Class java.awt.font.GlyphMetrics

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Java Platform 1.2
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Class java.awt.font.GlyphMetrics

java.lang.Object
  |
  +--java.awt.font.GlyphMetrics

public final class GlyphMetrics
extends Object

GlyphMetrics represents infomation for a single glyph. GlyphMetrics instances are produced by Font and are applicable to a specific glyph in a particular Font.

Glyphs are either STANDARD, LIGATURE, COMBINING, or COMPONENT.

STANDARD glyphs are commonly used to represent single characters.
LIGATURE glyphs are used to represent sequences of characters.
COMPONENT glyphs in a GlyphVector do not correspond to a particular character in a text model. Instead, COMPONENT glyphs are added for typographical reasons (such as Arabicjustification).
COMBINING glyphs embellish STANDARD or LIGATURE glyphs, such as accent marks. Carets do not appear before COMBINING glyphs.

Other metrics available through GlyphMetrics are the advance, bounds, and left and right side bearings. The advance of a glyph is the distance from the glyph's origin to the origin of the next glyph. Note that, in a GlyphVector, the distance from a glyph to its following glyph may not be the glyph's advance. The bounds is the smallest rectangle which completely contains the visible portion of the glyph. The bounds rectangle is relative to the glyph's origin. The left-side bearing is the distance from the glyph origin to the left of its bounds rectangle. If the left-side bearing is negative, part of the glyph is drawn to the left of its origin. The right-side bearing is the distance from the right side of the bounds rectangle to the next glyph origin (the origin plus the advance). If negative, part of the glyph is drawn to the right of the next glyph's origin.

Although instances of GlyphMetrics may be directly constructed, they are almost always obtained from a GlyphVector. Once constructed, GlyphMetrics are immutable.

Example:

Querying a Font for glyph information

 Font font = ...;
 int glyphIndex = ...;
 GlyphMetrics metrics = GlyphVector.getGlyphMetrics(glyphIndex);
 int isStandard = metrics.isStandard();
 float glyphAdvance = metrics.getAdvance();

See Also:: Font, GlyphVector

Field Summary
static byte	COMBINING This code indicates a glyph that represents a combining character, such as an umlaut.
static byte	COMPONENT This code indicates a glyph with no corresponding character in the backing store.
static byte	LIGATURE This code indicates a glyph that represents multiple characters as a ligature, for example 'fi' or 'ffi'.
static byte	STANDARD This code indicates a glyph that represents a single standard character.
static byte	WHITESPACE This code indicates a glyph with no visual representation.

Constructor Summary
GlyphMetrics(float advance, Rectangle2D bounds, byte glyphType) Construct a GlyphMetrics.

Method Summary
float	getAdvance() Return the advance width (height) of the glyph.
Rectangle2D	getBounds2D() Return the black box bounds of the glyph.
float	getLSB() Return the left (top) side bearing of the glyph.
float	getRSB() Return the right (bottom) side bearing of the glyph.
int	getType() Return the raw glyph type code.
boolean	isCombining() Return true if this is a combining glyph.
boolean	isComponent() Return true if this is a component glyph.
boolean	isLigature() Return true if this is a ligature glyph.
boolean	isStandard() Return true if this is a standard glyph.
boolean	isWhitespace() Return true if this is a whitespace glyph.

Methods inherited from class java.lang.Object
clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait

Field Detail

STANDARD

public static final byte STANDARD

This code indicates a glyph that represents a single standard character.

LIGATURE

public static final byte LIGATURE

This code indicates a glyph that represents multiple characters as a ligature, for example 'fi' or 'ffi'. It is followed by filler glyphs for the remaining characters. Filler and combining glyphs can be intermixed to control positioning of accent marks on the logically preceeding ligature.

COMBINING

public static final byte COMBINING

This code indicates a glyph that represents a combining character, such as an umlaut. There is no caret position between this glyph and the preceeding glyph.

COMPONENT

public static final byte COMPONENT

This code indicates a glyph with no corresponding character in the backing store. The glyph is associated with the character represented by the logicaly preceeding non-component glyph. This is used for kashida justification or other visual modifications to existing glyphs. There is no caret position between this glyph and the preceeding glyph.

WHITESPACE

public static final byte WHITESPACE

This code indicates a glyph with no visual representation. It can be added to the other code values to indicate an invisible glyph.

Constructor Detail

GlyphMetrics

public GlyphMetrics(float advance,
                    Rectangle2D bounds,
                    byte glyphType)

Construct a GlyphMetrics.

Parameters:: advance - the advance width (height) of the glyph; bounds - the black box bounds of the glyph.; glyphType - the type of the glyph

Method Detail

getAdvance

public float getAdvance()

Return the advance width (height) of the glyph.

getBounds2D

public Rectangle2D getBounds2D()

Return the black box bounds of the glyph.

getLSB

public float getLSB()

Return the left (top) side bearing of the glyph. This is the distance from 0, 0 to the left (top) of the glyph bounds. If the bounds of the glyph is to the left of (above) the origin, the LSB is negative.

getRSB

public float getRSB()

Return the right (bottom) side bearing of the glyph. This is the distance from the right (bottom) of the glyph bounds to the advance. If the bounds of the glyph is to the right of (below) the advance, the RSB is negative.

getType

public int getType()

Return the raw glyph type code.

isStandard

public boolean isStandard()

Return true if this is a standard glyph.

isLigature

public boolean isLigature()

Return true if this is a ligature glyph.

isCombining

public boolean isCombining()

Return true if this is a combining glyph.

isComponent

public boolean isComponent()

Return true if this is a component glyph.

isWhitespace

public boolean isWhitespace()

Return true if this is a whitespace glyph.