CommentBox Help
Help is available for each task,
or you can go straight to the CommentBox
source code to see a solution.
Task 1
Create an Applet to hold one
instance of CommentBox so that you can test the component.
You need to create a class separate from your CommentBox class.
You can call it CommentBoxTest. In this class, create
an instance of CommentBox and add it to the container.
import java.awt.*;
public class CommentBoxTest extends java.applet.Applet {
public void init() {
CommentBox test = new CommentBox();
add(test);
}
}
Task 2
Create a class called CommentBox as a subclass of FormElement.
public class CommentBox extends FormElement {
...
}
Task 3
In the class CommentBox, create a centered Label and a TextArea below it. Make the TextArea display three lines of 55 characters.
You have to create a constructor to initialize the components needed by
the compound component, and add them to the current Container.
In this case, the Container is a Panel since FormElement subclasses Panel:
class CommentBox extends FormElement {
protected TextArea text;
protected String label = "Comments";
public CommentBox() {
setLayout(new BorderLayout());
text = new TextArea(3, 55);
add("North", new Label(label, Label.CENTER));
add("Center", text);
}
...
}
text and label are instance variables so that other methods
in this class will have access to them.
Task 4
Implement the method isEmpty of FormElement to return true if the TextArea is empty.
public boolean isEmpty() {
return text.getText().equals("");
}
Task 5
Implement the method getContents of FormElement. It should return the Label and the contents of the CommentBox.
public String getContents() {
return label + " " + text.getText();
}
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