/*
  * Checks if the preferences have changed from the cached preferences.
  */
 private boolean prefsChanged() {
   return (prefs.getResolution() != resolution.getSelectedItem())
       || (prefs.getFullscreen() != fullscreen.isSelected())
       || (prefs.getBitrate() != bitrate.getValue())
       || (prefs.getUseOpenGlRenderer() != openGlRenderer.isSelected())
       || (prefs.getLocalAudio() != localAudio.isSelected());
 }
  /** Constructs all components of the frame and makes the frame visible to the user. */
  public void build() {

    JPanel mainPanel = new JPanel();
    mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));

    resolution = new JComboBox<Resolution>();
    for (Resolution res : Resolution.values()) {
      resolution.addItem(res);
    }

    resolution.setSelectedItem(prefs.getResolution());

    bitrateLabel = new JLabel("Maximum Bitrate = " + prefs.getBitrate() + " Mbps", JLabel.CENTER);
    bitrate = new JSlider(JSlider.HORIZONTAL, 0, 100, prefs.getBitrate());
    bitrate.setMajorTickSpacing(20);
    bitrate.setMinorTickSpacing(1);
    bitrate.setPaintLabels(true);
    bitrate.setPaintTicks(true);
    bitrate.setToolTipText(Integer.toString(bitrate.getValue()) + " Mbps");

    bitrate.addChangeListener(
        new ChangeListener() {
          public void stateChanged(ChangeEvent ce) {
            bitrate.setToolTipText(Integer.toString(bitrate.getValue()) + " Mbps");
            bitrateLabel.setText("Maximum Bitrate = " + bitrate.getValue() + " Mbps");
          }
        });

    resolution.addActionListener(
        new ActionListener() {
          public void actionPerformed(ActionEvent arg0) {
            Resolution newRes = (Resolution) resolution.getSelectedItem();
            bitrate.setValue(newRes.defaultBitrate);
          }
        });

    fullscreen = new JCheckBox("Fullscreen");
    fullscreen.setSelected(prefs.getFullscreen());

    openGlRenderer = new JCheckBox("Use OpenGL Renderer (Experimental)");
    openGlRenderer.setSelected(prefs.getUseOpenGlRenderer());

    localAudio = new JCheckBox("Play audio on host PC");
    localAudio.setSelected(prefs.getLocalAudio());

    Box resolutionBox = Box.createHorizontalBox();
    resolutionBox.add(Box.createHorizontalGlue());
    resolutionBox.add(resolution);
    resolutionBox.add(Box.createHorizontalGlue());

    Box bitrateLabelBox = Box.createHorizontalBox();
    bitrateLabelBox.add(Box.createHorizontalGlue());
    bitrateLabelBox.add(bitrateLabel);
    bitrateLabelBox.add(Box.createHorizontalGlue());

    Box bitrateBox = Box.createHorizontalBox();
    bitrateBox.add(Box.createHorizontalGlue());
    bitrateBox.add(bitrate);
    bitrateBox.add(Box.createHorizontalGlue());

    Box fullscreenBox = Box.createHorizontalBox();
    fullscreenBox.add(Box.createHorizontalGlue());
    fullscreenBox.add(fullscreen);
    fullscreenBox.add(Box.createHorizontalGlue());

    Box openGlRendererBox = Box.createHorizontalBox();
    openGlRendererBox.add(Box.createHorizontalGlue());
    openGlRendererBox.add(openGlRenderer);
    openGlRendererBox.add(Box.createHorizontalGlue());

    Box localAudioBox = Box.createHorizontalBox();
    localAudioBox.add(Box.createHorizontalGlue());
    localAudioBox.add(localAudio);
    localAudioBox.add(Box.createHorizontalGlue());

    mainPanel.add(Box.createVerticalStrut(10));
    mainPanel.add(resolutionBox);
    mainPanel.add(Box.createVerticalStrut(5));
    mainPanel.add(bitrateLabelBox);
    mainPanel.add(Box.createVerticalStrut(5));
    mainPanel.add(bitrateBox);
    mainPanel.add(Box.createVerticalStrut(5));
    mainPanel.add(fullscreenBox);
    mainPanel.add(Box.createVerticalStrut(5));
    mainPanel.add(openGlRendererBox);
    mainPanel.add(Box.createVerticalStrut(5));
    mainPanel.add(localAudioBox);
    mainPanel.add(Box.createVerticalGlue());

    this.addWindowListener(
        new WindowAdapter() {
          @Override
          public void windowClosing(WindowEvent e) {
            super.windowClosing(e);
            if (prefsChanged()) {
              writePreferences();
            }
          }
        });

    this.getContentPane().add(mainPanel);

    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
    // center on screen
    this.setLocation(
        (int) dim.getWidth() / 2 - this.getWidth() / 2,
        (int) dim.getHeight() / 2 - this.getHeight() / 2);

    this.setVisible(true);
  }