TextAttribute - JRE Emulation | JRE Emulation
public final class

TextAttribute

extends AttributedCharacterIterator.Attribute
java.lang.Object
   ↳ java.text.AttributedCharacterIterator.Attribute
     ↳ java.awt.font.TextAttribute

Class Overview

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 and new Float(2.0) indicate the same WEIGHT.
  • Attribute values of type Number (used for WEIGHT, WIDTH, POSTURE, SIZE, JUSTIFICATION, and TRACKING) can vary along their natural range and are not restricted to the predefined constants. Number.floatValue() is used to get the actual value from the Number.
  • The values for WEIGHT, WIDTH, and POSTURE are interpolated by the system, which can select the 'nearest available' font or use other techniques to approximate the user's request.

Summary

Fields
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 Paints.
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 WEIGHT_BOLD.
public static final Float WEIGHT_DEMILIGHT An intermediate weight between WEIGHT_LIGHT and WEIGHT_STANDARD.
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 WEIGHT_BOLD.
public static final Float WEIGHT_LIGHT The standard light weight.
public static final Float WEIGHT_MEDIUM An intermediate weight between WEIGHT_REGULAR and WEIGHT_BOLD.
public static final Float WEIGHT_REGULAR The standard weight.
public static final Float WEIGHT_SEMIBOLD A moderately heavier weight than WEIGHT_REGULAR.
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.
[Expand]
Inherited Fields
From class java.text.AttributedCharacterIterator.Attribute
Protected Constructors
TextAttribute(String name)
Constructs a TextAttribute with the specified name.
Protected Methods
Object readResolve()
Resolves instances being deserialized to the predefined constants.
Inherited Methods
[Expand]
From class java.text.AttributedCharacterIterator.Attribute
From class java.lang.Object

Fields

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.

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 ERROR(/java.text.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.

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 ERROR(/java.text.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.

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.

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.

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).

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

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.

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.

public static final Float JUSTIFICATION_FULL

Justify the line to the full requested width. This is the default value for JUSTIFICATION.

See Also

public static final Float JUSTIFICATION_NONE

Do not allow the line to be justified.

See Also

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.

public static final Integer KERNING_ON

Request standard kerning.

See Also

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.

public static final Integer LIGATURES_ON

Request standard optional ligatures.

See Also

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

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.

public static final Float POSTURE_OBLIQUE

The standard italic posture.

See Also

public static final Float POSTURE_REGULAR

The standard posture, upright. This is the default value for POSTURE.

See Also

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 ERROR(/java.text.Bidi#DIRECTION_DEFAULT_LEFT_TO_RIGHT).

The constants RUN_DIRECTION_RTL and RUN_DIRECTION_LTR are provided.

This determines the value passed to the ERROR(/java.text.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.

public static final Boolean RUN_DIRECTION_LTR

Left-to-right run direction.

See Also

public static final Boolean RUN_DIRECTION_RTL

Right-to-left run direction.

See Also

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.

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.

public static final Boolean STRIKETHROUGH_ON

A single strikethrough.

See Also

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.

public static final Integer SUPERSCRIPT_SUB

Standard subscript.

See Also

public static final Integer SUPERSCRIPT_SUPER

Standard superscript.

See Also

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.

public static final Boolean SWAP_COLORS_ON

Swap foreground and background.

See Also

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.

public static final Float TRACKING_LOOSE

Perform loose tracking.

See Also

public static final Float TRACKING_TIGHT

Perform tight tracking.

See Also

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.

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.

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.

See Also

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.

public static final Float WEIGHT_BOLD

The standard bold weight.

See Also

public static final Float WEIGHT_DEMIBOLD

A moderately lighter weight than WEIGHT_BOLD.

See Also

public static final Float WEIGHT_DEMILIGHT

An intermediate weight between WEIGHT_LIGHT and WEIGHT_STANDARD.

See Also

public static final Float WEIGHT_EXTRABOLD

An extra heavy weight.

See Also

public static final Float WEIGHT_EXTRA_LIGHT

The lightest predefined weight.

See Also

public static final Float WEIGHT_HEAVY

A moderately heavier weight than WEIGHT_BOLD.

See Also

public static final Float WEIGHT_LIGHT

The standard light weight.

See Also

public static final Float WEIGHT_MEDIUM

An intermediate weight between WEIGHT_REGULAR and WEIGHT_BOLD.

See Also

public static final Float WEIGHT_REGULAR

The standard weight. This is the default value for WEIGHT.

See Also

public static final Float WEIGHT_SEMIBOLD

A moderately heavier weight than WEIGHT_REGULAR.

See Also

public static final Float WEIGHT_ULTRABOLD

The heaviest predefined weight.

See Also

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.

public static final Float WIDTH_CONDENSED

The most condensed predefined width.

See Also

public static final Float WIDTH_EXTENDED

The most extended predefined width.

See Also

public static final Float WIDTH_REGULAR

The standard width. This is the default value for WIDTH.

See Also

public static final Float WIDTH_SEMI_CONDENSED

A moderately condensed width.

See Also

public static final Float WIDTH_SEMI_EXTENDED

A moderately extended width.

See Also

Protected Constructors

protected TextAttribute (String name)

Constructs a TextAttribute with the specified name.

Parameters
name the attribute name to assign to this TextAttribute

Protected Methods

protected Object readResolve ()

Resolves instances being deserialized to the predefined constants.

Returns
  • the Attribute this instance represents.