GUIs - Multimedia Introduction to Programming Using Java - page 467

E4. Write (and test) a subclass of JFrame that has five components:
• in the east, a JLabel that contains “EAST”;
• in the west, a JLabel that contains “WEST”;
• in the north, a JButton that says “north”;
• in the south, a JButton that says “south”;
• in the center, a JTextField that initially contains “this is a text field”.
Sections 17.1.2 and17.1.3 give you the necessary information.
E5. Write (and test) a subclass of JFrame that contains:
•a JLabel in the west that contains “color”;
•a JTextField in the east that initially contains: “red”;
Include a method getTheField() that returns the value in the JTextField , a
method setTheField(s) that changes the field to String s , and methods make-
FieldEditable() and makeFieldUneditable() with obvious meaning. Test
all this in the Interactions pane of DrJava by creating and showing an instance of
the subclass, calling the methods, and changing the value in the JTextField (by
typing into the field) several times. See Sec. 17.2.2.
E6. Write (and test) a subclass of JFrame that contains:
• a JTextArea in the west that initially contains: "The west\nwindow" and
has no scroll bars.
• a JTextArea in the east that initially contains: "The east\nwindow" and
has scrollbars, if necessary.
Make both of the text areas 6 rows by 10 columns. Using DrJava's Interactions
pane, create and show an instance of this subclass and experiment with typing
text into the two text areas.
Add methods dontWrap() and wrap() to the subclass, which cause the text
not to wrap and to wrap. Create and show an instance of this subclass and exper-
iment with typing text and the wrap-nowrap methods.
See Sec. 17.2.2.
E7. Write (and test) a subclass of JFrame that contains:
• a JTextArea in the west that initially contains: "The west\nwindow" and
has no scroll bars.
• a JTextArea in the east that initially contains: "The east\nwindow" and
has scrollbars, if necessary.
Make both of the text areas 6 rows by 10 columns. Include methods getWest-
Area() and getEastArea() that return the values in the text areas and methods
setEastArea(s) and setWestArea(s ) that change the fields to String s . Test
all this in the Interactions pane of DrJava by creating and showing an instance of
the subclass, calling the methods, and changing the values in the text areas (by
typing into them) several times. See Sec. 17.2.2.
E8. Write (and test) a subclass of JFrame that contains:
•a JCheckBox in the east, with title “rain”;
•a JRadioButton in the west, with title “hot”.