JavaTM 2 Platform Std. Ed. v1.6.0
java.awt.font
Class GlyphMetrics
java.lang.Object
java.awt.font.GlyphMetrics
public final class GlyphMetrics - extends Object
The GlyphMetrics class represents infomation for a
single glyph. A glyph is the visual representation of one or more
characters. Many different glyphs can be used to represent a single
character or combination of characters. 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 Arabic justification.
- 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
components of the advance, the visual bounds, and the left and right
side bearings.
Glyphs for a rotated font, or obtained from a GlyphVector
which has applied a rotation to the glyph, can have advances that
contain both X and Y components. Usually the advance only has one
component.
The advance of a glyph is the distance from the glyph's origin to the
origin of the next glyph along the baseline, which is either vertical
or horizontal. Note that, in a GlyphVector ,
the distance from a glyph to its following glyph might not be the
glyph's advance, because of kerning or other positioning adjustments.
The bounds is the smallest rectangle that completely contains the
outline 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. Note that the bounds does not necessarily enclose all the pixels
affected when rendering the glyph, because of rasterization and pixel
adjustment effects.
Although instances of GlyphMetrics can be directly
constructed, they are almost always obtained from a
GlyphVector . Once constructed, GlyphMetrics
objects 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
Indicates a glyph that represents a combining character,
such as an umlaut. |
static byte |
COMPONENT
Indicates a glyph with no corresponding character in the
backing store. |
static byte |
LIGATURE
Indicates a glyph that represents multiple characters
as a ligature, for example 'fi' or 'ffi'. |
static byte |
STANDARD
Indicates a glyph that represents a single standard
character. |
static byte |
WHITESPACE
Indicates a glyph with no visual representation. |
Constructor Summary |
GlyphMetrics(boolean horizontal,
float advanceX,
float advanceY,
Rectangle2D bounds,
byte glyphType)
Constructs a GlyphMetrics object. |
GlyphMetrics(float advance,
Rectangle2D bounds,
byte glyphType)
Constructs a GlyphMetrics object. |
Method Summary |
float |
getAdvance()
Returns the advance of the glyph along the baseline (either
horizontal or vertical). |
float |
getAdvanceX()
Returns the x-component of the advance of the glyph. |
float |
getAdvanceY()
Returns the y-component of the advance of the glyph. |
Rectangle2D |
getBounds2D()
Returns the bounds of the glyph. |
float |
getLSB()
Returns the left (top) side bearing of the glyph. |
float |
getRSB()
Returns the right (bottom) side bearing of the glyph. |
int |
getType()
Returns the raw glyph type code. |
boolean |
isCombining()
Returns true if this is a combining glyph. |
boolean |
isComponent()
Returns true if this is a component glyph. |
boolean |
isLigature()
Returns true if this is a ligature glyph. |
boolean |
isStandard()
Returns true if this is a standard glyph. |
boolean |
isWhitespace()
Returns 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 |
STANDARD
public static final byte STANDARD
- Indicates a glyph that represents a single standard
character.
- See Also:
- Constant Field Values
LIGATURE
public static final byte LIGATURE
- 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.
- See Also:
- Constant Field Values
COMBINING
public static final byte COMBINING
- Indicates a glyph that represents a combining character,
such as an umlaut. There is no caret position between this glyph
and the preceeding glyph.
- See Also:
- Constant Field Values
COMPONENT
public static final byte COMPONENT
- 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.
- See Also:
- Constant Field Values
WHITESPACE
public static final byte WHITESPACE
- Indicates a glyph with no visual representation. It can
be added to the other code values to indicate an invisible glyph.
- See Also:
- Constant Field Values
GlyphMetrics
public GlyphMetrics(float advance,
Rectangle2D bounds,
byte glyphType)
- Constructs a
GlyphMetrics object.
- Parameters:
advance - the advance width of the glyphbounds - the black box bounds of the glyphglyphType - the type of the glyph
GlyphMetrics
public GlyphMetrics(boolean horizontal,
float advanceX,
float advanceY,
Rectangle2D bounds,
byte glyphType)
- Constructs a
GlyphMetrics object.
- Parameters:
horizontal - if true, metrics are for a horizontal baseline,
otherwise they are for a vertical baselineadvanceX - the X-component of the glyph's advanceadvanceY - the Y-component of the glyph's advancebounds - the visual bounds of the glyphglyphType - the type of the glyph- Since:
- 1.4
getAdvance
public float getAdvance()
- Returns the advance of the glyph along the baseline (either
horizontal or vertical).
- Returns:
- the advance of the glyph
getAdvanceX
public float getAdvanceX()
- Returns the x-component of the advance of the glyph.
- Returns:
- the x-component of the advance of the glyph
- Since:
- 1.4
getAdvanceY
public float getAdvanceY()
- Returns the y-component of the advance of the glyph.
- Returns:
- the y-component of the advance of the glyph
- Since:
- 1.4
getBounds2D
public Rectangle2D getBounds2D()
- Returns the bounds of the glyph. This is the bounding box of the glyph outline.
Because of rasterization and pixel alignment effects, it does not necessarily
enclose the pixels that are affected when rendering the glyph.
- Returns:
- a
Rectangle2D that is the bounds of the glyph.
getLSB
public float getLSB()
- Returns 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.
- Returns:
- the left side bearing of the glyph.
getRSB
public float getRSB()
- Returns 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.
- Returns:
- the right side bearing of the glyph.
getType
public int getType()
- Returns the raw glyph type code.
- Returns:
- the raw glyph type code.
isStandard
public boolean isStandard()
- Returns
true if this is a standard glyph.
- Returns:
true if this is a standard glyph;
false otherwise.
isLigature
public boolean isLigature()
- Returns
true if this is a ligature glyph.
- Returns:
true if this is a ligature glyph;
false otherwise.
isCombining
public boolean isCombining()
- Returns
true if this is a combining glyph.
- Returns:
true if this is a combining glyph;
false otherwise.
isComponent
public boolean isComponent()
- Returns
true if this is a component glyph.
- Returns:
true if this is a component glyph;
false otherwise.
isWhitespace
public boolean isWhitespace()
- Returns
true if this is a whitespace glyph.
- Returns:
true if this is a whitespace glyph;
false otherwise.
Copyright 2003 Sun Microsystems, Inc. All rights reserved
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