Subtracts all of the polygons which make up the area covered
by the argument from the collection of polygons the receiver
maintains to describe its area.
@param region the region to subtract
@exception IllegalArgumentException <ul>
<li>ERROR_NULL_ARGUMENT - if the argument is null</li>
<li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li>
</ul>
@exception SWTException <ul>
<li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
</ul>
Subtracts all of the polygons which make up the area covered by the argument from the collection of polygons the receiver maintains to describe its area.
@param region the region to subtract
@exception IllegalArgumentException <ul> <li>ERROR_NULL_ARGUMENT - if the argument is null</li> <li>ERROR_INVALID_ARGUMENT - if the argument has been disposed</li> </ul> @exception SWTException <ul> <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> </ul>
@since 3.0