package headfirst.combined.djview;    import java.awt.*;import java.awt.event.*;import javax.swing.*;public class DJView implements ActionListener,  BeatObserver, BPMObserver {	BeatModelInterface model;	ControllerInterface controller;    JFrame viewFrame;    JPanel viewPanel;	BeatBar beatBar;	JLabel bpmOutputLabel;    JFrame controlFrame;    JPanel controlPanel;    JLabel bpmLabel;    JTextField bpmTextField;    JButton setBPMButton;    JButton increaseBPMButton;    JButton decreaseBPMButton;    JMenuBar menuBar;    JMenu menu;    JMenuItem startMenuItem;    JMenuItem stopMenuItem;    public DJView(ControllerInterface controller, BeatModelInterface model) {			this.controller = controller;		this.model = model;		model.registerObserver((BeatObserver)this);		model.registerObserver((BPMObserver)this);    }        public void createView() {		// Create all Swing components here        viewPanel = new JPanel(new GridLayout(1, 2));        viewFrame = new JFrame("View");        viewFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        viewFrame.setSize(new Dimension(100, 80));        bpmOutputLabel = new JLabel("offline", SwingConstants.CENTER);		beatBar = new BeatBar();		beatBar.setValue(0);        JPanel bpmPanel = new JPanel(new GridLayout(2, 1));		bpmPanel.add(beatBar);        bpmPanel.add(bpmOutputLabel);        viewPanel.add(bpmPanel);        viewFrame.getContentPane().add(viewPanel, BorderLayout.CENTER);        viewFrame.pack();        viewFrame.setVisible(true);	}        public void createControls() {		// Create all Swing components here        JFrame.setDefaultLookAndFeelDecorated(true);        controlFrame = new JFrame("Control");        controlFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        controlFrame.setSize(new Dimension(100, 80));        controlPanel = new JPanel(new GridLayout(1, 2));        menuBar = new JMenuBar();        menu = new JMenu("DJ Control");        startMenuItem = new JMenuItem("Start");        menu.add(startMenuItem);        startMenuItem.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent event) {                controller.start();            }        });        stopMenuItem = new JMenuItem("Stop");        menu.add(stopMenuItem);         stopMenuItem.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent event) {                controller.stop();            }        });        JMenuItem exit = new JMenuItem("Quit");        exit.addActionListener(new ActionListener() {            public void actionPerformed(ActionEvent event) {                System.exit(0);            }        });        menu.add(exit);        menuBar.add(menu);        controlFrame.setJMenuBar(menuBar);        bpmTextField = new JTextField(2);        bpmLabel = new JLabel("Enter BPM:", SwingConstants.RIGHT);        setBPMButton = new JButton("Set");        setBPMButton.setSize(new Dimension(10,40));        increaseBPMButton = new JButton(">>");        decreaseBPMButton = new JButton("<<");        setBPMButton.addActionListener(this);        increaseBPMButton.addActionListener(this);        decreaseBPMButton.addActionListener(this);        JPanel buttonPanel = new JPanel(new GridLayout(1, 2));		buttonPanel.add(decreaseBPMButton);		buttonPanel.add(increaseBPMButton);        JPanel enterPanel = new JPanel(new GridLayout(1, 2));        enterPanel.add(bpmLabel);        enterPanel.add(bpmTextField);        JPanel insideControlPanel = new JPanel(new GridLayout(3, 1));        insideControlPanel.add(enterPanel);        insideControlPanel.add(setBPMButton);        insideControlPanel.add(buttonPanel);        controlPanel.add(insideControlPanel);                bpmLabel.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));        bpmOutputLabel.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));        controlFrame.getRootPane().setDefaultButton(setBPMButton);        controlFrame.getContentPane().add(controlPanel, BorderLayout.CENTER);        controlFrame.pack();        controlFrame.setVisible(true);    }	public void enableStopMenuItem() {    	stopMenuItem.setEnabled(true);	}	public void disableStopMenuItem() {    	stopMenuItem.setEnabled(false);	}	public void enableStartMenuItem() {    	startMenuItem.setEnabled(true);	}	public void disableStartMenuItem() {    	startMenuItem.setEnabled(false);	}    public void actionPerformed(ActionEvent event) {		if (event.getSource() == setBPMButton) {			int bpm = Integer.parseInt(bpmTextField.getText());        	controller.setBPM(bpm);		} else if (event.getSource() == increaseBPMButton) {			controller.increaseBPM();		} else if (event.getSource() == decreaseBPMButton) {			controller.decreaseBPM();		}    }	public void updateBPM() {		if (model != null) {			int bpm = model.getBPM();			if (bpm == 0) {				if (bpmOutputLabel != null) {        			bpmOutputLabel.setText("offline");				}			} else {				if (bpmOutputLabel != null) {        			bpmOutputLabel.setText("Current BPM: " + model.getBPM());				}			}		}	}  	public void updateBeat() {		if (beatBar != null) {			 beatBar.setValue(100);		}	}}