Add image to JPanel

[maja neskovic]

Hello!

I have made applet using Swing, which has one JPanel and one DesktopPane with labels and sliders. I want to draw shapes and images on JPanel, but I don't know how to do it. I tried to draw image, but I lose all my panels and got just picture. I think that main problem is that I don't know how to access to my JPanel on which I want to draw and then to make drawing. Can anybody help?

Here is my code (I made JFrame with all JPanel and DesktopPane and then copied code to applet ):

 
package org.me.pack;

import javax.swing.JApplet;
import javax.swing.ImageIcon;
import javax.swing.JApplet;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
import javax.swing.Timer;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedInputStream;

public class NewJApplet extends JApplet {
 private javax.swing.JLabel brrutera;
    private javax.swing.JPanel glavnipanel;
    private javax.swing.JSlider jSlider1;
    private javax.swing.JDesktopPane panel1;
    private javax.swing.JLabel plus1;
    private javax.swing.JLabel plus2;
    private javax.swing.JLabel protok;
    private javax.swing.JSlider slider1;
    private javax.swing.JSlider slider2;
    private javax.swing.JSlider slider3;
    private javax.swing.JSlider slider4;
    private javax.swing.JLabel tl;
    private javax.swing.JTextField tp;
    private javax.swing.JTextField tq;
    private javax.swing.JTextField tt;
    private javax.swing.JLabel udaljenost;
    private javax.swing.JLabel velicina;
    
    public void init() {
        panel1 = new javax.swing.JDesktopPane();
        jSlider1 = new javax.swing.JSlider();
        slider1 = new javax.swing.JSlider();
        velicina = new javax.swing.JLabel();
        udaljenost = new javax.swing.JLabel();
        slider2 = new javax.swing.JSlider();
        brrutera = new javax.swing.JLabel();
        slider3 = new javax.swing.JSlider();
        protok = new javax.swing.JLabel();
        slider4 = new javax.swing.JSlider();
        tl = new javax.swing.JLabel();
        plus1 = new javax.swing.JLabel();
        plus2 = new javax.swing.JLabel();
        tt = new javax.swing.JTextField();
        tp = new javax.swing.JTextField();
        tq = new javax.swing.JTextField();
        glavnipanel = new javax.swing.JPanel();

         panel1.setBackground(new java.awt.Color(255, 255, 255));
        panel1.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0), 1, true));
        jSlider1.setBounds(-200, -70, 200, 70);
        panel1.add(jSlider1, javax.swing.JLayeredPane.DEFAULT_LAYER);

        slider1.setBackground(new java.awt.Color(255, 255, 255));
        slider1.setPaintLabels(true);
        slider1.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
        slider1.setBounds(190, 10, 200, 25);
        panel1.add(slider1, javax.swing.JLayeredPane.DEFAULT_LAYER);

        velicina.setText("Odaberite veličinu fajla (u MB):");
        velicina.setBounds(10, 20, 180, 14);
        panel1.add(velicina, javax.swing.JLayeredPane.DEFAULT_LAYER);

        udaljenost.setText("Udaljenost (u km)");
        udaljenost.setBounds(10, 50, 170, 14);
        panel1.add(udaljenost, javax.swing.JLayeredPane.DEFAULT_LAYER);

        slider2.setBackground(new java.awt.Color(255, 255, 255));
        slider2.setBounds(190, 40, 200, 25);
        panel1.add(slider2, javax.swing.JLayeredPane.DEFAULT_LAYER);

        brrutera.setText("Broj rutera:");
        brrutera.setBounds(10, 80, 170, 14);
        panel1.add(brrutera, javax.swing.JLayeredPane.DEFAULT_LAYER);

        slider3.setBackground(new java.awt.Color(255, 255, 255));
        slider3.setBounds(190, 70, 200, 25);
        panel1.add(slider3, javax.swing.JLayeredPane.DEFAULT_LAYER);

        protok.setText("Protok (u MB/s):");
        protok.setBounds(10, 110, 170, 14);
        panel1.add(protok, javax.swing.JLayeredPane.DEFAULT_LAYER);

        slider4.setBackground(new java.awt.Color(255, 255, 255));
        slider4.setBounds(190, 100, 200, 25);
        panel1.add(slider4, javax.swing.JLayeredPane.DEFAULT_LAYER);

        tl.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
        tl.setText("Tl =");

        plus1.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
        plus1.setText("+");

        plus2.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
        plus2.setText("+");

        tt.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
        tt.setText("Tt");
        tt.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
            }
        });

        tp.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
        tp.setText("Tp");
        tp.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
            }
        });

        tq.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
        tq.setText("Tq");
        tq.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
            }
        });

        glavnipanel.setBackground(new java.awt.Color(255, 255, 255));
        glavnipanel.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));

        javax.swing.GroupLayout glavnipanelLayout = new javax.swing.GroupLayout(glavnipanel);
        glavnipanel.setLayout(glavnipanelLayout);
        glavnipanelLayout.setHorizontalGroup(
            glavnipanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 563, Short.MAX_VALUE)
        );
        glavnipanelLayout.setVerticalGroup(
            glavnipanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 212, Short.MAX_VALUE)
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(glavnipanel, javax.swing.GroupLayout.Alignment.LEADING,
javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
                        .addComponent(panel1, javax.swing.GroupLayout.PREFERRED_SIZE, 397, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(30, 30, 30)
                        .addComponent(tl)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(tt, javax.swing.GroupLayout.PREFERRED_SIZE,
 javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(plus1)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(tp, javax.swing.GroupLayout.PREFERRED_SIZE,
 javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(plus2)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(tq, javax.swing.GroupLayout.PREFERRED_SIZE,
 javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(glavnipanel, javax.swing.GroupLayout.DEFAULT_SIZE, 
javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(tl)
                        .addComponent(plus1)
                        .addComponent(tt, javax.swing.GroupLayout.PREFERRED_SIZE,
 javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(tp, javax.swing.GroupLayout.PREFERRED_SIZE,
 javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(plus2)
                        .addComponent(tq, javax.swing.GroupLayout.PREFERRED_SIZE,
 javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(panel1, javax.swing.GroupLayout.PREFERRED_SIZE, 141, 
javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap())
        );


    }



}

   

[Maneesh Godbole]

Check out http://faq.javaranch.com/java/BackgroundImageOnJPanel

[maja neskovic]

I already saw it, but I am not sure that I understand. How to specify that I want drawing image and shapes on my JPanel (which is in JApplet)?

[Maneesh Godbole]

maja neskovic wrote:I already saw it, but I am not sure that I understand. How to specify that I want drawing image and shapes on my JPanel (which is in JApplet)?

Strange. The code you posted does not attempt any painting at all.

1) Subclass JPanel
2) Override paintComponent and include the painting code*
3) Use the an instance of this panel in your applet.

* For custom painting/drawing objects, the Graphics class has convenient drawXXX and fillXXX methods you can use. You should be using the graphics instance available as an argument in the paintComponent. Also check out the Graphics2D class for more advanced painting options. You just cast it like

Graphics2D g2=(Graphics2D)g;

and then invoke the required methods on the g2.

[maja neskovic]

For the 1. point: should I remove all code related to my JPanel (which I called glavnipanel) from JApplet code(which I posted) and move all to the subclass? How to maintain connection of subclass with JApplet? I'm sorry if I'm asking silly questions, but I'm beginner in this

[Maneesh Godbole]

maja neskovic wrote:For the 1. point: should I remove all code related to my JPanel (which I called glavnipanel) from JApplet code(which I posted) and move all to the subclass? How to maintain connection of subclass with JApplet? I'm sorry if I'm asking silly questions, but I'm beginner in this

Subclass JPanel. Call it say MajaPanel. Put the paint code in this class.
In your existing code, just switch

glavnipanel = new javax.swing.JPanel();

to

glavnipanel = new your.package.MajaPanel();

That's it. Your existing "connection" is retained.

And not need to say sorry. No question is silly. Asking questions and finding the answers is how we all learn.
So go ahead and ask all you want

[maja neskovic]

Thank you for your support I'm very gratefull!

I'll try as you said and ask again

[maja neskovic]

I did like you said, make the connection, but I still can't display the image. This is what i did in MajaPanel (I inserted image like I did in my previous applet made in AWT - that was my 1. applet where image drawing worked):

 
package org.me.pack;

import javax.swing.JPanel;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import java.net.*;

public class MajaPanel extends JPanel {
    private static BasicStroke bs1 = new BasicStroke(3.0f);
    BufferedImage bmp;
    BufferedImage bimg;

 public void init() {
      URL slika;
        try {
            slika = new URL("http://www.wolflodge.org/prophecy/endofdays_2/White_Rabbit.gif");
            try {
                bmp = ImageIO.read(slika);
            } catch (IOException ex) {
                Logger.getLogger(Simulacija.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (MalformedURLException ex) {
            Logger.getLogger(Simulacija.class.getName()).log(Level.SEVERE, null, ex);
        }
 }

public void render(int w, int h, Graphics2D g2) {
        g2.drawImage(bmp, null, this);
        }
        public Graphics2D createGraphics2D(int w, int h) {
        Graphics2D g2 = null;
        if (bimg == null || bimg.getWidth() != w || bimg.getHeight() != h) {
            bimg = (BufferedImage) createImage(w, h);
        }
        g2 = bimg.createGraphics();
        g2.setStroke(bs1);
         g2.setBackground(getBackground());
        g2.clearRect(0, 0, w, h);
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        return g2;
}

public void paint(Graphics g) {

	Dimension d1 = getSize();
        Graphics2D g2 = createGraphics2D(d1.width, d1.height);
        render(d1.width, d1.height, g2);
        g.drawImage(bimg, 0, 0, this);
        g2.dispose();
    }
}
   

[Maneesh Godbole]

Maneesh Godbole wrote: You just cast it like

Graphics2D g2=(Graphics2D)g;

and then invoke the required methods on the g2.

maja neskovic wrote:Graphics2D g2 = createGraphics2D(d1.width, d1.height);

Why aren't you casting?

[maja neskovic]

I'm sorry, I missed that part. What is meant by casting? I just replaced my code which you quoted with your quoted code, and wrote g2 everywhere where I messed with painting in my code (replaced g)... Is it ok?

Now I can't see the MajaPanel in my JApplet. I make mistake again, do I?

[Ulf Dittmer]

I make mistake again, do I?

That impossible to say without seeing the relevant parts of the code.

[maja neskovic]

Here is the code of the JPanel which I created:

  
package org.me.pack;

import javax.swing.JPanel;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import java.net.*;

public class MajaPanel extends JPanel {
    private static BasicStroke bs1 = new BasicStroke(3.0f);
    BufferedImage bmp;
    BufferedImage bimg;

 public void init() {
      URL slika;
        try {
            slika = new URL("http://www.wolflodge.org/prophecy/endofdays_2/White_Rabbit.gif");
            try {
                bmp = ImageIO.read(slika);
            } catch (IOException ex) {
                Logger.getLogger(Simulacija.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (MalformedURLException ex) {
            Logger.getLogger(Simulacija.class.getName()).log(Level.SEVERE, null, ex);
        }
 }

public void render(int w, int h, Graphics2D g2) {
        g2.drawImage(bmp, null, this);
        }
        public Graphics2D createGraphics2D(int w, int h) {
        Graphics2D g2 = null;
        if (bimg == null || bimg.getWidth() != w || bimg.getHeight() != h) {
            bimg = (BufferedImage) createImage(w, h);
        }
        g2 = bimg.createGraphics();
        g2.setStroke(bs1);
         g2.setBackground(getBackground());
        g2.clearRect(0, 0, w, h);
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        return g2;
}

public void paint(Graphics g) {

	Dimension d1 = getSize();
        Graphics2D g2=(Graphics2D)g;
        render(d1.width, d1.height, g2);
        g.drawImage(bimg, 0, 0, this);
        g2.dispose();
    }
}
  

I hope it's helpfull

[Ulf Dittmer]

It's not really useful, because we don't know how it's being used by the applet.

Note that Swing does not use the "paint" method, though - it uses "paintComponent": http://java.sun.com/products/jfc/tsc/articles/painting/

[maja neskovic]

Ok, thank you

I found one good example for this problem, I modify it and made JPanel look like this:

  
package org.me.pack;
import javax.swing.*;
import javax.imageio.ImageIO;
import java.net.URL;
import java.awt.Image;
import java.awt.Graphics;
public class MajaPanel extends JPanel
{
  public Image backgroundImage;
  public MajaPanel()
  {
      try
      {
         this.backgroundImage = ImageIO.read(new URL("http://www.bsp-bc.com/images/racunar-00.jpg"));
      }
      catch(Exception e)
      {
         throw new RuntimeException(e);
      }
  }
  public static void main(String[] args)
  {
     JFrame frame = new JFrame("Background Image Test");
     frame.setContentPane(new MajaPanel());
     frame.getContentPane().setLayout(null);
     frame.setSize(565,214);
     frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
     frame.setVisible(true);
  }

  protected void paintComponent(Graphics g)
  {
     g.drawImage(backgroundImage,50,50,null);
  }
}

   

I hope it can help to anybody with similar problems. I'm going to work, if there any problem occures, I'll have to post it here

Greetings!

[Rob Spoor]

Add "super.paintComponent(g)" as the first call of your paint component. Otherwise the default painting of the JPanel will not be done. By adding this call you are first painting the JPanel itself, then painting the image over it.

[maja neskovic]

Added Thank you, Rob

[Rob Spoor]

You're welcome.

[Maneesh Godbole]

Pity you cross posted this one too just like your other post http://www.java-forums.org/new-java/29024-drawing-image-jpanel.html
Pity for me that is. I feel silly wasting my time.

Like Rob Camick told you in this thread https://coderanch.com/t/496280/GUI/java/make-slider-resize-rectangle-move BeForthrightWhenCrossPostingToOtherSites

[maja neskovic]

I didn't know about that rule, sorry...