Overview of the VkApp Class

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-

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.