The following example illustates the possibilities to customize the interactive interface of GraphWin.

To illustrate the adding of families of functions to GraphWin we use the functions for computing components of graphs. These functions all have the same interface. They take a graph and compute node arrays of ints, and return an int. Any such function can be added to a GraphWin using the caller.

    void call_comp(GraphWin& gw, int (*comp)
                  (const graph& G, node_array<int>& compnum));

    void dfs_num(GraphWin& gw);
    void span_tree(GraphWin& gw);

On the right there is a screenshot of the program. Clicking on the picture shows the window in original size.

#include <LEDA/graphics/graphwin.h>
#include <LEDA/graph/graph.h>
#include <LEDA/graph/basic_graph_alg.h>
#include <LEDA/graph/node_array.h>
#include <LEDA/graph/graph_alg.h>
#include <LEDA/graph/graph_misc.h>
	
using namespace leda;

void call_comp(GraphWin& gw, int (*comp)(const graph& G, 
			   node_array<int>& compnum))
{
  graph& G=gw.get_graph();
  node_array<int> compnum(G);
  comp(G,compnum);
  
  node v;forall_nodes(v,G) {
    int i=compnum[v];
    gw.set_label(v,string("%d",i));
    gw.set_color(v,(color)(i%16));
  }
	
  if (gw.get_flush()==false) gw.redraw();
}

void dfs_num(GraphWin& gw) 
{
  graph& G=gw.get_graph();
  node_array<int> dfsnum(G);
  node_array<int> compnum(G);
  DFS_NUM(G,dfsnum,compnum);

  node v;forall_nodes(v,G) 
    gw.set_label(v,string("%d|%d",dfsnum[v],compnum[v]));
	
  if (gw.get_flush()==false) gw.redraw();
}

void span_tree(GraphWin& gw) 
{
  graph& G=gw.get_graph();
  list<edge> L=SPANNING_TREE(G);
  gw.set_color(L,red);  gw.set_width(L,2);
		
  if (gw.get_flush()==false) gw.redraw();
}

int main()
{
  GraphWin gw;

  //add two simple function calls,
  gw.add_simple_call(dfs_num, "dfsnum");
  gw.add_simple_call(span_tree, "spanning");

  //a member function call, and a
  gw.add_member_call(&GraphWin::reset,"reset");

  //menu with three non-simple functions using
  //a common call function
  int menu1=gw.add_menu("Components");
  gw_add_call(gw,COMPONENTS,call_comp,
              "simply connected", menu1);
  gw_add_call(gw,COMPONENTS1,call_comp,
              "simply connected1", menu1);
  gw_add_call(gw,STRONG_COMPONENTS,call_comp,
              "strongly connected", menu1);

  //we delete some of the standard menus,
  gw.set_default_menu(M_COMPLETE & ~M_HELP);
	
  gw.display(); gw.edit();

  gw.get_window().screenshot("customize_ii");

  return 0;	
}