Java Swing Font Width isFixedWidthFont(String fontName, Component component)

Description

Checks if the font specified by the font name is fixed width font.

License

Open Source License

Parameter

Parameter	Description
fontName	the font name
component	the component where the font will be displayed.

Return

true if the font is fixed width. Otherwise false.

Declaration

public static boolean isFixedWidthFont(String fontName,
        Component component) 

Method Source Code

//package com.java2s;
import javax.swing.*;

import java.awt.*;

public class Main {
    /**/* w  ww . j av  a  2 s  . c  o  m*/
     * Checks if the font specified by the font name is fixed width font. Fixed width font means all chars have the
     * exact same width.
     *
     * @param fontName  the font name
     * @param component the component where the font will be displayed.
     * @return true if the font is fixed width. Otherwise false.
     */
    public static boolean isFixedWidthFont(String fontName,
            Component component) {
        if (fontName.endsWith(" Bold") || fontName.endsWith(" ITC")
                || fontName.endsWith(" MT") || fontName.endsWith(" LET")
                || fontName.endsWith(".bold")
                || fontName.endsWith(".italic"))
            return false;
        try {
            Font font = new Font(fontName, 0, 12);
            if (!font.canDisplay('W'))
                return false;
            Font boldFont = font.deriveFont(Font.BOLD);
            FontMetrics fm = component.getFontMetrics(font);
            FontMetrics fmBold = component.getFontMetrics(boldFont);
            int l1 = fm.charWidth('l');
            int l2 = fmBold.charWidth('l');
            if (l1 == l2) {
                int w1 = fm.charWidth('W');
                int w2 = fmBold.charWidth('W');
                if (w1 == w2 && l1 == w1) {
                    int s1 = fm.charWidth(' ');
                    int s2 = fmBold.charWidth(' ');
                    if (s1 == s2) {
                        return true;
                    }
                }
            }
        } catch (Throwable throwable) {
            // ignore it and return false
        }
        return false;
    }

    /**
     * Copied from JDK's SwingUtilities2.java
     * <p/>
     * Returns the FontMetrics for the current Font of the passed in Graphics.  This method is used when a Graphics is
     * available, typically when painting.  If a Graphics is not available the JComponent method of the same name should
     * be used.
     * <p/>
     * Callers should pass in a non-null JComponent, the exception to this is if a JComponent is not readily available
     * at the time of painting.
     * <p/>
     * This does not necessarily return the FontMetrics from the Graphics.
     *
     * @param c JComponent requesting FontMetrics, may be null
     * @param g Graphics Graphics
     */
    public static FontMetrics getFontMetrics(JComponent c, Graphics g) {
        return getFontMetrics(c, g, g.getFont());
    }

    /**
     * Copied from JDK's SwingUtilities2.java
     * <p/>
     * Returns the FontMetrics for the specified Font. This method is used when a Graphics is available, typically when
     * painting.  If a Graphics is not available the JComponent method of the same name should be used.
     * <p/>
     * Callers should pass in a non-null JComponent, the exception to this is if a JComponent is not readily available
     * at the time of painting.
     * <p/>
     * This does not necessarily return the FontMetrics from the Graphics.
     *
     * @param c    JComponent requesting FontMetrics, may be null
     * @param c    Graphics Graphics
     * @param font Font to get FontMetrics for
     */
    public static FontMetrics getFontMetrics(JComponent c, Graphics g,
            Font font) {
        if (c != null) {
            // Note: We assume that we're using the FontMetrics
            // from the widget to layout out text, otherwise we can get
            // mismatches when printing.
            return c.getFontMetrics(font);
        }
        return Toolkit.getDefaultToolkit().getFontMetrics(font);
    }
}

Related

1. getHTMLTextForWidth(JComponent comp, double bboxWth, String txt, Font font)
2. getStringWidth(final Font aFont, final String aString)
3. getStringWidth(Font font, String str)
4. getTextWidth(final String text, final Font font)
5. getTextWidth(Font font, String text)