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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package java.awt;

import java.awt.Graphics2D;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;
import java.awt.geom.Rectangle2D;
import java.text.CharacterIterator;


The FontMetrics class defines a font metrics object, which
encapsulates information about the rendering of a particular font on a
particular screen.


Note to subclassers: Since many of these methods form closed,
mutually recursive loops, you must take care that you implement
at least one of the methods in each such loop to prevent
infinite recursion when your subclass is used.
In particular, the following is the minimal suggested set of methods
to override in order to ensure correctness and prevent infinite
recursion (though other subsets are equally feasible):





Note that the implementations of these methods are
inefficient, so they are usually overridden with more efficient
toolkit-specific implementations.


When an application asks to place a character at the position
(x, y), the character is placed so that its
reference point (shown as the dot in the accompanying image) is
put at that position. The reference point specifies a horizontal
line called the baseline of the character. In normal
printing, the baselines of characters should align.


In addition, every character in a font has an ascent, a
descent, and an advance width. The ascent is the
amount by which the character ascends above the baseline. The
descent is the amount by which the character descends below the
baseline. The advance width indicates the position at which AWT
should place the next character.


An array of characters or a string can also have an ascent, a
descent, and an advance width. The ascent of the array is the
maximum ascent of any character in the array. The descent is the
maximum descent of any character in the array. The advance width
is the sum of the advance widths of each of the characters in the
character array.  The advance of a String is the
distance along the baseline of the String.  This
distance is the width that should be used for centering or
right-aligning the String.

Note that the advance of a String is not necessarily
the sum of the advances of its characters measured in isolation
because the width of a character can vary depending on its context.
For example, in Arabic text, the shape of a character can change
in order to connect to other characters.  Also, in some scripts,
certain character sequences can be represented by a single shape,
called a ligature.  Measuring characters individually does
not account for these transformations.

Font metrics are baseline-relative, meaning that they are generally independent of the rotation applied to the font (modulo possible grid hinting effects). See Font. 
Author:     Jim Graham
See Also:
Since:      JDK1.0
/**
 * The <code>FontMetrics</code> class defines a font metrics object, which
 * encapsulates information about the rendering of a particular font on a
 * particular screen.
 * <p>
 * <b>Note to subclassers</b>: Since many of these methods form closed,
 * mutually recursive loops, you must take care that you implement
 * at least one of the methods in each such loop to prevent
 * infinite recursion when your subclass is used.
 * In particular, the following is the minimal suggested set of methods
 * to override in order to ensure correctness and prevent infinite
 * recursion (though other subsets are equally feasible):
 * <ul>
 * <li>{@link #getAscent()}
 * <li>{@link #getLeading()}
 * <li>{@link #getMaxAdvance()}
 * <li>{@link #charWidth(char)}
 * <li>{@link #charsWidth(char[], int, int)}
 * </ul>
 * <p>
 * <img src="doc-files/FontMetrics-1.gif" alt="The letter 'p' showing its 'reference point'" border=15 align
 * ALIGN=right HSPACE=10 VSPACE=7>
 * Note that the implementations of these methods are
 * inefficient, so they are usually overridden with more efficient
 * toolkit-specific implementations.
 * <p>
 * When an application asks to place a character at the position
 * (<i>x</i>,&nbsp;<i>y</i>), the character is placed so that its
 * reference point (shown as the dot in the accompanying image) is
 * put at that position. The reference point specifies a horizontal
 * line called the <i>baseline</i> of the character. In normal
 * printing, the baselines of characters should align.
 * <p>
 * In addition, every character in a font has an <i>ascent</i>, a
 * <i>descent</i>, and an <i>advance width</i>. The ascent is the
 * amount by which the character ascends above the baseline. The
 * descent is the amount by which the character descends below the
 * baseline. The advance width indicates the position at which AWT
 * should place the next character.
 * <p>
 * An array of characters or a string can also have an ascent, a
 * descent, and an advance width. The ascent of the array is the
 * maximum ascent of any character in the array. The descent is the
 * maximum descent of any character in the array. The advance width
 * is the sum of the advance widths of each of the characters in the
 * character array.  The advance of a <code>String</code> is the
 * distance along the baseline of the <code>String</code>.  This
 * distance is the width that should be used for centering or
 * right-aligning the <code>String</code>.
 * <p>Note that the advance of a <code>String</code> is not necessarily
 * the sum of the advances of its characters measured in isolation
 * because the width of a character can vary depending on its context.
 * For example, in Arabic text, the shape of a character can change
 * in order to connect to other characters.  Also, in some scripts,
 * certain character sequences can be represented by a single shape,
 * called a <em>ligature</em>.  Measuring characters individually does
 * not account for these transformations.
 * <p>Font metrics are baseline-relative, meaning that they are
 * generally independent of the rotation applied to the font (modulo
 * possible grid hinting effects).  See {@link java.awt.Font Font}.
 *
 * @author      Jim Graham
 * @see         java.awt.Font
 * @since       JDK1.0
 */
public abstract class FontMetrics implements java.io.Serializable {

    static {
        /* ensure that the necessary native libraries are loaded */
        Toolkit.loadLibraries();
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }
    }

    private static final FontRenderContext
        DEFAULT_FRC = new FontRenderContext(null, false, false);

    
The actual Font from which the font metrics are created. This cannot be null. 
See Also:
@serial
/**
     * The actual {@link Font} from which the font metrics are
     * created.
     * This cannot be null.
     *
     * @serial
     * @see #getFont()
     */
    protected Font font;

    /*
     * JDK 1.1 serialVersionUID
     */
    private static final long serialVersionUID = 1681126225205050147L;

    
Creates a new FontMetrics object for finding out
height and width information about the specified Font
and specific character glyphs in that Font.

Params:
  • font – the Font
See Also:
/**
     * Creates a new <code>FontMetrics</code> object for finding out
     * height and width information about the specified <code>Font</code>
     * and specific character glyphs in that <code>Font</code>.
     * @param     font the <code>Font</code>
     * @see       java.awt.Font
     */
    protected FontMetrics(Font font) {
        this.font = font;
    }

    
Gets the Font described by this
FontMetrics object.

Returns:   the Font described by this
FontMetrics object.
/**
     * Gets the <code>Font</code> described by this
     * <code>FontMetrics</code> object.
     * @return    the <code>Font</code> described by this
     * <code>FontMetrics</code> object.
     */
    public Font getFont() {
        return font;
    }

    
Gets the FontRenderContext used by this
FontMetrics object to measure text.


Note that methods in this class which take a Graphics
parameter measure text using the FontRenderContext
of that Graphics object, and not this
FontRenderContext

Returns:   the FontRenderContext used by this
FontMetrics object.
Since:1.6
/**
     * Gets the <code>FontRenderContext</code> used by this
     * <code>FontMetrics</code> object to measure text.
     * <p>
     * Note that methods in this class which take a <code>Graphics</code>
     * parameter measure text using the <code>FontRenderContext</code>
     * of that <code>Graphics</code> object, and not this
     * <code>FontRenderContext</code>
     * @return    the <code>FontRenderContext</code> used by this
     * <code>FontMetrics</code> object.
     * @since 1.6
     */
    public FontRenderContext getFontRenderContext() {
        return DEFAULT_FRC;
    }

    
Determines the standard leading of the
Font described by this FontMetrics
object.  The standard leading, or
interline spacing, is the logical amount of space to be reserved
between the descent of one line of text and the ascent of the next
line. The height metric is calculated to include this extra space.

See Also:
Returns:   the standard leading of the Font.
/**
     * Determines the <em>standard leading</em> of the
     * <code>Font</code> described by this <code>FontMetrics</code>
     * object.  The standard leading, or
     * interline spacing, is the logical amount of space to be reserved
     * between the descent of one line of text and the ascent of the next
     * line. The height metric is calculated to include this extra space.
     * @return    the standard leading of the <code>Font</code>.
     * @see   #getHeight()
     * @see   #getAscent()
     * @see   #getDescent()
     */
    public int getLeading() {
        return 0;
    }

    
Determines the font ascent of the Font
described by this FontMetrics object. The font ascent
is the distance from the font's baseline to the top of most
alphanumeric characters. Some characters in the Font
might extend above the font ascent line.

See Also:
Returns:    the font ascent of the Font.
/**
     * Determines the <em>font ascent</em> of the <code>Font</code>
     * described by this <code>FontMetrics</code> object. The font ascent
     * is the distance from the font's baseline to the top of most
     * alphanumeric characters. Some characters in the <code>Font</code>
     * might extend above the font ascent line.
     * @return     the font ascent of the <code>Font</code>.
     * @see        #getMaxAscent()
     */
    public int getAscent() {
        return font.getSize();
    }

    
Determines the font descent of the Font
described by this
FontMetrics object. The font descent is the distance
from the font's baseline to the bottom of most alphanumeric
characters with descenders. Some characters in the
Font might extend
below the font descent line.

See Also:
Returns:    the font descent of the Font.
/**
     * Determines the <em>font descent</em> of the <code>Font</code>
     * described by this
     * <code>FontMetrics</code> object. The font descent is the distance
     * from the font's baseline to the bottom of most alphanumeric
     * characters with descenders. Some characters in the
     * <code>Font</code> might extend
     * below the font descent line.
     * @return     the font descent of the <code>Font</code>.
     * @see        #getMaxDescent()
     */
    public int getDescent() {
        return 0;
    }

    
Gets the standard height of a line of text in this font.  This
is the distance between the baseline of adjacent lines of text.
It is the sum of the leading + ascent + descent. Due to rounding
this may not be the same as getAscent() + getDescent() + getLeading().
There is no guarantee that lines of text spaced at this distance are
disjoint; such lines may overlap if some characters overshoot
either the standard ascent or the standard descent metric.

See Also:
Returns:   the standard height of the font.
/**
     * Gets the standard height of a line of text in this font.  This
     * is the distance between the baseline of adjacent lines of text.
     * It is the sum of the leading + ascent + descent. Due to rounding
     * this may not be the same as getAscent() + getDescent() + getLeading().
     * There is no guarantee that lines of text spaced at this distance are
     * disjoint; such lines may overlap if some characters overshoot
     * either the standard ascent or the standard descent metric.
     * @return    the standard height of the font.
     * @see       #getLeading()
     * @see       #getAscent()
     * @see       #getDescent()
     */
    public int getHeight() {
        return getLeading() + getAscent() + getDescent();
    }

    
Determines the maximum ascent of the Font
described by this FontMetrics object.  No character
extends further above the font's baseline than this height.

See Also:
Returns:   the maximum ascent of any character in the
Font.
/**
     * Determines the maximum ascent of the <code>Font</code>
     * described by this <code>FontMetrics</code> object.  No character
     * extends further above the font's baseline than this height.
     * @return    the maximum ascent of any character in the
     * <code>Font</code>.
     * @see       #getAscent()
     */
    public int getMaxAscent() {
        return getAscent();
    }

    
Determines the maximum descent of the Font
described by this FontMetrics object.  No character
extends further below the font's baseline than this height.

See Also:
Returns:   the maximum descent of any character in the
Font.
/**
     * Determines the maximum descent of the <code>Font</code>
     * described by this <code>FontMetrics</code> object.  No character
     * extends further below the font's baseline than this height.
     * @return    the maximum descent of any character in the
     * <code>Font</code>.
     * @see       #getDescent()
     */
    public int getMaxDescent() {
        return getDescent();
    }

    
For backward compatibility only.

See Also:
Returns:   the maximum descent of any character in the
Font.
Deprecated:As of JDK version 1.1.1,
replaced by getMaxDescent().
/**
     * For backward compatibility only.
     * @return    the maximum descent of any character in the
     * <code>Font</code>.
     * @see #getMaxDescent()
     * @deprecated As of JDK version 1.1.1,
     * replaced by <code>getMaxDescent()</code>.
     */
    @Deprecated
    public int getMaxDecent() {
        return getMaxDescent();
    }

    
Gets the maximum advance width of any character in this
Font.  The advance is the
distance from the leftmost point to the rightmost point on the
string's baseline.  The advance of a String is
not necessarily the sum of the advances of its characters.

Returns:   the maximum advance width of any character
           in the Font, or -1 if the
           maximum advance width is not known.
/**
     * Gets the maximum advance width of any character in this
     * <code>Font</code>.  The advance is the
     * distance from the leftmost point to the rightmost point on the
     * string's baseline.  The advance of a <code>String</code> is
     * not necessarily the sum of the advances of its characters.
     * @return    the maximum advance width of any character
     *            in the <code>Font</code>, or <code>-1</code> if the
     *            maximum advance width is not known.
     */
    public int getMaxAdvance() {
        return -1;
    }

    
Returns the advance width of the specified character in this
Font.  The advance is the
distance from the leftmost point to the rightmost point on the
character's baseline.  Note that the advance of a
String is not necessarily the sum of the advances
of its characters.

This method doesn't validate the specified character to be a valid Unicode code point. The caller must validate the character value using 
Character.isValidCodePoint if necessary. 
Params:
  • codePoint – the character (Unicode code point) to be measured
See Also:
Returns:   the advance width of the specified character
           in the Font described by this
           FontMetrics object.
/**
     * Returns the advance width of the specified character in this
     * <code>Font</code>.  The advance is the
     * distance from the leftmost point to the rightmost point on the
     * character's baseline.  Note that the advance of a
     * <code>String</code> is not necessarily the sum of the advances
     * of its characters.
     *
     * <p>This method doesn't validate the specified character to be a
     * valid Unicode code point. The caller must validate the
     * character value using {@link
     * java.lang.Character#isValidCodePoint(int)
     * Character.isValidCodePoint} if necessary.
     *
     * @param codePoint the character (Unicode code point) to be measured
     * @return    the advance width of the specified character
     *            in the <code>Font</code> described by this
     *            <code>FontMetrics</code> object.
     * @see   #charsWidth(char[], int, int)
     * @see   #stringWidth(String)
     */
    public int charWidth(int codePoint) {
        if (!Character.isValidCodePoint(codePoint)) {
            codePoint = 0xffff; // substitute missing glyph width
        }

        if (codePoint < 256) {
            return getWidths()[codePoint];
        } else {
            char[] buffer = new char[2];
            int len = Character.toChars(codePoint, buffer, 0);
            return charsWidth(buffer, 0, len);
        }
    }

    
Returns the advance width of the specified character in this
Font.  The advance is the
distance from the leftmost point to the rightmost point on the
character's baseline.  Note that the advance of a
String is not necessarily the sum of the advances
of its characters.

Note: This method cannot handle  supplementary
characters. To support all Unicode characters, including supplementary characters, use the charWidth(int) method. 
Params:
  • ch – the character to be measured
See Also:
Returns:    the advance width of the specified character
                 in the Font described by this
                 FontMetrics object.
/**
     * Returns the advance width of the specified character in this
     * <code>Font</code>.  The advance is the
     * distance from the leftmost point to the rightmost point on the
     * character's baseline.  Note that the advance of a
     * <code>String</code> is not necessarily the sum of the advances
     * of its characters.
     *
     * <p><b>Note:</b> This method cannot handle <a
     * href="../lang/Character.html#supplementary"> supplementary
     * characters</a>. To support all Unicode characters, including
     * supplementary characters, use the {@link #charWidth(int)} method.
     *
     * @param ch the character to be measured
     * @return     the advance width of the specified character
     *                  in the <code>Font</code> described by this
     *                  <code>FontMetrics</code> object.
     * @see        #charsWidth(char[], int, int)
     * @see        #stringWidth(String)
     */
    public int charWidth(char ch) {
        if (ch < 256) {
            return getWidths()[ch];
        }
        char data[] = {ch};
        return charsWidth(data, 0, 1);
    }

    
Returns the total advance width for showing the specified
String in this Font.  The advance
is the distance from the leftmost point to the rightmost point
on the string's baseline.


Note that the advance of a String is
not necessarily the sum of the advances of its characters.

Params:
  • str – the String to be measured
Throws:
See Also:
Returns:   the advance width of the specified String
                 in the Font described by this
                 FontMetrics.
/**
     * Returns the total advance width for showing the specified
     * <code>String</code> in this <code>Font</code>.  The advance
     * is the distance from the leftmost point to the rightmost point
     * on the string's baseline.
     * <p>
     * Note that the advance of a <code>String</code> is
     * not necessarily the sum of the advances of its characters.
     * @param str the <code>String</code> to be measured
     * @return    the advance width of the specified <code>String</code>
     *                  in the <code>Font</code> described by this
     *                  <code>FontMetrics</code>.
     * @throws NullPointerException if str is null.
     * @see       #bytesWidth(byte[], int, int)
     * @see       #charsWidth(char[], int, int)
     * @see       #getStringBounds(String, Graphics)
     */
    public int stringWidth(String str) {
        int len = str.length();
        char data[] = new char[len];
        str.getChars(0, len, data, 0);
        return charsWidth(data, 0, len);
    }

    
Returns the total advance width for showing the specified array
of characters in this Font.  The advance is the
distance from the leftmost point to the rightmost point on the
string's baseline.  The advance of a String
is not necessarily the sum of the advances of its characters.
This is equivalent to measuring a String of the
characters in the specified range.

Params:
  • data – the array of characters to be measured
  • off – the start offset of the characters in the array
  • len – the number of characters to be measured from the array
Throws:
See Also:
Returns:   the advance width of the subarray of the specified
              char array in the font described by
              this FontMetrics object.
/**
     * Returns the total advance width for showing the specified array
     * of characters in this <code>Font</code>.  The advance is the
     * distance from the leftmost point to the rightmost point on the
     * string's baseline.  The advance of a <code>String</code>
     * is not necessarily the sum of the advances of its characters.
     * This is equivalent to measuring a <code>String</code> of the
     * characters in the specified range.
     * @param data the array of characters to be measured
     * @param off the start offset of the characters in the array
     * @param len the number of characters to be measured from the array
     * @return    the advance width of the subarray of the specified
     *               <code>char</code> array in the font described by
     *               this <code>FontMetrics</code> object.
     * @throws    NullPointerException if <code>data</code> is null.
     * @throws    IndexOutOfBoundsException if the <code>off</code>
     *            and <code>len</code> arguments index characters outside
     *            the bounds of the <code>data</code> array.
     * @see       #charWidth(int)
     * @see       #charWidth(char)
     * @see       #bytesWidth(byte[], int, int)
     * @see       #stringWidth(String)
     */
    public int charsWidth(char data[], int off, int len) {
        return stringWidth(new String(data, off, len));
    }

    
Returns the total advance width for showing the specified array
of bytes in this Font.  The advance is the
distance from the leftmost point to the rightmost point on the
string's baseline.  The advance of a String
is not necessarily the sum of the advances of its characters.
This is equivalent to measuring a String of the
characters in the specified range.

Params:
  • data – the array of bytes to be measured
  • off – the start offset of the bytes in the array
  • len – the number of bytes to be measured from the array
Throws:
See Also:
Returns:   the advance width of the subarray of the specified
              byte array in the Font
                 described by
              this FontMetrics object.
/**
     * Returns the total advance width for showing the specified array
     * of bytes in this <code>Font</code>.  The advance is the
     * distance from the leftmost point to the rightmost point on the
     * string's baseline.  The advance of a <code>String</code>
     * is not necessarily the sum of the advances of its characters.
     * This is equivalent to measuring a <code>String</code> of the
     * characters in the specified range.
     * @param data the array of bytes to be measured
     * @param off the start offset of the bytes in the array
     * @param len the number of bytes to be measured from the array
     * @return    the advance width of the subarray of the specified
     *               <code>byte</code> array in the <code>Font</code>
     *                  described by
     *               this <code>FontMetrics</code> object.
     * @throws    NullPointerException if <code>data</code> is null.
     * @throws    IndexOutOfBoundsException if the <code>off</code>
     *            and <code>len</code> arguments index bytes outside
     *            the bounds of the <code>data</code> array.
     * @see       #charsWidth(char[], int, int)
     * @see       #stringWidth(String)
     */
    public int bytesWidth(byte data[], int off, int len) {
        return stringWidth(new String(data, 0, off, len));
    }

    
Gets the advance widths of the first 256 characters in the
Font.  The advance is the
distance from the leftmost point to the rightmost point on the
character's baseline.  Note that the advance of a
String is not necessarily the sum of the advances
of its characters.

Returns:   an array storing the advance widths of the
                characters in the Font
                described by this FontMetrics object.
/**
     * Gets the advance widths of the first 256 characters in the
     * <code>Font</code>.  The advance is the
     * distance from the leftmost point to the rightmost point on the
     * character's baseline.  Note that the advance of a
     * <code>String</code> is not necessarily the sum of the advances
     * of its characters.
     * @return    an array storing the advance widths of the
     *                 characters in the <code>Font</code>
     *                 described by this <code>FontMetrics</code> object.
     */
    public int[] getWidths() {
        int widths[] = new int[256];
        for (char ch = 0 ; ch < 256 ; ch++) {
            widths[ch] = charWidth(ch);
        }
        return widths;
    }

    
Checks to see if the Font has uniform line metrics.  A
composite font may consist of several different fonts to cover
various character sets.  In such cases, the
FontLineMetrics objects are not uniform.
Different fonts may have a different ascent, descent, metrics and
so on.  This information is sometimes necessary for line
measuring and line breaking.

See Also:
Returns:true if the font has uniform line metrics;
false otherwise.
/**
     * Checks to see if the <code>Font</code> has uniform line metrics.  A
     * composite font may consist of several different fonts to cover
     * various character sets.  In such cases, the
     * <code>FontLineMetrics</code> objects are not uniform.
     * Different fonts may have a different ascent, descent, metrics and
     * so on.  This information is sometimes necessary for line
     * measuring and line breaking.
     * @return <code>true</code> if the font has uniform line metrics;
     * <code>false</code> otherwise.
     * @see java.awt.Font#hasUniformLineMetrics()
     */
    public boolean hasUniformLineMetrics() {
        return font.hasUniformLineMetrics();
    }

    
Returns the LineMetrics object for the specified String in the specified Graphics context. 
Params:
  • str – the specified String
  • context – the specified Graphics context
See Also:
Returns:a LineMetrics object created with the
specified String and Graphics context.
/**
     * Returns the {@link LineMetrics} object for the specified
     * <code>String</code> in the specified {@link Graphics} context.
     * @param str the specified <code>String</code>
     * @param context the specified <code>Graphics</code> context
     * @return a <code>LineMetrics</code> object created with the
     * specified <code>String</code> and <code>Graphics</code> context.
     * @see java.awt.Font#getLineMetrics(String, FontRenderContext)
     */
    public LineMetrics getLineMetrics( String str, Graphics context) {
        return font.getLineMetrics(str, myFRC(context));
    }

    
Returns the LineMetrics object for the specified String in the specified Graphics context. 
Params:
  • str – the specified String
  • beginIndex – the initial offset of str
  • limit – the end offset of str
  • context – the specified Graphics context
See Also:
Returns:a LineMetrics object created with the
specified String and Graphics context.
/**
     * Returns the {@link LineMetrics} object for the specified
     * <code>String</code> in the specified {@link Graphics} context.
     * @param str the specified <code>String</code>
     * @param beginIndex the initial offset of <code>str</code>
     * @param limit the end offset of <code>str</code>
     * @param context the specified <code>Graphics</code> context
     * @return a <code>LineMetrics</code> object created with the
     * specified <code>String</code> and <code>Graphics</code> context.
     * @see java.awt.Font#getLineMetrics(String, int, int, FontRenderContext)
     */
    public LineMetrics getLineMetrics( String str,
                                            int beginIndex, int limit,
                                            Graphics context) {
        return font.getLineMetrics(str, beginIndex, limit, myFRC(context));
    }

    
Returns the LineMetrics object for the specified character array in the specified Graphics context. 
Params:
  • chars – the specified character array
  • beginIndex – the initial offset of chars
  • limit – the end offset of chars
  • context – the specified Graphics context
See Also:
Returns:a LineMetrics object created with the
specified character array and Graphics context.
/**
     * Returns the {@link LineMetrics} object for the specified
     * character array in the specified {@link Graphics} context.
     * @param chars the specified character array
     * @param beginIndex the initial offset of <code>chars</code>
     * @param limit the end offset of <code>chars</code>
     * @param context the specified <code>Graphics</code> context
     * @return a <code>LineMetrics</code> object created with the
     * specified character array and <code>Graphics</code> context.
     * @see java.awt.Font#getLineMetrics(char[], int, int, FontRenderContext)
     */
    public LineMetrics getLineMetrics(char [] chars,
                                            int beginIndex, int limit,
                                            Graphics context) {
        return font.getLineMetrics(
                                chars, beginIndex, limit, myFRC(context));
    }

    
Returns the LineMetrics object for the specified CharacterIterator in the specified Graphics context. 
Params:
  • ci – the specified CharacterIterator
  • beginIndex – the initial offset in ci
  • limit – the end index of ci
  • context – the specified Graphics context
See Also:
Returns:a LineMetrics object created with the
specified arguments.
/**
     * Returns the {@link LineMetrics} object for the specified
     * {@link CharacterIterator} in the specified {@link Graphics}
     * context.
     * @param ci the specified <code>CharacterIterator</code>
     * @param beginIndex the initial offset in <code>ci</code>
     * @param limit the end index of <code>ci</code>
     * @param context the specified <code>Graphics</code> context
     * @return a <code>LineMetrics</code> object created with the
     * specified arguments.
     * @see java.awt.Font#getLineMetrics(CharacterIterator, int, int, FontRenderContext)
     */
    public LineMetrics getLineMetrics(CharacterIterator ci,
                                            int beginIndex, int limit,
                                            Graphics context) {
        return font.getLineMetrics(ci, beginIndex, limit, myFRC(context));
    }

    
Returns the bounds of the specified String in the
specified Graphics context.  The bounds is used
to layout the String.

Note: The returned bounds is in baseline-relative coordinates (see class notes). 
Params:
  • str – the specified String
  • context – the specified Graphics context
See Also:
Returns:a Rectangle2D that is the bounding box of the specified String in the specified
Graphics context.
/**
     * Returns the bounds of the specified <code>String</code> in the
     * specified <code>Graphics</code> context.  The bounds is used
     * to layout the <code>String</code>.
     * <p>Note: The returned bounds is in baseline-relative coordinates
     * (see {@link java.awt.FontMetrics class notes}).
     * @param str the specified <code>String</code>
     * @param context the specified <code>Graphics</code> context
     * @return a {@link Rectangle2D} that is the bounding box of the
     * specified <code>String</code> in the specified
     * <code>Graphics</code> context.
     * @see java.awt.Font#getStringBounds(String, FontRenderContext)
     */
    public Rectangle2D getStringBounds( String str, Graphics context) {
        return font.getStringBounds(str, myFRC(context));
    }

    
Returns the bounds of the specified String in the
specified Graphics context.  The bounds is used
to layout the String.

Note: The returned bounds is in baseline-relative coordinates (see class notes). 
Params:
  • str – the specified String
  • beginIndex – the offset of the beginning of str
  • limit – the end offset of str
  • context – the specified Graphics context
See Also:
Returns:a Rectangle2D that is the bounding box of the
specified String in the specified
Graphics context.
/**
     * Returns the bounds of the specified <code>String</code> in the
     * specified <code>Graphics</code> context.  The bounds is used
     * to layout the <code>String</code>.
     * <p>Note: The returned bounds is in baseline-relative coordinates
     * (see {@link java.awt.FontMetrics class notes}).
     * @param str the specified <code>String</code>
     * @param beginIndex the offset of the beginning of <code>str</code>
     * @param limit the end offset of <code>str</code>
     * @param context the specified <code>Graphics</code> context
     * @return a <code>Rectangle2D</code> that is the bounding box of the
     * specified <code>String</code> in the specified
     * <code>Graphics</code> context.
     * @see java.awt.Font#getStringBounds(String, int, int, FontRenderContext)
     */
    public Rectangle2D getStringBounds( String str,
                                        int beginIndex, int limit,
                                        Graphics context) {
        return font.getStringBounds(str, beginIndex, limit,
                                        myFRC(context));
    }

   
Returns the bounds of the specified array of characters
in the specified Graphics context.
The bounds is used to layout the String
created with the specified array of characters,
beginIndex and limit.

Note: The returned bounds is in baseline-relative coordinates (see class notes). 
Params:
  • chars – an array of characters
  • beginIndex – the initial offset of the array of
characters
  • limit – the end offset of the array of characters
  • context – the specified Graphics context
See Also:
Returns:a Rectangle2D that is the bounding box of the
specified character array in the specified
Graphics context.
/**
     * Returns the bounds of the specified array of characters
     * in the specified <code>Graphics</code> context.
     * The bounds is used to layout the <code>String</code>
     * created with the specified array of characters,
     * <code>beginIndex</code> and <code>limit</code>.
     * <p>Note: The returned bounds is in baseline-relative coordinates
     * (see {@link java.awt.FontMetrics class notes}).
     * @param chars an array of characters
     * @param beginIndex the initial offset of the array of
     * characters
     * @param limit the end offset of the array of characters
     * @param context the specified <code>Graphics</code> context
     * @return a <code>Rectangle2D</code> that is the bounding box of the
     * specified character array in the specified
     * <code>Graphics</code> context.
     * @see java.awt.Font#getStringBounds(char[], int, int, FontRenderContext)
     */
    public Rectangle2D getStringBounds( char [] chars,
                                        int beginIndex, int limit,
                                        Graphics context) {
        return font.getStringBounds(chars, beginIndex, limit,
                                        myFRC(context));
    }

   
Returns the bounds of the characters indexed in the specified
CharacterIterator in the
specified Graphics context.

Note: The returned bounds is in baseline-relative coordinates (see class notes). 
Params:
  • ci – the specified CharacterIterator
  • beginIndex – the initial offset in ci
  • limit – the end index of ci
  • context – the specified Graphics context
See Also:
Returns:a Rectangle2D that is the bounding box of the
characters indexed in the specified CharacterIterator
in the specified Graphics context.
/**
     * Returns the bounds of the characters indexed in the specified
     * <code>CharacterIterator</code> in the
     * specified <code>Graphics</code> context.
     * <p>Note: The returned bounds is in baseline-relative coordinates
     * (see {@link java.awt.FontMetrics class notes}).
     * @param ci the specified <code>CharacterIterator</code>
     * @param beginIndex the initial offset in <code>ci</code>
     * @param limit the end index of <code>ci</code>
     * @param context the specified <code>Graphics</code> context
     * @return a <code>Rectangle2D</code> that is the bounding box of the
     * characters indexed in the specified <code>CharacterIterator</code>
     * in the specified <code>Graphics</code> context.
     * @see java.awt.Font#getStringBounds(CharacterIterator, int, int, FontRenderContext)
     */
    public Rectangle2D getStringBounds(CharacterIterator ci,
                                        int beginIndex, int limit,
                                        Graphics context) {
        return font.getStringBounds(ci, beginIndex, limit,
                                        myFRC(context));
    }

    
Returns the bounds for the character with the maximum bounds
in the specified Graphics context.

Params:
  • context – the specified Graphics context
See Also:
Returns:a Rectangle2D that is the
bounding box for the character with the maximum bounds.
/**
     * Returns the bounds for the character with the maximum bounds
     * in the specified <code>Graphics</code> context.
     * @param context the specified <code>Graphics</code> context
     * @return a <code>Rectangle2D</code> that is the
     * bounding box for the character with the maximum bounds.
     * @see java.awt.Font#getMaxCharBounds(FontRenderContext)
     */
    public Rectangle2D getMaxCharBounds(Graphics context) {
        return font.getMaxCharBounds(myFRC(context));
    }

    private FontRenderContext myFRC(Graphics context) {
        if (context instanceof Graphics2D) {
            return ((Graphics2D)context).getFontRenderContext();
        }
        return DEFAULT_FRC;
    }


    
Returns a representation of this FontMetrics
object's values as a String.

Returns:   a String representation of this
FontMetrics object.
Since:    JDK1.0.
/**
     * Returns a representation of this <code>FontMetrics</code>
     * object's values as a <code>String</code>.
     * @return    a <code>String</code> representation of this
     * <code>FontMetrics</code> object.
     * @since     JDK1.0.
     */
    public String toString() {
        return getClass().getName() +
            "[font=" + getFont() +
            "ascent=" + getAscent() +
            ", descent=" + getDescent() +
            ", height=" + getHeight() + "]";
    }

    
Initialize JNI field and method IDs

/**
     * Initialize JNI field and method IDs
     */
    private static native void initIDs();
}