org.foray.fotree.value
Class DtKeep

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.DtKeep

All Implemented Interfaces:

PropertyValue

public class DtKeep
extends Datatype

A keep datatype in XSL. Used for the XSL-FO properties keep-together, keep-with-next, and keep-with-previous. This datatype is described in the XSL-FO Standard 1.0, at Section 4.8 and Section 5.11.

Field Summary

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

Constructor Summary

DtKeep(PropertyValue withinLine, PropertyValue withinColumn, PropertyValue withinPage)
Constructor.

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.
static DtKeep	createKeepDT() Factory method that creates a new, default SpaceDT instance.
Color	evalColor() Return the color value of "this".
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.
static PropertyValue	getDefaultKeepValue() Returns the default keep value.
byte	getUnitPower() Each numeric has a "unit power".
int	getWithinColumn() Returnw the "within-column" component.
int	getWithinLine() Returnw the "within-line" component.
int	getWithinPage() Returnw the "within-page" component.
boolean	lengthRequiresFontSize() Indicates whether the computation of the length will require an accurate font-size parameter.
void	setWithinColumn(PropertyValue newWithinColumn) Sets the "within-column" component.
void	setWithinLine(PropertyValue newWithinLine) Sets the "within-line" component.
void	setWithinPage(PropertyValue newWithinPage) Sets the "within-page" component.

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

Constructor Detail

DtKeep

public DtKeep(PropertyValue withinLine,
              PropertyValue withinColumn,
              PropertyValue withinPage)
       throws PropertyException

Constructor.

Parameters:

withinLine - The "within-line" component.

withinColumn - The "within-column" component.

withinPage - The "within-page" component.

Throws:

PropertyException - If the parameter values do not evaluate to integers.

Method Detail

setWithinLine

public void setWithinLine(PropertyValue newWithinLine)
                   throws PropertyException

Sets the "within-line" component.

Parameters:

newWithinLine - The new "within-line" value.

Throws:

PropertyException - If the parameter value does not evaluate to an integer.

setWithinColumn

public void setWithinColumn(PropertyValue newWithinColumn)
                     throws PropertyException

Sets the "within-column" component.

Parameters:

newWithinColumn - The new "within-column" value.

Throws:

PropertyException - If the parameter value does not evaluate to an integer.

setWithinPage

public void setWithinPage(PropertyValue newWithinPage)
                   throws PropertyException

Sets the "within-page" component.

Parameters:

newWithinPage - The new "within-page" value.

Throws:

PropertyException - If the parameter value does not evaluate to an integer.

getWithinLine

public int getWithinLine()

Returnw the "within-line" component.

Returns:

The "within-line" component.

getWithinColumn

public int getWithinColumn()

Returnw the "within-column" component.

Returns:

The "within-column" component.

getWithinPage

public int getWithinPage()

Returnw the "within-page" component.

Returns:

The "within-page" component.

createKeepDT

public static DtKeep createKeepDT()

Factory method that creates a new, default SpaceDT instance.

Returns:

A new, default SpaceDT instance.

getDefaultKeepValue

public static PropertyValue getDefaultKeepValue()

Returns the default keep value.

Returns:

The default keep value, which evaluates to Integer.MIN_VALUE.

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.

canEvalColor

public boolean canEvalColor()

Description copied from interface: PropertyValue

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

Returns:

True iff this property value is a color.

evalColor

public Color evalColor()

Description copied from interface: PropertyValue

Return the color value of "this".

Returns:

The color representation of the value of "this".

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.