CBSE Class 12 Informatics Practices GUI Dialogs And Tables Assignment

Brief Summary of the Chapter:

This chapter tells us about how we can create dialogs in Java Swing through NetBeans IDE.

KEY POINTS:
• A Dialog: It is a small separate window that appears to either provide or request to/from the user.
• Java Swing provides four dialog types: a) JDialog(General purpose dialogs) b) JOptionPane (Pre-defined styles) c) JFileChooser (dialog for choosing files) and d) JColorChooser(dialog for choosing colour)

• JOptionPane dialog Type:
There are four built-in dialog styles:
1) Message dialog → JOption.ShowMessageDialog() displays the message dialog
2) Input dialog → JOption.ShowInputDialog() displays the input dialog
3) Confirm dialog → JOption.ShowConfirmDialog() displays the confirm dialog
4) Option dialog → JOption.ShowOptionDialog() displays the option dialog

Solved Questions:

1. What is dialog in Java?
Ans: A dialog is a small separate window that appears to either provide or request to / from the user.

2. Write the import statement required for using JOptionPane class.
Ans: import javax.swing.JOptionPane;

3. What is showConfirmDialog ( ) method of JOptionPane class do ?
Ans: This method displays a dialog with several buttons and returns as int option type corresponding to the button pressed ( mostly one from Yes, No or Cancel)

4. What is showInputDialog ( ) method of JOptionPane class do ?
Ans: This method displays a dialog which is intended to receive user input, and returns a String if the input component is a text field. It displays two buttons : OK and Cancel.

5. What is the difference between a dialog created with JDialog and a dialog created with JOptionPane?
Ans: The dialog created with JDialog can be customised in any form the user wants. Also with JDialog, a window’s default cloasing behaviour is available with minimize, maximaize and close buttons.
A dialog created with JOptionPane can be one of the four pre-defined styles. Also, it only offers a close button for window closing.

Unsolved Questions:

1. What are the various type of dialog options supported by JOptionPane?

2. Name four methods associated with JOption dialog.

3. Explain the various possible value for Option type property of JOptionPane dialog.