1. Object-Oriented Software Engineering
PersonGui (Mark 2)
Case Study (cntd)

2. Contents PersonGui (Mark 2) Class Daigram PersonMaker Class
Handling user input with dialogs
Sequence Diagram for Dailogs
Show Person Attributes Sequence Diagram
Person Class Diagram
Person Constructor Sequence Diagram
JFileChooser

3. Class Diagram JPanel JTextArea ActionListener JToolBar JScrollPane
<<interface>>
ActionListener
JTextArea 1
JToolBar 1
JScrollPane
PersonGui 1
JTextField 1
JFrame 1
<<abstract>>
MouseAdapter
PersonMaker 1 1 *
PopupListener
Person

4. <<interface>>
The PersonMaker Class
JPanel
<<interface>>
ActionListener
JToolBar
PersonGui
PersonMaker
Basic classes
defining application
Person

5. PersonMaker Class PersonGui Mark 1 Could only display
one set of attributes.
Only needed one instance
of Person class.

6. PersonMaker Class PersonGui Mark 2 Creates many instances of Person.
PersonMaker manages this functionality
on behalf of the PersonGui class

7. PersonMaker Use Case user Define Age :PersonGui dude:PersonMaker
setAge(ageString);

8. PersonMaker setAge method
public void setAge (String stringAge) {
string_age = stringAge;
try {
age = new Double(stringAge);
} catch (NumberFormatException exp1) {
string_age = handleTextInput("Age");
//Why could this result in an error?
age = new Double(string_age); }
instance field, stores original string so that if numeric value
is flawed can still refer to original during lifetime of
object
Attempt to convert string to
numeric value of type
Double.
Exception causes dialog
box via
handleTextInput.
See Lecture 5 for exception handling.
Full code available on web site

9. PersonMaker handleTextInput
public String handleTextInput (String dis_text) {
String s =
(String)JOptionPane.showInputDialog(
null,
dis_text,
"PersonMaker Class",
JOptionPane.PLAIN_MESSAGE,
"Fluffy");
return s; }

10. PersonMaker handleTextInput
JOptionPane.showInputDialog causes this dialog to appear

11. handleTextInput Sequence Diagram
Option Dialog has
anonymous buttons
Static method,
invoked on class
not object
dude:
PersonMaker
:JButton
JOptionPane
showInputDialog( )
left_mouse_click
e:Action
Event
<<create>>
notify(e )
query event
String s
Represents approximately events that occur in handleTextInput

12. <<include>>
PersonMaker Use Case
PersonGui
dude:Person
Make_Person( )
user
text
Display Attributes in
seperate JFrame
Choose Image
for Person
<<include>>

13. containing attributes
public String Make_Person ( ) {
Show_Attributes_InFrame ( );
return
"This Person has these attributes: \n " +
"\n\tFirst Name \t= " + getFirstName( ) +
"\n\tLast Name \t= " + getLastName( ) +
"\n\tHeight \t= " + getPersonHeight( ) +
"\n\tAge \t= " + getPersonAge( ) + "\n"; }
Calls internal method
to construct JFrame
containing attributes
Returns composite
string of attributes
to be displayed in
JTextArea

14. Show_Attributes_InFrame
newContentPane
:Person
dude:Person
frame:JFrame
<<create>>
Content Pane of
JFrame is instance
of Person Class.
(This class is
responsible for
choice of image.)
<<create>>
setContentPane
(newContentPane)
pack( )
setVisible(true)
Three classes used
to create JFrame
and its contents.
Shows contents of
JFrame can be
completely separate
from its container

15. <<interface>>
Person Class Diagram
<<interface>>
ActionListener
JPanel
Person
GridBagLayout
File
JFileChooser
Depends on these classes.
I.e. has local fields that are
instances of these classes.
See lecture 6 for more details.

16. Person Constructor Sequence Diagram
file:File
<<create>>
fc:JFileChooser
<<create>>
getSelectedFile( )
file
label_drag:
JLabel
<<create>> from dragon
dragon:
ImageIcon
<<create>> from imgURL
imgURL:
java.net.URL
<<create>> from icon_file_name
getCanonicalPath( )
icon_file_name
Finally add new JLabel to GridBagLayout.
Note this is only approximate description.

18. Creating an ImageIcon
When creating ImageIcon from a string value, need to use different code than that of the createImageIcon method
try {
java.net.URL imgURL = new URL("file:///"+icon_file_name);
dragon = new ImageIcon(imgURL, "new icon image");
label_drag = new JLabel(dragon);
} catch (java.net.MalformedURLException exp1) {
System.out.println("MalformedURLException : \n"
+ icon_file_name + "\n====\n"); }
Section of code in Person constructor that makes an ImageIcon from the string given by the JFileChooser

19. The JFileChooser Class
int returnVal = fc.showOpenDialog(Person.this);
Returns an integer.
Also uses static fields to store data about choice
of file for later use.

20. JFileChooser Class Diagram
JComponent
JFileChooser
public static int APPROVE_OPTION
public static int CANCEL_OPTION
public void showOpenDialog(Component parent)
public File getSelectedFile( )
(Only some of the fields and methods are shown here)

21. JFileChooser Constructor
JFileChooser(File currentDirectory)
Constructs a JFileChooser using the given File as the path.
JFileChooser()
Constructs a JFileChooser pointing to the user's default directory.
String cwd = "images";
file = new File(cwd);
if (file != null) {
fc = new JFileChooser(file);
} else {
fc = new JFileChooser(); }

22. The approve option int returnVal = fc.showOpenDialog(Person.this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
file = fc.getSelectedFile();
// now do something with the file
// in our case create an icon image from it }

23. The cancel option int returnVal = fc.showOpenDialog(Person.this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
file = fc.getSelectedFile();
// now do something with the file
// in our case create an icon image from it
} else if (returnVal == JFileChooser.CANCEL_OPTION ) {
// now do something in case where user
// cancels selection }