Re: [jgrapht-users] jgraph question

[Alex M. <am...@di...>]

Thanks for the link.  I am able to run the given JGraphXAdapter code
successfully, but when I try to integrate it in my own code I get a blank
screen.  Maybe it's because of the cell location stuff.  In that link
somebody said "The most trickey for me was having to set-up the cell
location and dimension, before applying layouts."  I'm not sure what that
means, but I have a feeling I am having the same problem.  When I try to
apply my own layout by modifying the JGraphXAdapter, I added the following
code in the main() method:

      mxIGraphLayout layout = new mxFastOrganicLayout( graph );

      // layout using morphing
      graph.getModel().beginUpdate();
      try
      {
         layout.execute( graph.getDefaultParent() );
      }
      finally
      {
         mxMorphing morph = new mxMorphing( graphComponent, 20, 1.2, 20 );

         morph.addListener( mxEvent.DONE, new mxIEventListener()
         {
            @Override
            public void invoke( Object arg0, mxEventObject arg1 )
            {
               graph.getModel().endUpdate();
               // fitViewport();
            }
         } );

         morph.startAnimation();
      }

But I got this exception:
Exception in thread "main" java.lang.NullPointerException
	at com.mxgraph.layout.mxGraphLayout.getVertexBounds(Unknown Source)
	at com.mxgraph.layout.mxFastOrganicLayout.execute(Unknown Source)
	at com.dii.fuzzy.gui.JGraphXAdapter.main(JGraphXAdapter.java:243)

Then I tried this code instead to do the layout and got the exact same
exception.

      mxFastOrganicLayout layout = new mxFastOrganicLayout( graph );

      // set some properties
      
      layout.setForceConstant( 40 ); // the higher, the more separated
      layout.setDisableEdgeStyle( false ); // true transforms the edges and
makes them direct lines

      // layout graph
      layout.execute( graph.getDefaultParent() );

Does anyone have an idea on how to avoid this exception when trying to
layout the graph?  Is it because I don't have the right cell location or
dimensions like that person posted?

Thanks,
Alex