OnSurfaceLost occurs when a surface is lost.
__property TNotifyEvent OnSurfaceLost;
Description
There are two reasons for losing a surface.
First, a video mode change results in a surface lost. So if you're pressing Alt+Tab to
change task, it's likely that DirectX will lose all the surfaces. In this case, when you
change back to the DirectX application, Ivory Draw tries to restore the lost surfaces.
It first calls the OnSurfaceLost event for all of the
lost surfaces, then invokes the TIvoryDraw::OnSurfaceLost
event.
The second reason for losing a surface is
that you call the RecreateOffScreen method of the surface.
In this case, Ivory Draw first recreates the surface and calls its OnSurfaceLost event,
then invokes the TIvoryDraw::OnSurfaceLost event.