private void buildEdges() {
		mEdges.clear();

		System.out.println("BuildEdges...");

		if (mPaths == null) {
			return;
		}

		ListIterator li = mPaths.listIterator();

		while (li.hasNext()) {
			RoutePath rp = (RoutePath) li.next();

			String color = rp.getColor();

			ListIterator ti = rp.getPath().listIterator();
			Node last = null;

			while (ti.hasNext()) {
				Trip t = (Trip) ti.next();
				ListIterator vi = t.getVertices().listIterator();
				while (vi.hasNext()) {
					Vertex v = (Vertex) vi.next();
					Node cur = new Node(v.get_shape_pt_lat(),
							v.get_shape_pt_lon());
					if (last != null) {
						// add edge
						Edge e = new Edge(last, cur);
						e.setColor(color);
						mEdges.add(e);
					}
					last = cur;
				}
			}
		}
	}