Checks the validity of both the class object's internal automation and container.
|TRUE||Both the automation handle and the container handle are valid.|
|FALSE||The automation handle, the container handle or both handles is/are invalid.|
For the paint automation the automation handle becomes valid after calling the LRasterPaintWindow::Initialize.
The container handle is created, initialized and added to the automation when LRasterPaintWindow::SetBitmap is called.
For an example, refer to LRasterPaintWindow::CreateToolbar.