Test whether the font is first-class in Java

I'm listing all the constant width fonts available on the user's machine I can get all fonts in swing in the following ways:

String[] fonts = GraphicsEnvironment.getLocalGraphicsEnvironment()
                                    .getAvailableFontFamilyNames();

Is there any way to figure out what is uniform?

Thank you in advance

Solution

You can use the getwidths () method of the fontmetrics course According to Javadoc:

You can use the charwidth (char) method of the fontmetrics class For example:

Set<String> monospaceFontFamilyNames = new HashSet<String>();

GraphicsEnvironment graphicsEnvironment = GraphicsEnvironment.getLocalGraphicsEnvironment();
String[] fontFamilyNames = graphicsEnvironment.getAvailableFontFamilyNames();

BufferedImage bufferedImage = new BufferedImage(1,1,BufferedImage.TYPE_INT_ARGB);
Graphics graphics = bufferedImage.createGraphics();

for (String fontFamilyName : fontFamilyNames) {
    boolean isMonospaced = true;

    int fontStyle = Font.PLAIN;
    int fontSize = 12;
    Font font = new Font(fontFamilyName,fontStyle,fontSize);
    FontMetrics fontMetrics = graphics.getFontMetrics(font);

    int firstCharacterWidth = 0;
    boolean hasFirstCharacterWidth = false;
    for (int codePoint = 0; codePoint < 128; codePoint++) { 
        if (Character.isValidCodePoint(codePoint) && (Character.isLetter(codePoint) || Character.isDigit(codePoint))) {
            char character = (char) codePoint;
            int characterWidth = fontMetrics.charWidth(character);
            if (hasFirstCharacterWidth) {
                if (characterWidth != firstCharacterWidth) {
                    isMonospaced = false;
                    break;
                }
            } else {
                firstCharacterWidth = characterWidth;
                hasFirstCharacterWidth = true;
            }
        }
    }

    if (isMonospaced) {
        monospaceFontFamilyNames.add(fontFamilyName);
    }
}

graphics.dispose();