Image Overflows Allocated Space in JPanel: Seeking Assistance

Question

I would need your help again. When, in the following code, I try to add an image to the JPanel, it completely ignores the space allocated by GridBagLayout and GridBagConstraints. Indeed, the image occupies all the space it can without adhering to any constraints. I believe the issue stems from the fact that the image is too large (5000px * 3333px), but it's supposed to be confined to the allocated space. Thank you for your assistance.

Code right here :

public class RProfile extends JPanel {
    private Membre membre;
    private RLine lineH;

    public RProfile(Membre user){
        this.membre = user;
        setBackground(new Color(5, 14, 26));
        setLayout(new GridBagLayout());

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.gridwidth = 1;
        gbc.gridheight = 1;
        gbc.fill = BOTH;
        gbc.anchor = WEST;
        gbc.weightx = 16.9;
        gbc.weighty = 1;
        gbc.insets = new Insets(0,0,0,0);
        add(new RMembre(user), gbc);

        gbc.gridx = 1;
        gbc.fill = GridBagConstraints.BOTH;
        gbc.anchor = GridBagConstraints.NORTH;
        gbc.weightx = 0;
        gbc.weighty = 1;
        gbc.insets = new Insets(0,0,0,0);
        lineH = new RLine(0, 0, 3, 1000, new Color(0, 71, 79)); // Updated endX to 0
        add(lineH, gbc);

        gbc.gridx = 2;
        gbc.gridy = 0;
        gbc.gridwidth = 1;
        gbc.gridheight = 1;
        gbc.fill = BOTH;
        gbc.anchor = CENTER;
        gbc.weightx = 100;
        gbc.weighty = 1;
        ImageIcon photoIcon = new ImageIcon("./res/img/faction/Alliance.png");
        JLabel photoLabel = new JLabel(photoIcon);
        add(photoLabel, gbc);
    }

    public void linePreferedSize(int lh){
        lineH.setPreferredSize(new Dimension(THICKNESS, lh));
    }
}

I also tried to create my own class with Buffered but nothing solved my problem :

package fr.riya.entity.graphic;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class RImage extends JPanel {

     private BufferedImage cardImage;

    public RImage() {
        try {
            cardImage = ImageIO.read(new File("./res/img/space/04.jpg"));
        } 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);
    }
}

gbc.gridx = 2;
        gbc.gridy = 0;
        gbc.gridwidth = 1;
        gbc.gridheight = 1;
        gbc.fill = NONE;
        gbc.anchor = CENTER;
        gbc.weightx = 0;
        gbc.weighty = 0;
        RImage rImage = new RImage();
        rImage.setPreferredSize(new Dimension(500, 500));
        add(rImage, gbc);

I tried to set a Prefered Size, changed image Sized and more thing explain in code

Answer 1

Your "core" problem revolves around here...

@Override
public Dimension getPreferredSize() {
    return cardImage != null ? new Dimension(cardImage.getWidth(), cardImage.getHeight()) : super.getPreferredSize();
}

@Override
public Dimension getMinimumSize() {
    return getPreferredSize();
}

Personally, I'd be careful about messing with minimumSize or at least would consider some alternatives, but that's me.

The "real" problem is if you then try and call setPreferredSize, the setting is going to be ignore because you've overridden the getPreferredSize method.

So, what's the answer? Well, it's complicated.

The first thing you want to do is modify the getPreferredSize method to check to see if the preferredSize has been set or not. If it has, return its value instead, otherwise, execute your custom logic.

@Override
public Dimension getPreferredSize() {
    if (isPreferredSizeSet()) {
        return super.getPreferredSize();
    }
    return cardImage != null ? new Dimension(cardImage.getWidth(), cardImage.getHeight()) : super.getPreferredSize();
}

The next part is more difficult. You now need to make decisions about what to do with the image if the available space is smaller. Do you fit or fill the image to the available space? You should also beware that Java's default scaling work flows tend to be optimised towards speed over quality.

Take a look at Quality of Image after resize very low -- Java for some more examples.

Now with that in hand, we can create a simple, re-usable, component which can be used to set it's preferredSize and will, based on the scaleType setting, fit or fill the scaled image to the available space.

nb: this is based on Scale the ImageIcon automatically to label size

The crest image was originally 246x304 and the background 3840x2160.

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main {

    public static void main(String[] args) {
        new Main();
    }

    public Main() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    JFrame frame = new JFrame("Test");
                    frame.add(new TestPane());
                    frame.pack();
                    frame.setLocationRelativeTo(null);
                    frame.setVisible(true);
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        });
    }

    protected class TestPane extends JPanel {

        public TestPane() throws IOException {
            setLayout(new GridBagLayout());

            BufferedImage crest = ImageIO.read(getClass().getResource("/resources/images/Gryffindor.png"));
            BufferedImage background = ImageIO.read(getClass().getResource("/resources/images/mando01.jpg"));

            ScalablePane crestPane = new ScalablePane(crest);
            crestPane.setPreferredSize(new Dimension(100, 100));

            ScalablePane bgPane = new ScalablePane(background, ScalablePane.ScaleType.FILL);
            bgPane.setPreferredSize(new Dimension(800, 800));


            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.anchor = GridBagConstraints.NORTH;
            add(crestPane, gbc);


            gbc.gridx = 1;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.BOTH;
            gbc.gridheight = GridBagConstraints.REMAINDER;
            add(bgPane, gbc);
        }

    }

    public class ScalablePane extends JPanel {
        enum ScaleType {
            FIT, FILL
        }

        private Image master;
        private ScaleType scaleType = ScaleType.FIT;
        private Image scaled;

        public ScalablePane(Image master) {
            this(master, ScaleType.FIT);
        }

        public ScalablePane(Image master, ScaleType scaleType) {
            this.master = master;
            setScaleType(scaleType);
        }

        @Override
        public Dimension getPreferredSize() {
            if (isPreferredSizeSet()) {
                return super.getPreferredSize();
            }
            return master == null ? super.getPreferredSize() : new Dimension(master.getWidth(this), master.getHeight(this));
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Image toDraw = null;
            if (scaled != null) {
                toDraw = scaled;
            } else if (master != null) {
                toDraw = master;
            }

            if (toDraw != null) {
                int x = (getWidth() - toDraw.getWidth(this)) / 2;
                int y = (getHeight() - toDraw.getHeight(this)) / 2;
                g.drawImage(toDraw, x, y, this);
            }
        }

        @Override
        public void invalidate() {
            generateScaledInstance();
            super.invalidate();
        }

        public void setScaleType(ScaleType scaleType) {
            this.scaleType = scaleType;
            repaint();
        }

        public ScaleType getScaleType() {
            return scaleType;
        }

        protected void generateScaledInstance() {
            scaled = null;
            switch (getScaleType()) {
                case FILL:
                    scaled = getScaledInstanceToFill(master, getSize());
                    break;
                case FIT:
                    scaled = getScaledInstanceToFit(master, getSize());
                    break;
            }
        }

        protected BufferedImage toBufferedImage(Image master) {
            Dimension masterSize = new Dimension(master.getWidth(this), master.getHeight(this));
            BufferedImage image = createCompatibleImage(masterSize);
            Graphics2D g2d = image.createGraphics();
            g2d.drawImage(master, 0, 0, this);
            g2d.dispose();
            return image;
        }

        public Image getScaledInstanceToFit(Image master, Dimension size) {
            Dimension masterSize = new Dimension(master.getWidth(this), master.getHeight(this));
            return getScaledInstance(
                    toBufferedImage(master),
                    getScaleFactorToFit(masterSize, size),
                    RenderingHints.VALUE_INTERPOLATION_BILINEAR,
                    true);
        }

        public Image getScaledInstanceToFill(Image master, Dimension size) {
            Dimension masterSize = new Dimension(master.getWidth(this), master.getHeight(this));
            return getScaledInstance(
                    toBufferedImage(master),
                    getScaleFactorToFill(masterSize, size),
                    RenderingHints.VALUE_INTERPOLATION_BILINEAR,
                    true);
        }

        public Dimension getSizeToFit(Dimension original, Dimension toFit) {
            double factor = getScaleFactorToFit(original, toFit);
            Dimension size = new Dimension(original);
            size.width *= factor;
            size.height *= factor;
            return size;
        }

        public Dimension getSizeToFill(Dimension original, Dimension toFit) {
            double factor = getScaleFactorToFill(original, toFit);
            Dimension size = new Dimension(original);
            size.width *= factor;
            size.height *= factor;
            return size;
        }

        public double getScaleFactor(int iMasterSize, int iTargetSize) {
            return (double) iTargetSize / (double) iMasterSize;
        }

        public double getScaleFactorToFit(Dimension original, Dimension toFit) {
            double dScale = 1d;
            if (original != null && toFit != null) {
                double dScaleWidth = getScaleFactor(original.width, toFit.width);
                double dScaleHeight = getScaleFactor(original.height, toFit.height);
                dScale = Math.min(dScaleHeight, dScaleWidth);
            }
            return dScale;
        }

        public double getScaleFactorToFill(Dimension masterSize, Dimension targetSize) {
            double dScaleWidth = getScaleFactor(masterSize.width, targetSize.width);
            double dScaleHeight = getScaleFactor(masterSize.height, targetSize.height);

            return Math.max(dScaleHeight, dScaleWidth);
        }

        public BufferedImage createCompatibleImage(Dimension size) {
            return createCompatibleImage(size.width, size.height);
        }

        public BufferedImage createCompatibleImage(int width, int height) {
            GraphicsConfiguration gc = getGraphicsConfiguration();
            if (gc == null) {
                gc = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
            }

            BufferedImage image = gc.createCompatibleImage(width, height, Transparency.TRANSLUCENT);
            image.coerceData(true);
            return image;
        }

        protected BufferedImage getScaledInstance(BufferedImage img, double dScaleFactor, Object hint, boolean bHighQuality) {
            BufferedImage imgScale = img;
            int iImageWidth = (int) Math.round(img.getWidth() * dScaleFactor);
            int iImageHeight = (int) Math.round(img.getHeight() * dScaleFactor);

            if (dScaleFactor <= 1.0d) {
                imgScale = getScaledDownInstance(img, iImageWidth, iImageHeight, hint, bHighQuality);
            } else {
                imgScale = getScaledUpInstance(img, iImageWidth, iImageHeight, hint, bHighQuality);
            }

            return imgScale;
        }

        protected BufferedImage getScaledDownInstance(
                BufferedImage img,
                int targetWidth,
                int targetHeight,
                Object hint,
                boolean higherQuality) {

            int type = (img.getTransparency() == Transparency.OPAQUE)
                    ? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;

            BufferedImage ret = (BufferedImage) img;

            if (targetHeight > 0 || targetWidth > 0) {
                int w, h;
                if (higherQuality) {
                    // Use multi-step technique: start with original size, then
                    // scale down in multiple passes with drawImage()
                    // until the target size is reached
                    w = img.getWidth();
                    h = img.getHeight();
                } else {
                    // Use one-step technique: scale directly from original
                    // size to target size with a single drawImage() call
                    w = targetWidth;
                    h = targetHeight;
                }

                do {
                    if (higherQuality && w > targetWidth) {
                        w /= 2;
                        if (w < targetWidth) {
                            w = targetWidth;
                        }
                    }
                    if (higherQuality && h > targetHeight) {
                        h /= 2;
                        if (h < targetHeight) {
                            h = targetHeight;
                        }
                    }

                    BufferedImage tmp = new BufferedImage(Math.max(w, 1), Math.max(h, 1), type);
                    Graphics2D g2 = tmp.createGraphics();
                    g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
                    g2.drawImage(ret, 0, 0, w, h, null);
                    g2.dispose();

                    ret = tmp;
                } while (w != targetWidth || h != targetHeight);
            } else {
                ret = new BufferedImage(1, 1, type);
            }

            return ret;
        }

        protected BufferedImage getScaledUpInstance(
                BufferedImage img,
                int targetWidth,
                int targetHeight,
                Object hint,
                boolean higherQuality) {

            int type = BufferedImage.TYPE_INT_ARGB;

            BufferedImage ret = (BufferedImage) img;
            int w, h;
            if (higherQuality) {
                // Use multi-step technique: start with original size, then
                // scale down in multiple passes with drawImage()
                // until the target size is reached
                w = img.getWidth();
                h = img.getHeight();
            } else {
                // Use one-step technique: scale directly from original
                // size to target size with a single drawImage() call
                w = targetWidth;
                h = targetHeight;
            }

            do {
                if (higherQuality && w < targetWidth) {
                    w *= 2;
                    if (w > targetWidth) {
                        w = targetWidth;
                    }
                }

                if (higherQuality && h < targetHeight) {
                    h *= 2;
                    if (h > targetHeight) {
                        h = targetHeight;
                    }
                }

                BufferedImage tmp = new BufferedImage(w, h, type);
                Graphics2D g2 = tmp.createGraphics();
                g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
                g2.drawImage(ret, 0, 0, w, h, null);
                g2.dispose();

                ret = tmp;
                tmp = null;
            } while (w != targetWidth || h != targetHeight);
            return ret;
        }
    }
}

You should also beware that doing things like cardImage = ImageIO.read(new File("./res/img/space/04.jpg")); are inherently dangerous. You don't tend to have control over what context your program might be executed from and this will change the "working directory", meaning your program won't be able to find the files it needs.

A better solution is "embedding" the resources within the application context (this will essentially pack the resources into the resulting Jar) and will allow you to more easily load them at runtime (note the use of getClass().getResource(...) in the example), regardless of the "working directory" context. How this is done will be depend on your IDE and build system, so you'll need to research that yourself.