If the painter was invoked by WINDOW DEFINE, then no other objects can be added. Layout mode is restricted to changing the dimensions and attributes of the paint window only. If the window does not already exist (i.e. there is no definition data for it in the Zim Data Dictionary), the painter creates a paint window with default attributes. If the window does exist, the painter loads and displays that window as the paint window.
Both the Import and Generate functions are unavailable under WINDOW DEFINE.