javax.swing.plaf.basic.BasicGraphicsUtils#getStringWidth ( )源码实例Demo

private static void testStringWidth() {

        String str = "12345678910\u036F";
        JComponent comp = createComponent(str);
        Font font = comp.getFont();
        FontMetrics fontMetrics = comp.getFontMetrics(font);
        float stringWidth = BasicGraphicsUtils.getStringWidth(comp, fontMetrics, str);

        if (stringWidth == fontMetrics.stringWidth(str)) {
            throw new RuntimeException("Numeric shaper is not used!");
        }

        if (stringWidth != getLayoutWidth(str, font, NUMERIC_SHAPER)) {
            throw new RuntimeException("Wrong text width!");
        }
    }
 

private static void testStringClip() {

        String str = "1234567890";
        JComponent comp = createComponent(str);
        FontMetrics fontMetrics = comp.getFontMetrics(comp.getFont());

        int width = (int) BasicGraphicsUtils.getStringWidth(comp, fontMetrics, str);

        String clip = BasicGraphicsUtils.getClippedString(comp, fontMetrics, str, width);
        checkClippedString(str, clip, str);

        clip = BasicGraphicsUtils.getClippedString(comp, fontMetrics, str, width + 1);
        checkClippedString(str, clip, str);

        clip = BasicGraphicsUtils.getClippedString(comp, fontMetrics, str, -1);
        checkClippedString(str, clip, "...");

        clip = BasicGraphicsUtils.getClippedString(comp, fontMetrics, str, 0);
        checkClippedString(str, clip, "...");

        clip = BasicGraphicsUtils.getClippedString(comp, fontMetrics,
                str, width - width / str.length());
        int endIndex = str.length() - 3;
        checkClippedString(str, clip, str.substring(0, endIndex) + "...");
    }
 

private static void checkNullArgumentsGetStringWidth(JComponent comp,
        String text) {

    FontMetrics fontMetrics = comp.getFontMetrics(comp.getFont());
    BasicGraphicsUtils.getStringWidth(null, fontMetrics, text);
    float result = BasicGraphicsUtils.getStringWidth(comp, fontMetrics, null);

    if (result != 0) {
        throw new RuntimeException("The string length is not 0");
    }

    try {
        BasicGraphicsUtils.getStringWidth(comp, null, text);
    } catch (NullPointerException e) {
        return;
    }

    throw new RuntimeException("NPE is not thrown");
}
 

private static void testDrawString(boolean underlined) {
    String str = "AOB";
    JComponent comp = createComponent(str);

    BufferedImage buffImage = createBufferedImage(WIDTH, HEIGHT);
    Graphics2D g2 = buffImage.createGraphics();

    g2.setColor(DRAW_COLOR);
    g2.setFont(comp.getFont());

    FontMetrics fontMetrices = comp.getFontMetrics(comp.getFont());
    float width = BasicGraphicsUtils.getStringWidth(comp, fontMetrices, str);
    float x = (WIDTH - width) / 2;
    int y = 3 * HEIGHT / 4;

    if (underlined) {
        BasicGraphicsUtils.drawStringUnderlineCharAt(comp, g2, str, 1, x, y);
    } else {
        BasicGraphicsUtils.drawString(comp, g2, str, x, y);
    }
    g2.dispose();

    float xx = BasicGraphicsUtils.getStringWidth(comp, fontMetrices, "A") +
            BasicGraphicsUtils.getStringWidth(comp, fontMetrices, "O")/2;

    checkImageContainsSymbol(buffImage, (int) xx, underlined ? 3 : 2);
}
 

public static int stringWidth(JComponent c, FontMetrics fm, String string) {
	return (int) BasicGraphicsUtils.getStringWidth(c, fm, string);
}