COP3330-02 Object-Oriented Programming

Spring 2003

Program 5 (GUI)

Due: April 17, 2003

Objectives:

The objectives of this assignment are to get hands-on experience:

• using containers such as JFrame
• using graphical components such as JButton
• adding graphical components to containers
• controlling the arrangement of the components using layout managers
• using anonymous inner classes for event handling
• writing text data to files

Overview:

You will create an application that allows the user to create journal entries. The user will enter a date, specify the nature of the entry, enter the text of the entry, and save the entry to disk. The nature of any entry is either personal or business.

Warning:

You are to follow these instructions precisely. Although you are encouraged to experiment with other widgets, do not do so on this program. You are free to accomplish the GUI initialization in any order that you choose. You are free to choose your own variable names if they are not specified here.

Specifics:

You will write 2 classes: JournalFrame and JournalApp.

Class 1: JournalFrame:

The following template should be used:

public class JournalFrame extends JFrame {

// date label, textfield, and containing panel

private JLabel dateLabel = new JLabel("Date: ");

private JTextField dateField = new JTextField(20);

private JPanel datePanel = new JPanel(new FlowLayout());

...

public JournalFrame() {

...

}

private void initWidgets() {

...

}

private void saveEntry() {

...

}

} // JournalFrame

The class JournalFrame,

• Declares all widgets as private instance variables.
• Does all widget configuration in the initWidgets method.
• Is a subclass of JFrame.
• Exits the program when closed (Hint: call setDefaultCloseOperation in initWidgets).
• Has a no-arg constructor:
• Calls superclass constructor with title of window. (Title can be hard-coded string of your choosing).
• Calls initWidgets method.
• Has a content pane with a BorderLayout. Hint: A reference to the content pane of the frame can be retrieved using getContentPane().
• Contains 5 JPanels that are added directly to the content pane using the given constraints (i.e. NORTH, CENTER, etc).
• datePanel (NORTH)
• Contains a JLabel (with the text “Date: “).
• Contains a JTextField
• No text initially.
• Displays 20 characters.
• Layout is FlowLayout.
• radioPanel (WEST)
• Contains 2 JRadioButtons.
• personalButton (with the text “Personal”). Should be selected by default.
• businessButton (with the text “Business”).
• Layout is GridLayout (0 rows, 1 column).
• The buttons are mutually exclusive. Exactly one is selected at all times. Hint: ButtonGroup.
• statusPanel (SOUTH)
• Contains a JLabel (no text initially).
• Layout is FlowLayout.
• textAreaPanel (CENTER)
• Contains a JTextArea.
• No text initially.
• 10 rows by 30 columns.
• Layout is GridLayout (0 rows, 1 column).
• buttonPanel (EAST)
• Contains 2 JButtons
• clearButton (with the text “Clear Journal Entry”).
• When clicked,
• Sets text in date field to “”. Hint: use setText().
• Sets text in text area to “”.
• Sets status label to “”.
• You must use an anonymous inner class for this!
• saveButton (with the text “Save Journal Entry”).
• When clicked,
• Calls private saveEntry method.
• You must use an anonymous inner class for this!
• Layout is GridLayout (0 rows, 1 column).
• Has an initWidgets method.
• Prepares components.
• Sets up containment hierarchy (i.e. adds components to containers).
• Calls the pack method.
• Has a saveEntry method.
• If the personal button is selected,
• File to append to is personal.txt. (Hint: For append functionality, see available constructors for FileWriter).
• Else
• File to append to is business.txt. Do not use absolute paths on either of the filenames!
• Open file and write: (You must use a BufferedWriter!)
• Date field contents then advance a line. Hint: FileWriter.newLine().
• Text area contents then advance a line.
• Close the file.
• If an IOException occurs,
• Set status text to “Error: Entry could not be saved.”.
• Otherwise
• Clear date field.
• Clear text area.
• Set status text to “Saved journal entry!”.

Class 2: JournalApp:

• Has a main method.
• Instantiates a JournalFrame.
• Sets the frame visible.

Screenshots:

Your windows should look like these:

Figure 1 Prior to Saving

Figure 2 After Sucessful Save

Figure 3 After Unsuccessful Save

Figure 4 Panel Breakdown

Submittal:

Submittals should follow the program specifications of the class.

Write-up:

There is no write-up required for this program.

Tips:

· In the examples page, there is a class called ConsoleToFile (in the Input/Output download) that demonstrates how to write character data to a file.

· In the examples page, there are plenty of GUI classes (in the GUI download) to use as examples.