes to apply or discard the changes or cancel the Close operation. If there are no outstanding changes or if pending changes are retained for the next time the window is opened, remove the window.

View Shortcuts

Following are the recommended shortcut techniques for the common viewing commands.

Note
For more information on reserved and recommended shortcut keys, see Appendix B, "Keyboard Interface Summary."

Use double-clicking and the ENTER key to open a view of an object when that view command is the default command for the object. For example, double-clicking a folder opens the folder's primary window. But double-clicking a sound object plays the sound; this is because the Open command is the default command for folders, and the Play command is the default command for sound objects.