Question

My Swing-Application sets the size of the JFrame via GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds(), and all Elements are relative to this values, so basically the application adapts to the screen resolution.

Now I have a problem with my custom buttons. For now, I create three different ImageIcons (normal, rollover and pressed) and add them to the button. But naturally, if I run the application with a different resolution than 1920×1080 (which is my default), the buttons are too big.

I found this question (http://stackoverflow.com/questions/8234726/auto-resizing-jbutton-icon) and tried the solution by creating an Icon, put it on a Jlabel and add the label to the button, but nothing is displaid. Also, I do not need to resize the window.

What is the fastest and solution for this topic? An option would be to create all custom images individually for every resolution, add the x-value of the resolution at the end of the image name and make let’s say a switch case to check which image should be load, but I think this is a very expensive and time-consuming solution. Is there an efficient way to automatically size a loaded image to a certian size relative to the screen resolution?

Answer 1

If you have an Image, you can invoke getScaledInstance to retrieve a resized image.

If you have an ImageIcon,you can invoke getImage() on it, to retrieve an Image and then use the solution suggested above.

getScaledInstance returns an Image which you can wrap back into an ImageIcon and set on a JButton or a JLabel.

So, I would create my images with the highest resolution possible and then downscale them to the appropriate resolution.

Here is a small snippet (inspired from @mKorbel solution you started from):

import java.awt.BorderLayout;
import java.awt.Image;
import java.net.MalformedURLException;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;

public class ResizeIconInButton extends JFrame {

    private static final long serialVersionUID = 1L;
    private static final String IMAGE_PATH = "http://duke.kenai.com/misc/Bullfight.jpg";
    private JButton myButton = new JButton();

    public ResizeIconInButton() throws MalformedURLException {
        myButton.setIcon(new ImageIcon(new ImageIcon(new URL(IMAGE_PATH)).getImage().getScaledInstance(600, 400, Image.SCALE_SMOOTH)));
        add(myButton, BorderLayout.CENTER);
        setTitle("Resize Icon In Button");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                try {
                    ResizeIconInButton main = new ResizeIconInButton();
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

Small note: it is not recommended to extend JFrame but I tried to stay as close as possible to the original code.