We will create a graph with 4 nodes and 4 edges. Their "id number" will start from 0 just like in the figure below :

Following is the sample of code that created such a graph:

int main() {
  //create an empty graph
  Graph *graph=tlp::newGraph();

  //build the graph
  node n0=graph->addNode();
  node n1=graph->addNode();
  node n2=graph->addNode();
  node n3=graph->addNode();

  //add three edges
  edge e0=graph->addEdge(n1,n2);
  edge e1=graph->addEdge(n0,n1);
  edge e2=graph->addEdge(n2,n0);
  edge e3=graph->addEdge(n3,n0);
        		

As you can see, node 0 has three edges : edge 1,edge 2 and edge 3. And if we display its edges adjacency list (see last section for function void displayAdjacency(node n, Graph *graph) ) we obtain the following output :

 1 2 3  

Swapping edges can be easily done with the function, void Graph::swapEdgeOrder ( const node, const edge,const edge) that will, as said swap two edges in the adjacent list of a node. Following is an example of its use :

  //swap e1 and e3
  graph->swapEdgeOrder(n0, e1, e3);
        	    

As you can see, the adjacency list has changed :

  3 2 1  

An other way to change the edges order is to use a vector of type edge and the function : void Graph::setEdgeOrder (const node, const std::vector < edge > ), following is an example that will replace e1 and e3 in their original order :

  vector<edge> tmp(2);
  tmp[0]=e1;
  tmp[1]=e3;
  graph->setEdgeOrder(n0,tmp);
        	    

And the new order :

  1 2 3  

#include <iostream>
#include <tulip/Graph.h>
#include <tulip/MutableContainer.h>

/**
 * Tutorial 006
 *
 * Create a graph
 * Order the edges around the nodes
 */

using namespace std;
using namespace tlp;

void buildGraph(Graph *graph) {
  //add three nodes
  node n0=graph->addNode();
  node n1=graph->addNode();
  node n2=graph->addNode();
  //add three edges
  graph->addEdge(n1,n2);
  graph->addEdge(n0,n1);
  graph->addEdge(n2,n0);
}

void displayAdjacency(node n, Graph *graph) {
  Iterator<edge>*ite=graph->getInOutEdges(n);
  while(ite->hasNext())
    cout << ite->next().id << " ";
  delete ite;
  cout << endl;
}

int main() {
  //create an empty graph
  Graph *graph=tlp::newGraph();

  //build the graph
  node n0=graph->addNode();
  node n1=graph->addNode();
  node n2=graph->addNode();
  node n3=graph->addNode();

  //add three edges
  edge e0=graph->addEdge(n1,n2);
  edge e1=graph->addEdge(n0,n1);
  edge e2=graph->addEdge(n2,n0);
  edge e3=graph->addEdge(n3,n0);

  tlp::saveGraph(graph, "adj1.tlp");

  //display current order of edge around n1
  displayAdjacency(n0,graph);
  
  //swap e1 and e3
  graph->swapEdgeOrder(n0,e1,e3);
  

  //display the new order of edge around n1
  displayAdjacency(n0,graph);

  vector<edge> tmp(2);
  tmp[0]=e1;
  tmp[1]=e3;
  graph->setEdgeOrder(n0,tmp);
  //display the new order of edge around n1
  displayAdjacency(n0,graph);
  delete graph;
  return EXIT_SUCCESS;
}