org.foray.fotree.value
Class DtColor

java.lang.Object
  org.foray.fotree.value.Expr
      org.foray.fotree.value.ExprAdditive
          org.foray.fotree.value.ExprMultiplicative
              org.foray.fotree.value.ExprUnary
                  org.foray.fotree.value.ExprPrimary
                      org.foray.fotree.value.Datatype
                          org.foray.fotree.value.DtColor

All Implemented Interfaces:

PropertyValue

public final class DtColor
extends Datatype

A "color" property datatype in XSL-FO. See XSL-FO Std. 1.0, Sec. 5.11.

To prevent creation of multiple instances for the same underlying color, the constructor is private. To obtain an instance, use one of the following static methods instead: makeDtColor(String), makeDtColor(Color), or makeDtColor(float, float, float, float).

Field Summary

static Color	COLOR_RGB_TRANSPARENT A standard transparent color.
static byte	SRGB_ALPHA_COMPONENT Constant indicating the index to the Alpha component in the sRGB color space.
static byte	SRGB_BLUE_COMPONENT Constant indicating the index to the Blue component in the sRGB color space.
static byte	SRGB_COMPONENTS Constant indicating the number of components in the sRGB color space.
static byte	SRGB_GREEN_COMPONENT Constant indicating the index to the Green component in the sRGB color space.
static byte	SRGB_RED_COMPONENT Constant indicating the index to the Red component in the sRGB color space.

Fields inherited from class org.foray.fotree.value.Expr

OPERATION_ADD, OPERATION_DIVIDE, OPERATION_MOD, OPERATION_MULTIPLY, OPERATION_NEGATION, OPERATION_SUBTRACT, UNIT_POWER_AREA, UNIT_POWER_LENGTH, UNIT_POWER_NON_NUMERIC, UNIT_POWER_NUMERIC

Method Summary

boolean	canEvalColor() Indicates whether this property value has the ability to express itself as a Color.
boolean	canEvalInteger() Indicates whether this property value has the ability to express itself as an integer Numeric item.
boolean	canEvalKeyword() Indicates whether this property value can evaluate to a keyword.
boolean	canEvalLength() Indicates whether this expression can be evaluated to a unit power = 1 (length) or not.
boolean	canEvalNumeric() Indicates whether this property value has the ability to express itself as a Numeric item.
boolean	canEvalPercentage() Indicates whether this property value can evaluate to a percentage.
Color	evalColor() Returns the encapsulated Color.
int	evalInteger() Return this value as an int.
PvKeyword	evalKeyword() Returns the keyword value of this property value.
int	evalLength(int pointSize) Evaluates the expression to a unit power of 1 (length).
double	evalNumeric() Return the raw numeric value of "this", without regard to unit power.
float	evalPercentage() Returns the percentage value of this property value.
byte	getUnitPower() Each numeric has a "unit power".
Color	getValue() Returns the color value.
boolean	lengthRequiresFontSize() Indicates whether the computation of the length will require an accurate font-size parameter.
static DtColor	makeDtColor(Color color) Factory method that creates or retrieves a DtColor instance for a given color.
static DtColor	makeDtColor(float red, float green, float blue, float alpha) Factory method that creates or retrieves a DtColor instance for a set of color components.
static DtColor	makeDtColor(String input) Factory method which converts a named color into a ColorDT instance.
static DtColor	mapNameToColorRGB(String colorName) Returns a standard XSL-FO color from its name.
static DtColor	mapSecondaryNameToColorRGB(String colorName) Returns a color from its name, including standard XSL-FO named colors and the additional ones supplied by FOray.
static DtColor	parseColorDescription(String inputValue) Converts a String color description to a DtColor instance.
static float	parseShortRGBColor(String colorString, int componentIndex, boolean longFormat) Parses a specific color value out of a String in the form of #RGB (short format), or #RRGGBB (long format), returning the color value in the range 0 thru 1.

Methods inherited from class org.foray.fotree.value.Datatype

convertValueToFoValue

Methods inherited from class org.foray.fotree.value.Expr

evalColorException, evalIntegerException, evalKeywordException, evalLengthException, evalNumericException, evalPercentageException

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

COLOR_RGB_TRANSPARENT

public static final Color COLOR_RGB_TRANSPARENT

A standard transparent color.

SRGB_COMPONENTS

public static final byte SRGB_COMPONENTS

Constant indicating the number of components in the sRGB color space.

SRGB_RED_COMPONENT

public static final byte SRGB_RED_COMPONENT

Constant indicating the index to the Red component in the sRGB color space.

See Also:

Constant Field Values

SRGB_GREEN_COMPONENT

public static final byte SRGB_GREEN_COMPONENT

Constant indicating the index to the Green component in the sRGB color space.

See Also:

Constant Field Values

SRGB_BLUE_COMPONENT

public static final byte SRGB_BLUE_COMPONENT

Constant indicating the index to the Blue component in the sRGB color space.

See Also:

Constant Field Values

SRGB_ALPHA_COMPONENT

public static final byte SRGB_ALPHA_COMPONENT

Constant indicating the index to the Alpha component in the sRGB color space.

See Also:

Constant Field Values

Method Detail

getValue

public Color getValue()

Returns the color value.

Returns:

The color.

canEvalColor

public boolean canEvalColor()

Indicates whether this property value has the ability to express itself as a Color. Overrides the base class, because this function can evaluate to a color.

Returns:

True iff this property value is a color.

evalColor

public Color evalColor()

Returns the encapsulated Color.

Returns:

The encapsulated Color.

makeDtColor

public static DtColor makeDtColor(String input)

Factory method which converts a named color into a ColorDT instance.

Parameters:

input - The named color (for example, "blue" or "teal") to be converted.

Returns:

A ColorDT instance, or null if input is not a defined XSL-FO named color.

makeDtColor

public static DtColor makeDtColor(Color color)

Factory method that creates or retrieves a DtColor instance for a given color.

Parameters:

color - The color to wrap.

Returns:

The DtColor instance.

makeDtColor

public static DtColor makeDtColor(float red,
                                  float green,
                                  float blue,
                                  float alpha)

Factory method that creates or retrieves a DtColor instance for a set of color components.

Parameters:

red - The red value of the color to wrap (0 thru 1).

green - The green value of the color to wrap (0 thru 1).

blue - The blue value of the color to wrap (0 thru 1).

alpha - The alpha value of the color to wrap (0 thru 1).

Returns:

The DtColor instance.

mapNameToColorRGB

public static DtColor mapNameToColorRGB(String colorName)

Returns a standard XSL-FO color from its name.

Parameters:

colorName - The name of the color to be returned.

Returns:

The color instance or null if it is not found.

mapSecondaryNameToColorRGB

public static DtColor mapSecondaryNameToColorRGB(String colorName)

Returns a color from its name, including standard XSL-FO named colors and the additional ones supplied by FOray.

Parameters:

colorName - The name of the color to be returned.

Returns:

The color instance or null if it is not found.

parseColorDescription

public static DtColor parseColorDescription(String inputValue)
                                     throws PropertyException

Converts a String color description to a DtColor instance.

Parameters:

inputValue - The color description in one of the following formats: 1) a color name, 2) an #RGB description, or 3) an #RRGGBB description.

Returns:

The DtColor instance for the description.

Throws:

PropertyException - If the input value is not valid.

parseShortRGBColor

public static float parseShortRGBColor(String colorString,
                                       int componentIndex,
                                       boolean longFormat)

Parses a specific color value out of a String in the form of #RGB (short format), or #RRGGBB (long format), returning the color value in the range 0 thru 1.

Parameters:

colorString - The String containing the color descriptor, in the format #RGB (short format), or #RRGGBB (long format).

componentIndex - The index to the component to be parsed, one of SRGB_RED_COMPONENT, SRGB_GREEN_COMPONENT, or SRGB_BLUE_COMPONENT.

longFormat - Set to true if the input is in long format, false if it is in short format.

Returns:

The color value in the range 0 thru 1.

canEvalNumeric

public boolean canEvalNumeric()

Description copied from interface: PropertyValue

Indicates whether this property value has the ability to express itself as a Numeric item.

Returns:

True iff this property value is a numeric.

evalNumeric

public double evalNumeric()

Description copied from interface: PropertyValue

Return the raw numeric value of "this", without regard to unit power.

Returns:

A double representation of the value of "this". Type "double" is assumed to be the lowest-common-denominator of all numeric values.

canEvalLength

public boolean canEvalLength()

Description copied from interface: PropertyValue

Indicates whether this expression can be evaluated to a unit power = 1 (length) or not.

Returns:

True if the expression can be evaluated to a unit power of 1 (length).

getUnitPower

public byte getUnitPower()

Description copied from interface: PropertyValue

Each numeric has a "unit power". This number refers to the number of spatial dimensions in which the number operates. So, a number that has no relationship to space or refers to a point, has a length power of 0. A number that refers to length has a length power of 1 (1 dimension). Although there are none yet in XSL-FO, a number that referred to area (e.g. square inches) would, we suppose, have a length power of 2, and one referring to volume (e.g. cubic feet) would, we suppose have a length power of 3.

Returns:

The number of spatial dimensions in which this numeric item operates. For XSL-FO items, this should be either Expr.UNIT_POWER_NUMERIC or Expr.UNIT_POWER_LENGTH.

evalLength

public int evalLength(int pointSize)

Description copied from interface: PropertyValue

Evaluates the expression to a unit power of 1 (length).

Parameters:

pointSize - The point size, in millipoints, of the font. This is used in calculations that are relative to the point size. In cases where the computation of the font-size is expensive, check PropertyValue.lengthRequiresFontSize() first. If that method returns false, zero or some other constant can safely be passed, as it will be ignored anyway.

Returns:

The unit power 1 value (length) of this expression if the expression can be so evaluated, or Integer.MIN_VALUE otherwise. The value is expressed in millipoints.

lengthRequiresFontSize

public boolean lengthRequiresFontSize()

Description copied from interface: PropertyValue

Indicates whether the computation of the length will require an accurate font-size parameter.

Returns:

True iff the computation of the length will require an accurate font-size parameter.

canEvalInteger

public boolean canEvalInteger()

Description copied from interface: PropertyValue

Indicates whether this property value has the ability to express itself as an integer Numeric item.

Returns:

True iff this property value is an integer.

evalInteger

public int evalInteger()

Description copied from interface: PropertyValue

Return this value as an int. This method should only be executed on instances where PropertyValue.canEvalInteger() returns true. Doing so on other instances may result in an IllegalStateException.

Returns:

This value as an int.

canEvalKeyword

public boolean canEvalKeyword()

Description copied from interface: PropertyValue

Indicates whether this property value can evaluate to a keyword.

Returns:

True iff this property value can evaluate to a keyword.

evalKeyword

public PvKeyword evalKeyword()

Description copied from interface: PropertyValue

Returns the keyword value of this property value. This method should only be executed on instances where PropertyValue.canEvalKeyword() returns true. Doing so on other instances may result in an IllegalStateException.

Returns:

The keyword value of this property value.

canEvalPercentage

public boolean canEvalPercentage()

Description copied from interface: PropertyValue

Indicates whether this property value can evaluate to a percentage.

Returns:

True iff this property value can evaluate to a percentage.

evalPercentage

public float evalPercentage()

Description copied from interface: PropertyValue

Returns the percentage value of this property value. This method should only be executed on instances where PropertyValue.canEvalPercentage() returns true. Doing so on other instances may result in an IllegalStateException.

Returns:

The percentage value of this property value.