private void renderLevelBackground(Graphics2D g2) {
Image backgroundImage = model.getBackgroundImage();
g2.drawImage(backgroundImage, 0, 0, null);
}
This is my code, I know that the backgroundImage is loaded properly because if I getWidth/Height it gives me the correct values. Is there anyway to test if it's the image or if it's the method somehow? It just won't draw on my screen despite the fact that I've used the drawImage method many times in this project already, all of which work flawlessly.
Thanks
"Is there ever a reason drawImage won't actually draw an image?"
Possibility, there is no image due to a bad path provided. Use ImageIO.read() which will cause an exception if the image file is not found. For example
public class ImagePanel extends JPanel {
private BufferedImage image;
public ImagePanel() {
try {
image = ImageIO.read(getClass().getResource("/resources/image.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
If the image is not found, it will throw an IO exception.
Possibility, the panel to which you are drawing, has no preferred size (0 x 0), and you are adding it a container wit layout that respects preferred sizes, so the ImagePanel will not be able to show the image. For example
public class ImagePanel extends JPanel {
protected void paintComponent(...) {
...
}
JPanel panel = new JPanel(); // default FlowLayout that respects preferred sizes
panel.add(new ImagePanel());
To fix this, you can override the gerPreferredSize() of the ImagePanel
public class ImagePanel extends JPanel {
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
}
Possibility, you are not calling your method within the graphics context of the paint[Component] method.
protected void paintComponent(Graphics 2d) {
super.paintComponent(g);
Grapchics2D g2 = (Graphics2D)g;
renderLevelBackground(g2);
}
Other than that, these are all just guesses, and you should provide some more code code (preferably an MCVE) to help us better help you with the problem.
Possible Alternative to your approach. It seems like (from the little code snippet and it method signature semantics) you want to change the background image, when a level have changed. Consider using setBackgroundImage(BufferedImage image) method in your panel class, when the image is drawn. You can then set the background, whenever need be. Something like
public class BackgroundPanel extends JPanel {
private BufferedImage backgroundImage;
public void setBackgroundImage(BufferedImage image) {
this.backgroundImage = image;
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Grpahics2D g2 = (Graphics2D)g;
if (image != null) {
g2.drawImage(backgroundImage, 0, 0, this);
}
}
}
So whenever you call setBackgroundImage, the image will change, and be repainted.
You may need to explicitly tell the JComponent that you are painting onto that it needs to be redrawn with revalidate() and repaint()
Related
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.
im trying to insert a gif as a background for my app. I cut all frames and renamed them f1/f2/f3/f4/f5/f6/..... I would use a timer to change the frame so it looks like an animation.
There is a total of 42 frames, so f42.png is the last frame. The code seems to be fine, but there is no result. Any help?
Global variables:
private String backgroundFile;
public JPanel backgroundPanel, areaImage;
private BufferedImage background;
private javax.swing.Timer timerBackground;
Constructor where the Timer is initialized:
public Game()
{
entryWindow();
this.setLayout(null);
timerBackground = new javax.swing.Timer(100,this);
timerBackground.stop();
}
Animation method code:
private void backgroundAnimation()
{
backgroundFile = "f"+backgroundNum+".png";
try{
background=ImageIO.read(new File(backgroundFile));
}
catch(IOException e)
{
}
backgroundPanel = new JPanel()
{
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(background, 0, 0, 1100,800,null);
}
};
backgroundPanel.setBackground(Color.BLACK);
backgroundPanel.setBounds(0, 0, 1100, 800);
if (backgroundNum>42)backgroundNum++;
else backgroundNum=1;
add(backgroundPanel);
backgroundPanel.setVisible(true);
}
Action Listener for timer:
if (ae.getSource() == timerBackground)
{
backgroundAnimation();
}
In order to show JPanel, you need to add it to something like JFrame with an BorderLayout for instance, then you need to show the JFrame. JFrame is a application window, the JPanel can be only added and drawn on Window, it can't be viewed without something on which it can draw (like app Window). Beside that you don't need to create new JPanel each time the animation changes, just make a setter for the current image to show, and after assigning the image call repaint(), the ImagePanel could be like this:
public class ImagePanel extends JPanel {
private volatile BufferedImage image;
public void showImage(BufferedImage image) {
this.image=image;
repaint();
}
public void paintComponent(Graphics g) {
g.drawImage(image, 0,0,getWidth(),getHeight(),null);
}
}
add it to your JFrame at application start, also set the LayoutManager of JFrame to BorderLayout preferably, because without that your panel will have size(0,0) since you didn't set it, and it could be one of reasons why you don't see it (you can't see something which is 0 pixel in size, can you?).
Then in your timer just call the ImagePanel method public void showImage(BufferedImage image) with the image to show. If that's don't solve your problem, then post your entire code. As without that i'm just guessing, but those are common problems, so there's big chance you hit something from this.
I can see a few issues here
1. Assuming your Game class is extending JFrame, You need to add the JPanel to the ContentPane of the JFrame. Use one of the approaches setContentPane(backgroundPanel); or getContentPane().add(backgroundPanel)
You are not using a LayoutManager. So either use a LayoutManager or set the Size of the 'JFrame' and 'JPanel' explicitly using setBounds() method. I would recommend using a LayoutManager.
The JPanel or any Component for that matter does not automatically refresh itself. Once you change the image, you need to call repaint() on your JPanel.
You dont need to create a new JPanel every time you change the image. Just extend the JPanel and override the paintComponent()like you have done. Use the Timer to change the image of that single instance and call repaint() with every change.
The complete example, with hat output you are seeing will help understand the problem better and give you a solution. Please see How to create a Minimal, Complete, and Verifiable example
There are multiple problems here, but first let me answer your question:
You are creating a new JPanel and add it to the Game on every run through. That is wrong, since you add infinite panels to your Game
Also in your if/else you have a wrong condition. You increase the iterator when it is greater 42. You probably mean lesser than 42.
Here is how I would do it:
public class BackgroundPanel extends JPanel {
private int currImage = 0;
private BufferedImage[] backgroundImages;
public BackgroundPanel() {
int numberOfImages = 42;
backgroundImages = new BufferedImage[42];
for(int i = 1; i <= numberOfImages; i++) {
String backgroundFile = "f" + i + ".png";
backgroundImages[i] = ImageIO.read(new File(backgroundFile));
}
}
public void nextImage() {
/*if(currImage <= 42) currImage++;
else currImage = 1;*/
if(currImage++ > 42) currImage = 1;
repaint();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(backgroundImages[currImage], 0, 0, getWidth(), getHeight(), null);
}
}
You need to add this panel ONCE to your "Game":
//Somewhere in your Game
private BackgroundPanel backgroundPanel;
...
...
public Game() {
entryWindow();
this.setLayout(null);
backgroundPanel = new backgroundPanel();
backgroundPanel.setSize(getWidth(), getHeight());
add(backgroundPanel);
timerBackground = new javax.swing.Timer(100,this);
timerBackground.stop();
}
Your timer:
if (ae.getSource() == timerBackground) {
backgroundPanel.nextImage();
}
It's easier to put the background on JLabel. It requires only 3 lines of code and works fine! :) Hope it helps for anyone that will have the same problem :)
All you have to do is copy this code, change the name (i have all pictures in a folder called "Images") with any kind of Java supported picture/video/.... (just change the suffix .gif to your file format) and at last the size. Good luck! :)
public JLabel backgroundGIF;
backgroundGIF = new JLabel(new ImageIcon(getClass().getResource("Images/background.gif")));
backgroundGIF.setBounds(0,0,1100,800);
add(backgroundGIF);
I have a JFrame. It uses a JPanel as its content pane, and that JPanel uses GridBagLayout as its LayoutManager. That JPanel contains two more items: a button, and another JPanel. On program start, an image is loaded from file into the lowest-level JPanel as a BufferedImage using ImageIO.read(...). Here is where everything goes to pieces.
The image loads correctly, I can see a small corner of it on screen (14px square as specified in debugger). There is nothing I can figure out that will cause the layout to grow and fit the entire image in the lowest level JPanel on screen. The image in debuggers shows correct size of 500px. The preferred size of the CardImagePanel shows up correctly as the same size as the image. But the layout will not respect the preferred size unless I manually set the CardImagePanel size using setSize(...) which I'm pretty sure is not supposed to be necessary with GBL.
I have tried putting revalidate() and repaint() calls on every single JFrame, JPanel, layout, grid bag, image, etc throughout the entire program and just can't find the correct place or time to call them to make this thing work. Currently I've been trying to just let the image load incorrectly and use the button to force revalidation and repaint, but even this explicit call is not doing anything.
I'm losing my mind, I'll do anything to get this thing working.
Here is all my code for the whole stupid thing (minus imports and package specification.
P1s1.java:
public class P1s1 {
public static void main(String[] args) {
// TODO code application logic here
build();
}
public static void build()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(new Dimension(640, 480));
frame.setContentPane(new GuiPanel(frame));
frame.setVisible(true);
}
}
GuiPanel.java:
public class GuiPanel extends JPanel {
JFrame parentFrame;
JButton imageLoaderButton;
CardImagePanel cardImagePanel;
LayoutManager layout;
GridBagLayout gridBagLayout;
GridBagConstraints constraints;
public GuiPanel(JFrame frame)
{
parentFrame = frame;
constraints = new GridBagConstraints();
gridBagLayout = new GridBagLayout();
layout = gridBagLayout;
this.setLayout(layout);
this.setBorder(BorderFactory.createLineBorder(Color.black));
setupImageLoaderButton(imageLoaderButton);
cardImagePanel = new CardImagePanel();
this.add(cardImagePanel);
}
private void setupImageLoaderButton(JButton button)
{
button = new JButton("Click to load image!");
ActionListener imageLoaderListener;
imageLoaderListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
System.out.println("Button clicked.");
cardImagePanel.revalidate();
cardImagePanel.repaint();
GuiPanel.this.revalidate();
GuiPanel.this.repaint();
parentFrame.revalidate();
parentFrame.repaint();
}
};
button.addActionListener(imageLoaderListener);
this.add(button);
}
}
CardImagePanel.java:
public class CardImagePanel extends JPanel {
BufferedImage cardImage;
public CardImagePanel()
{
this.setBorder(BorderFactory.createLineBorder(Color.black));
try {
cardImage = ImageIO.read(new File("c:\\dev\\cards\\2_of_clubs.png"));
this.setPreferredSize(new Dimension(cardImage.getWidth(), cardImage.getHeight()));
} catch (IOException ex) {
System.out.println("Exception trying to load image file.");
}
}
// The getPreferredSize() override was suggested by MadProgrammer.
// It did not solve the issue, but see MadProgrammer's updated,
// accepted answer below for the correct solution. The rest of the
// code reflects my original attempt to solve the issue.
#Override
public Dimension getPreferredSize()
{
return cardImage != null ? new Dimension(cardImage.getWidth(), cardImage.getHeight()) : super.getPreferredImage();
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(cardImage, 0, 0, this);
}
}
GridBagLayout relies on a component telling it what size it would like to be (along with it's minimum and maximum size when it's relievent). You need to override the getPreferredSize method of the CardImagePanel, returning the size you would like the component to be
public class CardImagePanel extends JPanel {
BufferedImage cardImage;
public CardImagePanel() {
this.setBorder(BorderFactory.createLineBorder(Color.black));
try {
cardImage = ImageIO.read(new File("c:\\dev\\cards\\2_of_clubs.png"));
} catch (IOException ex) {
System.out.println("Exception trying to load image file.");
}
}
#Override
public Dimension getPreferredSize() {
return cardImage != null ? new Dimension(cardImage.getWidth(), cardImage.getHeight()) : super.getPreferredSize();
}
#Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(cardImage, 0, 0, this);
}
}
Have a look at How to Use GridBagLayout for more details
You CardImagePanel has no preferred size, so the layout manager doesn't know how to handle the size properly.
A couple of solutions:
There is no need to create a custom class to display the image. Just use a JLabel to display the image. The JLabel will return the preferred size of the image.
If you do use the CardImagePane, then you need to override the getPreferredsize() method of the CardImagePanel to return the size of the image.
this has been driving me crazy all day so I figured I'd post it here and see if someone else can work it out. First off I tried to add a background image, the default ImageIcon was not working so I went with overriding the paint method instead. #
public class ImageJPanel extends JPanel {
private static final long serialVersionUID = -1846386687175836809L;
Image image = null;
public ImageJPanel(){
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
ImageJPanel.this.repaint();
}
});
}
//Set the image.
public ImageJPanel(Image i) {
image=i;
setOpaque(false);
}
//Overide the paint component.
public void paint(Graphics g) {
if (image!=null) g.drawImage(image, 0, 0, null);
super.paint(g);
}
}
Once I used that it worked fine, however now I want to add images to my buttons but it is not working. Here is how my buttons work:
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Images images = new Images();
JPanel j = new ImageJPanel(images.menuBackground);
j.setLayout(null);
JButton Button_1= new JButton("Button_1",new ImageIcon("images/gui/Button.png"));
Insets insets = j.getInsets();
Dimension size = Button_1.getPreferredSize();
Button_1.setBounds(300 + insets.left, 150+ insets.top, size.width, size.height);
Singleplayer.setSize(200, 50);
j.add(Button_1);
frame.add(j);
frame.setSize(800,600);
frame.setResizable(false);
Button_1.addMouseListener(singleplayerPressed);
frame.setVisible(true);
All my images are .png, could that affect it?
Let's start with this:
public void paint(Graphics g) {
if (image!=null) g.drawImage(image, 0, 0, null);
super.paint(g);
}
This is the wrong approach. Firstly, you really don't want to override the paint method UNLESS you absolutely know that this is the correct approach to your problem (and without knowing more, I'd suggest it isn't).
Secondly, you paint your image on the component, then promptly paint over the top of it...(super.paint(g); can have the ability to paint over your work, I know the panel is opaque, but this is still a very bad approach).
Use paintComponent instead
protected void paintComponent(Graphics g) {
super.paint(g);
if (image!=null) g.drawImage(image, 0, 0, null);
}
PNG images are fine, they are supported by Swing out of the box.
Make sure that your program can see the image. Is it been loaded from the file source or is it a resource within you JAR?
Try this:
System.out.println(new File("images/gui/Button.png").exits());
If your program can see the file, it will return true other wise the program can not see the file and that is your problem.
Try this:
ImageIcon image = new ImageIcon(this.getClass()
.getResource("images/gui/Button.png"));
Side note, you should override paintComponent() not paint(). Also make sure to call super implementation before doing all your painting. For more details see Lesson: Performing Custom Painting tutorial.
So im making a gui, and i have a background image for it. i dont know how to make it set as the background, so any help with that would be good. an explination would also be good. also, after we get that image as a background, how do we get the image resize to the size of the window. such as
image.setSize(frame.getHeight(), frame.getWidth());
but i dont know if that would work. the image name is ABC0001.jpg and the frame name is frame. thanks!
To get the image to resize, you can either use
public void paintComponent(Graphics g) {
g.drawImage(img, 0, 0, getWidth(), getHeight(), this); // draw the image
}
or you can use a componentlistener, implemented like:
final Image img = ...;
ComponentListener cl = new ComponentAdapter() {
public void componentResized(ComponentEvent ce) {
Component c = ce.getComponent();
img = im1.getScaledInstance(c.getWidth(), c.getHeight(), Image.SCALE_SMOOTH);
}
};
Image quality will degrade over time with the second solution, so it is recommended that you keep the original and the copy separate.
Create a class the extends JPanel. Have that class load the image by overriding paintComponent
class BackgroundPanel extends JPanel
{
Image img;
public BackgroundPanel()
{
// Read the image and place it in the variable img so it can be used in paintComponent
img = Toolkit.getDefaultToolkit().createImage("ABC0001.jpg");
}
public void paintComponent(Graphics g)
{
g.drawImage(img, 0, 0, null); // draw the image
}
}
Now that you have this class, simply add this to your JFrame (or whereever you want the background).
//create refrence if you want to add stuff ontop of the panel
private BackgroundPanel backGroundPanel;
//constructor
add(backGroundPanel, BorderLayout.CENTER);
The size of the background will fill the entire frame so no need to scale it unless you want it smaller