MDI Form in SWING

(Creating MDI Form in SWING)Design a class, which extends JFrame and has three objects of three classes whose name are ColorPanel, CitiesPanel, and FlavourPanel. All the three classes (ColorPanel: Names of colors inside it, CitiesPanel: Names of cities inside it, and FlavourPanel- Names of Icecream flavours) extend JInternalFrame and have a method, which makes the Panel visible.

The main JFrame has an object of JDesktopPane and this object holds the three panels, which are displayed on the click of the menu bar item.

Packages used:

1.      javax.swing.*     : Provides a set of "lightweight" (all-Java language) components that, to the maximum degree possible, work the same on all platforms.

2.      java.awt.*            : Contains all of the classes for creating user interfaces and for painting graphics and images.

3.      java.awt.event.*    : Provides interfaces and classes for dealing with different types of events fired by AWT components.

Classes used:

·         JMenuBar   : An implementation of a menu bar. JMenu objects are added to the menu bar to construct a menu

·         JMenu         : An implementation of a menu -- a popup window containing JMenuItems that is displayed when the user selects an item on the JMenuBar.

·         JMenuItem   : An implementation of an item in a menu. A menu item is essentially a button sitting in a list.

·         JDesktopPane : A container used to create a multiple-document interface or a virtual desktop.

Logical flow of the program:

·         A menu is created with an object of JMenuBar which holds a JMenu object.

·         This JMenu object contains three JMenuItem objects,each attached to ActionListener.Clicking on those menuitems will lead to an JInternalFrame object on the JDesktopPane.

·         Object of JDesktopPane class is created which holds objects of JInternalFrame class.

·         Each JInternalFrame object contains a JPanel container holding different components.

Important Notes :

·         In all swing program the package that should be imported is “javax.swing.*”.

·         If in the program JApplet is inherited then the “init()” method is used to initialize the applet.

·         If in the program JFrame is inherited then the inheriting class’s constructor initializes the swing application.

1.      If super() method is called ,it should be the first line inside the constructor.

2.      Frame’s visibility and size must be set.