+ /* Check if this stop already exists. If so, just leave */
+ for (it = stops_.begin(); it != stops_.end(); it++)
+ if (*it == stop)
+ return;
+
+ /* The stop did not already exist, so add it */
+ stops_.push_back (stop);
+}
+
+float Elevator::distance_from (Position &pos) const
+{
+ if (position_ > pos)
+ return position_ - pos;
+
+ return pos - position_;
+}
+
+float Elevator::distance_from (Stop &s) const
+{
+ Direction d = s.getDirection();
+ Position p = s.getPosition ();
+
+ /* If direction doesn't matter, then only position does */
+ if (d == ALL || direction_ == IDLE)
+ return distance_from (p);
+
+ /* If we're not in the same direction, then we're "really far" away */
+ if (d != direction_)
+ return INT_MAX;
+
+ /* We must be in the correct direction, so pure distance is fine */
+ return distance_from (p);
+}
+
+void Elevator::transition_move_up ()
+{
+ direction_ = UP;
+ position_ += ELEVATOR_STEP;
+
+ // TODO: Call into the GUI to update the position
+ gui_update_position_label (number_, (float)position_, direction_);
+ std::cout << "Updating the GUI with our position: " << position_ << std::endl;
+}
+
+void Elevator::transition_move_down ()
+{
+ direction_ = DOWN;
+ position_ -= ELEVATOR_STEP;
+
+ // TODO: Call into the GUI to update the position
+ gui_update_position_label (number_, (float)position_, direction_);
+ std::cout << "Updating the GUI with our position: " << position_ << std::endl;
+}
+
+void Elevator::transition_move_idle ()
+{
+ direction_ = IDLE;
+ // TODO: Call into the GUI to update the position
+ gui_update_position_label (number_, (float)position_, direction_);
+ // do not change position while IDLE
+}
+
+void Elevator::transition_open_door ()
+{
+ /* Calculate the number of Stops above and below our
+ * current position */
+ StopList::const_iterator it;
+ Stop current = Stop(position_, direction_);
+ int stops_above = 0;
+ int stops_below = 0;
+
+ for (it = stops_.begin(); it != stops_.end(); it++)
+ {
+ if (current < *it)
+ ++stops_above;
+
+ if (current > *it)
+ ++stops_below;
+ }
+
+ /* If we are going to switch direction, clear all stops here,
+ * regardless of direction.
+ *
+ * Otherwise, just clear this stop */
+ if (direction_ == UP && stops_above == 0)