A JTree with JProgressBar's for its nodes

[Paul Statham]

Hi Folks,

GUI code is not my forte as you'll probably be able to tell, essentially I want to have what I've described in the title. I came across this stackoverflow answer http://stackoverflow.com/questions/7036036/adding-multiple-jprogressbar-to-tablecolumn-of-jtable/7036206#7036206 which is specific to a JTable.

I have butchered this and spent quite some time trying to do essentially the same thing but with a JTree instead. The problem I have is the progress bars do not automatically refresh as they do the JTable example I found, instead they only refresh when they are clicked on, for the life of me I can't work out why? Also the second problem I have is that when I first expand my JTree, the expand icon disappears! Here's the code

package com.testingarea;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.util.List;
import java.util.Random;

import javax.swing.BorderFactory;
import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JTree;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.WindowConstants;
import javax.swing.plaf.IconUIResource;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;

public class TestTreesThreaded {

  private DefaultMutableTreeNode root;
  private DefaultTreeModel model;

  private JTree tree = new JTree();

  private Component makeUI() {
    root = new DefaultMutableTreeNode();    
    tree.setCellRenderer(new ProgressBarRenderer());

    EventQueue.invokeLater(new Runnable() {
      @Override
      public void run() {
        //Start adding nodes to the root node and process
        //the values in the progress bar
        startTask(root, false);
        startTask(new DefaultMutableTreeNode(), true);
        startTask(new DefaultMutableTreeNode(), true);
        startTask(new DefaultMutableTreeNode(), true);
      }
    });
    model = new DefaultTreeModel(root);
    tree.setModel(model);
    JPanel p = new JPanel(new BorderLayout());    
    p.add(tree);
    return p;
  }  

  private void startTask(final DefaultMutableTreeNode treeNode, boolean isChild) {
    SwingWorker<Integer, Integer> worker = new SwingWorker<Integer, Integer>() {

      private int sleepDummy = new Random().nextInt(100) + 1;
      private int lengthOfTask = 120;

      @Override
      protected Integer doInBackground() throws Exception {
        int current = 0;
        while(current < lengthOfTask && !isCancelled()) {
          current++;
          try {
            Thread.sleep(sleepDummy);
          } catch (InterruptedException ie) {
            break;
          }
          publish(100 * current / lengthOfTask);
        }
        return sleepDummy * lengthOfTask;
      }

      /**
       * Attach a user object to the node, in this case
       * it is an Integer with the latest value triggered by publish
       * process will fire getTreeCellRendererComponent of the
       * ProgressBarRenderer
       */
      @Override
      protected void process(List<Integer> c) {
        treeNode.setUserObject(c.get(c.size() - 1));
      }

      @Override
      protected void done() {
        int i = -1;
        try {
          i = get();
        } catch (Exception e) {
          e.printStackTrace();
        }
        System.out.println("Value: " +i);
      }

    };
    if(isChild) {
      root.add(treeNode);
    }
    worker.execute();    
  }

  public static void main(String... args) {
    EventQueue.invokeLater(new Runnable() {

      @Override
      public void run() {
        createAndShowGUI();
      }
    });
  }

  public static void createAndShowGUI() {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    frame.getContentPane().add(new TestTreesThreaded().makeUI());
    frame.setSize(320, 240);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }

}

@SuppressWarnings("serial")
class ProgressBarRenderer extends DefaultTreeCellRenderer {

  private final JProgressBar b = new JProgressBar(0, 100);

  public ProgressBarRenderer() {
    super();    
    setOpaque(true);
    setClosedIcon(new IconUIResource(new NodeIcon('+')));
    setOpenIcon(new IconUIResource(new NodeIcon('-')));
    b.setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
  }

  @Override
  public Component getTreeCellRendererComponent(JTree tree, final Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
    if(((DefaultMutableTreeNode) value).getUserObject() instanceof String || ((DefaultMutableTreeNode) value).getUserObject() == null) {
      super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
      return this;
    }
    Integer i = (Integer) ((DefaultMutableTreeNode) value).getUserObject();
    b.setValue(i);
    b.setStringPainted(true);    
    return b;    
  }

  public JProgressBar getProgressBar() {
    return b;
  }

}

class NodeIcon implements Icon {

  private static final int SIZE = 9;

  private char type;

  public NodeIcon(char type) {
    this.type = type;
  }

  public void paintIcon(Component c, Graphics g, int x, int y) {
    g.setColor(UIManager.getColor("Tree.background"));
    g.fillRect(x, y, SIZE - 1, SIZE - 1);

    g.setColor(UIManager.getColor("Tree.hash").darker());
    g.drawRect(x, y, SIZE - 1, SIZE - 1);

    g.setColor(UIManager.getColor("Tree.foreground"));
    g.drawLine(x + 2, y + SIZE / 2, x + SIZE - 3, y + SIZE / 2);
    if (type == '+') {
      g.drawLine(x + SIZE / 2, y + 2, x + SIZE / 2, y + SIZE - 3);
    }
  }

  public int getIconWidth() {
    return SIZE;
  }

  public int getIconHeight() {
    return SIZE;
  }
}

[Paul Clapham]

I didn't read most of your code, but what has to happen is this: when a JProgressBar changes, it has to tell the model that it changed so that listeners to the model (i.e. the JTree) can react accordingly (i.e. redraw the node). If your tree model extends DefaultTreeModel, which apparently it does, that would require you to call "model.nodeChanged(treeNode)" where "treeNode" is the TreeNode object which contains that JProgressBar.

[Paul Statham]

Paul Clapham wrote:I didn't read most of your code, but what has to happen is this: when a JProgressBar changes, it has to tell the model that it changed so that listeners to the model (i.e. the JTree) can react accordingly (i.e. redraw the node). If your tree model extends DefaultTreeModel, which apparently it does, that would require you to call "model.nodeChanged(treeNode)" where "treeNode" is the TreeNode object which contains that JProgressBar.

Perfect thank you, I'm glad it was something simple!

[m Korbel]

Perfect thank you, I'm glad it was something simple!


- this notifier missing in JTree/DefaultTreeModel API

- you have to notify programatically by myTreeModel.nodeChanged()