The VkApp class, derived from the VkComponent class, provides facilities required by all ViewKit ObjectPak applications. In all of your ViewKit ObjectPak applications you must create a single instance of VkApp or a class derived from VkApp.

Initialization and event-
handling

The primary responsibility of VkApp is to handle the initialization and event-handling operations common to all Xt-based applications. When you write a ViewKit ObjectPak application, instead of calling Xt functions such as XtAppInitialize(3) and XtAppMainLoop(3), you simply instantiate and use a VkApp object.

Support for application-
level tasks

The VkApp class also provides support for other application-level tasks. For example, VkApp provides functions for quitting your application; showing, hiding, iconifying, and opening all of the application's windows; handling application busy states; maintaining product version information; and setting the application's cursor shape.

Information storage

The VkApp class also stores some essential information that can be accessed throughout an application. This information includes:

• A pointer to the X Display structure associated with the application's connection to the server
• The XtAppContext structure required by many Xt functions
• The application's name
• The application's class name

This information is maintained in the private portion of the class and is available through public access functions.