Data processing system for defining and processing objects in response to system user operations

In a data processing system including a plurality of interconnected workstations, each having an attached display device, in which said system defines and processes objects in response to operations performed by a system user, defines a plurality of virtual screens of display data with which views of objects can be associated, and provides for selection of a virtual screen whereby views of objects associated with a selected screen are displayed on a display device, the improvement comprising:

• means for defining distinct anterior and posterior display layers for said display device with said anterior layer having a background such that a content of said posterior display layer can be viewed therethrough and within of said layers being assignable for display of said selected screen and another of said layers being dedicated for display of an additional screen;
• means including control logic means which is responsive to a predetermined user input operation and a presence of a display cursors within a boundary of at least one of said objects for transferring said at least one of said objects between said anterior and posterior display layers;
• wherein a view of said at least one of said objects varies in dependence upon a one of said display layers in which it is displayed;
• and
• means, in response to user interaction with said system, for selecting a virtual display screen as a shared display screen in an assignable display layer of each of said attached display devices such that said assignable display layer may be shared by users of said plurality of workstations.