icon on jlabel get the size of the jlabel

Question

I'm using a Jlabel with an icon in swing. I chose an image from my computer as the icon and I can't find a way to make it resize automatically to the size of the Jlabel. Because the image I want is much bigger then the size of the Jlabel i'm only seeing a small part of it. Is there any way to solve this problem so I won't need to resize each image before importing it to the project?

Answer 1

Might be your LayoutManger/lack there of thats interfering as JLabel should return correct size according to the content displayed.

Please post SSCCE to show specific problems.

Though regardless a large image will still need to be scaled, here is a nice method I usually use:

public static BufferedImage scaleImage(int w, int h, BufferedImage img) throws Exception {
    BufferedImage bi;
    bi = new BufferedImage(w, h, BufferedImage.TRANSLUCENT);
    Graphics2D g2d = (Graphics2D) bi.createGraphics();
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
    g2d.drawImage(img, 0, 0, w, h, null);
    g2d.dispose();
    return bi;
}

here is an example:

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;

public class Test {

    public Test() {
        initComponents();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Test();
            }
        });
    }

    private void initComponents() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        BufferedImage img = null;
        try {
            BufferedImage tmp = ImageIO.read(new URL("http://photos.appleinsider.com/12.08.30-Java.jpg"));
            img = scaleImage(200, 200, tmp);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        JLabel label = new JLabel(new ImageIcon((Image) img));
        frame.add(label);
        frame.pack();
        frame.setVisible(true);
    }

    public static BufferedImage scaleImage(int w, int h, BufferedImage img) throws Exception {
        BufferedImage bi;
        bi = new BufferedImage(w, h, BufferedImage.TRANSLUCENT);
        Graphics2D g2d = (Graphics2D) bi.createGraphics();
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
        g2d.drawImage(img, 0, 0, w, h, null);
        g2d.dispose();
        return bi;
    }
}