I'm not that familiar with Java and I'm a little clueless about my current problem.
I'm trying to draw an Image within a separate class of my Main JFrame, but it
always draw just a little piece of the picture (maybe 10x10px).
(A test with a Label worked)
Maybe I didn't used the g.drawImage method correct, or the JPanel don't have enough space??
MainWindow:
public class Deconvolutioner extends JFrame {
Draw z;
Picturearea picturearea;
class Draw extends JPanel {
public void paint(Graphics g) {
}
}
public Deconvolutioner() {
setTitle("Deconvolutioner");
setLocation(30,1);
setSize(1300,735);
super.setFont(new Font("Arial",Font.BOLD,11));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
FlowLayout flow = new FlowLayout(FlowLayout.CENTER);
this.setLayout(flow);
picturearea = new Picturearea();
this.add(picturearea);
add(z = new Draw());
setVisible(true);
}
class Open implements ActionListener {
public void actionPerformed(ActionEvent e) {
JFileChooser fileOpen = new JFileChooser();
FileFilter filter = new FileNameExtensionFilter("png & jpg files", "png",
"jpg");
fileOpen.addChoosableFileFilter(filter);
int returnVal = fileOpen.showDialog(null, "Open file");
if (returnVal == JFileChooser.APPROVE_OPTION) {
try {
String path = fileOpen.getSelectedFile().getPath();
URL url = new File(path).toURI().toURL();
BufferedImage img = ImageIO.read(url);
picturearea.setPicture(img);
} catch (IOException ex) {
System.err.println("Some IOException accured (set the right path?): ");
System.err.println(ex.getMessage());
}
} else {
}
repaint();
}
}
And the separate class:
public class Picturearea extends JPanel {
public BufferedImage image;
Draw z;
public Picturearea() {
add(z = new Draw());
setVisible(true);
}
class Draw extends JPanel {
#Override
public void paint(Graphics g) {
g.drawImage(image, 0, 0, this);
}
}
public void setPicture(BufferedImage picture) {
try {
image = picture;
} catch (Exception e) {
System.err.println("Some IOException accured (did you set the right path?): ");
System.err.println(e.getMessage());
}
repaint();
}
}
I'm grateful for every help.
thanks for your time.
You are using FlowLayout for JFrame's contentPane's layout. FlowLayout obeys component's preferredSize. Try setting preferredSize of your pictureArea by pictureArea.setPreferredSize(Dimension) or overriding getPreferredSize(Dimension) function in PictureArea class.
you are using paint(Graphics g) for custom painting:
#Override
public void paint(Graphics g) {
g.drawImage(image, 0, 0, this);
}
Do not override paint() for custom painting override paintComponent(Graphics g) instead. And You may need to scale your image to fit in the size of the JPanel. you can use g.drawImage(x, y, width, height, observer) function if you need to scale your image.
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, this);
}
Related
Simple problem for Swing regular costumers.
The idea is to load an image and use it as a background of a JPanel through a JComponent object. It seems to load just fine as the image information from toString() method is loading properly and the paintComponent() method is running, but for some reason it is not rendering correctly inside the JFrame leading to an empty frame. Here's the code:
RicochetFrame.java
public class RicochetFrame extends JFrame {
RicochetStartPanel startPanel;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
RicochetFrame window = new RicochetFrame();
window.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public RicochetFrame() throws IOException {
startPanel = new RicochetStartPanel();
this.getContentPane().add(startPanel);
this.setBounds(0, 0, 500, 500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//this.pack();
this.setVisible(true);
}
}
RicochetStartPanel.java
public class RicochetStartPanel extends JPanel {
RicochetStartPanel() throws IOException {
BufferedImage myImage = ImageIO.read(new File("frame_bg.jpg"));
this.add(new RicochetImagePanel(myImage));
this.setVisible(true);
this.validate();
this.repaint();
}
}
RicochetImagePanel.Java
public class RicochetImagePanel extends JComponent {
private Image image;
public RicochetImagePanel(Image image) {
this.setVisible(true);
this.image = image;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, this);
}
}
Your RicochetImagePanel is sizing itself to its preferred size => [0, 0]. Override its getPreferredSize() to return the dimensions of the image (if not null). Better still, why not simply display the image as an ImageIcon in a JLabel?
I have written the following example to give something runnable of a problem I am having. When you press the button the controlWhichImage switches to 2. The problem is that when it switches from the original image to a copy the image disappears.
public class PainterDemo01 extends JPanel implements ActionListener {
BufferedImage createdImage;
BufferedImage img;
int controlWhichImage;
JFrame mainFrame;
JButton changePicture;
public PainterDemo01(){
changePicture = new JButton("Press");
changePicture.addActionListener(this);
controlWhichImage = 1;
mainFrame = new JFrame();
mainFrame.add(this);
this.add(changePicture);
mainFrame.setPreferredSize(new Dimension(600,600));
mainFrame.setVisible(true);
mainFrame.pack();
img = loadImage();
}
public BufferedImage loadImage(){
img = null;
try {
img = ImageIO.read(new File("/home/gerry/Desktop/100_0647.JPG"));
} catch (IOException e){
System.out.println("no file here");
}
return img;
}
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
loadImage();
if (createdImage == null){
this.createdImage = new BufferedImage(this.getWidth(),this.getHeight(), BufferedImage.TYPE_INT_ARGB);
}
Graphics g2 = this.createdImage.getGraphics();
if (controlWhichImage == 1){
g2.drawImage(img,0,0,img.getWidth(),img.getHeight(),null);
g.drawImage(img, 0,0,img.getWidth(),img.getHeight(),null);
g2.dispose();
}
if (controlWhichImage == 2){
//Draw bufferedImage on to to JPanel
g.drawImage(this.createdImage,this.createdImage.getWidth(),this.createdImage.getHeight(),null);
}
}
#Override
public void actionPerformed(ActionEvent e){
controlWhichImage = 2;
repaint();
}
public static void main(String[] args) {
// TODO code application logic here
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new PainterDemo01().setVisible(true);
}
});
}
}
The problem is that getGraphics (or better named createGraphics) is called outside the if statement, also for 2, hence both causing a resource leak (as no g2.dispose is called), and also a clean slate.
if (controlWhichImage == 1) {
Graphics g2 = createdImage.getGraphics();
g2.drawImage(img,0,0,img.getWidth(),img.getHeight(),null);
g2.dispose();
}
Also do things like loading the image outside the paint code.
See this question if you want to know how to copy an BufferedImage:
How to copy BufferedImage
Of course! You have to go and paint the image at the outskirts. Please use this
g.drawImage(this.createdImage, 0, 0, this.createdImage.getWidth(),this.createdImage.getHeight(),null);
Use img obj since its already instantiated but not createdImage obj, createdImage contains null since its just declared but not instantiated. If you use createdImage obj means if you perform any operation upon createdImage obj then you will get NullPointerException.
Graphics g2 = this.img.getGraphics();
---------
I'm creating a java game. In the game there are a hero and a bubble. The hero is supposed to move when I press the arrow keys and the bubble is supposed to have continuous diagonal movement. When I add the hero or the bubble directly into to the JFrame separately I get the desired behavior, but when I add them both I just get a very small square! I tried to add them to the same JPanel and after add that JPanel to the JFrame but it is not working. Probably I have to define some type of layout to the JPanels.
What am I doing wrong?
Code:
public class Pang {
public static void main(String[] args) {
JFrame f=new JFrame();
JPanel gamePanel=new JPanel();
gamePanel.setPreferredSize(new Dimension(800, 600));
DrawHero d=new DrawHero();
DrawBubble bubble=new DrawBubble();
gamePanel.add(d);
gamePanel.add(bubble);
f.add(gamePanel);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(800, 600);
}
}
public class DrawHero extends JPanel implements ActionListener, KeyListener {
Timer myTimer = new Timer(5, this);
int x = 0, y = 0, dx = 0, dy = 0, step = 10;
private transient Image imageHero = null;
public DrawHero() {
myTimer.start();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
imageHero = getHeroImage();
g2.drawImage(imageHero, x, y, 40, 40, null);
}
public Image getHeroImage() {
Image image = null;
image = getImage("hero.png");
return image;
}
public Image getImage(String path) {
Image tempImage = null;
try {
URL heroiURL = DrawHero.class.getResource(path);
tempImage = Toolkit.getDefaultToolkit().getImage(heroiURL);
} catch (Exception e) {
System.out.println("Error loading hero image! - "
+ e.getMessage());
}
return tempImage;
}
public void actionPerformed(ActionEvent e) {
repaint();
}
public void moveUp() {
y = y - step;
}
public void moveDown() {
y = y + step;
}
public void moveLeft() {
x = x - step;
}
public void moveRight() {
x = x + step;
}
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == KeyEvent.VK_UP) {
moveUp();
}
if (keyCode == KeyEvent.VK_DOWN) {
moveDown();
}
if (keyCode == KeyEvent.VK_LEFT) {
moveLeft();
}
if (keyCode == KeyEvent.VK_RIGHT) {
moveRight();
}
}
public void keyTyped(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
}
}
public class DrawBubble extends JPanel implements ActionListener, KeyListener {
Timer myTimer = new Timer(5, this);
int x = 100, y = 200, dx = 0, dy = 0, step = 10;
private transient Image imageHero = null;
public DrawBubble() {
myTimer.start();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.fill(new Ellipse2D.Double(x, y, 40, 40));
}
public void actionPerformed(ActionEvent e) {
x=x+dx;
y=y+dy;
repaint();
}
public void moveBubble() {
dy=2;
dx=2;
}
public void keyPressed(KeyEvent e) {
moveBubble();
}
public void keyTyped(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
}
}
I recommend that neither the DrawHero nor DrawBubble (which should be called Hero nor Bubble respectively) should extend any JComponent. Instead each should simply know how to draw itself to a Graphics object passed to it, when requested to do so.
Then a single GameField or PlayingArea class should keep references to all the Bubble objects and the Hero and draw call the draw(Graphics) method of those objects.
Using this approach it is not necessary to worry about layouts within the GameField component (they become irrelevant).
That is the basic strategy I pursue for rendering the stationary objects in this answer to [Collision detection with complex shapes.
When I add the hero or the bubble directly into to the JFrame separately I get the desired behavior, but when I add them both i just get a very small square!
The default layout manager for a JFrame is a BorderLayout. When you use add(component) without a constraint the component goes to the CENTER. Only one component can be added to the CENTER, so only the last one added is displayed.
I tried to add them to the same JPanel and after add that JPanel to the JFrame but it is not working.
The default layout manager for a JPanel is the FlowLayout which respects the preferred size of component. The problem is you don't override the getPreferredSize() method so the size is (0, 0) and there is nothing to paint.
Probably I have to define some type of layout to the JPanels.
Actually since you want random motion you need to use a null layout on the panel and then use the setSize() and setLocation() method of your components to position the components.
Then when you do this the custom painting should always be done at (0, 0) instead of (x, y) since the location will control where the component is painted on the panel.
By unsing netbeans ide , I created a JDesktopPane inside the JFrame. and I cannot change the color of the jdesktopPane.. I tried all I can. But when I open the JFrame .. the JDesktopPane inside that JFrame is in some blue color background.
Please help me to change the background of JDesktopPane
I'm going to assume you're using GUI Builder with the default Nimbus look and feel (because you said you've tried everything, and I'll assume you've tried setBackground). The look and feel has the background set. But you have options around it.
You can just paint the background. You want to look at this answer for how to edit the auto-generated code. Then you can just to this, when you edit the code. Don't forget to hit ctrl+shift+I afterwards, to resolve all imports. I'm too lazy to write fully qualified names.
jDesktopPane1 = new javax.swing.JDesktopPane() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, getWidth(), getHeight());
}
};
If you want an image, you can paint an image
jDesktopPane1 = new javax.swing.JDesktopPane() {
private Image image;
{
try {
image = ImageIO.read(new URL("http://www.hdbackgroundspoint.com/wp-content/uploads/2013/12/16/345t34.jpeg"));
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, getWidth(), getHeight(), this);
}
};
You could also override the Nimbus default DesktopPane[Enabled].backgroundPainter. See Nimbus Defaults here
public static void main(String[] args) {
try {
for (UIManager.LookAndFeelInfo laf : UIManager
.getInstalledLookAndFeels()) {
if ("Nimbus".equals(laf.getName())) {
UIManager.setLookAndFeel(laf.getClassName());
UIManager.getLookAndFeelDefaults().put(
"DesktopPane[Enabled].backgroundPainter",
new DesktopPainter());
}
}
} catch (Exception e) {
e.printStackTrace();
}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new JDesktopPaneDemo();
}
});
}
static class DesktopPainter implements Painter<JComponent> {
private Image image;
public DesktopPainter() {
try {
image = ImageIO.read(new URL("http://www.hdbackgroundspoint.com/wp-content/uploads/2013/09/hh.jpeg"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void paint(Graphics2D g, JComponent object, int width, int height) {
g.drawImage(image, 0, 0, width, height, null);
}
}
I created a component to display Image in jPanel.But its not showing the image during design time.how to show Image on design time?
public class JImagePanel extends JPanel {
private BufferedImage _img=null;
public JImagePanel() {
super();
}
public void setImage(URL img) {
try{
this._img = ImageIO.read(img);
validate();
repaint();
}catch(Exception err){
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if(this._img!=null)
g.drawImage(_img, 0, 0, getWidth(), getHeight(), this);
}
}
if you want to display Icon/ImageIcon only, then better would be look for JLabel as painting background by using paintComponent(Graphics g)