SWING - SpringLayout Class

---

---

Introduction

The class SpringLayout positions the children of its associated container according to a set of constraints.

Class Declaration

Following is the declaration for javax.swing.SpringLayout class −

public class SpringLayout
   extends Object
      implements LayoutManager2

Field

Following are the fields for javax.swing.SpringLayout class −

• static String BASELINE − Specifies the baseline of a component.

• static String EAST − Specifies the right edge of a component's bounding rectangle.

• static String HEIGHT − Specifies the height of a component's bounding rectangle.

• static String HORIZONTAL_CENTER − Specifies the horizontal center of a component's bounding rectangle.

• static String NORTH − Specifies the top edge of a component's bounding rectangle.

• static String SOUTH − Specifies the bottom edge of a component's bounding rectangle.

• static String VERTICAL_CENTER − Specifies the vertical center of a component's bounding rectangle.

• static String WEST − Specifies the left edge of a component's bounding rectangle.

• static String WIDTH − Specifies the width of a component's bounding rectangle.

Class Constructors

Class Methods

Methods Inherited

This class inherits methods from the following class −

• java.lang.Object

SpringLayout Example

Create the following Java program using any editor of your choice in say D:/ > SWING > com > tutorialspoint > gui >

SwingLayoutDemo.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SwingSpringLayout {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;

   public SwingSpringLayout(){
      prepareGUI();
   }
   public static void main(String[] args){
      SwingSpringLayout swingLayoutDemo = new SwingSpringLayout();  
      swingLayoutDemo.showSpringLayoutDemo();       
   }
   private void prepareGUI(){
      mainFrame = new JFrame("Java SWING Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      headerLabel = new JLabel("",JLabel.CENTER );
      statusLabel = new JLabel("",JLabel.CENTER);        
      statusLabel.setSize(350,100);
      
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });
		controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }
   private void showSpringLayoutDemo(){
      headerLabel.setText("Layout in action: SpringLayout");   
      SpringLayout layout = new SpringLayout();

      JPanel panel = new JPanel();
      panel.setLayout(layout);
      JLabel label = new JLabel("Enter Name: ");
      JTextField textField = new JTextField("", 15);
      panel.add(label);
      panel.add(textField);

      layout.putConstraint(SpringLayout.WEST, label,5, SpringLayout.WEST, controlPanel);
      layout.putConstraint(SpringLayout.NORTH, label,5, SpringLayout.NORTH, controlPanel);
      layout.putConstraint(SpringLayout.WEST, textField,5, SpringLayout.EAST, label);
      layout.putConstraint(SpringLayout.NORTH, textField,5, SpringLayout.NORTH, 
         controlPanel);
      
      layout.putConstraint(SpringLayout.EAST, panel,5, SpringLayout.EAST, textField);
      layout.putConstraint(SpringLayout.SOUTH, panel,5, SpringLayout.SOUTH, textField);
      controlPanel.add(panel);
      mainFrame.setVisible(true);  
   } 
}

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

D:\SWING>javac com\tutorialspoint\gui\SwingLayoutDemo.java

If no error occurs, it means the compilation is successful. Run the program using the following command.

D:\SWING>java com.tutorialspoint.gui.SwingLayoutDemo

Verify the following output.