_GetHandle
if (_GetHandle((Handle)i).Contains(point))
FillRect(_GetHandle(DRAG_TOP_LEFT), B_MIXED_COLORS);
FillRect(_GetHandle(DRAG_TOP_RIGHT), B_MIXED_COLORS);
FillRect(_GetHandle(DRAG_BOTTOM_LEFT), B_MIXED_COLORS);
FillRect(_GetHandle(DRAG_BOTTOM_RIGHT), B_MIXED_COLORS);
BRect _GetHandle(Handle handle);