Bar Graph Design

Left-side/Right-side

mechanicalprocessing

creative,abstractreasoning

Why Is He Doing This?

The Problem:

Two frames (Views) and a data structure (Model).

Observer Pattern:

Observer Pattern Times Four:

JTextField: ActionListener receives event after you hit <return>.

The ActionListener updates the Data (Model) object.

JTextField

anonymousobject

ActionListener

addActionListener

actionPerformed

Observer Pattern Times Four:

Data: Is observed by the BarGraph (ChangeListener) for any changes to the model.

Data

BarGraph

ChangeListener

attach

stateChanged

Observer Pattern Times Four:

BarGraph: MouseListener receives event when you click on the bar graph.

mousePressed() moves the bar and updates Data object.

BarGraph

MouseAdapter

MouseListeneraddMouseListener

mousePressed

Observer Pattern Times Four:

Data: Is observed by TextFrame (ChangeListener) for any changes to data.

Data

TextFrame

ChangeListener

attachstateChanged

Class Diagram:

Sequence Diagram

Enter new number

Sequence Diagram:

Click on BarGraph:

Data.java

public class Data {public Data(ArrayList<Double> d) { data = d; listeners = new ArrayList<ChangeListener>(); }

public ArrayList<Double> getData() { return (ArrayList<Double>) (data.clone()); }

public void attach(ChangeListener c) { listeners.add(c); }

}

Data.java

public 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<Double> data; private ArrayList<ChangeListener> listeners; public static final double MAX = 100.0;

}

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);

}...}

TextFrame:

@Overridepublic void stateChanged(ChangeEvent e) {

// how I notify the text frame if the bar graph changesfor (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;

}

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 ...}

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