TextAttribute
public final class TextAttribute
extends AttributedCharacterIterator.Attribute
java.lang.Object | ||
↳ | java.text.AttributedCharacterIterator.Attribute | |
↳ | java.awt.font.TextAttribute |
The TextAttribute
class defines attribute keys and attribute values used for text rendering.
TextAttribute
instances are used as attribute keys to identify attributes in classes handling text attributes. Other constants defined in this class can be used as attribute values.
For each text attribute, the documentation provides:
- the type of its value,
- the relevant predefined constants, if any
- the default effect if the attribute is absent
- the valid values if there are limitations
- a description of the effect.
Values
- The values of attributes must always be immutable.
- Where value limitations are given, any value outside of that set is reserved for future use; the value will be treated as the default.
- The value
null
is treated the same as the default value and results in the default behavior. - If the value is not of the proper type, the attribute will be ignored.
- The identity of the value does not matter, only the actual value. For example,
TextAttribute.WEIGHT_BOLD
andnew Float(2.0)
indicate the sameWEIGHT
. - Attribute values of type
Number
(used forWEIGHT
,WIDTH
,POSTURE
,SIZE
,JUSTIFICATION
, andTRACKING
) can vary along their natural range and are not restricted to the predefined constants.Number.floatValue()
is used to get the actual value from theNumber
. - The values for
WEIGHT
,WIDTH
, andPOSTURE
are interpolated by the system, which can select the 'nearest available' font or use other techniques to approximate the user's request.
Summary
Fields | |
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public static final TextAttribute | BACKGROUND Attribute key for the paint used to render the background of the text. |
public static final TextAttribute | BIDI_EMBEDDING Attribute key for the embedding level of the text. |
public static final TextAttribute | CHAR_REPLACEMENT Attribute key for a user-defined glyph to display in lieu of the font's standard glyph for a character. |
public static final TextAttribute | FAMILY Attribute key for the font name. |
public static final TextAttribute | FONT Attribute key used to provide the font to use to render text. |
public static final TextAttribute | FOREGROUND Attribute key for the paint used to render the text. |
public static final TextAttribute | INPUT_METHOD_HIGHLIGHT Attribute key for input method highlight styles. |
public static final TextAttribute | INPUT_METHOD_UNDERLINE Attribute key for input method underlines. |
public static final TextAttribute | JUSTIFICATION Attribute key for the justification of a paragraph. |
public static final Float | JUSTIFICATION_FULL Justify the line to the full requested width. |
public static final Float | JUSTIFICATION_NONE Do not allow the line to be justified. |
public static final TextAttribute | KERNING Attribute key to request kerning. |
public static final Integer | KERNING_ON Request standard kerning. |
public static final TextAttribute | LIGATURES Attribute key for enabling optional ligatures. |
public static final Integer | LIGATURES_ON Request standard optional ligatures. |
public static final TextAttribute | NUMERIC_SHAPING Attribute key for converting ASCII decimal digits to other decimal ranges. |
public static final TextAttribute | POSTURE Attribute key for the posture of a font. |
public static final Float | POSTURE_OBLIQUE The standard italic posture. |
public static final Float | POSTURE_REGULAR The standard posture, upright. |
public static final TextAttribute | RUN_DIRECTION Attribute key for the run direction of the line. |
public static final Boolean | RUN_DIRECTION_LTR Left-to-right run direction. |
public static final Boolean | RUN_DIRECTION_RTL Right-to-left run direction. |
public static final TextAttribute | SIZE Attribute key for the font size. |
public static final TextAttribute | STRIKETHROUGH Attribute key for strikethrough. |
public static final Boolean | STRIKETHROUGH_ON A single strikethrough. |
public static final TextAttribute | SUPERSCRIPT Attribute key for superscripting and subscripting. |
public static final Integer | SUPERSCRIPT_SUB Standard subscript. |
public static final Integer | SUPERSCRIPT_SUPER Standard superscript. |
public static final TextAttribute | SWAP_COLORS Attribute key for swapping foreground and background |
public static final Boolean | SWAP_COLORS_ON Swap foreground and background. |
public static final TextAttribute | TRACKING Attribute key to control tracking. |
public static final Float | TRACKING_LOOSE Perform loose tracking. |
public static final Float | TRACKING_TIGHT Perform tight tracking. |
public static final TextAttribute | TRANSFORM Attribute key for the transform of a font. |
public static final TextAttribute | UNDERLINE Attribute key for underline. |
public static final Integer | UNDERLINE_LOW_DASHED Single pixel dashed low underline. |
public static final Integer | UNDERLINE_LOW_DOTTED Single pixel dotted low underline. |
public static final Integer | UNDERLINE_LOW_GRAY Double pixel gray low underline. |
public static final Integer | UNDERLINE_LOW_ONE_PIXEL Single pixel solid low underline. |
public static final Integer | UNDERLINE_LOW_TWO_PIXEL Double pixel solid low underline. |
public static final Integer | UNDERLINE_ON Standard underline. |
public static final TextAttribute | WEIGHT Attribute key for the weight of a font. |
public static final Float | WEIGHT_BOLD The standard bold weight. |
public static final Float | WEIGHT_DEMIBOLD A moderately lighter weight than |
public static final Float | WEIGHT_DEMILIGHT An intermediate weight between |
public static final Float | WEIGHT_EXTRABOLD An extra heavy weight. |
public static final Float | WEIGHT_EXTRA_LIGHT The lightest predefined weight. |
public static final Float | WEIGHT_HEAVY A moderately heavier weight than |
public static final Float | WEIGHT_LIGHT The standard light weight. |
public static final Float | WEIGHT_MEDIUM An intermediate weight between |
public static final Float | WEIGHT_REGULAR The standard weight. |
public static final Float | WEIGHT_SEMIBOLD A moderately heavier weight than |
public static final Float | WEIGHT_ULTRABOLD The heaviest predefined weight. |
public static final TextAttribute | WIDTH Attribute key for the width of a font. |
public static final Float | WIDTH_CONDENSED The most condensed predefined width. |
public static final Float | WIDTH_EXTENDED The most extended predefined width. |
public static final Float | WIDTH_REGULAR The standard width. |
public static final Float | WIDTH_SEMI_CONDENSED A moderately condensed width. |
public static final Float | WIDTH_SEMI_EXTENDED A moderately extended width. |
Inherited fields |
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Protected constructors | |
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TextAttribute(String name) Constructs a |
Protected methods | |
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Object | readResolve() Resolves instances being deserialized to the predefined constants. |
Inherited methods | |
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Fields
BACKGROUND
public static final TextAttribute BACKGROUND
Attribute key for the paint used to render the background of the text. Values are instances of Paint
. The default value is null, indicating that the background should not be rendered.
The logical bounds of the text will be filled using this Paint
, and then the text will be rendered on top of it (but see SWAP_COLORS
).
The visual bounds of the text is extended to include the logical bounds, if necessary. The outline is not affected.
See also:
BIDI_EMBEDDING
public static final TextAttribute BIDI_EMBEDDING
Attribute key for the embedding level of the text. Values are instances of Integer
. The default value is null
, indicating that the the Bidirectional algorithm should run without explicit embeddings.
Positive values 1 through 61 are embedding levels, negative values -1 through -61 are override levels. The value 0 means that the base line direction is used. These levels are passed in the embedding levels array to the Bidi
constructor.
Note: When this attribute is present anywhere in a paragraph, then any Unicode bidi control characters (RLO, LRO, RLE, LRE, and PDF) in the paragraph are disregarded, and runs of text where this attribute is not present are treated as though it were present and had the value 0.
See also:
CHAR_REPLACEMENT
public static final TextAttribute CHAR_REPLACEMENT
Attribute key for a user-defined glyph to display in lieu of the font's standard glyph for a character. Values are intances of GraphicAttribute. The default value is null, indicating that the standard glyphs provided by the font should be used.
This attribute is used to reserve space for a graphic or other component embedded in a line of text. It is required for correct positioning of 'inline' components within a line when bidirectional reordering (see Bidi
) is performed. Each character (Unicode code point) will be rendered using the provided GraphicAttribute. Typically, the characters to which this attribute is applied should be \uFFFC
.
The GraphicAttribute determines the logical and visual bounds of the text; the actual Font values are ignored.
FAMILY
public static final TextAttribute FAMILY
Attribute key for the font name. Values are instances of String
. The default value is "Default"
, which causes the platform default font family to be used.
The Font
class defines constants for the logical font names.
This defines the value passed as name
to the Font
constructor. Both logical and physical font names are allowed. If a font with the requested name is not found, the default font is used.
Note: This attribute is unfortunately misnamed, as it specifies the face name and not just the family. Thus values such as "Lucida Sans Bold" will select that face if it exists. Note, though, that if the requested face does not exist, the default will be used with regular weight. The "Bold" in the name is part of the face name, not a separate request that the font's weight be bold.
FONT
public static final TextAttribute FONT
Attribute key used to provide the font to use to render text. The default value is null, indicating that normal resolution of a Font
from attributes should be performed.
TextLayout
and AttributedCharacterIterator
work in terms of Maps
of TextAttributes
. Normally, all the attributes are examined and used to select and configure a Font
instance. If a FONT
attribute is present, though, its associated Font
will be used. This provides a way for users to override the resolution of font attributes into a Font
, or force use of a particular Font
instance. This also allows users to specify subclasses of Font
in cases where a Font
can be subclassed.
FONT
is used for special situations where clients already have a Font
instance but still need to use Map
-based APIs. Typically, there will be no other attributes in the Map
except the FONT
attribute. With Map
-based APIs the common case is to specify all attributes individually, so FONT
is not needed or desireable.
However, if both FONT
and other attributes are present in the Map
, the rendering system will merge the attributes defined in the Font
with the additional attributes. This merging process classifies TextAttributes
into two groups. One group, the 'primary' group, is considered fundamental to the selection and metric behavior of a font. These attributes are FAMILY
, WEIGHT
, WIDTH
, POSTURE
, SIZE
, TRANSFORM
, SUPERSCRIPT
, and TRACKING
. The other group, the 'secondary' group, consists of all other defined attributes, with the exception of FONT
itself.
To generate the new Map
, first the Font
is obtained from the FONT
attribute, and all of its attributes extracted into a new Map
. Then only the secondary attributes from the original Map
are added to those in the new Map
. Thus the values of primary attributes come solely from the Font
, and the values of secondary attributes originate with the Font
but can be overridden by other values in the Map
.
FOREGROUND
public static final TextAttribute FOREGROUND
Attribute key for the paint used to render the text. Values are instances of Paint
. The default value is null, indicating that the Paint
set on the Graphics2D
at the time of rendering is used.
Glyphs will be rendered using this Paint
regardless of the Paint
value set on the Graphics
(but see SWAP_COLORS
).
See also:
INPUT_METHOD_HIGHLIGHT
public static final TextAttribute INPUT_METHOD_HIGHLIGHT
Attribute key for input method highlight styles. The default value is null
, which means that input method styles should not be applied before rendering.
See also:
INPUT_METHOD_UNDERLINE
public static final TextAttribute INPUT_METHOD_UNDERLINE
Attribute key for input method underlines. Values are instances of Integer
. The default value is -1
, which means no underline.
Several constant values are provided, see UNDERLINE_LOW_ONE_PIXEL
, UNDERLINE_LOW_TWO_PIXEL
, UNDERLINE_LOW_DOTTED
, UNDERLINE_LOW_GRAY
, and UNDERLINE_LOW_DASHED
.
This may be used in conjunction with UNDERLINE
if desired. The primary purpose is for use by input methods. Other use of these underlines for simple ornamentation might confuse users.
The input method underline affects both the visual bounds and the outline of the text.
JUSTIFICATION
public static final TextAttribute JUSTIFICATION
Attribute key for the justification of a paragraph. Values are instances of Number
. The default value is 1, indicating that justification should use the full width provided. Values are pinned to the range [0..1].
The constants JUSTIFICATION_FULL
and JUSTIFICATION_NONE
are provided.
Specifies the fraction of the extra space to use when justification is requested on a TextLayout
. For example, if the line is 50 points wide and it is requested to justify to 70 points, a value of 0.75 will pad to use three-quarters of the remaining space, or 15 points, so that the resulting line will be 65 points in length.
Note: This should have the same value for all the text in a paragraph, otherwise the behavior is undetermined.
JUSTIFICATION_FULL
public static final Float JUSTIFICATION_FULL
Justify the line to the full requested width. This is the default value for JUSTIFICATION
.
See also:
JUSTIFICATION_NONE
public static final Float JUSTIFICATION_NONE
Do not allow the line to be justified.
See also:
KERNING
public static final TextAttribute KERNING
Attribute key to request kerning. Values are instances of Integer
. The default value is 0
, which does not request kerning.
The constant value KERNING_ON
is provided.
The default advances of single characters are not appropriate for some character sequences, for example "To" or "AWAY". Without kerning the adjacent characters appear to be separated by too much space. Kerning causes selected sequences of characters to be spaced differently for a more pleasing visual appearance.
KERNING_ON
public static final Integer KERNING_ON
Request standard kerning.
See also:
LIGATURES
public static final TextAttribute LIGATURES
Attribute key for enabling optional ligatures. Values are instances of Integer
. The default value is 0
, which means do not use optional ligatures.
The constant value LIGATURES_ON
is defined.
Ligatures required by the writing system are always enabled.
LIGATURES_ON
public static final Integer LIGATURES_ON
Request standard optional ligatures.
See also:
NUMERIC_SHAPING
public static final TextAttribute NUMERIC_SHAPING
Attribute key for converting ASCII decimal digits to other decimal ranges. Values are instances of NumericShaper
. The default is null
, which means do not perform numeric shaping.
When a numeric shaper is defined, the text is first processed by the shaper before any other analysis of the text is performed.
Note: This should have the same value for all the text in the paragraph, otherwise the behavior is undetermined.
See also:
POSTURE
public static final TextAttribute POSTURE
Attribute key for the posture of a font. Values are instances of Number
. The default value is POSTURE_REGULAR
.
Two constant values are provided, POSTURE_REGULAR
and POSTURE_OBLIQUE
. The value POSTURE_OBLIQUE
corresponds to the style value Font.ITALIC
as passed to the Font
constructor.
The value is roughly the slope of the stems of the font, expressed as the run over the rise. Positive values lean right.
The system can interpolate the provided value.
This will affect the font's italic angle as returned by Font.getItalicAngle
.
POSTURE_OBLIQUE
public static final Float POSTURE_OBLIQUE
The standard italic posture.
See also:
POSTURE_REGULAR
public static final Float POSTURE_REGULAR
The standard posture, upright. This is the default value for POSTURE
.
See also:
RUN_DIRECTION
public static final TextAttribute RUN_DIRECTION
Attribute key for the run direction of the line. Values are instances of Boolean
. The default value is null, which indicates that the standard Bidi algorithm for determining run direction should be used with the value Bidi.DIRECTION_DEFAULT_LEFT_TO_RIGHT
.
The constants RUN_DIRECTION_RTL
and RUN_DIRECTION_LTR
are provided.
This determines the value passed to the Bidi
constructor to select the primary direction of the text in the paragraph.
Note: This attribute should have the same value for all the text in a paragraph, otherwise the behavior is undetermined.
See also:
RUN_DIRECTION_LTR
public static final Boolean RUN_DIRECTION_LTR
Left-to-right run direction.
See also:
RUN_DIRECTION_RTL
public static final Boolean RUN_DIRECTION_RTL
Right-to-left run direction.
See also:
SIZE
public static final TextAttribute SIZE
Attribute key for the font size. Values are instances of Number
. The default value is 12pt.
This corresponds to the size
parameter to the Font
constructor.
Very large or small sizes will impact rendering performance, and the rendering system might not render text at these sizes. Negative sizes are illegal and result in the default size.
Note that the appearance and metrics of a 12pt font with a 2x transform might be different than that of a 24 point font with no transform.
STRIKETHROUGH
public static final TextAttribute STRIKETHROUGH
Attribute key for strikethrough. Values are instances of Boolean
. The default value is false
, which means no strikethrough.
The constant value STRIKETHROUGH_ON
is provided.
The strikethrough affects both the visual bounds and the outline of the text.
STRIKETHROUGH_ON
public static final Boolean STRIKETHROUGH_ON
A single strikethrough.
See also:
SUPERSCRIPT
public static final TextAttribute SUPERSCRIPT
Attribute key for superscripting and subscripting. Values are instances of Integer
. The default value is 0, which means that no superscript or subscript is used.
Two constant values are provided, see SUPERSCRIPT_SUPER
and SUPERSCRIPT_SUB
. These have the values 1 and -1 respectively. Values of greater magnitude define greater levels of superscript or subscripting, for example, 2 corresponds to super-superscript, 3 to super-super-superscript, and similarly for negative values and subscript, up to a level of 7 (or -7). Values beyond this range are reserved; behavior is platform-dependent.
SUPERSCRIPT
can impact the ascent and descent of a font. The ascent and descent can never become negative, however.
SUPERSCRIPT_SUB
public static final Integer SUPERSCRIPT_SUB
Standard subscript.
See also:
SUPERSCRIPT_SUPER
public static final Integer SUPERSCRIPT_SUPER
Standard superscript.
See also:
SWAP_COLORS
public static final TextAttribute SWAP_COLORS
Attribute key for swapping foreground and background Paints
. Values are instances of Boolean
. The default value is false
, which means do not swap colors.
The constant value SWAP_COLORS_ON
is defined.
If the FOREGROUND
attribute is set, its Paint
will be used as the background, otherwise the Paint
currently on the Graphics
will be used. If the BACKGROUND
attribute is set, its Paint
will be used as the foreground, otherwise the system will find a contrasting color to the (resolved) background so that the text will be visible.
See also:
SWAP_COLORS_ON
public static final Boolean SWAP_COLORS_ON
Swap foreground and background.
See also:
TRACKING
public static final TextAttribute TRACKING
Attribute key to control tracking. Values are instances of Number
. The default value is 0
, which means no additional tracking.
The constant values TRACKING_TIGHT
and TRACKING_LOOSE
are provided.
The tracking value is multiplied by the font point size and passed through the font transform to determine an additional amount to add to the advance of each glyph cluster. Positive tracking values will inhibit formation of optional ligatures. Tracking values are typically between -0.1
and 0.3
; values outside this range are generally not desireable.
TRACKING_LOOSE
public static final Float TRACKING_LOOSE
Perform loose tracking.
See also:
TRACKING_TIGHT
public static final Float TRACKING_TIGHT
Perform tight tracking.
See also:
TRANSFORM
public static final TextAttribute TRANSFORM
Attribute key for the transform of a font. Values are instances of TransformAttribute
. The default value is TransformAttribute.IDENTITY
.
The primary intent is to support scaling and skewing, though other effects are possible.
Some transforms will cause the baseline to be rotated and/or shifted. The text and the baseline are transformed together so that the text follows the new baseline. For example, with text on a horizontal baseline, the new baseline follows the direction of the unit x vector passed through the transform. Text metrics are measured against this new baseline. So, for example, with other things being equal, text rendered with a rotated TRANSFORM and an unrotated TRANSFORM will measure as having the same ascent, descent, and advance.
UNDERLINE
public static final TextAttribute UNDERLINE
Attribute key for underline. Values are instances of Integer
. The default value is -1, which means no underline.
The constant value UNDERLINE_ON
is provided.
The underline affects both the visual bounds and the outline of the text.
UNDERLINE_LOW_DASHED
public static final Integer UNDERLINE_LOW_DASHED
Single pixel dashed low underline.
See also:
UNDERLINE_LOW_DOTTED
public static final Integer UNDERLINE_LOW_DOTTED
Single pixel dotted low underline.
See also:
UNDERLINE_LOW_GRAY
public static final Integer UNDERLINE_LOW_GRAY
Double pixel gray low underline.
See also:
UNDERLINE_LOW_ONE_PIXEL
public static final Integer UNDERLINE_LOW_ONE_PIXEL
Single pixel solid low underline.
See also:
UNDERLINE_LOW_TWO_PIXEL
public static final Integer UNDERLINE_LOW_TWO_PIXEL
Double pixel solid low underline.
See also:
UNDERLINE_ON
public static final Integer UNDERLINE_ON
Standard underline.
See also:
WEIGHT
public static final TextAttribute WEIGHT
Attribute key for the weight of a font. Values are instances of Number
. The default value is WEIGHT_REGULAR
.
Several constant values are provided, see WEIGHT_EXTRA_LIGHT
, WEIGHT_LIGHT
, WEIGHT_DEMILIGHT
, WEIGHT_REGULAR
, WEIGHT_SEMIBOLD
, WEIGHT_MEDIUM
, WEIGHT_DEMIBOLD
, WEIGHT_BOLD
, WEIGHT_HEAVY
, WEIGHT_EXTRABOLD
, and WEIGHT_ULTRABOLD
. The value WEIGHT_BOLD
corresponds to the style value Font.BOLD
as passed to the Font
constructor.
The value is roughly the ratio of the stem width to that of the regular weight.
The system can interpolate the provided value.
WEIGHT_BOLD
public static final Float WEIGHT_BOLD
The standard bold weight.
See also:
WEIGHT_DEMIBOLD
public static final Float WEIGHT_DEMIBOLD
A moderately lighter weight than WEIGHT_BOLD
.
See also:
WEIGHT_DEMILIGHT
public static final Float WEIGHT_DEMILIGHT
An intermediate weight between WEIGHT_LIGHT
and WEIGHT_STANDARD
.
See also:
WEIGHT_EXTRABOLD
public static final Float WEIGHT_EXTRABOLD
An extra heavy weight.
See also:
WEIGHT_EXTRA_LIGHT
public static final Float WEIGHT_EXTRA_LIGHT
The lightest predefined weight.
See also:
WEIGHT_HEAVY
public static final Float WEIGHT_HEAVY
A moderately heavier weight than WEIGHT_BOLD
.
See also:
WEIGHT_LIGHT
public static final Float WEIGHT_LIGHT
The standard light weight.
See also:
WEIGHT_MEDIUM
public static final Float WEIGHT_MEDIUM
An intermediate weight between WEIGHT_REGULAR
and WEIGHT_BOLD
.
See also:
WEIGHT_REGULAR
public static final Float WEIGHT_REGULAR
The standard weight. This is the default value for WEIGHT
.
See also:
WEIGHT_SEMIBOLD
public static final Float WEIGHT_SEMIBOLD
A moderately heavier weight than WEIGHT_REGULAR
.
See also:
WEIGHT_ULTRABOLD
public static final Float WEIGHT_ULTRABOLD
The heaviest predefined weight.
See also:
WIDTH
public static final TextAttribute WIDTH
Attribute key for the width of a font. Values are instances of Number
. The default value is WIDTH_REGULAR
.
Several constant values are provided, see WIDTH_CONDENSED
, WIDTH_SEMI_CONDENSED
, WIDTH_REGULAR
, WIDTH_SEMI_EXTENDED
, WIDTH_EXTENDED
.
The value is roughly the ratio of the advance width to that of the regular width.
The system can interpolate the provided value.
WIDTH_CONDENSED
public static final Float WIDTH_CONDENSED
The most condensed predefined width.
See also:
WIDTH_EXTENDED
public static final Float WIDTH_EXTENDED
The most extended predefined width.
See also:
WIDTH_REGULAR
public static final Float WIDTH_REGULAR
The standard width. This is the default value for WIDTH
.
See also:
WIDTH_SEMI_CONDENSED
public static final Float WIDTH_SEMI_CONDENSED
A moderately condensed width.
See also:
WIDTH_SEMI_EXTENDED
public static final Float WIDTH_SEMI_EXTENDED
A moderately extended width.
See also:
Protected constructors
TextAttribute
protected TextAttribute (String name)
Constructs a TextAttribute
with the specified name.
Parameters | |
---|---|
name | String : the attribute name to assign to this TextAttribute |
Protected methods
readResolve
protected Object readResolve ()
Resolves instances being deserialized to the predefined constants.
Returns | |
---|---|
Object | the resolved Attribute object |
Throws | |
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InvalidObjectException |