org.apache.fop.fo.properties

Class PropertyMaker

Implemented Interfaces:
Cloneable
Known Direct Subclasses:
CharacterProperty.Maker, ColorProperty.Maker, CompoundPropertyMaker, EnumProperty.Maker, FontFamilyProperty.Maker, FontShorthandProperty.Maker, LengthProperty.Maker, ListProperty.Maker, NumberProperty.Maker, StringProperty.Maker, TextDecorationProperty.Maker, ToBeImplementedProperty.Maker

public class PropertyMaker
extends java.lang.Object
implements Cloneable

Base class for all property makers

Field Summary

protected boolean
contextDep
Indicates whether the property is context-dependant and therefore can't be cached.
protected CorrespondingPropertyMaker
corresponding
Maker for 'corresponding' properties *
protected Property
defaultProperty
default property *
protected String
defaultValue
the default value for the maker
protected int
propId
the property ID
protected boolean
setByShorthand
Indicates whether the property is set through a shorthand.

Constructor Summary

PropertyMaker(int propId)
Construct an instance of a Property.Maker for the given property.

Method Summary

void
addEnum(String constant, Property value)
Add a enum constant.
void
addKeyword(String keyword, String value)
Add a keyword-equiv to the maker.
void
addShorthand(PropertyMaker shorthand)
Add a shorthand to this maker.
void
addSubpropMaker(PropertyMaker subproperty)
Add a subproperty to this maker.
protected Property
checkEnumValues(String value)
For properties that contain enumerated values.
protected String
checkValueKeywords(String keyword)
Return a String to be parsed if the passed value corresponds to a keyword which can be parsed and used to initialize the property.
Object
clone()
Return a clone of the makers.
protected Property
compute(PropertyList propertyList)
Return a Property object representing the value of this property, based on other property values for this FO.
protected Property
convertProperty(Property p, PropertyList propertyList, FObj fo)
Return a Property object based on the passed Property object.
protected Property
convertPropertyDatatype(Property p, PropertyList propertyList, FObj fo)
For properties that have more than one legal way to be specified, this routine should be overridden to attempt to set them based upon the other methods.
Property
convertShorthandProperty(PropertyList propertyList, Property prop, FObj fo)
Converts a shorthand property
Property
findProperty(PropertyList propertyList, boolean tryInherit)
If the property is a relative property with a corresponding absolute value specified, the absolute value is used.
Property
get(int subpropertyId, PropertyList propertyList, boolean tryInherit, boolean tryDefault)
Return the property on the current FlowObject.
String
getName()
PercentBase
getPercentBase(PropertyList pl)
This is used to handle properties specified as a percentage of some "base length", such as the content width of their containing box.
int
getPropId()
Property
getShorthand(PropertyList propertyList)
For properties that can be set by shorthand properties, this method should return the Property, if any, that is parsed from any shorthand properties that affect this property.
Property
getSubprop(Property p, int subpropertyId)
Return a property value for the given component of a compound property.
PropertyMaker
getSubpropMaker(int subpropertyId)
Return a subproperty maker for the subpropertyId.
boolean
isInherited()
Default implementation of isInherited.
Property
make(PropertyList propertyList)
Return the default value.
Property
make(PropertyList propertyList, String value, FObj fo)
Create a Property object from an attribute specification.
Property
make(Property baseProperty, int subpropertyId, PropertyList propertyList, String value, FObj fo)
Make a property value for a compound property.
Property
makeNewProperty()
Create a new empty property.
void
setByShorthand(boolean setByShorthand)
Set the setByShorthand flag which only is applicable for subproperty makers.
void
setCorresponding(CorrespondingPropertyMaker corresponding)
Set the correspoding property information.
void
setDatatypeParser(ShorthandParser parser)
Set the shorthand datatype parser.
void
setDefault(String defaultValue)
Set the default value for this maker.
void
setDefault(String defaultValue, boolean contextDep)
Set the default value for this maker.
void
setInherited(boolean inherited)
Set the inherited flag.
void
setPercentBase(int percentBase)
Set the percent base identifier for this maker.
protected Property
setSubprop(Property baseProperty, int subpropertyId, Property subproperty)
Set a component in a compound property and return the modified compound property object.
void
useGeneric(PropertyMaker generic)
Copy all the values from the generic maker to this maker.

Field Details

contextDep

protected boolean contextDep
Indicates whether the property is context-dependant and therefore can't be cached.

corresponding

protected CorrespondingPropertyMaker corresponding
Maker for 'corresponding' properties *

defaultProperty

protected Property defaultProperty
default property *

defaultValue

protected String defaultValue
the default value for the maker

propId

protected int propId
the property ID

setByShorthand

protected boolean setByShorthand
Indicates whether the property is set through a shorthand.

Constructor Details

PropertyMaker

public PropertyMaker(int propId)
Construct an instance of a Property.Maker for the given property.
Parameters:
propId - The Constant ID of the property to be made.

Method Details

addEnum

public void addEnum(String constant,
                    Property value)
Add a enum constant.
Parameters:
constant - the enum constant
value - the Property value to use when the constant is specified

addKeyword

public void addKeyword(String keyword,
                       String value)
Add a keyword-equiv to the maker.
Parameters:
keyword - the keyword
value - the value to be used when the keyword is specified

addShorthand

public void addShorthand(PropertyMaker shorthand)
Add a shorthand to this maker. Only an Integer is added to the shorthands list. Later the Integers are replaced with references to the actual shorthand property makers.
Parameters:
shorthand - a property maker thar is that is checked for shorthand values.

addSubpropMaker

public void addSubpropMaker(PropertyMaker subproperty)
Add a subproperty to this maker.
Parameters:
subproperty - the PropertyMaker for the subproperty

checkEnumValues

protected Property checkEnumValues(String value)
For properties that contain enumerated values. This method should be overridden by subclasses.
Parameters:
value - the string containing the property value
Returns:
the Property encapsulating the enumerated equivalent of the input value

checkValueKeywords

protected String checkValueKeywords(String keyword)
Return a String to be parsed if the passed value corresponds to a keyword which can be parsed and used to initialize the property. For example, the border-width family of properties can have the initializers "thin", "medium", or "thick". The FOPropertyMapping file specifies a length value equivalent for these keywords, such as "0.5pt" for "thin".
Parameters:
keyword - the string value of property attribute.
Returns:
a String containing a parseable equivalent or null if the passed value isn't a keyword initializer for this Property

clone

public Object clone()
Return a clone of the makers. Used by useGeneric() to clone the subproperty makers of the generic compound makers.

compute

protected Property compute(PropertyList propertyList)
            throws PropertyException
Return a Property object representing the value of this property, based on other property values for this FO. A special case is properties which inherit the specified value, rather than the computed value.
Parameters:
propertyList - The PropertyList for the FO.
Returns:
Property A computed Property value or null if no rules are specified to compute the value.
Throws:
PropertyException - for invalid or inconsistent FO input

convertProperty

protected Property convertProperty(Property p,
                                   PropertyList propertyList,
                                   FObj fo)
            throws PropertyException
Return a Property object based on the passed Property object. This method is called if the Property object built by the parser isn't the right type for this property. It is overridden by subclasses.
Parameters:
p - The Property object return by the expression parser
propertyList - The PropertyList object being built for this FO.
fo - The parent FO for the FO whose property is being made.
Returns:
A Property of the correct type or null if the parsed value can't be converted to the correct type.
Throws:
PropertyException - for invalid or inconsistent FO input

convertPropertyDatatype

protected Property convertPropertyDatatype(Property p,
                                           PropertyList propertyList,
                                           FObj fo)
            throws PropertyException
For properties that have more than one legal way to be specified, this routine should be overridden to attempt to set them based upon the other methods. For example, colors may be specified using an RGB model, or they may be specified using an NCname.
Parameters:
p - property whose datatype should be converted
propertyList - collection of properties. (TODO: explain why this is needed, or remove it from the signature.)
fo - The parent FO for the FO whose property is being made. why this is needed, or remove it from the signature).
Returns:
an Property with the appropriate datatype used
Throws:
PropertyException - for invalid or inconsistent input

convertShorthandProperty

public Property convertShorthandProperty(PropertyList propertyList,
                                         Property prop,
                                         FObj fo)
            throws PropertyException
Converts a shorthand property
Parameters:
propertyList - the propertyList for which to convert
prop - the shorthand property
fo - ...
Returns:
the converted property
Throws:
PropertyException - ...

findProperty

public Property findProperty(PropertyList propertyList,
                             boolean tryInherit)
            throws PropertyException
If the property is a relative property with a corresponding absolute value specified, the absolute value is used. This is also true of the inheritance priority (I think...) If the property is an "absolute" property and it isn't specified, then we try to compute it from the corresponding relative property: this happens in computeProperty.
Parameters:
propertyList - the applicable property list
tryInherit - true if inherited properties should be examined.
Returns:
the property value
Throws:
PropertyException - if there is a problem evaluating the property

get

public Property get(int subpropertyId,
                    PropertyList propertyList,
                    boolean tryInherit,
                    boolean tryDefault)
            throws PropertyException
Return the property on the current FlowObject. Depending on the passed flags, this will try to compute it based on other properties, or if it is inheritable, to return the inherited value. If all else fails, it returns the default value.
Parameters:
subpropertyId - The subproperty id of the property being retrieved. Is 0 when retrieving a base property.
propertyList - The PropertyList object being built for this FO.
tryInherit - true if inherited properties should be examined.
tryDefault - true if the default value should be returned.
Returns:
the property value
Throws:
PropertyException - if there is a problem evaluating the property

getName

public String getName()
Returns:
the name of the property this maker is used for.

getPercentBase

public PercentBase getPercentBase(PropertyList pl)
            throws PropertyException
This is used to handle properties specified as a percentage of some "base length", such as the content width of their containing box. Overridden by subclasses which allow percent specifications. See the documentation on properties.xsl for details.
Parameters:
pl - the PropertyList containing the property. (TODO: explain what this is used for, or remove it from the signature.)
Returns:
an object implementing the PercentBase interface.
Throws:
PropertyException - if there is a problem while evaluating the base property

getPropId

public int getPropId()
Returns:
the name of the property for this Maker

getShorthand

public Property getShorthand(PropertyList propertyList)
            throws PropertyException
For properties that can be set by shorthand properties, this method should return the Property, if any, that is parsed from any shorthand properties that affect this property. This method expects to be overridden by subclasses. For example, the border-right-width property could be set implicitly from the border shorthand property, the border-width shorthand property, or the border-right shorthand property. This method should be overridden in the appropriate subclass to check each of these, and return an appropriate border-right-width Property object.
Parameters:
propertyList - the collection of properties to be considered
Returns:
the Property, if found, the correspons, otherwise, null
Throws:
PropertyException - if there is a problem while evaluating the shorthand

getSubprop

public Property getSubprop(Property p,
                           int subpropertyId)
Return a property value for the given component of a compound property.
Parameters:
p - A property value for a compound property type such as SpaceProperty.
subpropertyId - the id of the component whose value is to be returned. NOTE: this is only to ease porting when calls are made to PropertyList.get() using a component name of a compound property, such as get("space.optimum"). The recommended technique is: get("space").getOptimum(). Overridden by property maker subclasses which handle compound properties.
Returns:
the Property containing the subproperty

getSubpropMaker

public PropertyMaker getSubpropMaker(int subpropertyId)
Return a subproperty maker for the subpropertyId.
Parameters:
subpropertyId - The subpropertyId of the maker.
Returns:
The subproperty maker.

isInherited

public boolean isInherited()
Default implementation of isInherited.
Returns:
A boolean indicating whether this property is inherited.

make

public Property make(PropertyList propertyList)
            throws PropertyException
Return the default value.
Parameters:
propertyList - The PropertyList object being built for this FO.
Returns:
the Property object corresponding to the parameters
Throws:
PropertyException - for invalid or inconsisten FO input

make

public Property make(PropertyList propertyList,
                     String value,
                     FObj fo)
            throws PropertyException
Create a Property object from an attribute specification.
Parameters:
propertyList - The PropertyList object being built for this FO.
value - The attribute value.
fo - The parent FO for the FO whose property is being made.
Returns:
The initialized Property object.
Throws:
PropertyException - for invalid or inconsistent FO input

make

public Property make(Property baseProperty,
                     int subpropertyId,
                     PropertyList propertyList,
                     String value,
                     FObj fo)
            throws PropertyException
Make a property value for a compound property. If the property value is already partially initialized, this method will modify it.
Parameters:
baseProperty - The Property object representing the compound property, for example: SpaceProperty.
subpropertyId - The Constants ID of the subproperty (component) whose value is specified.
propertyList - The propertyList being built.
value - the value of the
fo - The parent FO for the FO whose property is being made.
Returns:
baseProperty (or if null, a new compound property object) with the new subproperty added
Throws:
PropertyException - for invalid or inconsistent FO input

makeNewProperty

public Property makeNewProperty()
Create a new empty property. Must be overriden in compound subclasses.
Returns:
a new instance of the Property for which this is a maker.

setByShorthand

public void setByShorthand(boolean setByShorthand)
Set the setByShorthand flag which only is applicable for subproperty makers. It should be true for the subproperties which must be assigned a value when the base property is assigned a attribute value directly.
Parameters:
setByShorthand - true if this subproperty must be set when the base property is set

setCorresponding

public void setCorresponding(CorrespondingPropertyMaker corresponding)
Set the correspoding property information.
Parameters:
corresponding - a corresponding maker where the isForcedCorresponding and compute methods are delegated to.

setDatatypeParser

public void setDatatypeParser(ShorthandParser parser)
Set the shorthand datatype parser.
Parameters:
parser - the shorthand parser

setDefault

public void setDefault(String defaultValue)
Set the default value for this maker.
Parameters:
defaultValue - the default value.

setDefault

public void setDefault(String defaultValue,
                       boolean contextDep)
Set the default value for this maker.
Parameters:
defaultValue - the default value
contextDep - true when the value context dependent and must not be cached.

setInherited

public void setInherited(boolean inherited)
Set the inherited flag.
Parameters:
inherited - true if this is an inherited property

setPercentBase

public void setPercentBase(int percentBase)
Set the percent base identifier for this maker.
Parameters:
percentBase - the percent base (ex. LengthBase.FONTSIZE)

setSubprop

protected Property setSubprop(Property baseProperty,
                              int subpropertyId,
                              Property subproperty)
Set a component in a compound property and return the modified compound property object. This default implementation returns the original base property without modifying it. It is overridden by property maker subclasses which handle compound properties.
Parameters:
baseProperty - The Property object representing the compound property, such as SpaceProperty.
subpropertyId - The ID of the component whose value is specified.
subproperty - A Property object holding the specified value of the component to be set.
Returns:
The modified compound property object.

useGeneric

public void useGeneric(PropertyMaker generic)
Copy all the values from the generic maker to this maker.
Parameters:
generic - a generic property maker.

Copyright 1999-2008 The Apache Software Foundation. All Rights Reserved.