Is Event Dispatcher Thread : Swing Thread « Threads « Java






Is Event Dispatcher Thread

Is Event Dispatcher Thread
  

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;

import javax.swing.AbstractAction;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;

public class IsEDTExample extends JPanel {
  private boolean keepRunning;

  private static int RED = 0;

  private static int BLUE = 1;

  private static int GREEN = 2;

  private static int VARIABLE = 3;

  private static int SIZE = 3;

  private int threadShade;

  private ColorTableModel tableModel= new ColorTableModel();

  private Thread colorShadeThread;

  public IsEDTExample() {
    JTable table = new JTable(tableModel);
    table.setRowHeight(100);
    table.setDefaultRenderer(Object.class, new ColorRenderer());
    add(table);

    add(new JLabel("Thread Color Shade:"));
    ButtonGroup group = new ButtonGroup();
    JRadioButton redOption = new JRadioButton("Red");
    group.add(redOption);
    redOption.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        threadShade = RED;
      }
    });

    JRadioButton blueOption = new JRadioButton("Blue");
    group.add(blueOption);
    blueOption.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        threadShade = BLUE;
      }
    });

    JRadioButton greenOption = new JRadioButton("Green");
    group.add(greenOption);
    greenOption.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        threadShade = GREEN;
      }
    });

    redOption.setSelected(true);
    this.threadShade = RED;

    add(redOption);
    add(greenOption);
    add(blueOption);

    add(new JButton(new RandomColorAction()));

    this.keepRunning = true;
    this.colorShadeThread = new Thread(new RandomColorShadeRunnable());
    this.colorShadeThread.start();
  }

  private class RandomColorAction extends AbstractAction {
    public RandomColorAction() {
      super("Create Random Color");
    }

    public void actionPerformed(ActionEvent e) {
      IsEDTExample.this.tableModel.generateRandomColor(VARIABLE);
    }
  }

  private class ColorTableModel extends AbstractTableModel {
    private Color[][] colors = new Color[3][3];

    public ColorTableModel() {
      for (int i = 0; i < SIZE; i++) {
        for (int x = 0; x < SIZE; x++) {
          colors[i][x] = Color.white;
        }
      }
    }

    public int getRowCount() {
      return SIZE;
    }

    public int getColumnCount() {
      return SIZE;
    }

    public Object getValueAt(int rowIndex, int columnIndex) {
      return colors[rowIndex][columnIndex];
    }

    public void generateRandomColor(int type) {
      Random random = new Random(System.currentTimeMillis());
      final int row = random.nextInt(SIZE);
      final int column = random.nextInt(SIZE);
      final Color color;
      if (type == RED) {
        color = new Color(random.nextInt(256), 0, 0);
      } else if (type == BLUE) {
        color = new Color(0, 0, random.nextInt(256));
      } else if (type == GREEN) {
        color = new Color(0, random.nextInt(256), 0);
      } else {
        color = new Color(random.nextInt(256), random.nextInt(256), random.nextInt(256));
      }

      if (SwingUtilities.isEventDispatchThread()) {
        colors[row][column] = color;
        fireTableCellUpdated(row, column);
      } else {
        SwingUtilities.invokeLater(new Runnable() {
          public void run() {
            colors[row][column] = color;
            fireTableCellUpdated(row, column);
          }
        });
      }
    }
  }

  private class ColorRenderer implements TableCellRenderer {
    private JLabel label;

    public ColorRenderer() {
      label = new JLabel();
      label.setOpaque(true);
      label.setPreferredSize(new Dimension(100, 100));
    }

    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
        boolean hasFocus, int row, int column) {
      label.setBackground((Color) value);
      return label;
    }
  }

  private class RandomColorShadeRunnable implements Runnable {
    public void run() {
      while (keepRunning) {
        tableModel.generateRandomColor(threadShade);
        try {
          Thread.sleep(500);
        } catch (InterruptedException e) {
        }
      }
    }
  }

  public static void main(String[] a) {
    JFrame f = new JFrame("Is Event Dispatch Thread Example");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.add(new IsEDTExample());
    f.pack();
    f.setVisible(true);
  }

}
           
         
    
  








Related examples in the same category

1.GUI clock
2.Race Conditions using Swing ComponentsRace Conditions using Swing Components
3.Eliminating race Conditions using Swing ComponentsEliminating race Conditions using Swing Components
4.Using the Runnable interfaceUsing the Runnable interface
5.Write your Beans this way so they can run in a multithreaded environmentWrite your Beans this way so they can run in a multithreaded environment
6.User interface responsiveness
7.InvokeExample: Swing and threadInvokeExample: Swing and thread
8.Counter: Swing and threadCounter: Swing and thread
9.Thread accuracy: Swing and threadsThread accuracy: Swing and threads
10.Swing and thread: invoke and waitSwing and thread: invoke and wait
11.Swing and threads: invoke laterSwing and threads: invoke later
12.Swing and threads: slideSwing and threads: slide
13.Swing and threads: scroll textSwing and threads: scroll text
14.Animation: Swing and threadAnimation: Swing and thread
15.Swing and Thread for length operationSwing and Thread for length operation
16.Swing and Thread: cancel a lengthy operationSwing and Thread: cancel a lengthy operation
17.Swing and Thread: repaintSwing and Thread: repaint
18.Thread and Swing 1Thread and Swing 1
19.Thread and Swing 2Thread and Swing 2
20.Thread and Swing 3Thread and Swing 3
21.Swing Type Tester 10Swing Type Tester 10
22.Swing and Threading
23.SwingUtilities.invokeLater and swing thread
24.An abstract class to perform lengthy GUI-interacting tasks in a dedicated thread.
25.This program demonstrates that a thread that runs in parallel with the event dispatch thread can cause errors in Swing components