Screen Stack

Some sites that implement screen oriented tasks consist of a set of pages organized in the form of a tree hierarchy.

For instance, the user starts at screen A which has some buttons that may open screens B or C. When the screen B is opened, the associated task has to be completed or canceled before the user is allowed to return to screen A. Screen B in itself can also have buttons that open screens D and E, and so on.

In each situation, a stack describes the structure of screens that have to be completed. This class can be used to implement stacks of screens that define the navigation of pages that the users of a Web application must follow. The stack is defined by the URLs of the pages.