测试字体在 Java 中是否等宽

java fonts swing

2022-09-03 14:21:42

我正在尝试列出用户计算机上所有可用的等宽字体。我可以通过以下方式获取 Swing 中的所有字体系列：

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

有没有办法弄清楚哪些是等宽的？

提前致谢。

答案 1

一种更简单的方法，不需要制作BufferedImage来获取图形对象等：

    Font fonts[] = GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
    List<Font> monoFonts1 = new ArrayList<>();

    FontRenderContext frc = new FontRenderContext(null, RenderingHints.VALUE_TEXT_ANTIALIAS_DEFAULT, RenderingHints.VALUE_FRACTIONALMETRICS_DEFAULT);
    for (Font font : fonts) {
        Rectangle2D iBounds = font.getStringBounds("i", frc);
        Rectangle2D mBounds = font.getStringBounds("m", frc);
        if (iBounds.getWidth() == mBounds.getWidth()) {
            monoFonts1.add(font);
        }
    }

答案 2

~~您可以使用 FontMetrics 类的 getWidths（）方法。根据JavaDoc：~~

获取字体中前 256 个字符的前进宽度。前进是角色基线上从最左边点到最右边点的距离。请注意，字符串的前进不一定是其字符前进的总和。

您可以使用 FontMetrics 类的方法。例如：charWidth(char)

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();