Chat bubble in Java Swing

Harsh RavalAugust 2nd, 2012Last Updated: August 12th, 2015

1 577 2 minutes read

This article will explain you “how to draw chat bubble in java swing application?” Chat bubble is same as call-out or thought bubble. Today most of the chat application is showing conversion in this format, so this article will help you to do the same in desktop application made in java swing.

Following class is used to draw first chat bubble: (Arrow at the left side of bubble)

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.geom.Area;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JPanel;
/**
 * @author harsh
 */
public class LeftArrowBubble extends JPanel {
   private static final long serialVersionUID = -5389178141802153305L;
   private int radius = 10;
   private int arrowSize = 12;
   private int strokeThickness = 3;
   private int padding = strokeThickness / 2;
   @Override
   protected void paintComponent(final Graphics g) {
      final Graphics2D g2d = (Graphics2D) g;
      g2d.setColor(new Color(0.5f, 0.8f, 1f));
      int x = padding + strokeThickness + arrowSize;
      int width = getWidth() - arrowSize - (strokeThickness * 2);
      int bottomLineY = getHeight() - strokeThickness;
      g2d.fillRect(x, padding, width, bottomLineY);
      g2d.setRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING,   RenderingHints.VALUE_ANTIALIAS_ON));
      g2d.setStroke(new BasicStroke(strokeThickness));
      RoundRectangle2D.Double rect = new RoundRectangle2D.Double(x, padding, width, bottomLineY, radius, radius);
      Polygon arrow = new Polygon();
      arrow.addPoint(20, 8);
      arrow.addPoint(0, 10);
      arrow.addPoint(20, 12);
      Area area = new Area(rect);
      area.add(new Area(arrow));
      g2d.draw(area);
   }
}

Following code is to draw second chat bubble. (Arrow at the right side of bubble):

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.geom.Area;
import java.awt.geom.RoundRectangle2D;
import javax.swing.JPanel;
/**
 * @author harsh
 */
public class RightArrowBubble extends JPanel {
   private static final long serialVersionUID = -5389178141802153305L;
   private int strokeThickness = 3;
   private int radius = 10;
   private int arrowSize = 12;
   private int padding = strokeThickness / 2;
   @Override
   protected void paintComponent(final Graphics g) {
      final Graphics2D g2d = (Graphics2D) g;
      g2d.setColor(new Color(0.5f, 0.5f, 1f));
      int bottomLineY = getHeight() - strokeThickness;
      int width = getWidth() - arrowSize - (strokeThickness * 2);
      g2d.fillRect(padding, padding, width, bottomLineY);
      RoundRectangle2D.Double rect = new RoundRectangle2D.Double(padding, padding, width, bottomLineY,  radius, radius);
      Polygon arrow = new Polygon();
      arrow.addPoint(width, 8);
      arrow.addPoint(width + arrowSize, 10);
      arrow.addPoint(width, 12);
      Area area = new Area(rect);
      area.add(new Area(arrow));
      g2d.setRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON));
      g2d.setStroke(new BasicStroke(strokeThickness));
      g2d.draw(area);
   }
}

And here is the code for using above 2 classes:

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import java.awt.HeadlessException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.GroupLayout;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
/**
 * @author harsh
 */
public class TestPanel extends JPanel {
 private static final long serialVersionUID = 9029457020704524363L;
 private JLabel messageLbl1, userImageLbl1, messageLbl, userImageLbl;
    private JPanel msgPanel1, msgPanel;
    String userImageUrl = "http://cdn1.iconfinder.com/data/icons/nuvola2/22x22/apps/personal.png";
    public TestPanel() throws MalformedURLException {
        userImageLbl = new JLabel();
        msgPanel = new LeftArrowBubble();
        messageLbl = new JLabel();
        messageLbl1 = new JLabel();
        msgPanel1 = new RightArrowBubble();
        userImageLbl1 = new JLabel();
 
        userImageLbl.setIcon(new ImageIcon(new URL(userImageUrl)));
        messageLbl.setText("Hi, How are you?");
 
        GroupLayout msgPanelLayout = new GroupLayout(msgPanel);
        msgPanel.setLayout(msgPanelLayout);
        msgPanelLayout.setHorizontalGroup(
            msgPanelLayout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(msgPanelLayout.createSequentialGroup()
                .addGap(21, 21, 21)
                .addComponent(messageLbl)
                .addContainerGap(162, Short.MAX_VALUE))
        );
        msgPanelLayout.setVerticalGroup(
            msgPanelLayout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(msgPanelLayout.createSequentialGroup()
                .addComponent(messageLbl)
                .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
 
        messageLbl1.setIcon(new ImageIcon(new URL(userImageUrl)));
        userImageLbl1.setText("I'm Good.");
 
        GroupLayout jPanel1Layout = new GroupLayout(msgPanel1);
        msgPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(171, Short.MAX_VALUE)
                .addComponent(userImageLbl1)
                .addGap(22, 22, 22))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addComponent(userImageLbl1)
                .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
 
        GroupLayout layout = new GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(userImageLbl)
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.TRAILING)
                    .addComponent(msgPanel1, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(msgPanel, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addComponent(messageLbl1)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                    .addComponent(userImageLbl)
                    .addComponent(msgPanel, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                    .addComponent(messageLbl1)
                    .addComponent(msgPanel1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                .addContainerGap(22, Short.MAX_VALUE))
        );
    }
    public static void main(String[] args) {
  SwingUtilities.invokeLater(new Runnable() {
   public void run() {
    try {
     JOptionPane.showMessageDialog(null, new TestPanel());
    } catch (HeadlessException e) {
     e.printStackTrace();
    } catch (MalformedURLException e) {
     e.printStackTrace();
    }
   }
  });
 }
}