IsEDTExample.java Source code

Introduction

Here is the source code for IsEDTExample.java

Source

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);
    }

}