1. Object-Oriented Software Engineering
PersonGui (Mark 1)
Case Study

2. Contents The PersonGui (Mark1) The The Person Gui (Mark1) ToolBar
PersonGui Constructor
Adding Buttons
Making Buttons
Handling Events

3. The Person Gui (Mark1): Use Cases
user
Define Age
Define Height
Display Attributes

4. The Person Gui (Mark1): Class Diagram
<<interface>>
ActionListener 1
JPanel
PersonGui class
has caused the JPanel
(which it extends) to
be linked to a JToolBar
JTextArea 1
PersonGui 1
JToolBar 1
JTextField 1 1
JFrame 1 1
Person
private Double height
private Double age
void setAge (String)
void setHeight (String)
String getAge ()
String getHeight ()
String Attributes_Description ()

5. Person private Double height private Double age void setAge (String)
public void setAge (String stringAge) {
age = new Double(stringAge); }
public void setHeight (String stringHeight) {
height = new Double(stringHeight); }
Person
private Double height
private Double age
void setAge (String)
void setHeight (String)
String getAge ()
String getHeight ()
String Attributes_Description ()
public String getAge () {
return age.toString(); }
public String getHeight () {
return height.toString(); }
public String Attributes_Discription () {
return
"This Person has height "
+ getHeight() +
" and has age " + getAge() + "\n"; }

6. The Person Gui (Mark1)
JFrame
JTextArea
JToolBar
JTextField

7. PersonGui Constructor: JToolBar
(Full code available from course web site)
public PersonGui() {
super(new BorderLayout());
JToolBar toolBar = new JToolBar("Still draggable");
addButtons(toolBar);
toolBar.setFloatable(false);
toolBar.setRollover(true);
textArea = new JTextArea(5, 30);
textArea.setEditable(false);
JScrollPane scrollPane = new JScrollPane(textArea);
setPreferredSize(new Dimension(750, 430));
add(toolBar, BorderLayout.PAGE_START);
add(scrollPane, BorderLayout.CENTER); }

8. PersonGui Constructor
super(new BorderLayout());
Causes the enclosed code to
act on the super-class that extends
PersonGui.
In general for a class extension can
invoke methods of parent (super) class
via
super.method(x,y,z)

9. Here's what happens if we don't call super.
public PersonGui() {
//super(new BorderLayout());
new BorderLayout();
//Create the toolbar.
BorderLayout
now attached
to toolbar, not
JPanel

10. PersonGui Constructor
Internal method call
JToolBar toolBar = new JToolBar("Still draggable");
addButtons(toolBar);
toolBar.setFloatable(false);
toolBar.setRollover(true);
If the rollover state is true then border of the
toolbar buttons will be drawn only when the
mouse pointer hovers over them.

11. toolBar.setFloatable(true);

12. toolBar.setRollover(true);

13. addButtons method Internal method call causes actions on text field
protected void addButtons(JToolBar toolBar) {
JButton button = null;
// add first button
button = makeNavigationButton(PRINT_ATTRIBUTES,
"Prints a String containing ageString and heightString",
"Print Attributes");
toolBar.add(button);
// add second button
button = makeNavigationButton(AGE,
"Sets the value of ageString",
"Define Age");
toolBar.addSeparator();
textField.setColumns(10);
textField.addActionListener(this);
textField.setActionCommand(TEXT_ENTERED);
toolBar.add(textField); }
Internal method call
causes actions on text field
to be notified to 'this' (i.e PersonGui class)

14. makeNavigationButton method
protected JButton makeNavigationButton(String actionCommand,
String toolTipText,
String altText) {
//Create and initialize the button.
JButton button = new JButton();
button.setActionCommand(actionCommand);
button.setToolTipText(toolTipText);
button.addActionListener(this);
button.setText(altText);
return button; }
causes actions on button
to be notified to 'this'

15. button.setActionCommand(AGE);
button press causes an ActionEvent
object to be created, with an action
command string set to AGE
button.setToolTipText("Sets the value of ageString");
when mouse hovers over button this text will appear

16. button.addActionListener(this);
creates an ActionListener that
is attached to the PersonGui
class

17. Handling Events: Implementing interface
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
String description = null;
if (PRINT_ATTRIBUTES.equals(cmd)) { //first button clicked
String text = dude.Attributes_Discription();
description = text + newline
} else if (AGE.equals(cmd)) { // second button clicked
ageString = textField.getText();
dude.setAge(ageString);
description = "The age of the person in: " + ageString + newline;
textField.setText("");
} else if (HEIGHT.equals(cmd)) { // third button clicked
} else if (TEXT_ENTERED.equals(cmd)) { // text field }
displayResult(description);

18. actionPerformed(ActionEvent e)
button:JButton
PersonGui
addActionListener(this)
left_mouse_click
e:Action
Event
<<create>>
notify(e )
String cmd = e.getActionCommand();

19. actionPerformed(ActionEvent e)
else if (AGE.equals(cmd)) { // second button clicked
ageString = textField.getText();
dude.setAge(ageString);
description = "The age of the person in: "
+ ageString + newline;
textField.setText(""); }
:PersonGui
textField:
dude:Person
getText()
ageString
setAge(ageString);
setText("")

20. PersonGui textField: dude:Person
else if (HEIGHT.equals(cmd)) { // third button clicked
heightString = textField.getText();
dude.setHeight(heightString);
description = "The height of the person is: " + heightString + newline;
textField.setText(""); }
PersonGui
textField:
dude:Person
getText()
heightString
setHeight(heightString);
setText("")

21. PersonGui dude:Person
if (PRINT_ATTRIBUTES.equals(cmd)) { //first button clicked
String text = dude.Attributes_Discription();
description = text + newline; }
PersonGui
dude:Person
Attributes_Discription( )
text

22. displayResult method Makes sure next append will
protected void displayResult(String actionDescription) {
textArea.append(actionDescription + newline);
textArea.setCaretPosition(textArea.getDocument().getLength()); }
Adds text after caret current
position
Makes sure next append will
occur at the end of document.