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Class System.CATCommand

System.IUnknown
  |
  +---System.IDispatch
    |
    +---System.CATBaseUnknown
      |
      +---System.CATEventSubscriber
        |
        +---CATCommand
 

public class CATCommand

Base class for all objects that need to collaborate through notifications.
All the existing commands are organized as a tree structure. Each command has a parent command and possibly children. The parent is passed as a parameter of the command constructor.

When the end-user interacts with the application, system events are produced that are turned into notifications, and sent to either the command that is involved, such as the push button pushed by the end user, or to the command that is the nearest to the user interaction, such as the manipulator set onto a document object's representation selected by the end user in a graphics viewer.

The notification is sent from command to command along the tree structure until it can be processed. If no command able to process the notification is found, it is sent to the command selector that resends it to the active command. This can decide to process the notification, or otherwise to do something else, possibly nothing.

See also:

CATCallbackManager, CATNotification