Transparent JFrame using JNA

In Make JFrame transparent I had shown a way to making frame’s transparent using AWTUtilities class. But using that class results in access restriction compile time error, resolution in Eclipse is also shown in that post. Now here is the version using java natives. I have used Java Native Access (JNA) library to call native functions to get the things done.

What is Java Native Access (JNA)?

JNA provides Java programs easy access to native shared libraries (DLLs on Windows) without writing anything but Java code—no JNI or native code is required.JNA allows you to call directly into native functions using natural Java method invocation.

The Code

import javax.swing.JFrame;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

import com.sun.jna.platform.WindowUtils;

public class TransparentFrame extends JFrame {
   public TransparentFrame() {
      setTitle("Transparent Frame");
      setSize(400,400);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      JSlider slider = new JSlider(JSlider.HORIZONTAL, 30, 100, 100);

      slider.addChangeListener(new ChangeListener() {
         @Override
         public void stateChanged(ChangeEvent e) {
            JSlider slider = (JSlider) e.getSource();
            if(!slider.getValueIsAdjusting()){
               WindowUtils.setWindowAlpha(TransparentFrame.this, slider.getValue()/100f);
            }
         }
      });
      add(slider);
      setVisible(true);
   }
   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
	 @Override
	 public void run() {
	    new TransparentFrame();
	 }
      });
   }
}

Here WindowUtils class is provided in JNA jar (platform.jar). The method setWindowAlpha of WindowUtils class is used to make a window transparent. First argument of this method is your frame/window and second argument is alpha value. This class also has a method called setWindowTransparent, which can also be used to make window transparent .

Dependencies

You will need following 2 jars to run this program: (Both jar files are available to download on GitHub for JNA.)

  • jna.jar
  • platform.jar

To run above code on Windows, you will need to set “sun.java2d.noddraw” system property before calling the WindowUtils function.

System.setProperty("sun.java2d.noddraw", "true");

Output

Additional Notes

I have tested this code on following machines:

  • Windows XP service pack 3 (32 bit)
  • Windows 7 (32 bit)
  • Cent OS 5 (32 bit)

If you test it on other machines or have code for other machines using JNA for the same functionality then feel free to share it as comment to this post.

Chat bubble in java swing

chatBubble

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:

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();
				}
			}
		});
	}
}

At least try it once and feel free to comment about it. 🙂

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