java.awt.font

Class TextAttribute

java.lang.Object

java.text.AttributedCharacterIterator.Attribute

java.awt.font.TextAttribute

All Implemented Interfaces:

Serializable

public final class TextAttribute
extends AttributedCharacterIterator.Attribute

The TextAttribute class defines attribute keys and attribute values used for text rendering.

TextAttribute instances are used as attribute keys to identify attributes in AttributedCharacterIterator, Font, and other classes handling text attributes. Other constants defined in this class are used as attribute values.

For each text attribute, the documentation describes:

• the type of their values,
• the valid values if there are limitations
• relevant constants
• the default effect if the attribute is absent (or has a null value).
• a description of the effect.
• the fallback behavior if the exact attribute requested is not available.

Types of Values

• The values of attributes must always be immutable.
• Where a list of limitations is given, any value outside of that set is reserved for future use, and ignored at present.
• If the value is null or not of the proper type then it has the default effect. The effect of a particular value can be interpolated, especially in the case of multiple master fonts. This interpolation is done based on the nearest defined constants above and below the request:
  

  interpolation = (request - below)/(above - below);

Interpolation

• Fonts should interpolate values in certain circumstances. For example, when the WEIGHT value is 2.13. If the nearest surrounding values in the font are WEIGHT_BOLD = 2.0 and WEIGHT_HEAVY = 2.25 then font would then interpret the WEIGHT request as being 52% of the way between what it considers BOLD and what it considers HEAVY. If the nearest surrounding values are WEIGHT_SEMIBOLD = 1.25 and WEIGHT_ULTRABOLD = 2.75 then the WEIGHT request is interpreted as being 58.67% of the way between SEMIBOLD and ULTRABOLD.
• Where a font does not have enough capability to handle a given request, such as superscript, then it should simulate it to the best of its ability. To determine if simulation is being performed, the client should query the font to see what actual attributes were used.

See Also:

AttributedCharacterIterator, Font, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static TextAttribute	FAMILY Attribute key for the unlocalized font family name.
static TextAttribute	FONT Attribute key for the font to use to render text.
static TextAttribute	FOREGROUND Attribute key for the foreground color adornment.
static TextAttribute	INPUT_METHOD_HIGHLIGHT Attribute key for input method highlight styles.
static TextAttribute	POSTURE Attribute key for the posture of a font.
static Float	POSTURE_OBLIQUE The standard italic posture.
static Float	POSTURE_REGULAR The standard posture, upright.
static TextAttribute	SIZE Attribute key for the font size.
static TextAttribute	STRIKETHROUGH Attribute key for the strikethrough adornment.
static Boolean	STRIKETHROUGH_ON A single strikethrough.
static TextAttribute	UNDERLINE Attribute key for underline adornments.
static Integer	UNDERLINE_ON Standard underline at the roman baseline for roman text, and below the decenders for other text.
static TextAttribute	WEIGHT Attribute key for the weight of a font.
static Float	WEIGHT_BOLD The standard bold weight.
static Float	WEIGHT_DEMIBOLD A moderately lighter weight than BOLD.
static Float	WEIGHT_DEMILIGHT An intermediate weight between LIGHT and STANDARD.
static Float	WEIGHT_EXTRA_LIGHT The lightest predefined weight.
static Float	WEIGHT_EXTRABOLD An extra heavy weight.
static Float	WEIGHT_HEAVY A moderately heavier weight than BOLD.
static Float	WEIGHT_LIGHT The standard light weight.
static Float	WEIGHT_MEDIUM An intermediate weight between the REGULAR and BOLD weights.
static Float	WEIGHT_REGULAR The standard weight.
static Float	WEIGHT_SEMIBOLD A moderately heavier weight than REGULAR.
static Float	WEIGHT_ULTRABOLD The heaviest predefined weight.

Fields inherited from class java.text.AttributedCharacterIterator.Attribute

INPUT_METHOD_SEGMENT, LANGUAGE, READING

Method Summary

Methods

Modifier and Type	Method and Description
protected Object	readResolve() Resolves instances being deserialized to the predefined constants.

Methods inherited from class java.text.AttributedCharacterIterator.Attribute

equals, getName, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

FAMILY

public static final TextAttribute FAMILY

Attribute key for the unlocalized font family name.

Key	FAMILY
Value	String
Constants	"Serif", "SansSerif"
Default	Host default;
Description	The name of the font family. If the family name is not found, the default font is used. The name should not be the full font name or specify other attributes (such as the name "Helvetica Bold"). Such names might result in the default font if the name does not match a known family name.

WEIGHT

public static final TextAttribute WEIGHT

Attribute key for the weight of a font.

Key	WEIGHT
Value	Float
Constants	WEIGHT_EXTRA_LIGHT = 0.5, WEIGHT_LIGHT = 0.75, WEIGHT_DEMILIGHT = 0.875, WEIGHT_REGULAR = 1.0, WEIGHT_SEMIBOLD = 1.25, WEIGHT_MEDIUM = 1.5, WEIGHT_DEMIBOLD = 1.75, WEIGHT_BOLD = 2.0, WEIGHT_HEAVY = 2.25, WEIGHT_EXTRABOLD = 2.5, WEIGHT_ULTRABOLD = 2.75
Default	WEIGHT_REGULAR
Description	The value is roughly the ratio of the stem width to that of the regular weight. If the font has a different value for specific constants, then the value is interpolated as described in the class description.
Fallback	Currently none. However, in the future, shape manipulations might be available to simulate weight variations for fonts that don't have them.

WEIGHT_EXTRA_LIGHT

public static final Float WEIGHT_EXTRA_LIGHT

The lightest predefined weight.

See Also:

WEIGHT

WEIGHT_LIGHT

public static final Float WEIGHT_LIGHT

The standard light weight.

See Also:

WEIGHT

WEIGHT_DEMILIGHT

public static final Float WEIGHT_DEMILIGHT

An intermediate weight between LIGHT and STANDARD.

See Also:

WEIGHT

WEIGHT_REGULAR

public static final Float WEIGHT_REGULAR

The standard weight. This weight is used if WEIGHT is unspecified.

See Also:

WEIGHT

WEIGHT_SEMIBOLD

public static final Float WEIGHT_SEMIBOLD

A moderately heavier weight than REGULAR.

See Also:

WEIGHT

WEIGHT_MEDIUM

public static final Float WEIGHT_MEDIUM

An intermediate weight between the REGULAR and BOLD weights.

See Also:

WEIGHT

WEIGHT_DEMIBOLD

public static final Float WEIGHT_DEMIBOLD

A moderately lighter weight than BOLD.

See Also:

WEIGHT

WEIGHT_BOLD

public static final Float WEIGHT_BOLD

The standard bold weight.

See Also:

WEIGHT

WEIGHT_HEAVY

public static final Float WEIGHT_HEAVY

A moderately heavier weight than BOLD.

See Also:

WEIGHT

WEIGHT_EXTRABOLD

public static final Float WEIGHT_EXTRABOLD

An extra heavy weight.

See Also:

WEIGHT

WEIGHT_ULTRABOLD

public static final Float WEIGHT_ULTRABOLD

The heaviest predefined weight.

See Also:

WEIGHT

POSTURE

public static final TextAttribute POSTURE

Attribute key for the posture of a font.

Key	POSTURE
Value	Float
Constants	POSTURE_REGULAR = 0, POSTURE_OBLIQUE = 0.20
Default	POSTURE_REGULAR
Description	The value is interpreted generally as a skew slope, positive leans to the right. If the font has a different value for specific constants, then the value is interpolated as described in the class description. With fonts that have italic faces, not only the skew of the character changes, but also the letter shapes might change. Notes: To set the value by angle, use: value = new Float(Math.tan(Math.PI*degrees/180.0) To determine the angle from the value, use: angle = Math.atan(value.floatValue())*180/Math.PI
Fallback	If an Oblique font is available and matches, use that.

POSTURE_REGULAR

public static final Float POSTURE_REGULAR

The standard posture, upright.

See Also:

POSTURE

POSTURE_OBLIQUE

public static final Float POSTURE_OBLIQUE

The standard italic posture.

See Also:

POSTURE

SIZE

public static final TextAttribute SIZE

Attribute key for the font size.

Key	SIZE
Value	Float
Default	from System Properties
Description	Represents point size.
Fallback	Currently None

FONT

public static final TextAttribute FONT

Attribute key for the font to use to render text.

Key	FONT
Value	Font
Default	None, perform default resolution
Description	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.

FOREGROUND

public static final TextAttribute FOREGROUND

Attribute key for the foreground color adornment.

Key	FOREGROUND
Value	Color
Default	Color.black
Description	Specify the foreground Color of the text.

UNDERLINE

public static final TextAttribute UNDERLINE

Attribute key for underline adornments.

Key	UNDERLINE
Value	Integer
Constants	UNDERLINE_ON = 0
Default	none
Description	An embellishment added to the glyphs rendered by a font.
Fallback

UNDERLINE_ON

public static final Integer UNDERLINE_ON

Standard underline at the roman baseline for roman text, and below the decenders for other text.

See Also:

UNDERLINE

STRIKETHROUGH

public static final TextAttribute STRIKETHROUGH

Attribute key for the strikethrough adornment.

Key	STRIKETHROUGH
Value	Boolean
Constants	true = on, false = off
Default	off
Description	An embellishment added to the glyphs rendered by a font.

STRIKETHROUGH_ON

public static final Boolean STRIKETHROUGH_ON

A single strikethrough.

See Also:

STRIKETHROUGH

INPUT_METHOD_HIGHLIGHT

public static final TextAttribute INPUT_METHOD_HIGHLIGHT

Attribute key for input method highlight styles.

Values are instances of InputMethodHighlight. These instances should be wrapped in Annotation instances if segments need to be highlighted separately.

Input method highlights are used while text is being composed using an input method. Text editing components should retain them even if they generally only deal with unstyled text, and make them available to the drawing routines.

See Also:

InputMethodHighlight

Method Detail

readResolve

protected Object readResolve()
                      throws InvalidObjectException

Resolves instances being deserialized to the predefined constants.

Overrides:

readResolve in class AttributedCharacterIterator.Attribute

Throws:

InvalidObjectException