Java Swing

Written by Shraddha Sheth Neel Shah

o Creating Windows o Creating a Window o Components and Containers o Basics of Components o Using Containers o Containers Layout Managers o Adding a Menu to a Window o Applets 

 JFC – JavaTM Foundation Classes  Encompass a group of features for constructing

graphical user interfaces (GUI).  Implemented without any native code.  “Swing” is the codename of the project that developed the first JFC components (JFC 1.11).  The name “Swing” is frequently used to refer to new components and related API.

JFC includes:  The Swing Components Dialog, Tabbed pane, Buttons, File Chooser, ...  Pluggable Look and Feel  Accessibility API Screen readers, Braille displays, ...  Java 2DTM API (Java 2 Platform only)  Drag and Drop (Java 2 Platform only) Between Java applications and native applications.

Each picture shows the same program but with a different look and feel javax.swing.plaf.metal.MetalLookAnd Feel

javax.swing.plaf.motif.MotifLookAndF eel

Javax.swing.plaf.windows.WindowsLo okAndFeel

 import javax.swing.UIManager;  static setLookAndFeel() method that is defined in the

UIManager class.  This method can throw an exception of ClassNotFoundException if the look-and-feel class cannot be found,  For example:  try {

 UIManager.setLookAndFeel(“com.sun.java.swing.plaf.mot

if.MotifLookAndFeel”);

 } catch(Exception e) {

 System.err.println(“Look and feel not set.”);

}

 UIManager.LookAndFeelInfo[]  looks =

UIManager.getInstalledLookAndFeels(); for( UIManager.LookAndFeelInfo look : looks)  System.out.println(look.getClassName());

Java Default Look And Feel  UIManager.setLookAndFeel

( UIManager.getCrossPlatformLookAndFeel( ));

Swing provides many standard GUI components

such as buttons, lists, menus, and text areas, which you combine to create your program's GUI. Swing provides containers such as a window.  top level: frames, dialogs  intermediate level: panel, scroll pane, tabbed pane, ...

View Components

Descendents of the java.awt.Container class Components that can contain other components. Use a layout manager to position and size the

components contained in them. Components are added to a container using one of the various forms of its add method  Depending on which layout manager is used by the

container

panel.add(component);

Every program that presents a Swing GUI

contains at least one top-level container. A Top level container provides the support that Swing components need to perform their painting and event-handling. Swing provides four top-level containers:  JFrame (Main window)  JDialog (Base For Dialogs)  JApplet (An applet display area within a browser

window)  JWindow (Secondary Display Devices)

 To appear on screen, every GUI component must

be part of a containment hierarchy, with a toplevel container as its root.  Each top-level container has a content pane that contains visible components in that top-level container’s GUI. A top-level container can not contain another

top level container.

A frame implemented as an instance of the

JFrame class, is a window that has decorations such as a border, a title and buttons for closing and iconifying the window. Applications with a GUI typically use at least one frame.

import javax.swing.*; public class HelloWorldSwing { public static void main(String[] args) { JFrame frame = new JFrame("HelloWorldSwing"); final JLabel label = new JLabel("Hello World"); frame.getContentPane().add(label); // OR USE THIS

frame.add(label);

// 1.4 JDK 5

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } }

Position (x,y) Name

.setName() .getName();

Size Foreground And Background Color Font Cursor State Visible Valid

(setEnabled ([True/False])) isEnable() (setVisible([True/False])) isVisible() isValid()

Position is defined by x and y coordinates of type int,

or by an object of type java.awt.Point. Size is defined by width and height, also values of

type int, or by an object of type java.awt.Dimension. A Rectangle specifies an area in a coordinate space

that is enclosed by the Rectangle object's upper-left point (x,y) in the coordinate space, its width, and its height.

The decorations on a frame are platform

dependent. A JApplet object has the same arrangement of panes as a JFrame object. Window class and its subclasses, as objects of type Window (or of a subclass type) can’t be contained in another container.