Re: Graph animation problem

[Yoann Pigné <yoann.pigne AT gmail.com>]

Hi Stephen, 

I guess the « walking »  class is somehow defined in your css file (that you 
did not provide). 

There are two errors in your code, in the actionPerformed of your button.

First, I guess you have a typo when you change the node attribute the second 
time. You might want to set another class than « walking » or maybe you want 
the remove that attribute (Node.removeAttribute()). 

Second, and it’s a major conceptual flaw, you cannot block the GUI thread 
with your « small pause ». When you do that, nothing gets updated in the UI. 
So you can’t expect to have the graph change colour or anything. 

I understand the « small  pause » simulates the time taken by an algorithm, 
but again you won’t be able to run the algorithm in the GUI thread **and** 
observe GUI modifications at the same time. 

The problem is not GraphStream here. You need to properly understand Swing’s 
concurrency model before you can go on with your project. 

I suggest you go read about this model and about SwingWorkers :  
https://docs.oracle.com/javase/tutorial/uiswing/concurrency/index.html

Good luck,
Yoann

> Le 11 mars 2017 à 21:24, Stephen Andrasi 
> <andristv94 AT gmail.com>
>  a écrit :
> 
> Hi, my name is Stephen.
> 
> I'm working on a project where my task is to make a graph algorithm 
> visualizer.
> 
> I have a Jbutton at the bottom of the window and above it there is the 
> graph.
> I have an "Animate" button to start the algorithm on the graph, but it does 
> not
> work.
> 
> I want to draw the edges step by step. (I added a little pause)
> What am I doing wrong? :( 
> 
> 
> 
> public class EZ{
> private static Graph graph = new SingleGraph("Graph");
> 
> public static class MyFrame extends JFrame
> {
>    private Viewer viewer = new
> Viewer(graph,Viewer.ThreadingModel.GRAPH_IN_GUI_THREAD);
>    private View view = viewer.addDefaultView(false);
>    private JButton button = new JButton("ASD");
>       public ViewerPipe pipe = viewer.newViewerPipe();
> 
>    public MyFrame()
>    {
> 
>       graph.addAttribute("ui.stylesheet", "url('src/style/graph.css')");
>       viewer.enableAutoLayout();
>       setLayout(new BorderLayout());
>       add((Component) view,BorderLayout.CENTER);
>       add(button, BorderLayout.AFTER_LAST_LINE);
>       setDefaultCloseOperation(EXIT_ON_CLOSE);
>       
>       button.addActionListener(new ActionListener() {
>           public void actionPerformed(ActionEvent e) {
>               
>                       graph.getNode("A").setAttribute("ui.class", 
> "walking");
>                       pipe.pump();
>                       long start = new Date().getTime();   // small pause 
>                       while(new Date().getTime() - start < 1000L){}
> 
>                       graph.getNode("A").setAttribute("ui.class", 
> "walking");
>                       pipe.pump();
>           }
>       });
>    }
> }
> 
> public static void main(String args[])
> {
>    SwingUtilities.invokeLater(new Runnable() 
>    {
> 
>       public void run() {
> 
>           graph.addNode("A").setAttribute("ui.label", "A");
>           graph.addNode("B").setAttribute("ui.label", "B");
>           graph.addNode("C").setAttribute("ui.label", "C");
>           graph.addEdge("AB", "A", "B").setAttribute("ui.label", "1");
>           graph.addEdge("BC", "B", "C").setAttribute("ui.label", "6");
>           graph.addEdge("CA", "C", "A").setAttribute("ui.label", "2");
>           
>           MyFrame frame = new MyFrame();
>           frame.setSize(500, 500);
>           frame.setLocationRelativeTo(null);
>           frame.setVisible(true);
>       }
>    });
> }
> }
> 
> 
> Greetings,
> Stephen