This method of the DirectDrawSurface Class determines if the surface memory associated with a DirectDrawSurface object has been freed.
public int isLost();
Returns DD_OK if the memory has not been freed.
You can use this method to reallocate surface memory. When a DirectDrawSurface object loses its surface memory, most methods perform no function.
Surfaces can lose their memory when the mode of the display card is changed, or when an application receives exclusive access to the display card and frees all the surface memory currently allocated on the display card.