Programmatically shrinking and expanding panes in Windows
In the Windows Framework a filter or command handler can now programmatically shrink the filter pane, the command handler pane, the instance list, or the navigate pane, and can also re-expand them.
Command handlers can also programmatically expand themselves to occupy the space used by the filters and instance list (Maximize), and restore themselves back to their original size.
See Expanding, Shrinking and Focusing Panes.