1. Bar Graph Design

2. Left-side/Right-sidemechanical processingcreative, abstract reasoning 3. Why Is He Doing This? 4. The Problem: Two frames (Views) and a data structure (Model).Observer Pattern: 5. Observer Pattern Times Four: JTextField: ActionListener receives event after you hit .The ActionListener updates the Data (Model) object.JTextField ActionListener addActionListener actionPerformedanonymous object 6. Observer Pattern Times Four: Data: Is observed by the BarGraph (ChangeListener) for any changes to the model.Data ChangeListenerattach stateChangedBarGraph 7. Observer Pattern Times Four: BarGraph: MouseListener receives event when you click on the bar graph. mousePressed() moves the bar and updates Data object. BarGraph MouseListener addMouseListenermousePressedMouse Adapter 8. Observer Pattern Times Four: Data: Is observed by TextFrame (ChangeListener) for any changes to data.Data ChangeListenerattach stateChangedTextFrame 9. Class Diagram: 10. Sequence Diagram Enter new number 11. Sequence Diagram: Click on BarGraph: 12. Data.javapublic class Data { public Data(ArrayList d) { data = d; listeners = new ArrayList(); } public ArrayList getData() { return (ArrayList) (data.clone()); } public void attach(ChangeListener c) { listeners.add(c); } } 13. Data.javapublic class Data { public void update(int loc, double val) { if (val > MAX) val = MAX; if (val < 0) val = 0; data.set(loc, new Double(val)); // for each listener, let the listener know a change has occurred for (ChangeListener l : listeners) { l.stateChanged(new ChangeEvent(this)); } } public Double get(int i) { return data.get(i); } private ArrayList data; private ArrayList listeners; public static final double MAX = 100.0; } 14. TextFrame: public class TextFrame extends JFrame implements ChangeListener { public TextFrame (Data md) { d = md; ActionListener l = new ActionListener() { public void actionPerformed(ActionEvent e) { JTextField c = (JTextField) e.getSource(); int ndx = findBox(c); if (ndx >= 0) d.update(ndx,Double.parseDouble(c.getText().trim())); } }; JPanel tPanel = new JPanel(); tPanel.setLayout(new BoxLayout(tPanel,BoxLayout.PAGE_AXIS));... }}tf = new JTextField[5]; for (int i = 0; i < 5; i++) { tf[i] = new JTextField(10); tf[i].addActionListener(l); tPanel.add(tf[i]); } add(tPanel, BorderLayout.CENTER); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); pack(); setVisible(true); 15. TextFrame: @Override public void stateChanged(ChangeEvent e) { // how I notify the text frame if the bar graph changes for (int i = 0; i < 5; i++){ double d1 = d.get(i).doubleValue(); String s = tf[i].getText().trim(); double d2; try { d2 = Double.parseDouble(s); } catch(NumberFormatException nfe ) { d2 = 0.0; } if (Math.abs(d1 - d2) > 0.01) tf[i].setText(new Double(d1).toString()); } } public int findBox(JTextField t) { int i = 0; while (i < 5) { if (t == tf[i]) return i; i++; } return -1; }}private Data d; private JtextField[ ] tf; 16. BarGraph: public class BarGraph extends JFrame implements ChangeListener { public BarGraph(Data md) { d = md; setLocation(0,300); Icon barIcon = new Icon() { public int getIconWidth() { return WIDTH; } public int getIconHeight() { return HEIGHT; }}public void paintIcon(Component c, Graphics g , int x, int y) { Graphics2D g2 = (Graphics2D) g; Color cl = g2.getColor(); for (int i = 0; i < 5; i++) { Rectangle2D.Double rectangle = new Rectangle2D.Double(0, (HEIGHT/6)*i, WIDTH*(d.get(i).doubleValue()/Data.MAX), (HEIGHT/6)); g2.setPaint(Color.cyan); g2.fill(rectangle); g2.setColor(Color.black); g2.draw(rectangle); } Rectangle2D.Double rectangle = new Rectangle2D.Double(0,375,WIDTH,(HEIGHT/6)); g2.setPaint(cl); g2.fill(rectangle);g2.setColor(cl);g2.draw(rectangle); } }; // end of barIcon panel ... 17. BarGraph: public class BarGraph extends JFrame implements ChangeListener { public BarGraph(Data md) { ... add(new JLabel(barIcon)); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); MouseListener m = new MouseAdapter() { public void mousePressed(MouseEvent e){ Point2D p = e.getPoint(); double dy = p.getY(); int barToMove = (int)(dy / BARHEIGHT); if (barToMove < 0 || barToMove > 4) return; double dx = p.getX(); double newV = (dx/WIDTH)* Data.MAX; d.update(barToMove, newV);} }; addMouseListener(m); pack(); setVisible(true); } // end constructor } // end class