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AWT CardLayout Class

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CardLayout

Introduction

The class CardLayout arranges each component in the container as a card. Only one card is visible at a time, and the container acts as a stack of cards.

Class declaration

Following is the declaration for java.awt.CardLayout class:

public class CardLayout
   extends Object
      implements LayoutManager2, Serializable

Class constructors

S.N.Constructor & Description
1CardLayout()Creates a new card layout with gaps of size zero.
2CardLayout(int hgap, int vgap)Creates a new card layout with the specified horizontal and vertical gaps.

Class methods

S.N.Method & Description
1void addLayoutComponent(Component comp, Object constraints)Adds the specified component to this card layout’s internal table of names.
2void addLayoutComponent(String name, Component comp)If the layout manager uses a per-component string, adds the component comp to the layout, associating it with the string specified by name.
3void first(Container parent)Flips to the first card of the container.
4int getHgap()Gets the horizontal gap between components.
5float getLayoutAlignmentX(Container parent)Returns the alignment along the x axis.
6float getLayoutAlignmentY(Container parent)Returns the alignment along the y axis.
7int getVgap()Gets the vertical gap between components.
8void invalidateLayout(Container target)Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
9void last(Container parent)Flips to the last card of the container.
10void layoutContainer(Container parent)Lays out the specified container using this card layout.
11Dimension maximumLayoutSize(Container target)Returns the maximum dimensions for this layout given the components in the specified target container.
12Dimension minimumLayoutSize(Container parent)Calculates the minimum size for the specified panel.
13void next(Container parent)Flips to the next card of the specified container.
14Dimension preferredLayoutSize(Container parent)Determines the preferred size of the container argument using this card layout.
15void previous(Container parent)Flips to the previous card of the specified container.
16void removeLayoutComponent(Component comp)Removes the specified component from the layout.
17void setHgap(int hgap)Sets the horizontal gap between components.
18void setVgap(int vgap)Sets the vertical gap between components.
19void show(Container parent, String name)Flips to the component that was added to this layout with the specified name, using addLayoutComponent.
20String toString()Returns a string representation of the state of this card layout.

Methods inherited

This class inherits methods from the following classes:

  • java.lang.Object

CardLayout Example

Create the following java program using any editor of your choice in say D:/ > AWT > com > adglob > gui >AwtLayoutDemo.java

package com.adglob.gui;

import java.awt.*;
import java.awt.event.*;

public class AwtLayoutDemo {
   private Frame mainFrame;
   private Label headerLabel;
   private Label statusLabel;
   private Panel controlPanel;
   private Label msglabel;

   public AwtLayoutDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      AwtLayoutDemo  awtLayoutDemo = new AwtLayoutDemo();  
      awtLayoutDemo.showCardLayoutDemo();       
   }
      
   private void prepareGUI(){
      mainFrame = new Frame("Java AWT Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new Label();
      headerLabel.setAlignment(Label.CENTER);
      statusLabel = new Label();        
      statusLabel.setAlignment(Label.CENTER);
      statusLabel.setSize(350,100);

      msglabel = new Label();
      msglabel.setAlignment(Label.CENTER);
      msglabel.setText("Welcome to Adglob AWT Tutorial.");

      controlPanel = new Panel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }

   private void showCardLayoutDemo(){
      headerLabel.setText("Layout in action: CardLayout");      

      final Panel panel = new Panel();
      panel.setBackground(Color.CYAN);
      panel.setSize(300,300);

      CardLayout layout = new CardLayout();
      layout.setHgap(10);
      layout.setVgap(10);
      panel.setLayout(layout);        

      Panel buttonPanel = new Panel(new FlowLayout());

      buttonPanel.add(new Button("OK"));
      buttonPanel.add(new Button("Cancel"));    

      Panel textBoxPanel = new Panel(new FlowLayout());

      textBoxPanel.add(new Label("Name:"));
      textBoxPanel.add(new TextField(20));

      panel.add("Button", buttonPanel);
      panel.add("Text", textBoxPanel);

      Choice choice = new Choice();
      choice.add("Button");
      choice.add("Text");

      choice.addItemListener(new ItemListener() {
         public void itemStateChanged(ItemEvent e) {
            CardLayout cardLayout = (CardLayout)(panel.getLayout());
            cardLayout.show(panel, (String)e.getItem());
         }
      });
      controlPanel.add(choice);
      controlPanel.add(panel);

      mainFrame.setVisible(true);  
   }
}

Compile the program using command prompt. Go to D:/ > AWT and type the following command.

D:\AWT>javac com\adglob\gui\AwtlayoutDemo.java

If no error comes that means compilation is successful. Run the program using following command.

D:\AWT>java com.adglob.gui.AwtlayoutDemo

Verify the following output

CardLayout

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