SlotOccupied
if (SlotOccupied(oldBounds, viewBounds) || intersectsDesktopElements) {
while (SlotOccupied(rect, viewBounds)
for (int32 i = 0; i < end && SlotOccupied(slotRect, destViewBounds); i++)
bool SlotOccupied(BRect poseRect, BRect viewBounds) const;