Getting wrong output in adding an image in JFrame - java

My problem is that when I create or draw an image in JFrame by using
public void paint(Graphics g)
{}
Method I am getting a black screen instead of the image the problem code snippet is
ImageIcon i=new ImageIcon("logo.png);
Image im=i.getImage();
public void paint(Graphics g)
{
g=getGraphics();
}
Please suggest me an alternative method or solution to my problem
Thanks in advance

Would you consider using a JPanel and overriding the paintComponent method? Something like this:
BufferedImage image = ... //i'll leave this blank since there are several ways to get a bufferedimage. I'll leave an eg: ImageIO.read(new File("/path/to/image"));
JPanel pane = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}};
and then adding the panel to your frame. You can do the same with the container in the JFrame. The logic is simillar.

Related

Updating an image in Java Swing shows strange behaviour

I want to update an image in Java Swing and tried two different methods of rendering these images.
Define a JLabel and set the icon of it
Override the paintComponent(Graphics g) function in a custom JPanel and call g.drawImage(img, 0, 0, null)
Rendering the first image works as expected in both ways, but if I'm trying to update the image, it doesn't replace but renders one layer above which is a problem, because the images I want to render are semi-transparent, so you can see the others through.
I'm already using the repaint() method.
Method 1
public void setImage(Image img) {
this.backgroundLabel.setIcon(new ImageIcon(img));
this.repaint();
}
Method 2
public void setImage(Image img) {
this.img = img;
this.repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, null);
}
I'm thankful for any tips! <3
The first thing line in paintComponent(Graphics g) should be
super.paintComponent(g);
This clears the panel, does any background painting if necessary, and any other support functions from the overridden paintComponent method. Otherwise, you will keep drawing images over the previous ones without first clearing them.
For anyone in the future with the same problem, here is the answer I came up with.
I didn't repainted the full frame, but only the JPanel.
I had to add
frame.repaint();
in setImage().

Having images as background of JPanel

I am new in Java and I am currently creating a game with graphics. I have this class that extends from JFrame. In this class, I have many JPanels that needs an image as background. As I know, to be able to paint images in the JPanel, I need to have a separate class that extends from JPanel and that class's paintComponent method will do the work. But I don't want to make separate classes for each JPanel, I have too many of them; and with the fact that I am only concerned with the background. How can I do this? is it with an anonymous inner class? How?
For better understanding I provided some code:
public GUI extends JFrame {
private JPanel x;
...
public GUI() {
x = new JPanel();
// put an image background to x
}
Why not make a single class that takes a Image??
public class ImagePane extends JPanel {
private Image image;
public ImagePane(Image image) {
this.image = image;
}
#Override
public Dimension getPreferredSize() {
return image == null ? new Dimension(0, 0) : new Dimension(image.getWidth(this), image.getHeight(this));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(image, 0, 0, this);
g2d.dispose();
}
}
You would even provide hints about where it should be painted.
This way, you could simply create an instance when ever you needed it
Updated
The other question is, why?
You could just use a JLabel which will paint the icon for you without any additional work...
See How to use labels for more details...
This is actually a bad idea, as JLabel does NOT use it's child components when calculating it's preferred size, it only uses the size of the image and the text properties when determining it's preferred size, this can result in the component been sized incorrectly
You don't have to make another class for it? You could just do:
x = new JPanel(){
public void paintComponent(Graphics g){
super.paintComponent(g);
//draw background image
}
};
You can do this in single line:
panelInstance.add(new JLabel(new ImageIcon(ImageIO.read(new File("Image URL")))));
I hope it will work for you.

ImageIcons not displayed - JAVA

My problem is that background image covers all ImageIcons I use in my JPanel. For example, in this code snippet, I'm trying to setIcon to one of the labels I have in my Panel. But the background image covers it. How can I fix this? It doesn't matter if I use label.setIcon() outside of paint method or inside of it.
public void paint(Graphics g) {
super.paint(g);
g.drawImage(backgroundImage, 0, 0, this);
label1.setIcon(iconImage);
}
Thanks in advance!
Set the layout of your base panel to BorderLayout
Add a JLabel to the base pane, setting its icon to the background image
Set the layout if the JLabel to what ever you need
Add the remaining components to this label
Try placing the label.seticon outside the overridden method.
Refer to:
How to set JFrame or JPanel Background Image in Eclipse Helios
you can implement it as;
public void paintComponent(Graphics g) {
g.drawImage(img, 0, 0, null);
}
OR
public void paint(Graphics g) {
if (img!=null) g.drawImage(img, 0, 0, null);
super.paint(g);
}

draw buffered image ontop of another buffered image

my goal is to draw some bufferedimage onto another. then all this stuff draw onto some other bufferedimage and so on. And finally draw this on top of a panel.
For now i'm trying to draw bufferedimage onto panel and nothing works. My bufferedimage looks completely white:
public class Main2 {
public static void main(String[] args) {
JFrame frame = new JFrame("asdf");
final JPanel panel = (JPanel) frame.getContentPane();
frame.setSize(500,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
panel.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
somepaint(panel);
}
});
}
private static void somepaint(JPanel panel) {
BufferedImage image = new BufferedImage(200,200,BufferedImage.TYPE_INT_ARGB);
image.getGraphics().setColor(Color.red);
image.getGraphics().fillRect(0, 0, 200, 200);
Graphics2D graphics = (Graphics2D) panel.getGraphics();
graphics.setColor(Color.magenta);
graphics.fillRect(0, 0, 500, 500);
graphics.drawImage(image, null, 0, 0); // draws white square instead of red one
}
}
thanks
Re:
private static void somepaint(JPanel panel) {
BufferedImage image = new BufferedImage(200,200,BufferedImage.TYPE_INT_ARGB);
image.getGraphics().setColor(Color.red);
image.getGraphics().fillRect(0, 0, 200, 200);
Graphics2D graphics = (Graphics2D) panel.getGraphics();
This is not how you draw inside of a JPanel or JComponent.
Don't call getGraphics() on a component as the Graphics object returned will be short-lived, and anything drawn with it will not persist. Instead do your JPanel's drawing inside of its paintComponent(Graphics G) method override. You will need to create a class that extends JPanel in order to override paintComponent(...).
Most importantly, to see how to do Swing graphics correctly, don't guess. You'll want to read the Swing Graphics Tutorials first as it will require you to toss out some incorrect assumptions (I know that this is what I had to do to get it right).
You need to rectify your parameters in the drawImage() call. Change this:
graphics.drawImage(image, null, 0, 0);
to
graphics.drawImage(image, 0, 0,null);
Check the Java docs for more details.

Background Image in JTextPane

How do I set a background image to a JTextPane - some sort of a watermark.
I tried this option - creating a child class of JTextPane and use the paint method to draw the image.
But then the text is displayed "below" the image than above.
Is there any "standard" or "well known" way to do this?
(BTW, I tried (something silly?) making the content type "text/html", and setting the image as the background image of a <div> but it did not help.)
Here's a working example:
import javax.swing.*;
import java.awt.*;
public class ScratchSpace {
public static void main(String[] args) {
JFrame frame = new JFrame("");
final MyTextPane textPane = new MyTextPane();
frame.add(textPane);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private static class MyTextPane extends JTextPane {
public MyTextPane() {
super();
setText("Hello World");
setOpaque(false);
// this is needed if using Nimbus L&F - see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6687960
setBackground(new Color(0,0,0,0));
}
#Override
protected void paintComponent(Graphics g) {
// set background green - but can draw image here too
g.setColor(Color.GREEN);
g.fillRect(0, 0, getWidth(), getHeight());
// uncomment the following to draw an image
// Image img = ...;
// g.drawImage(img, 0, 0, this);
super.paintComponent(g);
}
}
}
The important things to note:
your component must not be opaque...
so setOpaque(false);
override paintComponent(Graphics g), not paint.
paint your background, with an image
or drawing BEFORE calling
super.paintComponent(g);
If you want to master this stuff, I recommend reading "Filthy Rich Clients", a book all about how to bend Swing to your will.
Try changing the paint code to this.
public void paint(Graphics g)
{
g.setXORMode(Color.white);
g.drawImage(image,0, 0, this);
super.paint(g);
}
This would make your image to be painted before the text is rendered by the actual component's paint method.
Hmm., put a background image to the JFrame/JPanel containg the JTextPane,.. and keep the JTextPane transparent to some level.

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