How to save JPanel as JPEG with its components - java

I need to save a chessboard as a jpeg file. I know how to save a java component into JPEG. But my problem is that I use JButtons as cells and when I try to save the whole chessboard, only the panel is saved. Does anybody know how to save a JComponent WITH ITS CHILD COMPNENTS into JPEG (png etc.) Thank you in advance.

You can print a Component (such as JPanel) to any Graphics object. So, why not use the Graphics object of a BufferedImage and write it to disk.
void takePicture(JPanel panel) {
BufferedImage img = new BufferedImage(panel.getWidth(), panel.getHeight(), BufferedImage.TYPE_INT_RGB);
panel.print(img.getGraphics()); // or: panel.printAll(...);
try {
ImageIO.write(img, "jpg", new File("panel.jpg"));
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
This makes this JPanel
JPanel panel = new JPanel();
panel.add(new JButton("Hello"));
panel.add(new JButton("World"));
Look like this:
updated based on comments, many thanks to #MadProgrammer

Check out Screen Image. It will allow you to create an image of any component in the frame. If you choose to make an image of a panel all the child components are included in the image.

Use Robot class to create a screen capture of your screen.
Use this tutorial for help:
Screen Capture using Robot class
Now for your chessboard, clip the image by calling subImage method of BufferedImage class.
Here's the link on clipping BufferedImage
You can get Dimensions of you JPanel by calling getX(), getY(), getWidth() and getHeight() methods which you can pass into subImage method.
Manipulate the passing value by adding/substracting some value to get desired results.

Related

Background in JPanel repaint

I have a program that has multiple layers, in the bottom layer I have a JPanel that I have put a background image on. On top of this I have a JLayeredPane that has some draggable components. My problem is that when the user have uploaded a background image the draggable components are really lagging, my guess is that it's because of that swing is repainting the background image al the time when dragging. My question is if its anyway to make sure the image is not repainting all the time?
My code where I paint the image looks like this:
if (this.getLoadedBackgroundImage() != null) {
try {
BufferedImage bufferedImage = ImageIO.read(this.getLoadedBackgroundImage());
Image bImage = bufferedImage.getScaledInstance(this.getWidth() - 5 - jPanel6.getWidth() -5, this.getHeight() - jPanel2.getHeight() - jPanel3.getHeight() - tabPanel.getHeight(), Image.SCALE_FAST);
graphics2d.drawImage(bImage, 5, jPanel2.getHeight() + tabPanel.getHeight()+5, null);
} catch (IOException ex) {
Logger.getLogger(MainViewLayeredPane.class.getName()).log(Level.SEVERE, null, ex);
}
}
Don't load or resize the image the paintComponent method, these are expensive operations, instead, pre-cache it and only paint the cached version

Converting JPanel to Image to be added in iText PDF with white or transparent background

I am trying to convert a JPanel to Image and will be writing it to a PDF using iText.
I have searched ways on how to convert JPanel to Image and found two "Working" solutions.
private BufferedImage createImage(JPanel panel) {
int w = panel.getWidth();
int h = panel.getHeight();
BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = bi.createGraphics();
panel.print(g);
return bi;
}
public static java.awt.Image getImageFromPanel(JPanel component) {
BufferedImage image = new BufferedImage(component.getWidth(),
component.getHeight(), BufferedImage.TYPE_INT_ARGB);
component.paint(image.getGraphics());
return image;
}
As you can see, I already used "ARGB" to try to convert it to image with a transparent or white background but it doesnt work. See attached image.
Is there a way to convert it to image and print it to PDF with white or transparent background?
Below is the image converted from the JPanel using codes above
Image written on PDF
Bottom is the JPanel I want to convert to Image
JPanel I want to convert
Is there a way to convert it to image and print it to PDF with white or transparent background?
Well by default a JPanel is opaque and has its own background so the background get copied to the image.
I have never tried this before but maybe nesting panels something like this will work:
JPanel imagePanel = new JPanel();
imagePanel.setOpaque(false);
JPanel backgroundPanel = new JPanel( new BorderLayout() );
backgroundPanel.add( imagePanel );
frame.add( backgroundPanel );
So now the imagePanel should be be transparent when you create the BufferedImage. But it will inherit the background color of the backgroundPanel so it still looks correct in the frame.
I think the easiest way is to fit the Panel size to the inside components, then the components may cover all the Panel background

Resize and Redraw a image in a JPanel

I'm creating a simple java program to load a image and zoom in/out the image.
So far I have been able load the picture and zoom it. But when drawing the zoomed out image I can still see the previous image on the JPanel.
Code for loading the image
JFileChooser fileChooser = new JFileChooser();
fileChooser.setFileFilter(new FileNameExtensionFilter("Images(jpg,png,gif)", "jpg","png","gif"));
int opt = fileChooser.showOpenDialog(this);
if(opt == JFileChooser.APPROVE_OPTION){
String filePath = fileChooser.getSelectedFile().getAbsolutePath();
try {
bufImage = ImageIO.read(fileChooser.getSelectedFile());
} catch (IOException ex) {
Logger.getLogger(ImageZoom.class.getName()).log(Level.SEVERE, null, ex);
}
image = new ImageIcon(filePath);
imgWidth = image.getIconWidth();
imgHeight = image.getIconHeight();
imagePanel.getGraphics().drawImage(image.getImage(), 0, 100, image.getIconWidth(), image.getIconHeight(), imagePanel);
}
Code for zooming in
double scale_factor = 1.5;
imagePanel.getGraphics().drawImage(image.getImage(), 0, 100, (int)(imgWidth*=scale_factor), (int)(imgHeight*=scale_factor), imagePanel);
Code for zooming out
double scale_factor = 0.5;
imagePanel.getGraphics().drawImage(image.getImage(), 0, 100, (int)(imgWidth*=scale_factor), (int)(imgHeight*=scale_factor), imagePanel);
Can some one please suggest a way to only have the resized image on the panel?
This is how zooming out looks like. same problem occurs when opening a new picture.
I tried repainting the panel but then everything vanishes.
That's because imagePanel.getGraphics() isn't how custom painting works in Swing. Instead, create a custom class which extends from something like JPanel and override it's paintComponent method, painting your scaled image there (making sure to call super.paintComponent first)
See Painting in AWT and Swing and Performing Custom Painting for more details
For example:
zoom using mouse and graphics
Java image zooming japplet
Jpanel resize on repaint

Java GUI image size

So I have an assignment where I need to create a catalog.
The catalog needs to have a list, an image and a description.
My entire code works, so I have no issue with the coding as such.
I do have an issue with the image size.
How do I take care of images on a java gui program to make them all into one size when it is running.
Please let me know :D
When you read in an image, create a new BufferedImage that is the exact size that you desire, get it's Graphics object via getGraphics(), draw the original image into the new image using Graphics#drawImage(Image img, int x, int y, int width, int height, ImageObserver observer) where x and y are 0 and width and height are from the dimensions of the new image, dispose() of the Graphics object, and then display the new Image as an ImageIcon in a JLabel. Make sure though that the original image is the same size or larger than the new one, else your images will look gawd-awful.
For example, and note that this code may not be exactly correct since I don't have my IDE up:
BufferedImage originalImage = ImageIO.read(something); // read in original image
// create new empty image of desired size
BufferedImage newImage = new BufferedImage(desiredWidth, desiredHeight, BufferedImage.TYPE_INT_ARGB);
Graphics g = newImage.getGraphics(); // get its graphics object
// draw old image into new image
g.drawImage(originalImage, 0, 0, desiredWidth, desiredHeight, null);
g.dispose(); // get rid of Graphics object
// create ImageIcon and put in JLabel to display
Icon newIcon = new ImageIcon(newImage);
myJLabel.setIcon(newIcon);
I would propably create a JPanel to draw on one Image, and then work with the method:
myPanel.setSize(new Dimension(x,y))
or
myPanel.setPreferredSize(new Dimension....)
There is a method (image = imgobj.getScaledInstance(width, height, hints)) in awt.Image class which provides re-sizing capabilities very nicely, I always use this to re-size my images when I need. Please see here some examples :-), I hope it will work for you, it is the most convenient way to scale images I have ever seen. create a method pass the image to the method and size of the image you want and return the image back in return to reuse the code ;)

Java - Drawing Images Basically

I've come from Python to Java and am a bit confused. My main question is how to draw an image. I've looked on the oracle site but even when copy - pasting their code it didn't work. Here is what I had (excluding imports):
public class ImageTesting{
public void main(String[] args){
BufferedImage img = null;
try {
img = ImageIO.read(new File("/Volumes/Data/Users/me/Desktop/Button Img.png"));
Graphics g = null;
g.drawImage(img, 100, 100, this);
} catch (IOException e) {
System.out.println("Image Loading Failed");
}}}
The line I'm having problems is the g.drawImage(img, 100, 100, this); and complains about not having an image observer. It confuses me that that same line works in another code I have but works :/ What am I missing??!
You need something to display your image on.
The simplest method would be to use a JLabel, see How to use labels for mor examples
You need a window to display the label, see How to create GUIs with Swing for details
If, for some reason, you absolutely must paint the image manually, you will need to extend from something that is paintable, like JPanel and override its paintComponent method.
See How to perform custom painting for more details

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