Retrieve the window context or select interactively. If there is no window context, a window is selected interactively. The boolean select? argument (default #t) determines whether or not a window should be selected interactively if there is no current window context. The release? argument (default #t) determines whether or not interactive selection (if any) should wait for a mouse release event or just a press. The latter behavior is useful if the action being performed on the window is an interactive one involving mouse drags. The cursor argument is either a cursor object or #t to use the "skull and crossbones" cursor, or #f to use the standard circle cursor.