To Demonstrate GridBag Layout Program using Java | Internet Programming Lab Exercise

Algorithm Steps:

Step 1: Write a html applet tag with code property set to class name and comment the tag

Step 2: Import all necessary packages

Step 3: Define a class which extends applet class

Step 4: Declare all the necessary awt controls to be included in the purchase form

Step 5: In the init() method, do the following:

           i) Create a gridbag layout and set the applet's layout to gridbag layout

           ii) Create a gridbag constraint

           iii) Create a awt control

           iv) Set the gridbag constraints for this control

           v) Add the control to the applet

          vi) Similarly do the steps from iii) to v) for all other control

Java Program To Demonstrate GridBag Layout

import java.awt.*; import javax.swing.JButton; import javax.swing.JFrame; public class GridBagLayoutDemo { final static boolean shouldFill = true; final static boolean shouldWeightX = true; final static boolean RIGHT_TO_LEFT = false; public static void addComponentsToPane(Container pane) { if (RIGHT_TO_LEFT) { pane.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT); } JButton button; pane.setLayout(new GridBagLayout()); GridBagConstraints c = new GridBagConstraints(); if (shouldFill) { //natural height, maximum width c.fill = GridBagConstraints.HORIZONTAL; } button = new JButton("Button 1"); if (shouldWeightX) { c.weightx = 0.5; } c.fill = GridBagConstraints.HORIZONTAL; c.gridx = 0; c.gridy = 0; pane.add(button, c); button = new JButton("Button 2"); c.fill = GridBagConstraints.HORIZONTAL; c.weightx = 0.5; c.gridx = 1; c.gridy = 0; pane.add(button, c); button = new JButton("Button 3"); c.fill = GridBagConstraints.HORIZONTAL; c.weightx = 0.5; c.gridx = 2; c.gridy = 0; pane.add(button, c); button = new JButton("Long-Named Button 4"); c.fill = GridBagConstraints.HORIZONTAL; c.ipady = 40; //make this component tall c.weightx = 0.0; c.gridwidth = 3; c.gridx = 0; c.gridy = 1; pane.add(button, c); button = new JButton("5"); c.fill = GridBagConstraints.HORIZONTAL; c.ipady = 0; //reset to default c.weighty = 1.0; //request any extra vertical space c.anchor = GridBagConstraints.PAGE_END; //bottom of space c.insets = new Insets(10,0,0,0); //top padding c.gridx = 1; //aligned with button 2 c.gridwidth = 2; //2 columns wide c.gridy = 2; //third row pane.add(button, c); } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("GridBagLayoutDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Set up the content pane. addComponentsToPane(frame.getContentPane()); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }

SAMPLE OUTPUT SCREEN:

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