Develop Reference

setting background image for JScrollPane

Intro
I created a class ChatView that extends JPanel. I added it as a parameter to my JScrollPane (to get the scrolling effect) and overrode the paintComponent method in hope of setting a background image:
new JScrollPane(new ChatView){
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
ImageIcon background = new ImageIcon("files/background.png");
Image image = background.getImage();
image.getScaledInstance(980, 600, java.awt.Image.SCALE_SMOOTH);
if (image != null)
{
g.drawImage(image,0,0,this.getWidth(),this.getHeight(),null);
}
}
}
problem
This doesn't seem to do anything; however, the same method works on my class ChatView, which extends JPanel. the problem with adding it to my JPanel is that it stretches every time I add a new component that extends outside of the setPrefferredSize() of my JScrollPane; If I do not revalidate() and repaint() my JPanel, it cuts off or doesn't add the components. That's why I think it is necessary to add it to the JScrollPane, but how? or am i on the wrong track?
Code: attributes of my JScrollPane
public void addScroll(JScrollPane pnl, String str, int w, int h){
pnl.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
pnl.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
pnl.setSize(new Dimension(w, h));
pnl.setMinimumSize(new Dimension(w, h));
pnl.setPreferredSize(new Dimension(w, h));
pnl.getVerticalScrollBar().setUnitIncrement(16);
pnl.setBorder(BorderFactory.createLineBorder(black));
this.add(pnl, str);
}

Static Image behind JTextPane text in JScrollPane
^^link where I found the solution!! Below is a clean cheatsheet :)
JPanel jPanel = new JPanel() {
this.setOpaque(false);
};
JViewport viewport = new JViewport() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
ImageIcon background = new ImageIcon("images/background.png");
Image image = background.getImage();
image.getScaledInstance(width, height, java.awt.Image.SCALE_SMOOTH);
if (image != null) {
g.drawImage(image, 0, 0, w, h, null);
}
}
};
jScrollPane.setViewport(viewport);
jScrollPane.setViewportView(jPanel);

How can I display two JPanels with images on a JFrame, and both of the img to be visible?

I am trying to set as background an aquarium (which is a class that extends JPanel and contain the aquarium img), and on top a fish (which is also a class that extends a JPanel and contain the fish img).
The problem is that it shows only one image instead of fish in top of the aquarium (either aquarium, or fish depending on which one is added first to the JFrame).
Main
public class Core {
JFrame window;
JLabel label;
ImageIcon img;
Aquarium aquarium = new Aquarium();
JavaFish javaFish = new JavaFish();
public void start() {
window = new JFrame();
window.setPreferredSize(new Dimension(600, 400));
window.setVisible(true);
window.setTitle("Java Game");
aquarium.add(javaFish);
window.add(aquarium);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
Core c = new Core();
c.start();
}
}
Aquarium
public class Aquarium extends JPanel {
private BufferedImage img;
//Initiate aquarium width
public int width;
//Initiate aquarium height
public int height;
#Override
protected void paintComponent(Graphics g) {
width = getSize().width;
height = getSize().height;
try {
img = ImageIO.read(new File("img/AquariumBackground.png"));
} catch (IOException e) {
e.printStackTrace();
System.out.println("Image not fount!");
}
g.drawImage(img, 0, 0, width, height, this);
}
}
Fish
public class JavaFish extends JPanel {
BufferedImage img;
int xPos = 50;
int yPos = 50;
public JavaFish() {
this.setOpaque(false);
}
#Override
protected void paintComponent(Graphics g) {
BufferedImage JavaFish = LoadImage("img/JavaFish.png");
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(JavaFish, xPos, yPos, 100, 100, null);
repaint();
}
BufferedImage LoadImage(String FileName) {
img = null;
try {
img = ImageIO.read(new File (FileName));
} catch (IOException e) {
e.printStackTrace();
}
return img;
}
}

The problem is that it shows only one image instead of fish in top of the aquarium (either aquarium, or fish depending on which one is added first to the JFrame).
By default a JPanel uses a FlowLayout which respects the preferred size of any component added to it.
By default a JFrame uses a BorderLayout and if you don't specify a constraint the component gets added to the CENTER of the BorderLayout, which means the component is automatically resized to fill the space of the frame.
So the component you add to the frame will be sized to fill the frame. The component you add to the panel will have a size of (0, 0) so there is nothing to paint.
So some custom painting tips:
Override the getPreferredSize() method of the panel to return the size of the image so the layout manager can do its job
Invoke super.paintComponent(..) as the first statement to make sure the background gets cleared.
Don't read the image in the paintComponent() method. This method can be called whenever Swing determines the component needs to be repainted, so it not efficient to keep reading the image. Instead the image should be read in the constructor of the class.
Don't invoke repaint() in a painting method. This will cause an infinite painting loop.
Also, components should be added to the frame BEFORE you make the frame visible.
Having said all of the above, Alerra's suggestion in the comment to paint both images in the same panel is a good idea. It simplifies the painting and you can even paint multiple fish easily by keeping an ArrayList of imgages that you want to paint. Then you would just paint the background and then iterates through the ArrayList to paint the individual fish.
Check out Custom Painting Approaches for a working example. The example only draws Rectangle, but the concept is the same.

Display components over background image [duplicate]

How would I add the backgroung image to my JPanel without creating a new class or method, but simply by inserting it along with the rest of the JPanel's attributes?
I am trying to set a JPanel's background using an image, however, every example I find seems to suggest extending the panel with its own class.
I have been looking for a way to simply add the image without creating a whole new class and within the same method (trying to keep things organized and simple).
Here is an example of the method that sets my JPanel:
public static JPanel drawGamePanel(){
//Create game panel and attributes
JPanel gamePanel = new JPanel();
Image background = Toolkit.getDefaultToolkit().createImage("Background.png");
gamePanel.drawImage(background, 0, 0, null);
//Set Return
return gamePanel;
}

I am trying to set a JPanel's background using an image, however, every example I find seems to suggest extending the panel with its own class
yes you will have to extend JPanel and override the paintcomponent(Graphics g) function to do so.
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(bgImage, 0, 0, null);
}
I have been looking for a way to simply add the image without creating a whole new class and within the same method (trying to keep things organized and simple).
You can use other component which allows to add image as icon directly e.g. JLabel if you want.
ImageIcon icon = new ImageIcon(imgURL);
JLabel thumb = new JLabel();
thumb.setIcon(icon);
But again in the bracket trying to keep things organized and simple !! what makes you to think that just creating a new class will lead you to a messy world ?

Simplest way to set image as JPanel background
Don't use a JPanel. Just use a JLabel with an Icon then you don't need custom code.
See Background Panel for more information as well as a solution that will paint the image on a JPanel with 3 different painting options:
scaled
tiled
actual

As I know the way you can do it is to override paintComponent method that demands to inherit JPanel
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); // paint the background image and scale it to fill the entire space
g.drawImage(/*....*/);
}
The other way (a bit complicated) to create second custom JPanel and put is as background for your main
ImagePanel
public class ImagePanel extends JPanel
{
private static final long serialVersionUID = 1L;
private Image image = null;
private int iWidth2;
private int iHeight2;
public ImagePanel(Image image)
{
this.image = image;
this.iWidth2 = image.getWidth(this)/2;
this.iHeight2 = image.getHeight(this)/2;
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
if (image != null)
{
int x = this.getParent().getWidth()/2 - iWidth2;
int y = this.getParent().getHeight()/2 - iHeight2;
g.drawImage(image,x,y,this);
}
}
}
EmptyPanel
public class EmptyPanel extends JPanel{
private static final long serialVersionUID = 1L;
public EmptyPanel() {
super();
init();
}
#Override
public boolean isOptimizedDrawingEnabled() {
return false;
}
public void init(){
LayoutManager overlay = new OverlayLayout(this);
this.setLayout(overlay);
ImagePanel iPanel = new ImagePanel(new IconToImage(IconFactory.BG_CENTER).getImage());
iPanel.setLayout(new BorderLayout());
this.add(iPanel);
iPanel.setOpaque(false);
}
}
IconToImage
public class IconToImage {
Icon icon;
Image image;
public IconToImage(Icon icon) {
this.icon = icon;
image = iconToImage();
}
public Image iconToImage() {
if (icon instanceof ImageIcon) {
return ((ImageIcon)icon).getImage();
} else {
int w = icon.getIconWidth();
int h = icon.getIconHeight();
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gd.getDefaultConfiguration();
BufferedImage image = gc.createCompatibleImage(w, h);
Graphics2D g = image.createGraphics();
icon.paintIcon(null, g, 0, 0);
g.dispose();
return image;
}
}
/**
* #return the image
*/
public Image getImage() {
return image;
}
}

Draw the image on the background of a JPanel that is added to the frame. Use a layout manager to normally add your buttons and other components to the panel. If you add other child panels, perhaps you want to set child.setOpaque(false).
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.io.IOException;
import java.net.URL;
public class BackgroundImageApp {
private JFrame frame;
private BackgroundImageApp create() {
frame = createFrame();
frame.getContentPane().add(createContent());
return this;
}
private JFrame createFrame() {
JFrame frame = new JFrame(getClass().getName());
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
return frame;
}
private void show() {
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private Component createContent() {
final Image image = requestImage();
JPanel panel = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}
};
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
for (String label : new String[]{"One", "Dois", "Drei", "Quatro", "Peace"}) {
JButton button = new JButton(label);
button.setAlignmentX(Component.CENTER_ALIGNMENT);
panel.add(Box.createRigidArea(new Dimension(15, 15)));
panel.add(button);
}
panel.setPreferredSize(new Dimension(500, 500));
return panel;
}
private Image requestImage() {
Image image = null;
try {
image = ImageIO.read(new URL("http://www.johnlennon.com/wp-content/themes/jl/images/home-gallery/2.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
return image;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new BackgroundImageApp().create().show();
}
});
}
}

class Logo extends JPanel
{
Logo()
{
//code
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
ImageIcon img = new ImageIcon("logo.jpg");
g.drawImage(img.getImage(), 0, 0, this.getWidth(), this.getHeight(), null);
}
}

INITIALIZE YOUR JPANEL AS BELOW. NOTE THE MISSING SEMICOLON.. INSTEAD OPEN A CURLY BRACE THEN OVERRIDE THAT METHOD.. THIS WAY YOU DON'T HAVE TO EXTEND TO ANYTHING
ImageIcon img = new ImageIcon("background.jpg");
JPanel panel1 = new JPanel()
{
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(img.getImage(), 0, 0, null);
}
};

public demo1() {
initComponents();
ImageIcon img = new ImageIcon("C:\\Users\\AMIT TIWARI\\Documents\\NetBeansProjects\\try\\src\\com\\dd.jpeg"); //full path of image
Image img2 = img.getImage().getScaledInstance(mylabel.getWidth(), mylabel.getHeight(),1);
ImageIcon img3 = new ImageIcon(img2);
mylabel.setIcon(img3);
}

How to add background to JPanel and then add a JButton on that JPanel

//Calling function
ImagePanel Panel_2 = new ImagePanel(new ImageIcon("C:/Users/kagarwal/Downloads/intacct_logo_standard_web.png").getImage());
Panel_2.add(new JButton());
Panel_2.revalidate();
//Called function
public class ImagePanel extends JPanel {
private Image img;
public ImagePanel(String img) {
this(new ImageIcon(img).getImage());
}
public ImagePanel(Image img) {
this.img = img;
Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
setPreferredSize(size);
setMinimumSize(size);
setMaximumSize(size);
setSize(size);
setLayout(null);
}
public void paintComponent(Graphics g) {
g.drawImage(img, 0, 0, null);
}
}
Requirement is: that JPanel2 needs to have a background image, and on top of that we need to add JButton. But, issue here is that the newly added JButton does not appears in the given JPanel, it only shows background image. Am i missing refresh ?

The problem is in paintComponent, where you only ask the graphics object to draw the image.
But you should call the superclass paintComponent method by invoking super.paintComponent() passing the graphics object, in order to have all the components of the panel correctly displayed.

Simplest way to set image as JPanel background

How would I add the backgroung image to my JPanel without creating a new class or method, but simply by inserting it along with the rest of the JPanel's attributes?
I am trying to set a JPanel's background using an image, however, every example I find seems to suggest extending the panel with its own class.
I have been looking for a way to simply add the image without creating a whole new class and within the same method (trying to keep things organized and simple).
Here is an example of the method that sets my JPanel:
public static JPanel drawGamePanel(){
//Create game panel and attributes
JPanel gamePanel = new JPanel();
Image background = Toolkit.getDefaultToolkit().createImage("Background.png");
gamePanel.drawImage(background, 0, 0, null);
//Set Return
return gamePanel;
}

I am trying to set a JPanel's background using an image, however, every example I find seems to suggest extending the panel with its own class
yes you will have to extend JPanel and override the paintcomponent(Graphics g) function to do so.
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(bgImage, 0, 0, null);
}
I have been looking for a way to simply add the image without creating a whole new class and within the same method (trying to keep things organized and simple).
You can use other component which allows to add image as icon directly e.g. JLabel if you want.
ImageIcon icon = new ImageIcon(imgURL);
JLabel thumb = new JLabel();
thumb.setIcon(icon);
But again in the bracket trying to keep things organized and simple !! what makes you to think that just creating a new class will lead you to a messy world ?

Simplest way to set image as JPanel background
Don't use a JPanel. Just use a JLabel with an Icon then you don't need custom code.
See Background Panel for more information as well as a solution that will paint the image on a JPanel with 3 different painting options:
scaled
tiled
actual

As I know the way you can do it is to override paintComponent method that demands to inherit JPanel
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); // paint the background image and scale it to fill the entire space
g.drawImage(/*....*/);
}
The other way (a bit complicated) to create second custom JPanel and put is as background for your main
ImagePanel
public class ImagePanel extends JPanel
{
private static final long serialVersionUID = 1L;
private Image image = null;
private int iWidth2;
private int iHeight2;
public ImagePanel(Image image)
{
this.image = image;
this.iWidth2 = image.getWidth(this)/2;
this.iHeight2 = image.getHeight(this)/2;
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
if (image != null)
{
int x = this.getParent().getWidth()/2 - iWidth2;
int y = this.getParent().getHeight()/2 - iHeight2;
g.drawImage(image,x,y,this);
}
}
}
EmptyPanel
public class EmptyPanel extends JPanel{
private static final long serialVersionUID = 1L;
public EmptyPanel() {
super();
init();
}
#Override
public boolean isOptimizedDrawingEnabled() {
return false;
}
public void init(){
LayoutManager overlay = new OverlayLayout(this);
this.setLayout(overlay);
ImagePanel iPanel = new ImagePanel(new IconToImage(IconFactory.BG_CENTER).getImage());
iPanel.setLayout(new BorderLayout());
this.add(iPanel);
iPanel.setOpaque(false);
}
}
IconToImage
public class IconToImage {
Icon icon;
Image image;
public IconToImage(Icon icon) {
this.icon = icon;
image = iconToImage();
}
public Image iconToImage() {
if (icon instanceof ImageIcon) {
return ((ImageIcon)icon).getImage();
} else {
int w = icon.getIconWidth();
int h = icon.getIconHeight();
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gd.getDefaultConfiguration();
BufferedImage image = gc.createCompatibleImage(w, h);
Graphics2D g = image.createGraphics();
icon.paintIcon(null, g, 0, 0);
g.dispose();
return image;
}
}
/**
* #return the image
*/
public Image getImage() {
return image;
}
}

Draw the image on the background of a JPanel that is added to the frame. Use a layout manager to normally add your buttons and other components to the panel. If you add other child panels, perhaps you want to set child.setOpaque(false).
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.io.IOException;
import java.net.URL;
public class BackgroundImageApp {
private JFrame frame;
private BackgroundImageApp create() {
frame = createFrame();
frame.getContentPane().add(createContent());
return this;
}
private JFrame createFrame() {
JFrame frame = new JFrame(getClass().getName());
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
return frame;
}
private void show() {
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private Component createContent() {
final Image image = requestImage();
JPanel panel = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}
};
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
for (String label : new String[]{"One", "Dois", "Drei", "Quatro", "Peace"}) {
JButton button = new JButton(label);
button.setAlignmentX(Component.CENTER_ALIGNMENT);
panel.add(Box.createRigidArea(new Dimension(15, 15)));
panel.add(button);
}
panel.setPreferredSize(new Dimension(500, 500));
return panel;
}
private Image requestImage() {
Image image = null;
try {
image = ImageIO.read(new URL("http://www.johnlennon.com/wp-content/themes/jl/images/home-gallery/2.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
return image;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new BackgroundImageApp().create().show();
}
});
}
}

class Logo extends JPanel
{
Logo()
{
//code
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
ImageIcon img = new ImageIcon("logo.jpg");
g.drawImage(img.getImage(), 0, 0, this.getWidth(), this.getHeight(), null);
}
}

INITIALIZE YOUR JPANEL AS BELOW. NOTE THE MISSING SEMICOLON.. INSTEAD OPEN A CURLY BRACE THEN OVERRIDE THAT METHOD.. THIS WAY YOU DON'T HAVE TO EXTEND TO ANYTHING
ImageIcon img = new ImageIcon("background.jpg");
JPanel panel1 = new JPanel()
{
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(img.getImage(), 0, 0, null);
}
};

public demo1() {
initComponents();
ImageIcon img = new ImageIcon("C:\\Users\\AMIT TIWARI\\Documents\\NetBeansProjects\\try\\src\\com\\dd.jpeg"); //full path of image
Image img2 = img.getImage().getScaledInstance(mylabel.getWidth(), mylabel.getHeight(),1);
ImageIcon img3 = new ImageIcon(img2);
mylabel.setIcon(img3);
}