Abstract: A system and method for enabling a tracing of program execution within an object-oriented programming language environment. A new tracing class is created which is derived from the original class. When tracing is desired, a user creates instances of the tracing subclass instead of the original class and this instance is used in place of the original object. When tracing is not desired, a user merely creates and uses an instance of the original class. The new tracing subclass incorporates "print" statements, which permit observation of the control of code flow within the object.

Abstract: A system and method for performing efficient clipping to visible windows. A window clip buffer is established for each window being written directly to the front frame buffer. The window clip buffer is initialized as having the same dimensions as the window itself and each pixel position is initially set to False (not visible.) The visible regions are determined and the buffer updated to True (visible) for those visible regions. As each pixel is being drawn the window clip buffer is tested. The pixel is drawn to the frame buffer only where the window clip buffer pixel is true (visible.) Changes to window positions on the screen causes the visible regions to be updated.

Abstract: A method for building an objectbase of persistent objects, includes naming an objectbase collection of objects, naming each object relative to a first collection of objects using a first key, assigning, to each new object to be added to the objectbase collection, a second key, generating a third key from the first and second keys, storing each object with the associated keys generating a reference to each object in the objectbase collection from the third key and one or more system identifiers, creating an instance of an object collection in a database client, identifying a class of each object in the object collection to the instance collection, generating a stream class for persistence of element objects, identifying to the instance collection a mapping between its attributes that are persistent and the corresponding database fields, identifying to the instance collection access control information in the form of one or more predicates, and activating the element objects using the stream.