CODEWITHSUNDEEP
javaimageswingjlabel
ripper234
ripper234

Reputation: 230008

Getting the "native size" of an image created with JLabel

I am using JLabel to create an image file from a string.

I have to specify an image dimensions (label.setSize(width, height)), otherwise I get an exception:

java.lang.IllegalArgumentException: Width (0) and height (0) cannot be <= 0
    at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:1016)
    at java.awt.image.BufferedImage.<init>(BufferedImage.java:338)
    at com.shopsnips.portal.services.ImageCreator.createFromText(ImageCreator.java:31)
    at com.shopsnips.portal.services.ImageCreator.main(ImageCreator.java:18)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)

I can control the font size using 

label.setFont(new Font("Serif", Font.BOLD, 26));

When I use a font or text that is too large to fit the fixed dimentions, the label is truncated and "..." is included instead. Is there a way to identify the optimal/maximal font size that still fits in the dimensions I set?

Or alternatively, how can I find out whether the current settings (font size + dimensions) will cause the text to be truncated?

Here is some source:

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;

public class ImageCreator {
    private ImageCreator(){}

    private final static String FONT = "Freestyle Script";

    public static void main(String[] args) {
        Path outputFile = Paths.get("c:\\tmp\\img\\test.png");

        createFromText("Hello World - this is a long text", outputFile, 150, 50);
    }

    /**
* <p>Create an image from text. <p/>
* <p/>
* https://stackoverflow.com/a/4437998/11236
*/
    public static void createFromText(String text, Path outputFile, int width, int height) {
        JLabel label = new JLabel(text, SwingConstants.CENTER);
        label.setSize(width, height);
        label.setFont(new Font(FONT, Font.BOLD, 24));

        BufferedImage image = new BufferedImage(
                label.getWidth(), label.getHeight(),
                BufferedImage.TYPE_INT_ARGB);

        Graphics g = null;
        try {
            // paint the html to an image
            g = image.getGraphics();
            g.setColor(Color.BLACK);
            label.paint(g);
        } finally {
            if (g != null) {
                g.dispose();
            }
        }

        // get the byte array of the image (as jpeg)
        try {
            ImageIO.write(image, "png", outputFile.toFile());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

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Upvotes: 1

Views: 643

Answers (3)

ripper234
ripper234

Reputation: 230008

I don't like any of the answers given (or there are not detailed enough for me to make use of right now).

Instead, I just used this heuristic to choose a font size:

private static int chooseFontSize(String text) {
    int largeFont = 28;
    int mediumFont = 22;
    int tinyFont = 16;
    if (text.length() > 25) {
        return tinyFont;
    }
    if (text.length() > 15) {
        return mediumFont;
    }
    return largeFont;
}

Upvotes: 0

Andrew Thompson
Andrew Thompson

Reputation: 168825

label.setFont(new Font("Serif", Font.BOLD, 26)); ..Is there a way to identify the optimal/maximal font size that still fits in the dimensions I set?

For getting the size of text, look to FontMetrics or a GlyphVector.

A 'quick and dirty' way to get the size of text is to drop it into a label & interrogate the label for the preferred size.

Taking these figures, the font size can be adjusted accordingly.

Upvotes: 2

mKorbel
mKorbel

Reputation: 109815

1) put BuferedImage as Icon to the JLabel,

2) don't setSize let this job for LayoutManager

3) answer by @Jeffrey was too close to the correct answer, BuferedImage if exist can return both dimensions

4) for better help sooner please post a SSCCE, because I/we can't see code on your monitor, nor exceptions generated from your Java classes

Upvotes: 2

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