From: William Victor Mote Date: Sat, 30 Nov 2002 07:24:10 +0000 (+0000) Subject: white-space and line-ending fixes X-Git-Tag: Alt-Design-integration-base~287 X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=64b3c5ede295343029ded69bb7f035ddd47409f3;p=xmlgraphics-fop.git white-space and line-ending fixes git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@195684 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/design/alt.design/AbsolutePosition.png.xml b/docs/design/alt.design/AbsolutePosition.png.xml index 7b2cde0bc..57af6a926 100644 --- a/docs/design/alt.design/AbsolutePosition.png.xml +++ b/docs/design/alt.design/AbsolutePosition.png.xml @@ -9,7 +9,7 @@ Exp pbw $ --> AbsolutePosition diagram + email="pbwest@powerup.com.au"/> diff --git a/docs/design/alt.design/BorderCommonStyle.png.xml b/docs/design/alt.design/BorderCommonStyle.png.xml index f57865bc2..a81ba9cae 100644 --- a/docs/design/alt.design/BorderCommonStyle.png.xml +++ b/docs/design/alt.design/BorderCommonStyle.png.xml @@ -8,7 +8,7 @@ BorderCommonStyle diagram + email="pbwest@powerup.com.au"/> diff --git a/docs/design/alt.design/PropNames.png.xml b/docs/design/alt.design/PropNames.png.xml index 829509d8b..c851da75e 100644 --- a/docs/design/alt.design/PropNames.png.xml +++ b/docs/design/alt.design/PropNames.png.xml @@ -9,7 +9,7 @@ ..fo.PropNames diagram + email="pbwest@powerup.com.au"/> diff --git a/docs/design/alt.design/Properties.png.xml b/docs/design/alt.design/Properties.png.xml index f2a53578c..749ac651e 100644 --- a/docs/design/alt.design/Properties.png.xml +++ b/docs/design/alt.design/Properties.png.xml @@ -9,7 +9,7 @@ ..fo.Properties diagram + email="pbwest@powerup.com.au"/> diff --git a/docs/design/alt.design/PropertyConsts.png.xml b/docs/design/alt.design/PropertyConsts.png.xml index 73d509cae..69f71afcc 100644 --- a/docs/design/alt.design/PropertyConsts.png.xml +++ b/docs/design/alt.design/PropertyConsts.png.xml @@ -8,7 +8,7 @@ ..fo.PropertyConsts diagram + email="pbwest@powerup.com.au"/> diff --git a/docs/design/alt.design/VerticalAlign.png.xml b/docs/design/alt.design/VerticalAlign.png.xml index 6ff21bb00..61c60b354 100644 --- a/docs/design/alt.design/VerticalAlign.png.xml +++ b/docs/design/alt.design/VerticalAlign.png.xml @@ -9,7 +9,7 @@ VerticalAlign diagram + email="pbwest@powerup.com.au"/> diff --git a/docs/design/alt.design/alt.properties.xml b/docs/design/alt.design/alt.properties.xml index 6a3f7be3b..51caba702 100644 --- a/docs/design/alt.design/alt.properties.xml +++ b/docs/design/alt.design/alt.properties.xml @@ -14,153 +14,153 @@ - The following discussion focusses on the relationship between - Flow Objects in the Flow Object tree, and properties. There - is no (or only passing) discussion of the relationship between - properties and traits, and by extension, between properties - and the Area tree. The discussion is illustrated with some - pseudo-UML diagrams. + The following discussion focusses on the relationship between + Flow Objects in the Flow Object tree, and properties. There + is no (or only passing) discussion of the relationship between + properties and traits, and by extension, between properties + and the Area tree. The discussion is illustrated with some + pseudo-UML diagrams.

- Property handling is complex and expensive. Varying numbers of - properties apply to individual Flow Objects - (FOs) in the FO - tree but any property may effectively be - assigned a value on any element of the tree. If that property - is inheritable, its defined value will then be available to - any children of the defining FO. + Property handling is complex and expensive. Varying numbers of + properties apply to individual Flow Objects + (FOs) in the FO + tree but any property may effectively be + assigned a value on any element of the tree. If that property + is inheritable, its defined value will then be available to + any children of the defining FO.

- (XSL 1.0 Rec) 5.1.4 Inheritance - ...The inheritable properties can be placed on any formatting - object. + (XSL 1.0 Rec) 5.1.4 Inheritance + ...The inheritable properties can be placed on any formatting + object.

- Even if the value is not inheritable, it may be accessed by - its children through the inherit keyword or the - from-parent() core function, and potentially by - any of its descendents through the - from-nearest-specified-value() core function. + Even if the value is not inheritable, it may be accessed by + its children through the inherit keyword or the + from-parent() core function, and potentially by + any of its descendents through the + from-nearest-specified-value() core function.

- In addition to the assigned values of properties, almost every - property has an initial value which is used - when no value has been assigned. + In addition to the assigned values of properties, almost every + property has an initial value which is used + when no value has been assigned.

- The difficulty and expense of handling properties comes from - this univeral inheritance possibility. The list of properties - which are assigned values on any particular FO - element will not generally be large, but a current value is - required for each property which applies to the FO - being processed. + The difficulty and expense of handling properties comes from + this univeral inheritance possibility. The list of properties + which are assigned values on any particular FO + element will not generally be large, but a current value is + required for each property which applies to the FO + being processed.

- The environment from which these values may be selected - includes, for each FO, for each applicable property, - the value assigned on this FO, the value which - applied to the parent of this FO, the nearest value - specified on an ancestor of this element, and the initial - value of the property. + The environment from which these values may be selected + includes, for each FO, for each applicable property, + the value assigned on this FO, the value which + applied to the parent of this FO, the nearest value + specified on an ancestor of this element, and the initial + value of the property.

-

- This determines the minimum set of properties and associated - property value assignments that is necessary for the - processing of any individual FO. Implicit in this - set is the set of properties and associated values, - effective on the current FO, that were assigned on - that FO. -

-

- This minimum requirement - the initial value, the - nearest ancestor specified value, the parent computed value - and the value assigned to the current element - - suggests a stack implementation. -

+

+ This determines the minimum set of properties and associated + property value assignments that is necessary for the + processing of any individual FO. Implicit in this + set is the set of properties and associated values, + effective on the current FO, that were assigned on + that FO. +

+

+ This minimum requirement - the initial value, the + nearest ancestor specified value, the parent computed value + and the value assigned to the current element - + suggests a stack implementation. +

-

- One possibility is to push to the stack only a minimal set - of required elements. When a value is assigned, the - relevant form or forms of that value (specified, computed, - actual) are pushed onto the stack. As long as each - FO maintains a list of the properties which were - assigned from it, the value can be popped when the focus of - FO processing retreats back up the FO tree. -

-

- The complication is that, for elements which are not - automatically inherited, when an FO is encountered - which does not assign a value to the - property, the initial value must either be already at the - top of the stack or be pushed onto the stack. -

-

- As a first approach, the simplest procedure may be to push a - current value onto the stack for every element - initial - values for non-inherited properties and the parental value - otherwise. Then perform any processing of assigned values. - This simplifies program logic at what is hopefully a small - cost in memory and processing time. It may be tuned in a - later iteration. -

- -

- Initial attempts at this implementation have used - LinkedLists as the stacks, on the assumption - that -

- - -
  • random access would not be required
    • -
  • - pushing and popping of list elements requires nearly - constant (low) time -
    • -
  • no penalty for first addition to an empty list
    • -
  • efficient access to both bottom and top of stack
    • -     -

    - However, it may be required to perform stack access - operations from an arbitrary place on the stack, in which - case it would probably be more efficient to use - ArrayLists instead. -

    -     +

    + One possibility is to push to the stack only a minimal set + of required elements. When a value is assigned, the + relevant form or forms of that value (specified, computed, + actual) are pushed onto the stack. As long as each + FO maintains a list of the properties which were + assigned from it, the value can be popped when the focus of + FO processing retreats back up the FO tree. +

    +

    + The complication is that, for elements which are not + automatically inherited, when an FO is encountered + which does not assign a value to the + property, the initial value must either be already at the + top of the stack or be pushed onto the stack. +

    +

    + As a first approach, the simplest procedure may be to push a + current value onto the stack for every element - initial + values for non-inherited properties and the parental value + otherwise. Then perform any processing of assigned values. + This simplifies program logic at what is hopefully a small + cost in memory and processing time. It may be tuned in a + later iteration. +

    + +

    + Initial attempts at this implementation have used + LinkedLists as the stacks, on the assumption + that +

    + + +
  • random access would not be required
    • +
  • + pushing and popping of list elements requires nearly + constant (low) time +
    • +
  • no penalty for first addition to an empty list
    • +
  • efficient access to both bottom and top of stack
    • +     +

    + However, it may be required to perform stack access + operations from an arbitrary place on the stack, in which + case it would probably be more efficient to use + ArrayLists instead. +

    +     -

    - An individual stack would contain values for a particular - property, and the context of the stack is the property class - as a whole. The property instances would be represented by - the individual values on the stack. If properties are to be - represented as instantiations of the class, the stack - entries would presumably be references to, or at least - referenced from, individual property objects. However, the - most important information about individual property - instances is the value assigned, and the relationship of - this property object to its ancestors and its descendents. - Other information would include the ownership of a property - instance by a particular FO, and, in the other - direction, the membership of the property in the set of - properties for which an FO has defined values. -

    -

    - In the presence of a stack, however, none of this required - information mandates the instantiation of properties. All - of the information mentioned so far can be effectively - represented by a stack position and a link to an - FO. If the property stack is maintained in - parallel with a stack of FOs, even that link is - implicit in the stack position. -

    +

    + An individual stack would contain values for a particular + property, and the context of the stack is the property class + as a whole. The property instances would be represented by + the individual values on the stack. If properties are to be + represented as instantiations of the class, the stack + entries would presumably be references to, or at least + referenced from, individual property objects. However, the + most important information about individual property + instances is the value assigned, and the relationship of + this property object to its ancestors and its descendents. + Other information would include the ownership of a property + instance by a particular FO, and, in the other + direction, the membership of the property in the set of + properties for which an FO has defined values. +

    +

    + In the presence of a stack, however, none of this required + information mandates the instantiation of properties. All + of the information mentioned so far can be effectively + represented by a stack position and a link to an + FO. If the property stack is maintained in + parallel with a stack of FOs, even that link is + implicit in the stack position. +

    - Next: property classes overview. + Next: property classes overview.

    diff --git a/docs/design/alt.design/classes-overview.xml b/docs/design/alt.design/classes-overview.xml index fab8e921d..d00762466 100644 --- a/docs/design/alt.design/classes-overview.xml +++ b/docs/design/alt.design/classes-overview.xml @@ -9,192 +9,192 @@ Property classes overview + email="pbwest@powerup.com.au"/> -

    - If individual properties can have a "virtual reality" on the - stack, where is the stack itself to be instantiated? One - possibility is to have the stacks as static - data structures within the individual property classes. - However, the reduction of individual property instances to - stack entries allows the possibility of further - virtualization of property classes. If the individual - properties can be represented by an integer, i.e. a - static final int, the set of individual - property stacks can be collected together into one array. - Where to put such an overall collection? Creating an - über-class to accommodate everything that applies to - property classes as a whole allows this array to be defined - as a static final something[]. -

    +

    + If individual properties can have a "virtual reality" on the + stack, where is the stack itself to be instantiated? One + possibility is to have the stacks as static + data structures within the individual property classes. + However, the reduction of individual property instances to + stack entries allows the possibility of further + virtualization of property classes. If the individual + properties can be represented by an integer, i.e. a + static final int, the set of individual + property stacks can be collected together into one array. + Where to put such an overall collection? Creating an + über-class to accommodate everything that applies to + property classes as a whole allows this array to be defined + as a static final something[]. +

    -

    - This approach has been taken for the experimental code. - Rather than simply creating a overall class containing - common elements of properties and acting as a superclass, - advantage has been taken of the facility for nesting of - top-level classes. All of the individual property classes - are nested within the Properties class. - This has advantages and disadvantages. -

    -
    -
    Disadvantages
    -
    - The file becomes extremely cumbersome. This can cause - problems with "intelligent" editors. E.g. - XEmacs syntax highlighting virtually grinds to a - halt with the current version of this file.

    - - Possible problems with IDEs. There may be speed problems - or even overflow problems with various IDEs. The current - version of this and related files had only been tried with - the [X]Emacs JDE environment, without difficulties - apart from the editor speed problems mentioned - above.

    - - Retro look and feel. Not the done Java thing.

    -
    -
    Advantages
    -
    - Everything to do with properties in the one place (more or - less.)

    - - Eliminates the need for a large part of the (sometimes) - necessary evil of code generation. The One Big File of - foproperties.xml, with its ancillary xsl, is - absorbed into the One Bigger File of - Properties.java. The huge advantage of this - is that it is Java. -
    -
    +

    + This approach has been taken for the experimental code. + Rather than simply creating a overall class containing + common elements of properties and acting as a superclass, + advantage has been taken of the facility for nesting of + top-level classes. All of the individual property classes + are nested within the Properties class. + This has advantages and disadvantages. +

    +
    +
    Disadvantages
    +
    + The file becomes extremely cumbersome. This can cause + problems with "intelligent" editors. E.g. + XEmacs syntax highlighting virtually grinds to a + halt with the current version of this file.

    + + Possible problems with IDEs. There may be speed problems + or even overflow problems with various IDEs. The current + version of this and related files had only been tried with + the [X]Emacs JDE environment, without difficulties + apart from the editor speed problems mentioned + above.

    + + Retro look and feel. Not the done Java thing.

    +
    +
    Advantages
    +
    + Everything to do with properties in the one place (more or + less.)

    + + Eliminates the need for a large part of the (sometimes) + necessary evil of code generation. The One Big File of + foproperties.xml, with its ancillary xsl, is + absorbed into the One Bigger File of + Properties.java. The huge advantage of this + is that it is Java. +
    +
    -

    - In fact, in order to keep the size of the file down to more - a more manageable level, the property information classes of - static data and methods have been split tentatively into - three: -

    -
    -
    -
    PropNames
    -
    - Contains an array, propertyNames, of the names of - all properties, and a set of enumeration constants, one - for each property name in the PropertyNames - array. These constants index the name of the properties - in propertyNames, and must be manually kept in - sync with the entries in the array. (This was the last of - the classes split off from the original single class; - hence the naming tiredness.) -

    -
    -
    PropertyConsts
    -
    - Contains two basic sets of data:
    - Property-indexed arrays and property set - definitions.

    - - Property-indexed arrays are elaborations - of the property indexing idea discussed in relation to the - arrays of property stacks. One of the arrays is

    - - public static final LinkedList[] - propertyStacks

    - - This is an array of stacks, implemented as - LinkedLists, one for each property.

    - - The other arrays provide indexed access to fields which - are, in most cases, common to all of the properties. An - exception is

    - - public static final Method[] - complexMethods

    - - which contains a reference to the method - complex() which is only defined for - properties which have complex value parsing requirements. - It is likely that a similar array will be defined for - properties which allow a value of auto.

    - - The property-indexed arrays are initialized by - static initializers in this class. The - PropNames class and - Properties - nested classes are scanned in order to obtain or derive - the data necessary for initialization.

    - - Property set definitions are - HashSets of properties (represented by - integer constants) which belong to each of the categories - of properties defined. They are used to simplify the - assignment of property sets to individual FOs. - Representative HashSets include - backgroundProps and - tableProps.

    -
    -
    Properties
    -
    -
    - This class contains only sets of constants for use by the - individual property classes, but it also importantly - serves as a container for all of the property classes, and - some convenience pseudo-property classes.

    - - Constants sets include:

    - - Datatype constants. A bitmap set of - integer constants over a possible range of 2^0 to 2^31 - (represented as -2147483648). E.g.
    - INTEGER = 1
    - ENUM = 524288

    - Some of the definitions are bit-ORed - combinations of the basic values. Used to set the - dataTypes field of the property - classes.

    - - Trait mapping constants. A bitmap set of - integer constants over a possible range of 2^0 to 2^31 - (represented as -2147483648), representing the manner in - which a property maps into a trait. Used to set - the traitMapping field of the property - classes.

    - - Initial value constants. A sequence of - integer constants representing the datatype of the initial - value of a property. Used to set the - initialValueType field of the property - classes.

    - - Inheritance value constants. A sequence - of integer constants representing the way in which the - property is normally inherited. Used to set the - inherited field of the property - classes.

    - - Nested property classes. The - Properties class serves as the holding pen for - all of the individual property classes, and for property - pseudo-classes which contain data common to a number of - actual properties, e.g. ColorCommon. -
    -
    +

    + In fact, in order to keep the size of the file down to more + a more manageable level, the property information classes of + static data and methods have been split tentatively into + three: +

    +
    +
    +
    PropNames
    +
    + Contains an array, propertyNames, of the names of + all properties, and a set of enumeration constants, one + for each property name in the PropertyNames + array. These constants index the name of the properties + in propertyNames, and must be manually kept in + sync with the entries in the array. (This was the last of + the classes split off from the original single class; + hence the naming tiredness.) +

    +
    +
    PropertyConsts
    +
    + Contains two basic sets of data:
    + Property-indexed arrays and property set + definitions.

    + + Property-indexed arrays are elaborations + of the property indexing idea discussed in relation to the + arrays of property stacks. One of the arrays is

    + + public static final LinkedList[] + propertyStacks

    + + This is an array of stacks, implemented as + LinkedLists, one for each property.

    + + The other arrays provide indexed access to fields which + are, in most cases, common to all of the properties. An + exception is

    + + public static final Method[] + complexMethods

    + + which contains a reference to the method + complex() which is only defined for + properties which have complex value parsing requirements. + It is likely that a similar array will be defined for + properties which allow a value of auto.

    + + The property-indexed arrays are initialized by + static initializers in this class. The + PropNames class and + Properties + nested classes are scanned in order to obtain or derive + the data necessary for initialization.

    + + Property set definitions are + HashSets of properties (represented by + integer constants) which belong to each of the categories + of properties defined. They are used to simplify the + assignment of property sets to individual FOs. + Representative HashSets include + backgroundProps and + tableProps.

    +
    +
    Properties
    +
    +
    + This class contains only sets of constants for use by the + individual property classes, but it also importantly + serves as a container for all of the property classes, and + some convenience pseudo-property classes.

    + + Constants sets include:

    + + Datatype constants. A bitmap set of + integer constants over a possible range of 2^0 to 2^31 + (represented as -2147483648). E.g.
    + INTEGER = 1
    + ENUM = 524288

    + Some of the definitions are bit-ORed + combinations of the basic values. Used to set the + dataTypes field of the property + classes.

    + + Trait mapping constants. A bitmap set of + integer constants over a possible range of 2^0 to 2^31 + (represented as -2147483648), representing the manner in + which a property maps into a trait. Used to set + the traitMapping field of the property + classes.

    + + Initial value constants. A sequence of + integer constants representing the datatype of the initial + value of a property. Used to set the + initialValueType field of the property + classes.

    + + Inheritance value constants. A sequence + of integer constants representing the way in which the + property is normally inherited. Used to set the + inherited field of the property + classes.

    + + Nested property classes. The + Properties class serves as the holding pen for + all of the individual property classes, and for property + pseudo-classes which contain data common to a number of + actual properties, e.g. ColorCommon. +
    +

    - Previous: alt.properties + Previous: alt.properties

    - Next: Properties classes + Next: Properties classes

    diff --git a/docs/design/alt.design/compound-properties.xml b/docs/design/alt.design/compound-properties.xml index 3b20add15..94d4b2580 100644 --- a/docs/design/alt.design/compound-properties.xml +++ b/docs/design/alt.design/compound-properties.xml @@ -14,204 +14,204 @@ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
    Property typeSectionInherited'inherit'
    <length-range>
    minimum
    optimum
    maximum
    block-progression-dimension7.14.1noyes
    inline-progression-dimension7.14.5noyes
    leader-length7.21.4yesyes
    <length-conditional>
    length
    conditionality
    border-after-width7.7.12noyes
    border-before-width7.7.9noyes
    border-end-width7.7.18noyes
    border-start-width7.7.15noyes
    padding-after7.7.32noyes
    padding-before7.7.31noyes
    padding-end7.7.34noyes
    padding-start7.7.33noyes
    <length-bp-ip-direction>
    block-progression-direction
    inline-progression-direction
    border-separation7.26.5yesyes
    <space>
    minimum
    optimum
    maximum
    precedence
    conditionality
    letter-spacing7.16.2yesyes
    line-height7.15.4yesyes
    space-after7.10.6noyes
    space-before7.10.5noyes
    space-end7.11.1noyes
    space-start7.11.2noyes
    word-spacing7.16.8yesyes
    <keep>
    within-line
    within-column
    within-page
    keep-together7.19.3yesyes
    keep-with-next7.19.4noyes
    keep-with-previous7.19.5noyes
    Property typeSectionInherited'inherit'
    <length-range>
    minimum
    optimum
    maximum
    block-progression-dimension7.14.1noyes
    inline-progression-dimension7.14.5noyes
    leader-length7.21.4yesyes
    <length-conditional>
    length
    conditionality
    border-after-width7.7.12noyes
    border-before-width7.7.9noyes
    border-end-width7.7.18noyes
    border-start-width7.7.15noyes
    padding-after7.7.32noyes
    padding-before7.7.31noyes
    padding-end7.7.34noyes
    padding-start7.7.33noyes
    <length-bp-ip-direction>
    block-progression-direction
    inline-progression-direction
    border-separation7.26.5yesyes
    <space>
    minimum
    optimum
    maximum
    precedence
    conditionality
    letter-spacing7.16.2yesyes
    line-height7.15.4yesyes
    space-after7.10.6noyes
    space-before7.10.5noyes
    space-end7.11.1noyes
    space-start7.11.2noyes
    word-spacing7.16.8yesyes
    <keep>
    within-line
    within-column
    within-page
    keep-together7.19.3yesyes
    keep-with-next7.19.4noyes
    keep-with-previous7.19.5noyes
     diff --git a/docs/design/alt.design/coroutines.xml b/docs/design/alt.design/coroutines.xml index 8d39d1730..b76eab1b8 100644 --- a/docs/design/alt.design/coroutines.xml +++ b/docs/design/alt.design/coroutines.xml @@ -15,103 +15,103 @@

    - All general page layout systems have to solve the same - fundamental problem: expressing a flow of text with its own - natural structure as a series of pages corresponding to the - physical and logical structure of the output medium. This - simple description disguises many complexities. Version 1.0 - of the Recommendation, in Section 3, Introduction to - Formatting , includes the following comments. + All general page layout systems have to solve the same + fundamental problem: expressing a flow of text with its own + natural structure as a series of pages corresponding to the + physical and logical structure of the output medium. This + simple description disguises many complexities. Version 1.0 + of the Recommendation, in Section 3, Introduction to + Formatting , includes the following comments.

    - [Formatting] comprises several steps, some of which depend on - others in a non-sequential way.
    ...and...
    - [R]efinement is not necessarily a straightforward, sequential - procedure, but may involve look-ahead, back-tracking, or - control-splicing with other processes in the formatter. + [Formatting] comprises several steps, some of which depend on + others in a non-sequential way.
    ...and...
    + [R]efinement is not necessarily a straightforward, sequential + procedure, but may involve look-ahead, back-tracking, or + control-splicing with other processes in the formatter.

    Section 3.1, Conceptual Procedure, includes:

    - The procedure works by processing formatting objects. Each - object, while being processed, may initiate processing in - other objects. While the objects are hierarchically - structured, the processing is not; processing of a given - object is rather like a co-routine which may pass control to - other processes, but pick up again later where it left off. + The procedure works by processing formatting objects. Each + object, while being processed, may initiate processing in + other objects. While the objects are hierarchically + structured, the processing is not; processing of a given + object is rather like a co-routine which may pass control to + other processes, but pick up again later where it left off. -

    - If one looks only at the flow side of the equation, it's - difficult to see what the problem might be. The ordering of - the elements of the flow is preserved in the area tree, and - where elements are in an hierarchical relationship in the - flow, they will generally be in an hierarchical relationship - in the area tree. In such circumstances, the recursive - processing of the flow seems quite natural. -

    -

    - The problem becomes more obvious when one thinks about the - imposition of an unrelated page structure over the - hierarchical structure of the document content. Take, e.g., - the processing of a nested flow structure which, at a certain - point, is scanning text and generating line-areas, nested - within other block areas and possibly other line areas. The - page fills in the middle of this process. Processing at the - lowest level in the tree must now suspend, immediately - following the production of the line-area which filled the - page. This same event, however, must also trigger the closing - and flushing to the area tree of every open area of which the last - line-area was a descendant. -

    -

    - Once all of these areas have been closed, some dormant process - or processes must wake up, flush the area sub-tree - representing the page, and open a new page sub-tree in the - area tree. Then the whole nested structure of flow objects - and area production must be re-activated, at the point in - processing at which the areas of the previous page were - finalised, but with the new page environment. The most - natural way of expressing the temporal relationship of these - processes is by means of co-routines. -

    -

    - Normal sub-routines (methods) display a hierarchical - relationship where process A suspends on invoking process B, - which on termination returns control to A which resumes from - the point of suspension. Co-routines instead have a parallel - relationship. Process A suspends on invoking process B, but - process B also suspends on returning control to process A. To - process B, this return of control appears to be an invocation - of process A. When process A subsequently invokes B and - suspends, B behaves as though its previous invocation of A has - returned, and it resumes from the point of that invocation. - So control bounces between the two, each one resuming where it - left off.

    - Figure 1 -

    -
    -

    - For example, think of a page-production method working on a - complex page-sequence-master. -

    - - void makePages(...) { - ... - while (pageSequence.hasNext()) { - ... - page = generateNextPage(...); - boolean over = flow.fillPage(page); - if (over) return; - } - } - -

    - The fillPage() method, when it fills a page, will - have unfinished business with the flow, which it will want to - resume at the next call; hence co-routines. One way to - implement them in Java is by threads synchronised on some - common argument-passing object. -

    +

    + If one looks only at the flow side of the equation, it's + difficult to see what the problem might be. The ordering of + the elements of the flow is preserved in the area tree, and + where elements are in an hierarchical relationship in the + flow, they will generally be in an hierarchical relationship + in the area tree. In such circumstances, the recursive + processing of the flow seems quite natural. +

    +

    + The problem becomes more obvious when one thinks about the + imposition of an unrelated page structure over the + hierarchical structure of the document content. Take, e.g., + the processing of a nested flow structure which, at a certain + point, is scanning text and generating line-areas, nested + within other block areas and possibly other line areas. The + page fills in the middle of this process. Processing at the + lowest level in the tree must now suspend, immediately + following the production of the line-area which filled the + page. This same event, however, must also trigger the closing + and flushing to the area tree of every open area of which the last + line-area was a descendant. +

    +

    + Once all of these areas have been closed, some dormant process + or processes must wake up, flush the area sub-tree + representing the page, and open a new page sub-tree in the + area tree. Then the whole nested structure of flow objects + and area production must be re-activated, at the point in + processing at which the areas of the previous page were + finalised, but with the new page environment. The most + natural way of expressing the temporal relationship of these + processes is by means of co-routines. +

    +

    + Normal sub-routines (methods) display a hierarchical + relationship where process A suspends on invoking process B, + which on termination returns control to A which resumes from + the point of suspension. Co-routines instead have a parallel + relationship. Process A suspends on invoking process B, but + process B also suspends on returning control to process A. To + process B, this return of control appears to be an invocation + of process A. When process A subsequently invokes B and + suspends, B behaves as though its previous invocation of A has + returned, and it resumes from the point of that invocation. + So control bounces between the two, each one resuming where it + left off.

    + Figure 1 +

    +
    +

    + For example, think of a page-production method working on a + complex page-sequence-master. +

    + + void makePages(...) { + ... + while (pageSequence.hasNext()) { + ... + page = generateNextPage(...); + boolean over = flow.fillPage(page); + if (over) return; + } + } + +

    + The fillPage() method, when it fills a page, will + have unfinished business with the flow, which it will want to + resume at the next call; hence co-routines. One way to + implement them in Java is by threads synchronised on some + common argument-passing object. +

    diff --git a/docs/design/alt.design/footnotes.xml b/docs/design/alt.design/footnotes.xml index 0e2ce4bba..a97f1aed6 100644 --- a/docs/design/alt.design/footnotes.xml +++ b/docs/design/alt.design/footnotes.xml @@ -15,122 +15,122 @@

    - Footnotes present difficulties for page layout primarily - because their point of invocation in the flow is different - from their point of appearance in the area tree. All of the - content lines of a footnote may appear on the same page as its - invocation point, all may appear on a following page, or the - lines may be split over a page or pages. (This characteristic - leads to another problem when a footnote overflows the last - page of flow content, but that difficulty will not be - discussed here.) This note considers some aspects of the - implementation of footnotes in a galley-based design. + Footnotes present difficulties for page layout primarily + because their point of invocation in the flow is different + from their point of appearance in the area tree. All of the + content lines of a footnote may appear on the same page as its + invocation point, all may appear on a following page, or the + lines may be split over a page or pages. (This characteristic + leads to another problem when a footnote overflows the last + page of flow content, but that difficulty will not be + discussed here.) This note considers some aspects of the + implementation of footnotes in a galley-based design.

    -

    - In the structure described in the introduction to FOP galleys, - footnotes would be pre-processed as galleys themselves, but - they would remain attached as subtrees to their points of - invocation in the main text. Allocation to a - footnote-reference-area would only occur in the resolution - to Area nodes. -

    -

    - When footnotes are introduced, the communication between - galleys and layout manager, as mentioned above, would be - affected. The returned information would two b-p-d values: - the primary line-area b-p-d impact and the footnote b-p-d - impact. The distinction is necessary for two reasons; to - alert the layout manager to the first footnote of the page, - and because the footnote b-p-d will always impact the - main-reference-area b-p-d, whereas the primary inline-area - may not, e.g. in the case of multiple span-areas. -

    +

    + In the structure described in the introduction to FOP galleys, + footnotes would be pre-processed as galleys themselves, but + they would remain attached as subtrees to their points of + invocation in the main text. Allocation to a + footnote-reference-area would only occur in the resolution + to Area nodes. +

    +

    + When footnotes are introduced, the communication between + galleys and layout manager, as mentioned above, would be + affected. The returned information would two b-p-d values: + the primary line-area b-p-d impact and the footnote b-p-d + impact. The distinction is necessary for two reasons; to + alert the layout manager to the first footnote of the page, + and because the footnote b-p-d will always impact the + main-reference-area b-p-d, whereas the primary inline-area + may not, e.g. in the case of multiple span-areas. +

    - - A possible method for multi-column layout and balancing - with footnotes, using a galley-based approach. - -

    - This note assumes a galley, as discussed elsewhere, flowing text with - footnotes and possibly other blocks into a possibly - multi-column area. The logic of flowing into multiple - columns is trivially applied to a single column. The galley - is manipulated within the context of the layout - tree. -

    -

    - Associated with the galley are two sets of data. - One contains the maps of all "natural" break-points and - the of all hyphenation break-points. This set is - constructed at the time of construction of the galley and - is a constant for a given galley. The second contains - dynamic data which represents one possible attempt to lay - out the galley. There may be multiple sets of such data - to reflect varying attempts. The data of this set are, - essentially, representations of line-areas, with the supporting - information necessary to determine these line-areas. -

    -

    - The line-area data includes the boundaries within the - galley of each line-area, the boundaries of each column - and the boundaries of the "page", or main area. When a - line-area boundary occurs at a hyphenation point, a - "virtual hyphen" is assumed and accounted for in the - i-p-d. As mentioned, individual footnote galleys will - hang from the parent galley. The associated data of the - footnote galleys is similar: a once-only break-points map, - and one or more line-area maps. No column boundaries are - required, but a page boundary is required at the end of - the last footnote or where a footnote breaks across a page - boundary. -

    -

    - A number of b-p-d values are also maintained. For each - line-area, the b-p-d, the main area b-p-d increment, the - footnote b-p-d increment and the footnote's page-related - b-p-d increment are required. The main-area b-p-d - increments for any particular line-area are dependent on - the column position of the line-area. Total b-p-d's are - also kept: total footnote b-p-d, total main area b-p-d, - and totals for each column.

    - Figure 1 Columns before first footnote. -

    -
    + + A possible method for multi-column layout and balancing + with footnotes, using a galley-based approach. + +

    + This note assumes a galley, as discussed elsewhere, flowing text with + footnotes and possibly other blocks into a possibly + multi-column area. The logic of flowing into multiple + columns is trivially applied to a single column. The galley + is manipulated within the context of the layout + tree. +

    +

    + Associated with the galley are two sets of data. + One contains the maps of all "natural" break-points and + the of all hyphenation break-points. This set is + constructed at the time of construction of the galley and + is a constant for a given galley. The second contains + dynamic data which represents one possible attempt to lay + out the galley. There may be multiple sets of such data + to reflect varying attempts. The data of this set are, + essentially, representations of line-areas, with the supporting + information necessary to determine these line-areas. +

    +

    + The line-area data includes the boundaries within the + galley of each line-area, the boundaries of each column + and the boundaries of the "page", or main area. When a + line-area boundary occurs at a hyphenation point, a + "virtual hyphen" is assumed and accounted for in the + i-p-d. As mentioned, individual footnote galleys will + hang from the parent galley. The associated data of the + footnote galleys is similar: a once-only break-points map, + and one or more line-area maps. No column boundaries are + required, but a page boundary is required at the end of + the last footnote or where a footnote breaks across a page + boundary. +

    +

    + A number of b-p-d values are also maintained. For each + line-area, the b-p-d, the main area b-p-d increment, the + footnote b-p-d increment and the footnote's page-related + b-p-d increment are required. The main-area b-p-d + increments for any particular line-area are dependent on + the column position of the line-area. Total b-p-d's are + also kept: total footnote b-p-d, total main area b-p-d, + and totals for each column.

    + Figure 1 Columns before first footnote. +

    +
    -

    - Figure 2 Adding a line area with first - footnote. -

    -
    -

    - Columns are balanced dynamically in the galley preliminary - layout. While the galley retains its basic linear - structure, the accompanying data structures accomplish - column distribution and balancing. As each line-area is - added, the columns are re-balanced. N.B. - This re-balancing involves only some of the dynamic data - associated with the participating galley(s). The data - structures associating breakpoints with the beginning and - end of individual line areas does not change in - re-balancing; only the association of line-area with column, - and, possibly, the various impact values for each line-area. -

    - Figure 3 Adding a line area with next - footnote. -

    -
    +

    + Figure 2 Adding a line area with first + footnote. +

    +
    +

    + Columns are balanced dynamically in the galley preliminary + layout. While the galley retains its basic linear + structure, the accompanying data structures accomplish + column distribution and balancing. As each line-area is + added, the columns are re-balanced. N.B. + This re-balancing involves only some of the dynamic data + associated with the participating galley(s). The data + structures associating breakpoints with the beginning and + end of individual line areas does not change in + re-balancing; only the association of line-area with column, + and, possibly, the various impact values for each line-area. +

    + Figure 3 Adding a line area with next + footnote. +

    +
    - To be developed. + To be developed. diff --git a/docs/design/alt.design/galleys.xml b/docs/design/alt.design/galleys.xml index e26f2755d..0175a583e 100644 --- a/docs/design/alt.design/galleys.xml +++ b/docs/design/alt.design/galleys.xml @@ -15,195 +15,195 @@ -

    - Jeffrey H. Kingston, in The - Design and Implementation of the Lout Document Formatting - Language Section 5, describes the - galley abstraction which he implemented in - Lout. A document to be formatted is a stream of - text and symbols, some of which are receptive - symbols. The output file is the first receptive - symbol; the formatting document is the first galley. The - archetypical example of a receptive symbol is - @FootPlace and its corresponding galley - definition, @FootNote. -

    -

    - Each galley should be thought of as a concurrent process, and - each is associated with a semaphore (or synchronisation - object.) Galleys are free to "promote" components into - receptive targets as long as

    -
      -
    • - an appropriate target has been encountered in the file, -
      • -
    • - the component being promoted contains no unresolved galley - targets itself, and -
      • -
    • - there is sufficient room for the galley component at the - target. -
      • -
    -

    - If these conditions are not met, the galley blocks on its - semaphore. When conditions change so that further progress - may be possible, the semaphore is signalled. Note that the - galleys are a hierarchy, and that the processing and - promotion of galley contents happens bottom-up. -

    +

    + Jeffrey H. Kingston, in The + Design and Implementation of the Lout Document Formatting + Language Section 5, describes the + galley abstraction which he implemented in + Lout. A document to be formatted is a stream of + text and symbols, some of which are receptive + symbols. The output file is the first receptive + symbol; the formatting document is the first galley. The + archetypical example of a receptive symbol is + @FootPlace and its corresponding galley + definition, @FootNote. +

    +

    + Each galley should be thought of as a concurrent process, and + each is associated with a semaphore (or synchronisation + object.) Galleys are free to "promote" components into + receptive targets as long as

    +
      +
    • + an appropriate target has been encountered in the file, +
      • +
    • + the component being promoted contains no unresolved galley + targets itself, and +
      • +
    • + there is sufficient room for the galley component at the + target. +
      • +
    +

    + If these conditions are not met, the galley blocks on its + semaphore. When conditions change so that further progress + may be possible, the semaphore is signalled. Note that the + galleys are a hierarchy, and that the processing and + promotion of galley contents happens bottom-up. +

    -

    - It is essential to note that galleys are self-managing; they - are effectively layout bots which require only a - receptive area. If a galley fills a receptive area (say, at - the completion of a page), the galley will wait on its - semaphore, and will remain stalled until a new receptive - area is uncovered in the continued processing (say, as the - filled page is flushed to output and a new empty page is - generated.) -

    -

    - Difficulties with this approach become evident when there - are mutual dependencies between receptive areas which - require negotiation between the respective galleys, and, in - some cases, arbitrary deadlock breaking when there is no - clear-cut resolution to conflicting demands. Footnote - processing and side floats are examples. A thornier example - is table column layout in auto mode, where the - column widths are determined by the contents. In - implementing galleys in FOP, these difficulties must be - taken into account, and some solutions proposed. -

    -

    - Galleys model the whole of the process of creating the final - formatted output; the document as a whole is regarded as a - galley which flushes in to the output file. -

    +

    + It is essential to note that galleys are self-managing; they + are effectively layout bots which require only a + receptive area. If a galley fills a receptive area (say, at + the completion of a page), the galley will wait on its + semaphore, and will remain stalled until a new receptive + area is uncovered in the continued processing (say, as the + filled page is flushed to output and a new empty page is + generated.) +

    +

    + Difficulties with this approach become evident when there + are mutual dependencies between receptive areas which + require negotiation between the respective galleys, and, in + some cases, arbitrary deadlock breaking when there is no + clear-cut resolution to conflicting demands. Footnote + processing and side floats are examples. A thornier example + is table column layout in auto mode, where the + column widths are determined by the contents. In + implementing galleys in FOP, these difficulties must be + taken into account, and some solutions proposed. +

    +

    + Galleys model the whole of the process of creating the final + formatted output; the document as a whole is regarded as a + galley which flushes in to the output file. +

    - -

    - This proposal for implementing galleys in FOP makes use of a - layout tree. As with the layout managers already - proposed, the layout tree acts as a bridge between the FO Tree and the Area Tree. If the elements of - the FO Tree are FO nodes, and the elements of the Area Tree - are Area nodes, representing areas to be drawn on the output - medium, the elements of the layout tree are galley - nodes and area tree fragments. - The area tree fragments are the final stages of the - resolution of the galleys; the output of the galleys will be - inserted directly into the Area Tree. The tree structure - makes it clear that the whole of the formatting process in - FOP, under this model, is a hierarchical series of galleys. - The dynamic data comes from fo:flow and fo:static-content, - and the higher-level receptive areas are derived from the - layout-master-set. -

    + +

    + This proposal for implementing galleys in FOP makes use of a + layout tree. As with the layout managers already + proposed, the layout tree acts as a bridge between the FO Tree and the Area Tree. If the elements of + the FO Tree are FO nodes, and the elements of the Area Tree + are Area nodes, representing areas to be drawn on the output + medium, the elements of the layout tree are galley + nodes and area tree fragments. + The area tree fragments are the final stages of the + resolution of the galleys; the output of the galleys will be + inserted directly into the Area Tree. The tree structure + makes it clear that the whole of the formatting process in + FOP, under this model, is a hierarchical series of galleys. + The dynamic data comes from fo:flow and fo:static-content, + and the higher-level receptive areas are derived from the + layout-master-set. +

    -

    - Galleys are processed in two basic processing environments: -

    - -

    - The galley at set-up is provided with both an - inline-progression-dimension (i-p-d) and - a block-progression-dimension (b-p-d). - In this case, no further intervention is necessary to lay - out the galley. The galley has the possibility of laying - itself out, creating all necessary area nodes. This does - not preclude the possibility that some children of this - galley will not be able to be so directly laid out, and - will fall into the second category. -

    -

    - While the option of "automatic" layout exists, to use - such a method would relinquish the possibility of - monitoring the results of such layout and performing - fine-tuning. -

    -     - -

    - The galley cannot immediately be provided with an i-p-d - ior a b-p-d. This will occur in some of the difficult - cases mentioned earlier. In these cases, the parent - galley acts as a layout manager, similar to the sense used - in another - discussion. The children, lacking full receptive - area dimensions, will proceed with galley pre-processing, - a procedure which will, of necessity, be followed - recursively by all of its children down to the atomic - elements of the galley. These atomic elements are the - individual fo:character nodes and images of fixed - dimensions. -

    -     +

    + Galleys are processed in two basic processing environments: +

    + +

    + The galley at set-up is provided with both an + inline-progression-dimension (i-p-d) and + a block-progression-dimension (b-p-d). + In this case, no further intervention is necessary to lay + out the galley. The galley has the possibility of laying + itself out, creating all necessary area nodes. This does + not preclude the possibility that some children of this + galley will not be able to be so directly laid out, and + will fall into the second category. +

    +

    + While the option of "automatic" layout exists, to use + such a method would relinquish the possibility of + monitoring the results of such layout and performing + fine-tuning. +

    +     + +

    + The galley cannot immediately be provided with an i-p-d + ior a b-p-d. This will occur in some of the difficult + cases mentioned earlier. In these cases, the parent + galley acts as a layout manager, similar to the sense used + in another + discussion. The children, lacking full receptive + area dimensions, will proceed with galley pre-processing, + a procedure which will, of necessity, be followed + recursively by all of its children down to the atomic + elements of the galley. These atomic elements are the + individual fo:character nodes and images of fixed + dimensions. +

    +     - -

    - Galley pre-processing involves the spatial resolution of - objects from the flows to the greatest extent possible - without information on the dimensions of the target area. - Line-areas have a block progression dimension which is - determined by their contents. To achieve full generality in - layouts of indeterminate dimensions, the contents of - line-areas should be laid out as though their inline - progression dimension were limited only by their content. - In terms of inline-areas, galleys would process text and - resolve the dimensions of included images. Text would be - collected into runs with the same alignment - characteristics. In the process, all possible "natural" and - hyphenation break-points can be determined. Where a - line-area contains mixed fonts or embedded images, the b-p-d - of the individual line-areas which are eventually stacked - will, in general, depend on the line break points, but the - advantage of this approach is that such actual selections - can be backed out and new break points selected with a - minimum of re-calculation. This can potentially occur - whenever a first attempt at page layout is backed out. -

    - Figure 1 -

    -
    -

    - Once this pre-processing has been achieved, it is - envisaged that a layout manager might make requests to the - galley of its ability to fill an area of a given - inline-progression-dimension. A positive response would - be accompanied by the block-progression-dimension. The - other possibilities are a partial fill, which would also - require b-p-d data, and a failure due to insufficient - i-p-d, in which case the minimum i-p-d requirement would - be returned. Note that decisions about the - actual dimensions of line-areas to be filled can be - deferred until all options have been tested. -

    -

    - The other primary form of information provided by a - pre-processed galley is its minimum and maximum i-p-d, so - that decisions can be made by the parent on the spacing of - table columns. Apart from information requests, - higher-level processes can either make requests of the - galleys for chunks of nominated sizes, or simply provide the - galley with an i-p-d and b-p-d, which will trigger the - flushing of the galley components into Area nodes. Until - they have flushed, the galleys must be able to respond to a - sequence of information requests, more or less in the manner - of a request iterator, and separately manage the flushing of - objects into the area tree. The purpose of the "request - iterator" would be to support "incremental" information - requests like getNextBreakPosition. -

    + +

    + Galley pre-processing involves the spatial resolution of + objects from the flows to the greatest extent possible + without information on the dimensions of the target area. + Line-areas have a block progression dimension which is + determined by their contents. To achieve full generality in + layouts of indeterminate dimensions, the contents of + line-areas should be laid out as though their inline + progression dimension were limited only by their content. + In terms of inline-areas, galleys would process text and + resolve the dimensions of included images. Text would be + collected into runs with the same alignment + characteristics. In the process, all possible "natural" and + hyphenation break-points can be determined. Where a + line-area contains mixed fonts or embedded images, the b-p-d + of the individual line-areas which are eventually stacked + will, in general, depend on the line break points, but the + advantage of this approach is that such actual selections + can be backed out and new break points selected with a + minimum of re-calculation. This can potentially occur + whenever a first attempt at page layout is backed out. +

    + Figure 1 +

    +
    +

    + Once this pre-processing has been achieved, it is + envisaged that a layout manager might make requests to the + galley of its ability to fill an area of a given + inline-progression-dimension. A positive response would + be accompanied by the block-progression-dimension. The + other possibilities are a partial fill, which would also + require b-p-d data, and a failure due to insufficient + i-p-d, in which case the minimum i-p-d requirement would + be returned. Note that decisions about the + actual dimensions of line-areas to be filled can be + deferred until all options have been tested. +

    +

    + The other primary form of information provided by a + pre-processed galley is its minimum and maximum i-p-d, so + that decisions can be made by the parent on the spacing of + table columns. Apart from information requests, + higher-level processes can either make requests of the + galleys for chunks of nominated sizes, or simply provide the + galley with an i-p-d and b-p-d, which will trigger the + flushing of the galley components into Area nodes. Until + they have flushed, the galleys must be able to respond to a + sequence of information requests, more or less in the manner + of a request iterator, and separately manage the flushing of + objects into the area tree. The purpose of the "request + iterator" would be to support "incremental" information + requests like getNextBreakPosition. +

    diff --git a/docs/design/alt.design/intro.xml b/docs/design/alt.design/intro.xml index 39fdc1e64..0af32f20e 100644 --- a/docs/design/alt.design/intro.xml +++ b/docs/design/alt.design/intro.xml @@ -13,71 +13,71 @@ - +

    - This section of the FOP web site contains notes on approaches - to an alternative design for FOP. The individual documents - here are fragmentary, being notes of particular issues, - without an overall framework as yet. + This section of the FOP web site contains notes on approaches + to an alternative design for FOP. The individual documents + here are fragmentary, being notes of particular issues, + without an overall framework as yet.

    - The main aims of this redesign effort are: + The main aims of this redesign effort are:

      -
    • full conformance with the Recommendation
      • -
    • increased performance
      • -
    • reduced memory footprint
      • -
    • no limitation on the size of files
      • +
    • full conformance with the Recommendation
      • +
    • increased performance
      • +
    • reduced memory footprint
      • +
    • no limitation on the size of files

    - In order to achieve these aims, the primary areas - of design interest are: + In order to achieve these aims, the primary areas + of design interest are:

      -
    • - Representing properties, for most purposes, as integers. -
      • -
    • - Distributing FOP processing over a number of threads with - single-point downstream communication and flow control by - means of traditional producer/consumer queues. The threads - so far under consideration are: -
        -
      • XML parser
        • -
      • FO tree builder
        • -
      • layout engine
        • -
      • Area tree builder
        • -
      -
      • -
    • - Representing trees with explicit Tree objects, rather than - as implicit relationships among other objects. -
      • -
    • - Caching integrated into the tree node access methods. -
      • +
    • + Representing properties, for most purposes, as integers. +
      • +
    • + Distributing FOP processing over a number of threads with + single-point downstream communication and flow control by + means of traditional producer/consumer queues. The threads + so far under consideration are: +
        +
      • XML parser
        • +
      • FO tree builder
        • +
      • layout engine
        • +
      • Area tree builder
        • +
      +
      • +
    • + Representing trees with explicit Tree objects, rather than + as implicit relationships among other objects. +
      • +
    • + Caching integrated into the tree node access methods. +
    -

    - The ALT DESIGN effort is not taking place on the - main line of development, represented by the HEAD - tag on the CVS trunk. The source is available via the - FOP_0-20-0_Alt-Design tag. This code has only a crude, - non-Ant build environment, and is expected only to - compile at this stage. Only the parser stage and the first - stage of FO tree building is present. However, the first - example of producer/consumer binding is working, the Tree - class with inner Tree.Node and inner - Tree.Node.iterators classes are available and - working. Property handling is quite advanced, and is likely - to be almost complete some time in July, 2002. -

    -

    - Only Peter - West is working on the ALT DESIGN sub-project. -

    +

    + The ALT DESIGN effort is not taking place on the + main line of development, represented by the HEAD + tag on the CVS trunk. The source is available via the + FOP_0-20-0_Alt-Design tag. This code has only a crude, + non-Ant build environment, and is expected only to + compile at this stage. Only the parser stage and the first + stage of FO tree building is present. However, the first + example of producer/consumer binding is working, the Tree + class with inner Tree.Node and inner + Tree.Node.iterators classes are available and + working. Property handling is quite advanced, and is likely + to be almost complete some time in July, 2002. +

    +

    + Only Peter + West is working on the ALT DESIGN sub-project. +

    diff --git a/docs/design/alt.design/keeps.xml b/docs/design/alt.design/keeps.xml index 9c428c46c..3ff533924 100644 --- a/docs/design/alt.design/keeps.xml +++ b/docs/design/alt.design/keeps.xml @@ -15,94 +15,94 @@

    - The layout galleys and the - layout tree - which is their context have been discussed elsewhere. Here we - discuss a possible method of implementing keeps and breaks - within the context of layout galleys and the layout tree. + The layout galleys and the + layout tree + which is their context have been discussed elsewhere. Here we + discuss a possible method of implementing keeps and breaks + within the context of layout galleys and the layout tree.

    -

    - Breaks may be handled by inserting a column- or page-break - pseudo-object into the galley stream. For break-before, the - object would be inserted before the area in which the flow - object, to which the property is attached, is leading. If - the flow object is leading in no ancestor context, the - pseudo-object is inserted before the object itself. - Corresponding considerations apply for break-after. - Selection of the position for these objects will be further - examined in the discussion on keeps. -

    +

    + Breaks may be handled by inserting a column- or page-break + pseudo-object into the galley stream. For break-before, the + object would be inserted before the area in which the flow + object, to which the property is attached, is leading. If + the flow object is leading in no ancestor context, the + pseudo-object is inserted before the object itself. + Corresponding considerations apply for break-after. + Selection of the position for these objects will be further + examined in the discussion on keeps. +

    -

    - Conceptually, all keeps can be represented by a - keep-together pseudo-area. The keep-together property - itself is expressed during layout by wrapping all of the - generated areas in a keep-together area. Keep-with-previous - on formatting object A becomes a keep-together area spanning - the first non-blank normal area leaf node, L, generated by A - or its offspring, and the last non-blank normal area leaf - node preceding L in the area tree. Likewise, keep-with-next - on formatting object A becomes a keep-together area spanning - the last non-blank normal area leaf node, L, generated by A - or its offspring, and the first non-blank normal area leaf - node following L in the area tree. -
    TODO REWORK THIS for block vs inline -

    -

    - The obvious problem with this arrangement is that the - keep-together area violate the hierarachical arrangement of - the layout tree. They form a concurrent structure focussed - on the leaf nodes. This seems to be the essential problem - of handling keep-with-(previous/next); that it cuts across - the otherwise tree-structured flow of processing. Such - problems are endemic in page layout. -

    -

    - In any case, it seems that the relationships between areas - that are of interest in keep processing need some form of - direct expression, parallel to the layout tree itself. - Restricting ourselves too block-level elements, and looking - only at the simple block stacking cases, we get a diagram - like the attached PNG. In order to track the relationships - through the tree, we need four sets of links. -

    -

    - Figure 1 -

    - -
    -

    - The three basic links are: -

    -
      - -
    • Leading edge to leading edge of first normal child.
      • -
    • Trailing edge to leading edge of next normal - sibling.
      • -
    • Trailing edge to trailing edge of parent.
      • -
    -

    - Superimposed on the basic links are bridging links which - span adjacent sets of links. These spanning links are the - tree violators, and give direct access to the areas which - are of interest in keep processing. They could be - implemented as double-linked lists, either within the layout - tree nodes or as separate structures. Gaps in the spanning - links are joined by simply reproducing the single links, as - in the diagram. The whole layout tree for a page is - effectively threaded in order of interest, as far as keeps - are concerned. -

    -

    - The bonus of this structure is that it looks like a superset - of the stacking constraints. It gives direct access to all - sets of adjacent edges and sets of edges whose space - specifiers need to be resolved. Fences can be easily enough - detected during the process of space resolution. -

    +

    + Conceptually, all keeps can be represented by a + keep-together pseudo-area. The keep-together property + itself is expressed during layout by wrapping all of the + generated areas in a keep-together area. Keep-with-previous + on formatting object A becomes a keep-together area spanning + the first non-blank normal area leaf node, L, generated by A + or its offspring, and the last non-blank normal area leaf + node preceding L in the area tree. Likewise, keep-with-next + on formatting object A becomes a keep-together area spanning + the last non-blank normal area leaf node, L, generated by A + or its offspring, and the first non-blank normal area leaf + node following L in the area tree. +
    TODO REWORK THIS for block vs inline +

    +

    + The obvious problem with this arrangement is that the + keep-together area violate the hierarachical arrangement of + the layout tree. They form a concurrent structure focussed + on the leaf nodes. This seems to be the essential problem + of handling keep-with-(previous/next); that it cuts across + the otherwise tree-structured flow of processing. Such + problems are endemic in page layout. +

    +

    + In any case, it seems that the relationships between areas + that are of interest in keep processing need some form of + direct expression, parallel to the layout tree itself. + Restricting ourselves too block-level elements, and looking + only at the simple block stacking cases, we get a diagram + like the attached PNG. In order to track the relationships + through the tree, we need four sets of links. +

    +

    + Figure 1 +

    + +
    +

    + The three basic links are: +

    +
      + +
    • Leading edge to leading edge of first normal child.
      • +
    • Trailing edge to leading edge of next normal + sibling.
      • +
    • Trailing edge to trailing edge of parent.
      • +
    +

    + Superimposed on the basic links are bridging links which + span adjacent sets of links. These spanning links are the + tree violators, and give direct access to the areas which + are of interest in keep processing. They could be + implemented as double-linked lists, either within the layout + tree nodes or as separate structures. Gaps in the spanning + links are joined by simply reproducing the single links, as + in the diagram. The whole layout tree for a page is + effectively threaded in order of interest, as far as keeps + are concerned. +

    +

    + The bonus of this structure is that it looks like a superset + of the stacking constraints. It gives direct access to all + sets of adjacent edges and sets of edges whose space + specifiers need to be resolved. Fences can be easily enough + detected during the process of space resolution. +

    diff --git a/docs/design/alt.design/properties-classes.xml b/docs/design/alt.design/properties-classes.xml index 216f2b9e0..6f652fd4d 100644 --- a/docs/design/alt.design/properties-classes.xml +++ b/docs/design/alt.design/properties-classes.xml @@ -15,125 +15,125 @@
    + top-level classes"/> -

    - Given the intention that individual properties have only a - virtual instantiation in the arrays of - PropertyConsts, these classes are intended to - remain as repositories of static data and methods. The name - of each property is entered in the - PropNames.propertyNames array of - Strings, and each has a unique integer constant - defined, corresponding to the offset of the property name in - that array. -

    - -
    -
    final int dataTypes
    -
    - This field defines the allowable data types which may be - assigned to the property. The value is chosen from the - data type constants defined in Properties, and - may consist of more than one of those constants, - bit-ORed together. -
    -
    final int traitMapping
    -
    - This field defines the mapping of properties to traits - in the Area tree. The value is chosen from the - trait mapping constants defined in Properties, - and may consist of more than one of those constants, - bit-ORed together. -
    -
    final int initialValueType
    -
    - This field defines the data type of the initial value - assigned to the property. The value is chosen from the - initial value type constants defined in - Properties. -
    -
    final int inherited
    -
    - This field defines the kind of inheritance applicable to - the property. The value is chosen from the inheritance - constants defined in Properties. -
    -
    -     - -
    -
    Enumeration types
    -
    - final String[] enums
    - This array contains the NCName text - values of the enumeration. In the current - implementation, it always contains a null value at - enum[0].

    +

    + Given the intention that individual properties have only a + virtual instantiation in the arrays of + PropertyConsts, these classes are intended to + remain as repositories of static data and methods. The name + of each property is entered in the + PropNames.propertyNames array of + Strings, and each has a unique integer constant + defined, corresponding to the offset of the property name in + that array. +

    + +
    +
    final int dataTypes
    +
    + This field defines the allowable data types which may be + assigned to the property. The value is chosen from the + data type constants defined in Properties, and + may consist of more than one of those constants, + bit-ORed together. +
    +
    final int traitMapping
    +
    + This field defines the mapping of properties to traits + in the Area tree. The value is chosen from the + trait mapping constants defined in Properties, + and may consist of more than one of those constants, + bit-ORed together. +
    +
    final int initialValueType
    +
    + This field defines the data type of the initial value + assigned to the property. The value is chosen from the + initial value type constants defined in + Properties. +
    +
    final int inherited
    +
    + This field defines the kind of inheritance applicable to + the property. The value is chosen from the inheritance + constants defined in Properties. +
    +
    +     + +
    +
    Enumeration types
    +
    + final String[] enums
    + This array contains the NCName text + values of the enumeration. In the current + implementation, it always contains a null value at + enum[0].

    - final String[] - enumValues
    When the number of - enumeration values is small, - enumValues is a reference to the - enums array.

    + final String[] + enumValues
    When the number of + enumeration values is small, + enumValues is a reference to the + enums array.

    - final HashMap - enumValues
    When the number of - enumeration values is larger, - enumValues is a - HashMap statically initialized to - contain the integer constant values corresponding to - each text value, indexed by the text - value.

    + final HashMap + enumValues
    When the number of + enumeration values is larger, + enumValues is a + HashMap statically initialized to + contain the integer constant values corresponding to + each text value, indexed by the text + value.

    - final int - enumeration-constants
    A - unique integer constant is defined for each of the - possible enumeration values.

    -
    -
    Many types: - final datatype - initialValue
    -
    - When the initial datatype does not have an implicit - initial value (as, for example, does type - AUTO) the initial value for the property is - assigned to this field. The type of this field will - vary according to the initialValueType - field. -
    -
    AUTO: PropertyValueList auto(property, - list)>
    -
    - When AUTO is a legal value type, the - auto() method must be defined in the property - class.
    - NOT YET IMPLEMENTED. -
    -
    COMPLEX: PropertyValueList complex(property, - list)>
    -
    - COMPLEX is specified as a value type when complex - conditions apply to the selection of a value type, or - when lists of values are acceptable. To process and - validate such a property value assignment, the - complex() method must be defined in the - property class. -
    -
    -     + final int + enumeration-constants
    A + unique integer constant is defined for each of the + possible enumeration values.

    +
    +
    Many types: + final datatype + initialValue
    +
    + When the initial datatype does not have an implicit + initial value (as, for example, does type + AUTO) the initial value for the property is + assigned to this field. The type of this field will + vary according to the initialValueType + field. +
    +
    AUTO: PropertyValueList auto(property, + list)>
    +
    + When AUTO is a legal value type, the + auto() method must be defined in the property + class.
    + NOT YET IMPLEMENTED. +
    +
    COMPLEX: PropertyValueList complex(property, + list)>
    +
    + COMPLEX is specified as a value type when complex + conditions apply to the selection of a value type, or + when lists of values are acceptable. To process and + validate such a property value assignment, the + complex() method must be defined in the + property class. +
    +
    +     -

    - The property pseudo-classes are classes, like - ColorCommon which contain values, particularly - enums, which are common to a number of actual - properties. -

    +

    + The property pseudo-classes are classes, like + ColorCommon which contain values, particularly + enums, which are common to a number of actual + properties. +

    - Previous: property classes overview. + Previous: property classes overview.

    diff --git a/docs/design/alt.design/propertyExpressions.xml b/docs/design/alt.design/propertyExpressions.xml index 0900a323a..7ebbcd4fe 100644 --- a/docs/design/alt.design/propertyExpressions.xml +++ b/docs/design/alt.design/propertyExpressions.xml @@ -15,214 +15,214 @@ - The following discussion of the experiments with alternate - property expression parsing is very much a work in progress, - and subject to sudden changes. + The following discussion of the experiments with alternate + property expression parsing is very much a work in progress, + and subject to sudden changes.

    - The parsing of property value expressions is handled by two - closely related classes: PropertyTokenizer and its - subclass, PropertyParser. - PropertyTokenizer, as the name suggests, handles - the tokenizing of the expression, handing tokens - back to its subclass, - PropertyParser. PropertyParser, in - turn, returns a PropertyValueList, a list of - PropertyValues. + The parsing of property value expressions is handled by two + closely related classes: PropertyTokenizer and its + subclass, PropertyParser. + PropertyTokenizer, as the name suggests, handles + the tokenizing of the expression, handing tokens + back to its subclass, + PropertyParser. PropertyParser, in + turn, returns a PropertyValueList, a list of + PropertyValues.

    - The tokenizer and parser rely in turn on the datatype - definition from the org.apache.fop.datatypes - package and the datatype static final int - constants from PropertyConsts. + The tokenizer and parser rely in turn on the datatype + definition from the org.apache.fop.datatypes + package and the datatype static final int + constants from PropertyConsts.

    -

    - The data types currently defined in - org.apache.fop.datatypes include: -

    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    Numbers and lengths
    Numeric - The fundamental numeric data type. Numerics of - various types are constructed by the classes listed - below. -
    - Constructor classes for Numeric
    AngleIn degrees(deg), gradients(grad) or - radians(rad)
    EmsRelative length in ems
    FrequencyIn hertz(Hz) or kilohertz(kHz)
    IntegerType -
    LengthIn centimetres(cm), millimetres(mm), - inches(in), points(pt), picas(pc) or pixels(px)
    Percentage -
    TimeIn seconds(s) or milliseconds(ms)
    Strings
    StringType - Base class for data types which result in a String. -
    Literal - A subclass of StringType for literals which - exceed the constraints of an NCName. -
    MimeType - A subclass of StringType for literals which - represent a mime type. -
    UriType - A subclass of StringType for literals which - represent a URI, as specified by the argument to - url(). -
    NCName - A subclass of StringType for literals which - meet the constraints of an NCName. -
    CountryAn RFC 3066/ISO 3166 country code.
    LanguageAn RFC 3066/ISO 639 language code.
    ScriptAn ISO 15924 script code.
    Enumerated types
    EnumType - An integer representing one of the tokens in a set of - enumeration values. -
    MappedEnumType - A subclass of EnumType. Maintains a - String with the value to which the associated - "raw" enumeration token maps. E.g., the - font-size enumeration value "medium" maps to - the String "12pt". -
    Colors
    ColorType - Maintains a four-element array of float, derived from - the name of a standard colour, the name returned by a - call to system-color(), or an RGB - specification. -
    Fonts
    FontFamilySet - Maintains an array of Strings containing a - prioritized list of possibly generic font family names. -
    Pseudo-types
    - A variety of pseudo-types have been defined as - convenience types for frequently appearing enumeration - token values, or for other special purposes. -
    Inherit - For values of inherit. -
    Auto - For values of auto. -
    None - For values of none. -
    Bool - For values of true/false. -
    FromNearestSpecified - Created to ensure that, when associated with - a shorthand, the from-nearest-specified-value() - core function is the sole component of the expression. -
    FromParent - Created to ensure that, when associated with - a shorthand, the from-parent() - core function is the sole component of the expression. -
    +

    + The data types currently defined in + org.apache.fop.datatypes include: +

    + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
    Numbers and lengths
    Numeric + The fundamental numeric data type. Numerics of + various types are constructed by the classes listed + below. +
    + Constructor classes for Numeric
    AngleIn degrees(deg), gradients(grad) or + radians(rad)
    EmsRelative length in ems
    FrequencyIn hertz(Hz) or kilohertz(kHz)
    IntegerType +
    LengthIn centimetres(cm), millimetres(mm), + inches(in), points(pt), picas(pc) or pixels(px)
    Percentage +
    TimeIn seconds(s) or milliseconds(ms)
    Strings
    StringType + Base class for data types which result in a String. +
    Literal + A subclass of StringType for literals which + exceed the constraints of an NCName. +
    MimeType + A subclass of StringType for literals which + represent a mime type. +
    UriType + A subclass of StringType for literals which + represent a URI, as specified by the argument to + url(). +
    NCName + A subclass of StringType for literals which + meet the constraints of an NCName. +
    CountryAn RFC 3066/ISO 3166 country code.
    LanguageAn RFC 3066/ISO 639 language code.
    ScriptAn ISO 15924 script code.
    Enumerated types
    EnumType + An integer representing one of the tokens in a set of + enumeration values. +
    MappedEnumType + A subclass of EnumType. Maintains a + String with the value to which the associated + "raw" enumeration token maps. E.g., the + font-size enumeration value "medium" maps to + the String "12pt". +
    Colors
    ColorType + Maintains a four-element array of float, derived from + the name of a standard colour, the name returned by a + call to system-color(), or an RGB + specification. +
    Fonts
    FontFamilySet + Maintains an array of Strings containing a + prioritized list of possibly generic font family names. +
    Pseudo-types
    + A variety of pseudo-types have been defined as + convenience types for frequently appearing enumeration + token values, or for other special purposes. +
    Inherit + For values of inherit. +
    Auto + For values of auto. +
    None + For values of none. +
    Bool + For values of true/false. +
    FromNearestSpecified + Created to ensure that, when associated with + a shorthand, the from-nearest-specified-value() + core function is the sole component of the expression. +
    FromParent + Created to ensure that, when associated with + a shorthand, the from-parent() + core function is the sole component of the expression. +
    -

    - The tokenizer returns one of the following token - values: -

    - +

    + The tokenizer returns one of the following token + values: +

    + static final int EOF = 0 ,NCNAME = 1 @@ -255,86 +255,86 @@ // never set as the end result of parsing a token. ,NO_UNIT = 27 ; - -

    - Most of these tokens are self-explanatory, but a few need - further comment. -

    -
    -
    AUTO
    -
    - Because of its frequency of occurrence, and the fact that - it is always the initial value for any property - which supports it, AUTO has been promoted into a - pseudo-type with its on datatype class. Therefore, it is - also reported as a token. -
    -
    NONE
    -
    - Similarly to AUTO, NONE has been promoted to a pseudo-type - because of its frequency. -
    -
    BOOL
    -
    - There is a de facto boolean type buried in the - enumeration types for many of the properties. It had been - specified as a type in its own right in this code. -
    -
    MIMETYPE
    -
    - The property content-type introduces this - complication. It can have two values of the form - content-type:mime-type - (e.g. content-type="content-type:xml/svg") or - namespace-prefix:prefix - (e.g. content-type="namespace-prefix:svg"). The - experimental code reduces these options to the payload - in each case: an NCName in the case of a - namespace prefix, and a MIMETYPE in the case of a - content-type specification. NCNames cannot - contain a "/". -
    -
    + +

    + Most of these tokens are self-explanatory, but a few need + further comment. +

    +
    +
    AUTO
    +
    + Because of its frequency of occurrence, and the fact that + it is always the initial value for any property + which supports it, AUTO has been promoted into a + pseudo-type with its on datatype class. Therefore, it is + also reported as a token. +
    +
    NONE
    +
    + Similarly to AUTO, NONE has been promoted to a pseudo-type + because of its frequency. +
    +
    BOOL
    +
    + There is a de facto boolean type buried in the + enumeration types for many of the properties. It had been + specified as a type in its own right in this code. +
    +
    MIMETYPE
    +
    + The property content-type introduces this + complication. It can have two values of the form + content-type:mime-type + (e.g. content-type="content-type:xml/svg") or + namespace-prefix:prefix + (e.g. content-type="namespace-prefix:svg"). The + experimental code reduces these options to the payload + in each case: an NCName in the case of a + namespace prefix, and a MIMETYPE in the case of a + content-type specification. NCNames cannot + contain a "/". +
    +
    -

    - The parser retuns a PropertyValueList, - necessary because of the possibility that a list of - PropertyValue elements may be returned from the - expressions of soem properties. -

    -

    - PropertyValueLists may contain - PropertyValues or other - PropertyValueLists. This latter provision is - necessitated for the peculiar case of of - text-shadow, which may contain whitespace separated - sublists of either two or three elements, separated from one - another by commas. To accommodate this peculiarity, comma - separated elements are added to the top-level list, while - whitespace separated values are always collected into - sublists to be added to the top-level list. -

    -

    - Other special cases include the processing of the core - functions from-parent() and - from-nearest-specified-value() when these - function calls are assigned to a shorthand property, or used - with a shorthand property name as an argument. In these - cases, the function call must be the sole component of the - expression. The pseudo-element classes - FromParent and - FromNearestSpecified are generated in these - circumstances so that an exception will be thrown if they - are involved in expression evaluation with other - components. (See Rec. Section 5.10.4 Property Value - Functions.) -

    -

    - The experimental code is a simple extension of the existing - parser code, which itself borrowed heavily from James - Clark's XT processor. -

    +

    + The parser retuns a PropertyValueList, + necessary because of the possibility that a list of + PropertyValue elements may be returned from the + expressions of soem properties. +

    +

    + PropertyValueLists may contain + PropertyValues or other + PropertyValueLists. This latter provision is + necessitated for the peculiar case of of + text-shadow, which may contain whitespace separated + sublists of either two or three elements, separated from one + another by commas. To accommodate this peculiarity, comma + separated elements are added to the top-level list, while + whitespace separated values are always collected into + sublists to be added to the top-level list. +

    +

    + Other special cases include the processing of the core + functions from-parent() and + from-nearest-specified-value() when these + function calls are assigned to a shorthand property, or used + with a shorthand property name as an argument. In these + cases, the function call must be the sole component of the + expression. The pseudo-element classes + FromParent and + FromNearestSpecified are generated in these + circumstances so that an exception will be thrown if they + are involved in expression evaluation with other + components. (See Rec. Section 5.10.4 Property Value + Functions.) +

    +

    + The experimental code is a simple extension of the existing + parser code, which itself borrowed heavily from James + Clark's XT processor. +

    diff --git a/docs/design/alt.design/spaces.xml b/docs/design/alt.design/spaces.xml index c9d56a057..80bb8c46d 100644 --- a/docs/design/alt.design/spaces.xml +++ b/docs/design/alt.design/spaces.xml @@ -15,162 +15,162 @@

    - The layout galleys and the - layout tree - which is the context of this discussion have been discussed - elsewhere. A previous document - discussed data structures which might facilitate the lining of - blocks necessary to implement keeps. Here we discuss the - similarities between the keep data structures and those - required to implement space-specifier resolution. + The layout galleys and the + layout tree + which is the context of this discussion have been discussed + elsewhere. A previous document + discussed data structures which might facilitate the lining of + blocks necessary to implement keeps. Here we discuss the + similarities between the keep data structures and those + required to implement space-specifier resolution.

    - - 4.3 Spaces and Conditionality - ... Space-specifiers occurring in sequence may interact with - each other. The constraint imposed by a sequence of - space-specifiers is computed by calculating for each - space-specifier its associated resolved space-specifier in - accordance with their conditionality and precedence. - - - 4.2.5 Stacking Constraints ... The intention of the - definitions is to identify areas at any level of the tree - which have only space between them. - -

    - The quotations above are pivotal to understanding the - complex discussion of spaces with which they are associated, - all of which exists to enable the resolution of adjacent - <space>s. It may be helpful to think of stacking - constraints as <space>s interaction or - <space>s stacking interaction. -

    + + 4.3 Spaces and Conditionality + ... Space-specifiers occurring in sequence may interact with + each other. The constraint imposed by a sequence of + space-specifiers is computed by calculating for each + space-specifier its associated resolved space-specifier in + accordance with their conditionality and precedence. + + + 4.2.5 Stacking Constraints ... The intention of the + definitions is to identify areas at any level of the tree + which have only space between them. + +

    + The quotations above are pivotal to understanding the + complex discussion of spaces with which they are associated, + all of which exists to enable the resolution of adjacent + <space>s. It may be helpful to think of stacking + constraints as <space>s interaction or + <space>s stacking interaction. +

    -

    - In the discussion of block stacking constraints in Section - 4.2.5, the notion of fence is introduced. For - block stacking constraints, a fence is defined as either a - reference-area boundary or a non-zero padding or border - specification. Fences, however, do not come into play - when determining the constraint between siblings. (See - Figure 1.) -

    -

    Figure 1

    -
    - - Figure 1 assumes a block-progression-direction of top to - bottom. - -

    - In Diagram a), block A has - non-zero padding and borders, in addition to non-zero - spaces. Note, however, that the space-after of A is - adjacent to the space-before of block P, so borders and - padding on these siblings have no impact on the interaction - of their <space>s. The stacking constraint A,P is - indicated by the red rectangle enclosing the space-after of - A and the space-before of P. -

    -

    - In Diagram b), block B is the - first block child of P. The stacking constraint A,P is as - before; the stacking constraint P,B is the space-before of - B, as indicated by the enclosing magenta rectangle. In this - case, however, the non-zero border of P prevents the - interaction of the A,P and P,B stacking constraints. There - is a fence-before P. The fence is notional; it has - no precise location, as the diagram may lead one to believe. -

    -

    - In Diagram c), because of the - zero-width borders and padding on block P, the fence-before - P is not present, and the adjacent <space>s of blocks - A, P and B are free to interact. In this case, the stacking - constraints A,P and P,B are as before, but now there is an - additional stacking constraint A,B, represented by the light - brown rectangle enclosing the other two stacking - constraints. -

    -

    - The other form of fence occurs when the parent block is a - reference area. Diagram b) of Figure - 2 illustrates this situation. Block C is a - reference-area, involving a 180 degree change of - block-progression-direction (BPD). In the diagram, the - inner edge of block C represents the content rectangle, with - its changed BPD. The thicker outer edge represents the - outer boundary of the padding, border and spaces of C. -

    -

    - While not every reference-area will change the - inline-progression-direction (IPD) and BPD of an area, no - attempt is made to discriminate these cases. A - reference-area always a fence. The fence comes into play in - analogous circumstances to non-zero borders or padding. - Space resolution between a reference area and its siblings - is not affected. -

    -

    - In the case of Diagram b), - these are block stacking constraints B,C and C,A. Within - the reference-area, bock stacing constraints C,D and E,C are - unaffected. However, the fence prevents block stacking - constraints such as B,E or D,A. When there is a change of - BPD, as Diagram b) makes - visually obvious, it is difficult to imagine which blocks - would have such a constraint, and what the ordering of the - constraint would be. -

    -

    Figure 2

    - -
    +

    + In the discussion of block stacking constraints in Section + 4.2.5, the notion of fence is introduced. For + block stacking constraints, a fence is defined as either a + reference-area boundary or a non-zero padding or border + specification. Fences, however, do not come into play + when determining the constraint between siblings. (See + Figure 1.) +

    +

    Figure 1

    +
    + + Figure 1 assumes a block-progression-direction of top to + bottom. + +

    + In Diagram a), block A has + non-zero padding and borders, in addition to non-zero + spaces. Note, however, that the space-after of A is + adjacent to the space-before of block P, so borders and + padding on these siblings have no impact on the interaction + of their <space>s. The stacking constraint A,P is + indicated by the red rectangle enclosing the space-after of + A and the space-before of P. +

    +

    + In Diagram b), block B is the + first block child of P. The stacking constraint A,P is as + before; the stacking constraint P,B is the space-before of + B, as indicated by the enclosing magenta rectangle. In this + case, however, the non-zero border of P prevents the + interaction of the A,P and P,B stacking constraints. There + is a fence-before P. The fence is notional; it has + no precise location, as the diagram may lead one to believe. +

    +

    + In Diagram c), because of the + zero-width borders and padding on block P, the fence-before + P is not present, and the adjacent <space>s of blocks + A, P and B are free to interact. In this case, the stacking + constraints A,P and P,B are as before, but now there is an + additional stacking constraint A,B, represented by the light + brown rectangle enclosing the other two stacking + constraints. +

    +

    + The other form of fence occurs when the parent block is a + reference area. Diagram b) of Figure + 2 illustrates this situation. Block C is a + reference-area, involving a 180 degree change of + block-progression-direction (BPD). In the diagram, the + inner edge of block C represents the content rectangle, with + its changed BPD. The thicker outer edge represents the + outer boundary of the padding, border and spaces of C. +

    +

    + While not every reference-area will change the + inline-progression-direction (IPD) and BPD of an area, no + attempt is made to discriminate these cases. A + reference-area always a fence. The fence comes into play in + analogous circumstances to non-zero borders or padding. + Space resolution between a reference area and its siblings + is not affected. +

    +

    + In the case of Diagram b), + these are block stacking constraints B,C and C,A. Within + the reference-area, bock stacing constraints C,D and E,C are + unaffected. However, the fence prevents block stacking + constraints such as B,E or D,A. When there is a change of + BPD, as Diagram b) makes + visually obvious, it is difficult to imagine which blocks + would have such a constraint, and what the ordering of the + constraint would be. +

    +

    Figure 2

    + +
    -

    - As complicated as space-specifiers become when - reference-areas are involved, the keep relationships as - described in the keeps document, are - unchanged. This is also illustrated in Figure 2. Diagram b) shows the - relative placement of blocks in the rendered output when a - 180 degree change of BPD occurs, with blocks D and E - stacking in the reverse direction to blocks B and C. - Diagram c) shows what happens when the page is too short to - accommodate the last block. D is still laid out, but E is - deferred to the next page. -

    -

    - Note that this rendering reality is expressed directly in - the area (and layout) tree view. Consequently, any keep - relationships expressed as links threading through the - layout tree will not need to be modified to account for - reference-area boundaries, as is the case with similar - space-specifier edge links. E.g., a keep-with-next - condition on block B can be resolved along the path of these - links (B->C->D) into a direct relationship of B->D, - irrespective of the reference-area boundary. -

    -

    - While the same relationships obviously hold when a reference - area induces no change of BPD, the situation for BPD changes - perpendicular to the parent's BPD may not be so clear. In - general, it probably does not make much sense to impose keep - conditions across such a boundary, but there seems to be - nothing preventing such conditions. They can be dealt with - in the same way, i.e., the next leaf block linked in area - tree order must be the next laid out. If a keep condition - is in place, an attempt must be made to meet it. A number - of unusual considerations would apply, e.g. the minimum - inline-progression-dimension of the first leaf block within - the reference-area as compared to the minimum IPD of - subsequent blocks, but prima facie, the essential - logic of the keeps links remains. -

    +

    + As complicated as space-specifiers become when + reference-areas are involved, the keep relationships as + described in the keeps document, are + unchanged. This is also illustrated in Figure 2. Diagram b) shows the + relative placement of blocks in the rendered output when a + 180 degree change of BPD occurs, with blocks D and E + stacking in the reverse direction to blocks B and C. + Diagram c) shows what happens when the page is too short to + accommodate the last block. D is still laid out, but E is + deferred to the next page. +

    +

    + Note that this rendering reality is expressed directly in + the area (and layout) tree view. Consequently, any keep + relationships expressed as links threading through the + layout tree will not need to be modified to account for + reference-area boundaries, as is the case with similar + space-specifier edge links. E.g., a keep-with-next + condition on block B can be resolved along the path of these + links (B->C->D) into a direct relationship of B->D, + irrespective of the reference-area boundary. +

    +

    + While the same relationships obviously hold when a reference + area induces no change of BPD, the situation for BPD changes + perpendicular to the parent's BPD may not be so clear. In + general, it probably does not make much sense to impose keep + conditions across such a boundary, but there seems to be + nothing preventing such conditions. They can be dealt with + in the same way, i.e., the next leaf block linked in area + tree order must be the next laid out. If a keep condition + is in place, an attempt must be made to meet it. A number + of unusual considerations would apply, e.g. the minimum + inline-progression-dimension of the first leaf block within + the reference-area as compared to the minimum IPD of + subsequent blocks, but prima facie, the essential + logic of the keeps links remains. +

    diff --git a/docs/design/alt.design/traits.xml b/docs/design/alt.design/traits.xml index c761af8d7..c983c371a 100644 --- a/docs/design/alt.design/traits.xml +++ b/docs/design/alt.design/traits.xml @@ -29,7 +29,7 @@ 4.2.2 Common Traits
    + >4.2.2 Common Traits
    7.27.7 writing-mode @@ -108,7 +108,7 @@ >5.6 Non-property Based Trait Generation - Set "true" on:
    + Set "true" on:
    simple-page-master
    title
    region-body
    @@ -121,7 +121,7 @@ table
    table-caption
    table-cell - + is-viewport-area @@ -232,7 +232,7 @@ overline-score-color - + through-score - + - - Other Indirectly Derived Traits - - - alignment-point - - + + Other Indirectly Derived Traits + + + alignment-point + + 4.1 Introduction - - - - alignment-baseline - - + + + + alignment-baseline + + 4.1 Introduction - - - - baseline-shift - - + + + + baseline-shift + + 4.1 Introduction - - - - dominant-baseline-identifier - - + + + + dominant-baseline-identifier + + 4.1 Introduction - - - - actual-baseline-table - - + + + + actual-baseline-table + + 4.1 Introduction - - - - start-intrusion-adjustment - - + + + + start-intrusion-adjustment + + 4.1 Introduction - - - - end-intrusion-adjustment - - + + + + end-intrusion-adjustment + + 4.1 Introduction - - - - page-number - - + + + + page-number + + 4.1 Introduction - - - - script - - + + + + script + + 4.1 Introduction - - + + diff --git a/docs/design/alt.design/user-agent-refs.xml b/docs/design/alt.design/user-agent-refs.xml index 19a199c68..2cca58beb 100644 --- a/docs/design/alt.design/user-agent-refs.xml +++ b/docs/design/alt.design/user-agent-refs.xml @@ -14,792 +14,792 @@ -

    - If the block-progression-dimension of the reference-area is - larger than that of the viewport-area and the overflow trait - for the reference-area is scroll, then the - inline-scroll-amount and block-scroll-amount are determined - by a scrolling mechanism, if any, provided by the - user agent. Otherwise, both are zero. -

    +

    + If the block-progression-dimension of the reference-area is + larger than that of the viewport-area and the overflow trait + for the reference-area is scroll, then the + inline-scroll-amount and block-scroll-amount are determined + by a scrolling mechanism, if any, provided by the + user agent. Otherwise, both are zero. +

    -

    - A computed value is in principle ready to be used, but a - user agent may not be able to make use of the value in a - given environment. For example, a user - agent may only be able to render borders with - integer pixel widths and may, therefore, have to adjust the - computed width to an integral number of media pixels. -

    +

    + A computed value is in principle ready to be used, but a + user agent may not be able to make use of the value in a + given environment. For example, a user + agent may only be able to render borders with + integer pixel widths and may, therefore, have to adjust the + computed width to an integral number of media pixels. +

    -

    - There is no XSL mechanism to specify a particular font; - instead, a selected font is chosen from the fonts available - to the User Agent based on a set of - selection criteria. The selection criteria are the following - font properties: "font-family", "font-style", - "font-variant", "font-weight", "font-stretch", and - "font-size", plus, for some formatting objects, one or more - characters. -

    +

    + There is no XSL mechanism to specify a particular font; + instead, a selected font is chosen from the fonts available + to the User Agent based on a set of + selection criteria. The selection criteria are the following + font properties: "font-family", "font-style", + "font-variant", "font-weight", "font-stretch", and + "font-size", plus, for some formatting objects, one or more + characters. +

    -

    - If the User Agent chooses a measurement for - a 'px' that does not match an integer number of device dots - in each axis it may produce undesirable effects... -

    +

    + If the User Agent chooses a measurement for + a 'px' that does not match an integer number of device dots + in each axis it may produce undesirable effects... +

    - -

    - The merge-property-values function returns a value of the - property whose name matches the argument, or if omitted - for the property for which the expression is being - evaluated. The value returned is the specified value on - the last fo:multi-property-set, of the parent - fo:multi-properties, that applies to the User - Agent state. If there is no such value, the - computed value of the parent fo:multi-properties is - returned... -

    -

    - The test for applicability of a User - Agent state is specified using the "active-state" - property. -

    -     + +

    + The merge-property-values function returns a value of the + property whose name matches the argument, or if omitted + for the property for which the expression is being + evaluated. The value returned is the specified value on + the last fo:multi-property-set, of the parent + fo:multi-properties, that applies to the User + Agent state. If there is no such value, the + computed value of the parent fo:multi-properties is + returned... +

    +

    + The test for applicability of a User + Agent state is specified using the "active-state" + property. +

    +     - -

    - The fo:multi-property-set is used to specify an - alternative set of formatting properties that, dependent - on a User Agent state, are applied to the - content. -

    -     - -

    - The fo:title formatting object is used to associate a - title with a given page-sequence. This title may be used - by an interactive User Agent to identify - the pages. For example, the content of the fo:title can be - formatted and displayed in a "title" window or in a "tool - tip". -

    -     + +

    + The fo:multi-property-set is used to specify an + alternative set of formatting properties that, dependent + on a User Agent state, are applied to the + content. +

    +     + +

    + The fo:title formatting object is used to associate a + title with a given page-sequence. This title may be used + by an interactive User Agent to identify + the pages. For example, the content of the fo:title can be + formatted and displayed in a "title" window or in a "tool + tip". +

    +     -

    - ... When pages are used with a User Agent - such as a Web browser, it is common that the each document - has only one page. The viewport used to view the page - determines the size of the page. When pages are placed on - non-interactive media, such as sheets of paper, pages - correspond to one or more of the surfaces of the paper. -

    +

    + ... When pages are used with a User Agent + such as a Web browser, it is common that the each document + has only one page. The viewport used to view the page + determines the size of the page. When pages are placed on + non-interactive media, such as sheets of paper, pages + correspond to one or more of the surfaces of the paper. +

    - -

    - ... This title may be used by an interactive User - Agent to identify the pages. -

    -     + +

    + ... This title may be used by an interactive User + Agent to identify the pages. +

    +     - -

    - The dimensions of the areas are determined by the font - metrics for the glyph. -

    -

    - When formatting an fo:character with a - "treat-as-word-space" value of "true", the User - Agent may use a different method for determining - the inline-progression-dimension of the area. -

    -     + +

    + The dimensions of the areas are determined by the font + metrics for the glyph. +

    +

    + When formatting an fo:character with a + "treat-as-word-space" value of "true", the User + Agent may use a different method for determining + the inline-progression-dimension of the area. +

    +     - -

    - Dynamic effects, whereby user actions (including - User Agent state) can influence the - behavior and/or representation of portions of a document, - can be achieved through the use of the formatting objects - included in this section: -

    -
      -
    • One-directional single-target links.
      • -
    • - The ability to switch between the display of two or more - formatting object subtrees. This can be used for, e.g., - expandable/collapsible table of contents, display of an - icon or a full table or graphic. -
      • -
    • - The ability to switch between different property values, - such as color or font-weight, depending on a - User Agent state, such as "hover". -
      • -
    -     + Objects"> + +

    + Dynamic effects, whereby user actions (including + User Agent state) can influence the + behavior and/or representation of portions of a document, + can be achieved through the use of the formatting objects + included in this section: +

    +
      +
    • One-directional single-target links.
      • +
    • + The ability to switch between the display of two or more + formatting object subtrees. This can be used for, e.g., + expandable/collapsible table of contents, display of an + icon or a full table or graphic. +
      • +
    • + The ability to switch between different property values, + such as color or font-weight, depending on a + User Agent state, such as "hover". +
      • +
    +     - -

    - ... There may be limits on how much space conditionally - generated areas can borrow from the - region-reference-area. It is left to the user - agent to decide these limits. -

    -

    - ... An interactive user agent may choose - to create "hot links" to the footnotes from the - footnote-citation, or create "hot links" to the - before-floats from an implicit citation, instead of - realizing conditional sub-regions. -

    -     + +

    + ... There may be limits on how much space conditionally + generated areas can borrow from the + region-reference-area. It is left to the user + agent to decide these limits. +

    +

    + ... An interactive user agent may choose + to create "hot links" to the footnotes from the + footnote-citation, or create "hot links" to the + before-floats from an implicit citation, instead of + realizing conditional sub-regions. +

    +     - -

    - ... The user agent may make its own - determination, after taking into account the intrusion - adjustments caused by one or more overlapping side-floats, - that the remaining space in the - inline-progression-direction is insufficient for the next - side-float or normal block-area. The user - agent may address this by causing the next - side-float or normal block-area to "clear" one of the - relevant side-floats, as described in the "clear" property - description, so the intrusion adjustment is sufficiently - reduced. Of the side-floats that could be cleared to meet - this constraint, the side-float that is actually cleared - must be the one whose after-edge is closest to the - before-edge of the parent reference-area. -

    -

    + +

    + ... The user agent may make its own + determination, after taking into account the intrusion + adjustments caused by one or more overlapping side-floats, + that the remaining space in the + inline-progression-direction is insufficient for the next + side-float or normal block-area. The user + agent may address this by causing the next + side-float or normal block-area to "clear" one of the + relevant side-floats, as described in the "clear" property + description, so the intrusion adjustment is sufficiently + reduced. Of the side-floats that could be cleared to meet + this constraint, the side-float that is actually cleared + must be the one whose after-edge is closest to the + before-edge of the parent reference-area. +

    +

    The user agent may determine sufficiency of space by using a fixed length, or by some heuristic such as whether an entire word fits into the available space, or by some combination, in order to handle text and images. -

    -     +

    +     - -

    - ... The second block-area and any additional block-areas - returned by an fo:footnote must be placed on the - immediately subsequent pages to the page containing the - first block-area returned by the fo:footnote, before any - other content is placed. If a subsequent page does not - contain a region-body, the user agent - must use the region-master of the last page that did - contain a region-body to hold the additional block-areas. -

    -     + +

    + ... The second block-area and any additional block-areas + returned by an fo:footnote must be placed on the + immediately subsequent pages to the page containing the + first block-area returned by the fo:footnote, before any + other content is placed. If a subsequent page does not + contain a region-body, the user agent + must use the region-master of the last page that did + contain a region-body to hold the additional block-areas. +

    +     -

    ...

    - -

    - 5. When the absolute-position is "fixed", the containing - block is defined by the nearest ancestor viewport area. If - there is no ancestor viewport area, the containing block - is defined by the user agent. -

    -     +

    ...

    + +

    + 5. When the absolute-position is "fixed", the containing + block is defined by the nearest ancestor viewport area. If + there is no ancestor viewport area, the containing block + is defined by the user agent. +

    +     -

    Initial: depends on user agent

    + '7.6.5 "pause-after" 7.6.6 "pause-before" 7.6.17 "voice-family"'> +

    Initial: depends on user agent

     - -

    - ... User agents may treat fixed as - scroll. However, it is recommended they interpret fixed - correctly, at least for the HTML and BODY elements, since - there is no way for an author to provide an image only for - those browsers that support fixed. -

    -     + +

    + ... User agents may treat fixed as + scroll. However, it is recommended they interpret fixed + correctly, at least for the HTML and BODY elements, since + there is no way for an author to provide an image only for + those browsers that support fixed. +

    +     - -

    - ... If border-before-width is specified using one of the - width keywords the .conditional component is set to - "discard" and the .length component to a User - Agent dependent length. -

    -     + +

    + ... If border-before-width is specified using one of the + width keywords the .conditional component is set to + "discard" and the .length component to a User + Agent dependent length. +

    +     - -

    - ... If an element's border color is not specified with a - "border" property, user agents must use - the value of the element's "color" property as the - computed value for the border color. -

    -     + +

    + ... If an element's border color is not specified with a + "border" property, user agents must use + the value of the element's "color" property as the + computed value for the border color. +

    +     -

    - Conforming HTML user agents may interpret - 'dotted', 'dashed', 'double', 'groove', 'ridge', 'inset', - and 'outset' to be 'solid'. -

    +

    + Conforming HTML user agents may interpret + 'dotted', 'dashed', 'double', 'groove', 'ridge', 'inset', + and 'outset' to be 'solid'. +

    - -

    - ... The interpretation of the first three values depends - on the user agent. -

    -     + +

    + ... The interpretation of the first three values depends + on the user agent. +

    +     -

    Initial: depends on user agent

    +

    Initial: depends on user agent

     -

    - There is no XSL mechanism to specify a particular font; - instead, a selected font is chosen from the fonts available - to the User Agent based on a set of - selection criteria. The selection criteria are the following - font properties: "font-family", "font-style", - "font-variant", "font-weight", "font-stretch", and - "font-size", plus, for some formatting objects, one or more - characters. -

    -

    - ... This fallback may be to seek a match using a - User Agent default "font-family", or it may - be a more elaborate fallback strategy where, for example, - "Helvetica" would be used as a fallback for "Univers". -

    -

    - If no match has been found for a particular character, there - is no selected font and the User Agent - should provide a visual indication that a character is not - being displayed (for example, using the 'missing character' - glyph). -

    +

    + There is no XSL mechanism to specify a particular font; + instead, a selected font is chosen from the fonts available + to the User Agent based on a set of + selection criteria. The selection criteria are the following + font properties: "font-family", "font-style", + "font-variant", "font-weight", "font-stretch", and + "font-size", plus, for some formatting objects, one or more + characters. +

    +

    + ... This fallback may be to seek a match using a + User Agent default "font-family", or it may + be a more elaborate fallback strategy where, for example, + "Helvetica" would be used as a fallback for "Univers". +

    +

    + If no match has been found for a particular character, there + is no selected font and the User Agent + should provide a visual indication that a character is not + being displayed (for example, using the 'missing character' + glyph). +

    - -

    - An <absolute-size> keyword refers to an entry in a - table of font sizes computed and kept by the user - agent. Possible values are:
    [ xx-small | - x-small | small | medium | large | x-large | xx-large ] -

    -     - -

    - A <relative-size> keyword is interpreted relative to - the table of font sizes and the font size of the parent - element. Possible values are:
    [ larger | smaller - ]
    For example, if the parent element has a font size - of "medium", a value of "larger" will make the font size - of the current element be "large". If the parent element's - size is not close to a table entry, the user - agent is free to interpolate between table - entries or round off to the closest one. The user - agent may have to extrapolate table values if the - numerical value goes beyond the keywords. -

    -     - -

    - A length value specifies an absolute font size (that is - independent of the user agent's font - table). -

    -     + +

    + An <absolute-size> keyword refers to an entry in a + table of font sizes computed and kept by the user + agent. Possible values are:
    [ xx-small | + x-small | small | medium | large | x-large | xx-large ] +

    +     + +

    + A <relative-size> keyword is interpreted relative to + the table of font sizes and the font size of the parent + element. Possible values are:
    [ larger | smaller + ]
    For example, if the parent element has a font size + of "medium", a value of "larger" will make the font size + of the current element be "large". If the parent element's + size is not close to a table entry, the user + agent is free to interpolate between table + entries or round off to the closest one. The user + agent may have to extrapolate table values if the + numerical value goes beyond the keywords. +

    +     + +

    + A length value specifies an absolute font size (that is + independent of the user agent's font + table). +

    +     - -

    - ... If a genuine small-caps font is not available, - user agents should simulate a small-caps - font... -

    -     + +

    + ... If a genuine small-caps font is not available, + user agents should simulate a small-caps + font... +

    +     - -

    - ... The association of other weights within a family to - the numerical weight values is intended only to preserve - the ordering of weights within that family. User - agents must map names to values in a way that - preserves visual order; a face mapped to a value must not - be lighter than faces mapped to lower values. There is no - guarantee on how a user agent will map - fonts within a family to weight values. However, the - following heuristics... -

    -     + +

    + ... The association of other weights within a family to + the numerical weight values is intended only to preserve + the ordering of weights within that family. User + agents must map names to values in a way that + preserves visual order; a face mapped to a value must not + be lighter than faces mapped to lower values. There is no + guarantee on how a user agent will map + fonts within a family to weight values. However, the + following heuristics... +

    +     - -

    - ... If the baseline-identifier does not exist in the - baseline-table for the glyph or other inline-area, then - the User Agent may either use heuristics - to determine where that missing baseline would be or may - use the dominant-baseline as a fallback. -

    -     + +

    + ... If the baseline-identifier does not exist in the + baseline-table for the glyph or other inline-area, then + the User Agent may either use heuristics + to determine where that missing baseline would be or may + use the dominant-baseline as a fallback. +

    +     - -

    - ... Because in most fonts the subscript position is - normally given relative to the "alphabetic" baseline, the - User Agent may compute the effective - position for sub/superscripts [sub: spec typo!] - when some other baseline is dominant. ... If there is no - applicable font data the User Agent may - use heuristics to determine the offset. -

    -     + +

    + ... Because in most fonts the subscript position is + normally given relative to the "alphabetic" baseline, the + User Agent may compute the effective + position for sub/superscripts [sub: spec typo!] + when some other baseline is dominant. ... If there is no + applicable font data the User Agent may + use heuristics to determine the offset. +

    +     -

    - ... If there is no baseline-table in the nominal font or if - the baseline-table lacks an entry for the desired baseline, - then the User Agent may use heuristics to - determine the position of the desired baseline. -

    +

    + ... If there is no baseline-table in the nominal font or if + the baseline-table lacks an entry for the desired baseline, + then the User Agent may use heuristics to + determine the position of the desired baseline. +

    - -

    - The User Agent is free to choose either - resampling, integer scaling, or any other scaling method. -

    -     - -

    - The User Agent should scale the image - such that each pixel in the original image is scaled to - the nearest integer number of device-pixels that yields an - image less-then-or-equal-to the image size derived from - the content-height, content-width, and scaling properties. -

    -     - -

    - The User Agent should resample the - supplied image to provide an image that fills the size - derived from the content-height, content-width, and - scaling properties. The user agent may - use any sampling method. -

    -     -

    - ... This is defined as a preference to allow the - user agent the flexibility to adapt to - device limitations and to accommodate over-constrained - situations involving min/max dimensions and scale factors. -

    + +

    + The User Agent is free to choose either + resampling, integer scaling, or any other scaling method. +

    +     + +

    + The User Agent should scale the image + such that each pixel in the original image is scaled to + the nearest integer number of device-pixels that yields an + image less-then-or-equal-to the image size derived from + the content-height, content-width, and scaling properties. +

    +     + +

    + The User Agent should resample the + supplied image to provide an image that fills the size + derived from the content-height, content-width, and + scaling properties. The user agent may + use any sampling method. +

    +     +

    + ... This is defined as a preference to allow the + user agent the flexibility to adapt to + device limitations and to accommodate over-constrained + situations involving min/max dimensions and scale factors. +

    -

    - ... The width of a replaced element's box is intrinsic and - may be scaled by the user agent if the - value of this property is different than 'auto'. -

    +

    + ... The width of a replaced element's box is intrinsic and + may be scaled by the user agent if the + value of this property is different than 'auto'. +

    - -

    - Tells user agents to set the computed - value to a "reasonable" value based on the font size of - the element. -

    -     -

    - ... When an element contains text that is rendered in more - than one font, user agents should determine - the "line-height" value according to the largest font size. -

    + +

    + Tells user agents to set the computed + value to a "reasonable" value based on the font size of + the element. +

    +     +

    + ... When an element contains text that is rendered in more + than one font, user agents should determine + the "line-height" value according to the largest font size. +

    -

    - ... The actual justification algorithm used is user - agent and written language dependent.
    - Conforming user agents may interpret the - value 'justify' as 'left' or 'right', depending on whether - the element's default writing direction is left-to-right or - right-to-left, respectively. -

    +

    + ... The actual justification algorithm used is user + agent and written language dependent.
    + Conforming user agents may interpret the + value 'justify' as 'left' or 'right', depending on whether + the element's default writing direction is left-to-right or + right-to-left, respectively. +

    -

    - ... User agents should render this - indentation as blank space. -

    +

    + ... User agents should render this + indentation as blank space. +

    - -

    - The spacing is the normal spacing for the current - font. This value allows the user agent to - alter the space between characters in order to justify - text. -

    -     - -

    - This value indicates inter-character space in addition to - the default space between characters. Values may be - negative, but there may be implementation-specific - limits. User agents may not further - increase or decrease the inter-character space in order to - justify text. -

    -     -

    - Character-spacing algorithms are user agent - dependent. Character spacing may also be influenced by - justification (see the "text-align" property).
    When the - resultant space between two characters is not the same as - the default space, user agents should not - use ligatures.
    Conforming user agents - may consider the value of the 'letter-spacing' property to - be 'normal'. -

    - -

    - ... For "normal": .optimum = "the normal spacing for the - current font" / 2, .maximum = auto, .minimum = auto, - .precedence = force, and .conditionality = discard. A - value of auto for a component implies that the limits are - User Agent specific. -

    -

    - ... The CSS statement that "Conforming user - agents may consider the value of the - 'letter-spacing' property to be 'normal'." does not apply - in XSL, if the User Agent implements the - "Extended" property set. -

    -

    - ... The algorithm for resolving the adjusted values - between word spacing and letter spacing is User - Agent dependent. -

    -     + +

    + The spacing is the normal spacing for the current + font. This value allows the user agent to + alter the space between characters in order to justify + text. +

    +     + +

    + This value indicates inter-character space in addition to + the default space between characters. Values may be + negative, but there may be implementation-specific + limits. User agents may not further + increase or decrease the inter-character space in order to + justify text. +

    +     +

    + Character-spacing algorithms are user agent + dependent. Character spacing may also be influenced by + justification (see the "text-align" property).
    When the + resultant space between two characters is not the same as + the default space, user agents should not + use ligatures.
    Conforming user agents + may consider the value of the 'letter-spacing' property to + be 'normal'. +

    + +

    + ... For "normal": .optimum = "the normal spacing for the + current font" / 2, .maximum = auto, .minimum = auto, + .precedence = force, and .conditionality = discard. A + value of auto for a component implies that the limits are + User Agent specific. +

    +

    + ... The CSS statement that "Conforming user + agents may consider the value of the + 'letter-spacing' property to be 'normal'." does not apply + in XSL, if the User Agent implements the + "Extended" property set. +

    +

    + ... The algorithm for resolving the adjusted values + between word spacing and letter spacing is User + Agent dependent. +

    +     -

    - ... If the element has no content or no text content (e.g., - the IMG element in HTML), user agents must - ignore this property. -

    - -

    - ... Conforming user agents are not - required to support this value. -

    -     +

    + ... If the element has no content or no text content (e.g., + the IMG element in HTML), user agents must + ignore this property. +

    + +

    + ... Conforming user agents are not + required to support this value. +

    +     -

    - ... Conforming user agents may consider the - value of "text-transform" to be "none" for characters that - are not from the ISO Latin-1 repertoire and for elements in - languages for which the transformation is different from - that specified by the case-conversion tables of Unicode or - ISO 10646. -

    +

    + ... Conforming user agents may consider the + value of "text-transform" to be "none" for characters that + are not from the ISO Latin-1 repertoire and for elements in + languages for which the transformation is different from + that specified by the case-conversion tables of Unicode or + ISO 10646. +

    -

    - ... Word spacing algorithms are user - agent-dependent. -

    - -

    - ... The algorithm for resolving the adjusted values - between word spacing and letter spacing is User - Agent dependent. -

    -     +

    + ... Word spacing algorithms are user + agent-dependent. +

    + +

    + ... The algorithm for resolving the adjusted values + between word spacing and letter spacing is User + Agent dependent. +

    +     -

    Initial: depends on user agent

    +

    Initial: depends on user agent

     - -

    - This is the default behavior. The User - Agent determines the best intent based on the - content type. For image content containing an embedded - profile, it shall be assumed that the intent specified - within the profile is the desired intent. Otherwise, the - user agent shall use the current profile - and force the intent, overriding any intent that might be - stored in the profile itself. -

    -     + +

    + This is the default behavior. The User + Agent determines the best intent based on the + content type. For image content containing an embedded + profile, it shall be assumed that the intent specified + within the profile is the desired intent. Otherwise, the + user agent shall use the current profile + and force the intent, overriding any intent that might be + stored in the profile itself. +

    +     - -

    - This value indicates that the content is clipped and that - if the user agent uses a scrolling - mechanism that is visible on the screen (such as a scroll - bar or a panner), that mechanism should be displayed for a - box whether or not any of its content is clipped. -

    -     - -

    - The behavior of the "auto" value is user - agent dependent, but should cause a scrolling - mechanism to be provided for overflowing boxes. -

    -     + +

    + This value indicates that the content is clipped and that + if the user agent uses a scrolling + mechanism that is visible on the screen (such as a scroll + bar or a panner), that mechanism should be displayed for a + box whether or not any of its content is clipped. +

    +     + +

    + The behavior of the "auto" value is user + agent dependent, but should cause a scrolling + mechanism to be provided for overflowing boxes. +

    +     - -

    - ... The choice of dot character is dependent on the - user agent. -

    -     + +

    + ... The choice of dot character is dependent on the + user agent. +

    +     -

    - ... User agents may choose to use the value - of "leader-length.optimum" to determine where to break the - line, then use the minimum and maximum values during line - justification. -

    +

    + ... User agents may choose to use the value + of "leader-length.optimum" to determine where to break the + line, then use the minimum and maximum values during line + justification. +

    - -

    - The User Agent determines which value of - "media-usage" (other than the "auto" value) is used. The - User Agent may consider the type of media - on which the presentation is to be placed in making this - determination.
    NOTE:
    For example, the - User Agent could use the following - decision process. If the media is not continuous and is of - fixed bounded size, then the "paginate" (described below) - is used. Otherwise, the "bounded-in-one-dimension" is - used. -

    -     - -

    - ... It is an error if more or less than one of - "page-height" or "page-width" is specified on the first - page master that is used. The User Agent - may recover as follows:... -

    -     - -

    - Only one page is generated per fo:page-sequence descendant - from the fo:root. Neither "page-height" nor "page-width" - may be specified on any page master that is used. If a - value is specified for either property, it is an error and - a User Agent may recover by ignoring the - specified value. ... -

    -     + +

    + The User Agent determines which value of + "media-usage" (other than the "auto" value) is used. The + User Agent may consider the type of media + on which the presentation is to be placed in making this + determination.
    NOTE:
    For example, the + User Agent could use the following + decision process. If the media is not continuous and is of + fixed bounded size, then the "paginate" (described below) + is used. Otherwise, the "bounded-in-one-dimension" is + used. +

    +     + +

    + ... It is an error if more or less than one of + "page-height" or "page-width" is specified on the first + page master that is used. The User Agent + may recover as follows:... +

    +     + +

    + Only one page is generated per fo:page-sequence descendant + from the fo:root. Neither "page-height" nor "page-width" + may be specified on any page master that is used. If a + value is specified for either property, it is an error and + a User Agent may recover by ignoring the + specified value. ... +

    +     - -

    - The "page-height" shall be determined, in the case of - continuous media, from the size of the User - Agent window... -

    -     - -

    - A User Agent may provide a way to declare - the media for which formatting is to be done. This may be - different from the media on which the formatted result is - viewed. For example, a browser User Agent - may be used to preview pages that are formatted for sheet - media. In that case, the size calculation is based on the - media for which formatting is done rather than the media - being currently used. -

    -     + +

    + The "page-height" shall be determined, in the case of + continuous media, from the size of the User + Agent window... +

    +     + +

    + A User Agent may provide a way to declare + the media for which formatting is to be done. This may be + different from the media on which the formatted result is + viewed. For example, a browser User Agent + may be used to preview pages that are formatted for sheet + media. In that case, the size calculation is based on the + media for which formatting is done rather than the media + being currently used. +

    +     - -

    - The "page-width" shall be determined, in the case of - continuous media, from the size of the User - Agent window... -

    -     + +

    + The "page-width" shall be determined, in the case of + continuous media, from the size of the User + Agent window... +

    +     - -

    - ... Rows, columns, row groups, and column groups cannot - have borders (i.e., user agents must - ignore the border properties for those elements). -

    -     + +

    + ... Rows, columns, row groups, and column groups cannot + have borders (i.e., user agents must + ignore the border properties for those elements). +

    +     -

    - ... For a caption that is on the left or right side of a - table box, on the other hand, a value other than "auto" for - "width" sets the width explicitly, but "auto" tells the - user agent to chose a "reasonable width". -

    +

    + ... For a caption that is on the left or right side of a + table box, on the other hand, a value other than "auto" for + "width" sets the width explicitly, but "auto" tells the + user agent to chose a "reasonable width". +

    - -

    - ... The User Agent shall round the value - of the angle to the closest of the permitted values. -

    -     + +

    + ... The User Agent shall round the value + of the angle to the closest of the permitted values. +

    +     - -

    - ... The determination of which characters should be - auto-rotated may vary across User Agents. -

    -     - -

    - ... The User Agent shall round the value - of the angle to the closest of the permitted values. -

    -     + +

    + ... The determination of which characters should be + auto-rotated may vary across User Agents. +

    +     + +

    + ... The User Agent shall round the value + of the angle to the closest of the permitted values. +

    +     - -

    - ... Fallback:
    If it is not possible to present the - characters in the correct order, then the - UserAgent should display either a - 'missing character' glyph or display some indication that - the content cannot be correctly rendered. -

    -     + +

    + ... Fallback:
    If it is not possible to present the + characters in the correct order, then the + UserAgent should display either a + 'missing character' glyph or display some indication that + the content cannot be correctly rendered. +

    +     -

    - ... This property specifies the content-type and may be used - by a User Agent to select a rendering - processor for the object. -

    - -

    - No identification of the content-type. The User - Agent may determine it by "sniffing" or by other - means. -

    -     +

    + ... This property specifies the content-type and may be used + by a User Agent to select a rendering + processor for the object. +

    + +

    + No identification of the content-type. The User + Agent may determine it by "sniffing" or by other + means. +

    +     -

    - ... If an element's border color is not specified with a - "border" property, user agents must use the - value of the element's "color" property as the computed - value for the border color. -

    +

    + ... If an element's border color is not specified with a + "border" property, user agents must use the + value of the element's "color" property as the computed + value for the border color. +

    -

    - ... Rows, columns, row groups, and column groups cannot have - borders (i.e., user agents must ignore the - border properties for those elements). -

    +

    + ... Rows, columns, row groups, and column groups cannot have + borders (i.e., user agents must ignore the + border properties for those elements). +

    -

    - ... If no font with the indicated characteristics exists on - a given platform, the user agent should - either intelligently substitute (e.g., a smaller version of - the "caption" font might be used for the "small-caption" - font), or substitute a user agent default - font. -

    +

    + ... If no font with the indicated characteristics exists on + a given platform, the user agent should + either intelligently substitute (e.g., a smaller version of + the "caption" font might be used for the "small-caption" + font), or substitute a user agent default + font. +

    -

    Initial: depends on user agent

    +

    Initial: depends on user agent

     -

    - ... Relative page boxes allow user agents - to scale a document and make optimal use of the target size. -

    -

    - ... User agents may allow users to control - the transfer of the page box to the sheet (e.g., rotating an - absolute page box that's being printed). -

    -
      -
    • - Rendering page boxes that do not fit a target sheet
      - If a page box does not fit the target sheet dimensions, - the user agent may choose to: -
        -
      • - Rotate the page box 90 degrees if this will make the - page box fit. -
        • -
      • Scale the page to fit the target.
        • -
      - The user agent should consult the user - before performing these operations. -
      • -
    • - Positioning the page box on the sheet
      When the page - box is smaller than the target size, the user - agent is free to place the page box anywhere on - the sheet. -
      • -
    +

    + ... Relative page boxes allow user agents + to scale a document and make optimal use of the target size. +

    +

    + ... User agents may allow users to control + the transfer of the page box to the sheet (e.g., rotating an + absolute page box that's being printed). +

    +
      +
    • + Rendering page boxes that do not fit a target sheet
      + If a page box does not fit the target sheet dimensions, + the user agent may choose to: +
        +
      • + Rotate the page box 90 degrees if this will make the + page box fit. +
        • +
      • Scale the page to fit the target.
        • +
      + The user agent should consult the user + before performing these operations. +
      • +
    • + Positioning the page box on the sheet
      When the page + box is smaller than the target size, the user + agent is free to place the page box anywhere on + the sheet. +
      • +
    - -

    - This value directs user agents to - collapse sequences of whitespace, and break lines as - necessary to fill line boxes. ... -

    -     - -

    - This value prevents user agents from - collapsing sequences of whitespace. ... -

    -     -

    - ... Conforming user agents may ignore the - 'white-space' property in author and user style sheets but - must specify a value for it in the default style sheet. -

    + +

    + This value directs user agents to + collapse sequences of whitespace, and break lines as + necessary to fill line boxes. ... +

    +     + +

    + This value prevents user agents from + collapsing sequences of whitespace. ... +

    +     +

    + ... Conforming user agents may ignore the + 'white-space' property in author and user style sheets but + must specify a value for it in the default style sheet. +

    diff --git a/docs/design/alt.design/xml-parsing.xml b/docs/design/alt.design/xml-parsing.xml index 240222352..4e7cf939d 100644 --- a/docs/design/alt.design/xml-parsing.xml +++ b/docs/design/alt.design/xml-parsing.xml @@ -15,209 +15,209 @@

    - This note proposes an alternative method of integrating the - output of the SAX parsing of the Flow Object (FO) tree into - FOP processing. The pupose of the proposed changes is to - provide for better decomposition of the process of analysing - and rendering an fo tree such as is represented in the output - from initial (XSLT) processing of an XML source document. + This note proposes an alternative method of integrating the + output of the SAX parsing of the Flow Object (FO) tree into + FOP processing. The pupose of the proposed changes is to + provide for better decomposition of the process of analysing + and rendering an fo tree such as is represented in the output + from initial (XSLT) processing of an XML source document.

    -

    - Figure 1 is a schematic representation of the process of SAX - parsing of an input source. SAX parsing involves the - registration, with an object implementing the - XMLReader interface, of a - ContentHandler which contains a callback - routine for each of the event types encountered by the - parser, e.g., startDocument(), - startElement(), characters(), - endElement() and endDocument(). - Parsing is initiated by a call to the parser() - method of the XMLReader. Note that the call to - parser() and the calls to individual callback - methods are synchronous: parser() will only - return when the last callback method returns, and each - callback must complete before the next is called.

    - Figure 1 -

    -
    -

    - In the process of parsing, the hierarchical structure of the - original FO tree is flattened into a number of streams of - events of the same type which are reported in the sequence - in which they are encountered. Apart from that, the API - imposes no structure or constraint which expresses the - relationship between, e.g., a startElement event and the - endElement event for the same element. To the extent that - such relationship information is required, it must be - managed by the callback routines. -

    -

    - The most direct approach here is to build the tree - "invisibly"; to bury within the callback routines the - necessary code to construct the tree. In the simplest case, - the whole of the FO tree is built within the call to - parser(), and that in-memory tree is subsequently - processed to (a) validate the FO structure, and (b) - construct the Area tree. The problem with this approach is - the potential size of the FO tree in memory. FOP has - suffered from this problem in the past. -

    +

    + Figure 1 is a schematic representation of the process of SAX + parsing of an input source. SAX parsing involves the + registration, with an object implementing the + XMLReader interface, of a + ContentHandler which contains a callback + routine for each of the event types encountered by the + parser, e.g., startDocument(), + startElement(), characters(), + endElement() and endDocument(). + Parsing is initiated by a call to the parser() + method of the XMLReader. Note that the call to + parser() and the calls to individual callback + methods are synchronous: parser() will only + return when the last callback method returns, and each + callback must complete before the next is called.

    + Figure 1 +

    +
    +

    + In the process of parsing, the hierarchical structure of the + original FO tree is flattened into a number of streams of + events of the same type which are reported in the sequence + in which they are encountered. Apart from that, the API + imposes no structure or constraint which expresses the + relationship between, e.g., a startElement event and the + endElement event for the same element. To the extent that + such relationship information is required, it must be + managed by the callback routines. +

    +

    + The most direct approach here is to build the tree + "invisibly"; to bury within the callback routines the + necessary code to construct the tree. In the simplest case, + the whole of the FO tree is built within the call to + parser(), and that in-memory tree is subsequently + processed to (a) validate the FO structure, and (b) + construct the Area tree. The problem with this approach is + the potential size of the FO tree in memory. FOP has + suffered from this problem in the past. +

    -

    - On the other hand, the callback code may become increasingly - complex as tree validation and the triggering of the Area - tree processing and subsequent rendering is moved into the - callbacks, typically the endElement() method. - In order to overcome acute memory problems, the FOP code was - recently modified in this way, to trigger Area tree building - and rendering in the endElement() method, when - the end of a page-sequence was detected. -

    -

    - The drawback with such a method is that it becomes difficult - to detemine the order of events and the circumstances in - which any particular processing events are triggered. When - the processing events are inherently self-contained, this is - irrelevant. But the more complex and context-dependent the - relationships are among the processing elements, the more - obscurity is engendered in the code by such "side-effect" - processing. -

    +

    + On the other hand, the callback code may become increasingly + complex as tree validation and the triggering of the Area + tree processing and subsequent rendering is moved into the + callbacks, typically the endElement() method. + In order to overcome acute memory problems, the FOP code was + recently modified in this way, to trigger Area tree building + and rendering in the endElement() method, when + the end of a page-sequence was detected. +

    +

    + The drawback with such a method is that it becomes difficult + to detemine the order of events and the circumstances in + which any particular processing events are triggered. When + the processing events are inherently self-contained, this is + irrelevant. But the more complex and context-dependent the + relationships are among the processing elements, the more + obscurity is engendered in the code by such "side-effect" + processing. +

    -

    - In order to solve the simultaneous problems of exposing the - structure of the processing and minimising in-memory - requirements, the experimental code separates the parsing of - the input source from the building of the FO tree and all - downstream processing. The callback routines become - minimal, consisting of the creation and buffering of - XMLEvent objects as a producer. All - of these objects are effectively merged into a single event - stream, in strict event order, for subsequent access by the - FO tree building process, acting as a - consumer. In itself, this does not reduce the - footprint. This occurs when the approach is generalised to - modularise FOP processing.

    Figure 2 -

    -
    -

    - The most useful change that this brings about is the switch - from passive to active XML element - processing. The process of parsing now becomes visible to - the controlling process. All local validation requirements, - all object and data structure building, is initiated by the - process(es) getting from the queue - in the case - above, the FO tree builder. -

    +

    + In order to solve the simultaneous problems of exposing the + structure of the processing and minimising in-memory + requirements, the experimental code separates the parsing of + the input source from the building of the FO tree and all + downstream processing. The callback routines become + minimal, consisting of the creation and buffering of + XMLEvent objects as a producer. All + of these objects are effectively merged into a single event + stream, in strict event order, for subsequent access by the + FO tree building process, acting as a + consumer. In itself, this does not reduce the + footprint. This occurs when the approach is generalised to + modularise FOP processing.

    Figure 2 +

    +
    +

    + The most useful change that this brings about is the switch + from passive to active XML element + processing. The process of parsing now becomes visible to + the controlling process. All local validation requirements, + all object and data structure building, is initiated by the + process(es) getting from the queue - in the case + above, the FO tree builder. +

    - -

    - The experimental code uses a class XMLEvent - to provide the objects which are placed in the queue. - XMLEvent includes a variety of methods to access - elements in the queue. Namespace URIs encountered in - parsing are maintined in a static - HashMap where they are associated with a unique - integer index. This integer value is used in the signature - of some of the access methods. -

    -
    -
    XMLEvent getEvent(SyncedCircularBuffer events)
    -
    - This is the basis of all of the queue access methods. It - returns the next element from the queue, which may be a - pushback element. -
    -
    XMLEvent getEndDocument(events)
    -
    - get and discard elements from the queue - until an ENDDOCUMENT element is found and returned. -
    -
    XMLEvent expectEndDocument(events)
    -
    - If the next element on the queue is an ENDDOCUMENT event, - return it. Otherwise, push the element back and throw an - exception. Each of the get methods (except - getEvent() itself) has a corresponding - expect method. -
    -
    XMLEvent get/expectStartElement(events)
    -
    Return the next STARTELEMENT event from the queue.
    -
    XMLEvent get/expectStartElement(events, String - qName)
    -
    - Return the next STARTELEMENT with a QName matching - qName. -
    -
    - XMLEvent get/expectStartElement(events, int uriIndex, - String localName) -
    -
    - Return the next STARTELEMENT with a URI indicated by the - uriIndex and a local name matching localName. -
    -
    - XMLEvent get/expectStartElement(events, LinkedList list) -
    -
    - list contains instances of the nested class - UriLocalName, which hold a - uriIndex and a localName. Return - the next STARTELEMENT with a URI indicated by the - uriIndex and a local name matching - localName from any element of - list. -
    -
    XMLEvent get/expectEndElement(events)
    -
    Return the next ENDELEMENT.
    -
    XMLEvent get/expectEndElement(events, qName)
    -
    Return the next ENDELEMENT with QName - qname.
    -
    XMLEvent get/expectEndElement(events, uriIndex, localName)
    -
    - Return the next ENDELEMENT with a URI indicated by the - uriIndex and a local name matching - localName. -
    -
    - XMLEvent get/expectEndElement(events, XMLEvent event) -
    -
    - Return the next ENDELEMENT with a URI matching the - uriIndex and localName - matching those in the event argument. This - is intended as a quick way to find the ENDELEMENT matching - a previously returned STARTELEMENT. -
    -
    XMLEvent get/expectCharacters(events)
    -
    Return the next CHARACTERS event.
    -
    + +

    + The experimental code uses a class XMLEvent + to provide the objects which are placed in the queue. + XMLEvent includes a variety of methods to access + elements in the queue. Namespace URIs encountered in + parsing are maintined in a static + HashMap where they are associated with a unique + integer index. This integer value is used in the signature + of some of the access methods. +

    +
    +
    XMLEvent getEvent(SyncedCircularBuffer events)
    +
    + This is the basis of all of the queue access methods. It + returns the next element from the queue, which may be a + pushback element. +
    +
    XMLEvent getEndDocument(events)
    +
    + get and discard elements from the queue + until an ENDDOCUMENT element is found and returned. +
    +
    XMLEvent expectEndDocument(events)
    +
    + If the next element on the queue is an ENDDOCUMENT event, + return it. Otherwise, push the element back and throw an + exception. Each of the get methods (except + getEvent() itself) has a corresponding + expect method. +
    +
    XMLEvent get/expectStartElement(events)
    +
    Return the next STARTELEMENT event from the queue.
    +
    XMLEvent get/expectStartElement(events, String + qName)
    +
    + Return the next STARTELEMENT with a QName matching + qName. +
    +
    + XMLEvent get/expectStartElement(events, int uriIndex, + String localName) +
    +
    + Return the next STARTELEMENT with a URI indicated by the + uriIndex and a local name matching localName. +
    +
    + XMLEvent get/expectStartElement(events, LinkedList list) +
    +
    + list contains instances of the nested class + UriLocalName, which hold a + uriIndex and a localName. Return + the next STARTELEMENT with a URI indicated by the + uriIndex and a local name matching + localName from any element of + list. +
    +
    XMLEvent get/expectEndElement(events)
    +
    Return the next ENDELEMENT.
    +
    XMLEvent get/expectEndElement(events, qName)
    +
    Return the next ENDELEMENT with QName + qname.
    +
    XMLEvent get/expectEndElement(events, uriIndex, localName)
    +
    + Return the next ENDELEMENT with a URI indicated by the + uriIndex and a local name matching + localName. +
    +
    + XMLEvent get/expectEndElement(events, XMLEvent event) +
    +
    + Return the next ENDELEMENT with a URI matching the + uriIndex and localName + matching those in the event argument. This + is intended as a quick way to find the ENDELEMENT matching + a previously returned STARTELEMENT. +
    +
    XMLEvent get/expectCharacters(events)
    +
    Return the next CHARACTERS event.
    +
    -

    - This same principle can be extended to the other major - sub-systems of FOP processing. In each case, while it is - possible to hold a complete intermediate result in memory, - the memory costs of that approach are too high. The - sub-systems - xml parsing, FO tree construction, Area tree - construction and rendering - must run in parallel if the - footprint is to be kept manageable. By creating a series of - producer-consumer pairs linked by synchronized buffers, - logical isolation can be achieved while rates of processing - remain coupled. By introducing feedback loops conveying - information about the completion of processing of the - elements, sub-systems can dispose of or precis those - elements without having to be tightly coupled to downstream - processes.

    - Figure 3 -

    -
    +

    + This same principle can be extended to the other major + sub-systems of FOP processing. In each case, while it is + possible to hold a complete intermediate result in memory, + the memory costs of that approach are too high. The + sub-systems - xml parsing, FO tree construction, Area tree + construction and rendering - must run in parallel if the + footprint is to be kept manageable. By creating a series of + producer-consumer pairs linked by synchronized buffers, + logical isolation can be achieved while rates of processing + remain coupled. By introducing feedback loops conveying + information about the completion of processing of the + elements, sub-systems can dispose of or precis those + elements without having to be tightly coupled to downstream + processes.

    + Figure 3 +

    +
    diff --git a/docs/design/float.svg b/docs/design/float.svg index 7bef863a2..4e32f7203 100755 --- a/docs/design/float.svg +++ b/docs/design/float.svg @@ -1,48 +1,48 @@ + "http://www.w3.org/TR/2000/CR-SVG-20001102/DTD/svg-20001102.dtd"> - - - - - - - - - - - - flow limit - float - effective height - - of float line - - - - - - - float anchor + + + + + + + + + + + + flow limit + float + effective height + + of float line + + + + + + + float anchor diff --git a/docs/design/fo_impl/fo_classes.xml b/docs/design/fo_impl/fo_classes.xml index adcf04055..f9de1d683 100644 --- a/docs/design/fo_impl/fo_classes.xml +++ b/docs/design/fo_impl/fo_classes.xml @@ -72,289 +72,289 @@ parent. The Name, Spec Content, and Breaks & Keeps information is definite. The type and multiplicity of generated areas is definite, as well as whether the generated areas are reference areas or not. The BaseClass and the -layout area information is FOP-implementation dependent. +layout area information is FOP-implementation dependent. Note: Numbers in parentheses refer to Notes. A * after an FO name indicates that the object is not yet implemented. - block - FObjMixed - - - normalblock - 1..* - BlockArea - - All (2) + block + FObjMixed + + + normalblock + 1..* + BlockArea + + All (2) - block-container - FObj - - - viewport/refblock - 1..* - AreaContainer - - All + block-container + FObj + + + viewport/refblock + 1..* + AreaContainer + + All - table-and-caption - FObj (1) - (table-caption?,table) - - normalblock - 1..* - AreaContainer - - All keeps + table-and-caption + FObj (1) + (table-caption?,table) + + normalblock + 1..* + AreaContainer + + All keeps - table - FObj - (table-column*,table-header?, table-footer?,table-body+) - - normalblock - 1..* - AreaContainer - - All + table + FObj + (table-column*,table-header?, table-footer?,table-body+) + + normalblock + 1..* + AreaContainer + + All - list-block - FObj - (list-item+) - - normalblock - 1..* - BlockArea - - All + list-block + FObj + (list-item+) + + normalblock + 1..* + BlockArea + + All - bidi-override - FObjMixed (1) - - - normalinline - 1..* - - - + bidi-override + FObjMixed (1) + + + normalinline + 1..* + + + - character - FObj - EMPTY - - normalinline - 1 - BlockArea - - kwn, kwp + character + FObj + EMPTY + + normalinline + 1 + BlockArea + + kwn, kwp - external-graphic - FObj - EMPTY - - viewport/refinline - 1 - ImageArea - - kwn, kwp + external-graphic + FObj + EMPTY + + viewport/refinline + 1 + ImageArea + + kwn, kwp - initial-property-set - FObj (1) - EMPTY - - + initial-property-set + FObj (1) + EMPTY + + - instream-foreign-object - FObj - XML - - viewport/refinline - 1 - ForeignObjectArea - - kwn, kwp + instream-foreign-object + FObj + XML + + viewport/refinline + 1 + ForeignObjectArea + + kwn, kwp - inline - FObjMixed - - - normalinline - 1..* - Area - - All keeps + inline + FObjMixed + + + normalinline + 1..* + Area + + All keeps - inline-container - FObj (1) - - - viewport/refinline - 1..* - - - All keeps + inline-container + FObj (1) + + + viewport/refinline + 1..* + + + All keeps - leader - FObjMixed - - - normalinline - 1 - BlockArea - - + leader + FObjMixed + + + normalinline + 1 + BlockArea + + - page-number - FObj - EMPTY - - normalinline - 1 - BlockArea (4) - - kwn, kwp + page-number + FObj + EMPTY + + normalinline + 1 + BlockArea (4) + + kwn, kwp - page-number-citation - FObj - EMPTY - - normalinline - 1 - BlockArea (4) - - kwn, kwp + page-number-citation + FObj + EMPTY + + normalinline + 1 + BlockArea (4) + + kwn, kwp - basic-link - FObjMixed - - - normalinline - 1..* - Area (4) - - All keeps + basic-link + FObjMixed + + + normalinline + 1..* + Area (4) + + All keeps - list-item-body - FObj - - - NoneNone - - Area - - kt + list-item-body + FObj + + + NoneNone + + Area + + kt - list-item - FObj - (list-item-label,list-item-body) - - normalblock - 1..* - BlockArea - - All + list-item + FObj + (list-item-label,list-item-body) + + normalblock + 1..* + BlockArea + + All - list-item-label - FObj - - - NoneNone - - Area - - kt + list-item-label + FObj + + + NoneNone + + Area + + kt - table-body - FObj - (table-row+|table-cell+) - - NoneNone - - AreaContainer (3) - - + table-body + FObj + (table-row+|table-cell+) + + NoneNone + + AreaContainer (3) + + - table-caption - FObj (1) - - - normalblock - 1..* - - - kt + table-caption + FObj (1) + + + normalblock + 1..* + + + kt - table-cell - FObj - - - normalblock - 1..* - AreaContainer - - + table-cell + FObj + + + normalblock + 1..* + AreaContainer + + - table-column - FObj - EMPTY - - + table-column + FObj + EMPTY + + - table-footer - TableBody - (table-row+|table-cell+) - - NoneNone - - AreaContainer (3) - - + table-footer + TableBody + (table-row+|table-cell+) + + NoneNone + + AreaContainer (3) + + - table-header - TableBody - (table-row+|table-cell+) - - NoneNone - - AreaContainer (3) - - + table-header + TableBody + (table-row+|table-cell+) + + NoneNone + + AreaContainer (3) + + - table-row - FObj - (table-cell+) - - All + table-row + FObj + (table-cell+) + + All diff --git a/docs/design/fo_impl/fo_classes.xsl b/docs/design/fo_impl/fo_classes.xsl index ad9e21690..bacb805df 100644 --- a/docs/design/fo_impl/fo_classes.xsl +++ b/docs/design/fo_impl/fo_classes.xsl @@ -1,14 +1,14 @@ - + - + xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" + xmlns:fo="http://www.w3.org/1999/XSL/Format"> + - + @@ -31,69 +31,69 @@ - + -

    +

    - + - + - - - - - - -
    NameBase ClassSpec ContentGenerated AreasBreaks and Keeps
    + + + + + + +
    NameBase ClassSpec ContentGenerated AreasBreaks and Keeps
     - - - -  * - - - - -   - + + + +  * + + + + +   + - -
      -
    • Class:   - Stacking:
      • -
    • Multiplicity:
      • -
    • Layout into: -  (parent)
      • - -
    • Reference Area(s)
      • -       -
    -     -   + +
      +
    • Class:   + Stacking:
      • +
    • Multiplicity:
      • +
    • Layout into: +  (parent)
      • + +
    • Reference Area(s)
      • +       +
    +     +  

    Notes:

    -
      - -
      2. -       -
    +
      + +
      2. +       +
    diff --git a/docs/design/page.svg b/docs/design/page.svg index 48b4a941a..f809cf749 100755 --- a/docs/design/page.svg +++ b/docs/design/page.svg @@ -1,50 +1,50 @@ + "http://www.w3.org/TR/2000/CR-SVG-20001102/DTD/svg-20001102.dtd"> - - - - - - - - - - - - - - - - - - - - Before Float - Footnote + + + + + + + + + + + + + + + + + + + + Before Float + Footnote