StatusBar.java

/*
 * Copyright (C) 2006 Sun Microsystems, Inc. All rights reserved. Use is
 * subject to license terms.
 */ 

package de.danielsenff.imageflow.gui;

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.Icon;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.Timer;
import javax.swing.border.EmptyBorder;

import org.jdesktop.application.Application;
import org.jdesktop.application.ResourceMap;
import org.jdesktop.application.TaskMonitor;



/**
 * A StatusBar panel that tracks a TaskMonitor.  Although one could certainly
 * create a more elaborate StatusBar class, this one is sufficient for the 
 * examples that need one.
 * <p>
 * This class loads resources from the ResourceBundle called
 * {@code resources.StatusBar}.
 * 
 */
public class StatusBar extends JPanel implements PropertyChangeListener {
	private final Insets zeroInsets = new Insets(0,0,0,0);
	private final JLabel messageLabel;
	private final JProgressBar progressBar;
	private final JLabel statusAnimationLabel;
	private final int messageTimeout;
	private final Timer messageTimer;
	private final Timer busyIconTimer;
	private final Icon idleIcon;
	private final Icon[] busyIcons = new Icon[15];
	private final int busyAnimationRate;
	private int busyIconIndex = 0;

	/**
	 * Constructs a panel that displays messages/progress/state 
	 * properties of the {@code taskMonitor's} foreground task.
	 * @param app 
	 * @param taskMonitor the {@code TaskMonitor} whose 
	 *     {@code PropertyChangeEvents} {@code this StatusBar} will track.
	 */
	public StatusBar(Application app, TaskMonitor taskMonitor) {
		super(new GridBagLayout());
		setBorder(new EmptyBorder(2, 0, 0, 0)); // top, left, bottom, right
		messageLabel = new JLabel();
		progressBar = new JProgressBar(0, 100);
		statusAnimationLabel = new JLabel();

		ResourceMap resourceMap = app.getContext().getResourceMap(StatusBar.class);
		messageTimeout = resourceMap.getInteger("messageTimeout");
		messageTimer = 	new Timer(messageTimeout, new ClearOldMessage()); 
		messageTimer.setRepeats(false);
		busyAnimationRate = resourceMap.getInteger("busyAnimationRate");
		idleIcon = resourceMap.getIcon("idleIcon");
		for (int i = 0; i < busyIcons.length; i++) {
			busyIcons[i] = resourceMap.getIcon("busyIcons[" + i + "]");
		}
		busyIconTimer = new Timer(busyAnimationRate, new UpdateBusyIcon()); 
		progressBar.setEnabled(false);
		statusAnimationLabel.setIcon(idleIcon);

		GridBagConstraints c = new GridBagConstraints();
		initGridBagConstraints(c);
		c.gridwidth = GridBagConstraints.REMAINDER;
		c.fill = GridBagConstraints.VERTICAL;
		c.weightx = 1.0;
//		add(new JSeparator(), c);

		initGridBagConstraints(c);
		c.insets = new Insets(6, 6, 0, 3); // top, left, bottom, right;
		c.weightx = 1.0;
		c.fill = GridBagConstraints.HORIZONTAL;
		add(messageLabel, c);

		initGridBagConstraints(c);
		c.insets = new Insets(6, 3, 0, 3); // top, left, bottom, right;
		add(progressBar, c);

		initGridBagConstraints(c);
		c.insets = new Insets(6, 3, 0, 6); // top, left, bottom, right;
		add(statusAnimationLabel, c);

		taskMonitor.addPropertyChangeListener(this);
	}

	public void setMessage(String s) {
		messageLabel.setText((s == null) ? "" : s);
		messageTimer.restart();
	}

	private void initGridBagConstraints(GridBagConstraints c) {
		c.anchor = GridBagConstraints.CENTER;
		c.fill = GridBagConstraints.NONE;
		c.gridwidth = 1;
		c.gridheight = 1;
		c.gridx = GridBagConstraints.RELATIVE;
		c.gridy = GridBagConstraints.RELATIVE;
		c.insets = zeroInsets;
		c.ipadx = 0;
		c.ipady = 0;
		c.weightx = 0.0;
		c.weighty = 0.0;
	}

	private class ClearOldMessage implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			messageLabel.setText("");
		}
	}

	private class UpdateBusyIcon implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			busyIconIndex = (busyIconIndex + 1) % busyIcons.length;
			statusAnimationLabel.setIcon(busyIcons[busyIconIndex]);
		}
	}

	/**
	 * 
	 */
	public void showBusyAnimation() {
		if (!busyIconTimer.isRunning()) {
			statusAnimationLabel.setIcon(busyIcons[0]);
			busyIconIndex = 0;
			busyIconTimer.start();
		}
	}

	/**
	 * 
	 */
	public void stopBusyAnimation() {
		busyIconTimer.stop();
		statusAnimationLabel.setIcon(idleIcon);
	}

	/** 
	 * The TaskMonitor (constructor arg) tracks a "foreground" task;
	 * this method is called each time a foreground task property
	 * changes.
	 */
	public void propertyChange(PropertyChangeEvent e) {
		String propertyName = e.getPropertyName();
		if ("started".equals(propertyName)) {
			showBusyAnimation();
			progressBar.setEnabled(true);
			progressBar.setIndeterminate(true);
		}
		else if ("done".equals(propertyName)) {
			stopBusyAnimation();
			progressBar.setIndeterminate(false);
			progressBar.setEnabled(false);
			progressBar.setValue(0);
		}
		else if ("message".equals(propertyName)) {
			String text = (String)(e.getNewValue());
			setMessage(text);
		}
		else if ("progress".equals(propertyName)) {
			int value = (Integer)(e.getNewValue());
			progressBar.setEnabled(true);
			progressBar.setIndeterminate(false);
			progressBar.setValue(value);
		}
	}
}