Class BlockStackingLayoutManager

    • Field Detail

      • parentArea

        protected BlockParent parentArea
        parent area
      • bpUnit

        protected int bpUnit
        Value of the block-progression-unit (non-standard property)
      • adjustedSpaceBefore

        protected int adjustedSpaceBefore
        space-before value adjusted for block-progression-unit handling
      • adjustedSpaceAfter

        protected int adjustedSpaceAfter
        space-after value adjusted for block-progression-unit handling
      • storedList

        protected java.util.List<KnuthElement> storedList
        Only used to store the original list when createUnitElements is called
      • breakBeforeServed

        protected boolean breakBeforeServed
        Indicates whether break before has been served or not
      • firstVisibleMarkServed

        protected boolean firstVisibleMarkServed
        Indicates whether the first visible mark has been returned by this LM, yet
      • referenceIPD

        protected int referenceIPD
        Reference IPD available
      • startIndent

        protected int startIndent
        the effective start-indent value
      • endIndent

        protected int endIndent
        the effective end-indent value
      • foSpaceBefore

        protected MinOptMax foSpaceBefore
        Holds the (one-time use) fo:block space-before and -after properties. Large fo:blocks are split into multiple Area. Blocks to accomodate the subsequent regions (pages) they are placed on. space-before is applied at the beginning of the first Block and space-after at the end of the last Block used in rendering the fo:block.
      • foSpaceAfter

        protected MinOptMax foSpaceAfter
        see foSpaceBefore
    • Constructor Detail

      • BlockStackingLayoutManager

        public BlockStackingLayoutManager​(FObj node)
        Parameters:
        node - the fo this LM deals with
    • Method Detail

      • getCurrentArea

        protected BlockParent getCurrentArea()
        Returns:
        current area being filled
      • setCurrentArea

        protected void setCurrentArea​(BlockParent parentArea)
        Set the current area being filled.
        Parameters:
        parentArea - the current area to be filled
      • addBlockSpacing

        public void addBlockSpacing​(double adjust,
                                    MinOptMax minoptmax)
        Add a block spacer for space before and space after a block. This adds an empty Block area that acts as a block space.
        Parameters:
        adjust - the adjustment value
        minoptmax - the min/opt/max value of the spacing
      • addChildToArea

        protected void addChildToArea​(Area childArea,
                                      BlockParent parentArea)
        Add the childArea to the passed area. Called by child LayoutManager when it has filled one of its areas. The LM should already have an Area in which to put the child. See if the area will fit in the current area. If so, add it. Otherwise initiate breaking.
        Parameters:
        childArea - the area to add: will be some block-stacked Area.
        parentArea - the area in which to add the childArea
      • addChildArea

        public void addChildArea​(Area childArea)
        Add the childArea to the current area. Called by child LayoutManager when it has filled one of its areas. The LM should already have an Area in which to put the child. See if the area will fit in the current area. If so, add it. Otherwise initiate breaking.
        Specified by:
        addChildArea in interface LayoutManager
        Overrides:
        addChildArea in class AbstractLayoutManager
        Parameters:
        childArea - the area to add: will be some block-stacked Area.
      • flush

        protected void flush()
        Force current area to be added to parent area.
      • getAuxiliaryPosition

        protected Position getAuxiliaryPosition()
        Returns:
        a cached auxiliary Position instance used for things like spaces.
      • neededUnits

        protected int neededUnits​(int len)
        Parameters:
        len - length in millipoints to span with bp units
        Returns:
        the minimum integer n such that n * bpUnit >= len
      • updateContentAreaIPDwithOverconstrainedAdjust

        protected int updateContentAreaIPDwithOverconstrainedAdjust()
        Determines and sets the content area IPD based on available reference area IPD, start- and end-indent properties. end-indent is adjusted based on overconstrained geometry rules, if necessary.
        Returns:
        the resulting content area IPD
      • updateContentAreaIPDwithOverconstrainedAdjust

        protected int updateContentAreaIPDwithOverconstrainedAdjust​(int contentIPD)
        Sets the content area IPD by directly supplying the value. end-indent is adjusted based on overconstrained geometry rules, if necessary.
        Parameters:
        contentIPD - the IPD of the content
        Returns:
        the resulting content area IPD
      • getNextKnuthElements

        public java.util.List getNextKnuthElements​(LayoutContext context,
                                                   int alignment)
        Get a sequence of KnuthElements representing the content of the node assigned to the LM.
        Specified by:
        getNextKnuthElements in interface LayoutManager
        Overrides:
        getNextKnuthElements in class AbstractLayoutManager
        Parameters:
        context - the LayoutContext used to store layout information
        alignment - the desired text alignment
        Returns:
        the list of KnuthElements
      • getNextKnuthElements

        public java.util.List getNextKnuthElements​(LayoutContext context,
                                                   int alignment,
                                                   java.util.Stack lmStack,
                                                   Position restartPosition,
                                                   LayoutManager restartAtLM)
        Returns an updated list of Knuth elements corresponding to this layout manager, after a change of IPD has been detected.
        Specified by:
        getNextKnuthElements in interface LayoutManager
        Overrides:
        getNextKnuthElements in class AbstractBaseLayoutManager
        Parameters:
        context - the layout context
        alignment - the alignment
        lmStack - the stack of LMs that are active at the IPD change
        restartPosition - the position corresponding to the element finishing the page before the IPD change
        restartAtLM - if not null, the layout manager from which to restart. That is, the IPD change occurs between two block elements and not inside a paragraph
        Returns:
        an updated list of elements, taking the new IPD into account
      • addFirstVisibleMarks

        protected void addFirstVisibleMarks​(java.util.List<ListElement> elements,
                                            LayoutContext context,
                                            int alignment)
        Checks if this LM's first "visible marks" (= borders, padding, spaces) have already been processed, and if necessary, adds corresponding elements to the specified list, and updates the given layout context accordingly.
        Parameters:
        elements - the element list
        context - the layout context
        alignment - the vertical alignment
      • addLastVisibleMarks

        protected void addLastVisibleMarks​(java.util.List<ListElement> elements,
                                           LayoutContext context,
                                           int alignment)
        Adds elements the LM's last/closing marks to the specified list, and updates the layout context accordingly.
        Parameters:
        elements - the element list
        context - the layout context
        alignment - the vertical alignment
      • breakBeforeServed

        protected boolean breakBeforeServed​(LayoutContext context,
                                            java.util.List<ListElement> elements)
        Check whether there is a break-before condition. If so, and the specified context allows it, add the necessary elements to the given elements list.
        Parameters:
        context - the layout context
        elements - the element list
        Returns:
        false if there is a break-before condition, and it has not been served; true otherwise
      • getNextChildElements

        protected java.util.List<ListElement> getNextChildElements​(LayoutManager childLM,
                                                                   LayoutContext context,
                                                                   LayoutContext childLC,
                                                                   int alignment,
                                                                   java.util.Stack<LayoutManager> lmStack,
                                                                   Position restartPosition,
                                                                   LayoutManager restartAtLM)
        Gets the next set of child elements for the given childLM. The default implementation basically copies the pending marks to the child layout context, and subsequently calls the appropriate variant of childLM.getNextKnuthElements(), passing it all relevant parameters.
        Parameters:
        childLM - the current child LM
        context - the layout context
        childLC - the child layout context
        alignment - the vertical alignment
        lmStack - the stack of currently active LMs (if any)
        restartPosition - the position to restart from (if any)
        restartAtLM - the LM to restart from (if any)
        Returns:
        list of elements corresponding to the content generated by childLM
      • addInBetweenBreak

        protected void addInBetweenBreak​(java.util.List<ListElement> contentList,
                                         LayoutContext parentLC,
                                         LayoutContext childLC)
        Adds a break element to the content list between individual child elements.
        Parameters:
        contentList - the content list
        parentLC - the parent layout context
        childLC - the currently active child layout context
      • negotiateBPDAdjustment

        public int negotiateBPDAdjustment​(int adj,
                                          KnuthElement lastElement)
        Negotiate BPD adjustment.
        Specified by:
        negotiateBPDAdjustment in interface BlockLevelLayoutManager
        Parameters:
        adj - amount to adjust
        lastElement - the last knuth element
        Returns:
        the resulting adjusted BPD
      • getChangedKnuthElements

        public java.util.List getChangedKnuthElements​(java.util.List oldList,
                                                      int alignment)
        Get a sequence of KnuthElements representing the content of the node assigned to the LM, after changes have been applied In the context of line breaking, this method is called after hyphenation has been performed, in order to receive the sequence of elements representing the text together with all possible hyphenation points. For example, if the text "representation" originates a single box element when getNextKnuthElements() is called, it will be now split in syllables (rep-re-sen-ta-tion) each one originating a box and divided by additional elements allowing a line break. In the context of page breaking, this method is called only if the pages need to be "vertically justified" modifying (also) the quantity of lines created by the paragraphs, and after a first page breaking has been performed. According to the result of the first page breaking, each paragraph now knows how many lines it must create (among the existing layout possibilities) and has to create a sequence of elements representing this layout; in particular, each box, representing a line, will contain a LineBreakPositions that will be used in the addAreas() phase. LMs having children look at the old list of elements in order to know which ones they must get the new elements from, as break conditions of preserved linefeeds can divide children into smaller groups (page sequences or paragraphs). LMs having no children can simply return the old elements if they have nothing to change. Inline LMs need to know the text alignment because it affects the elements representing feasible breaks between syllables.
        Specified by:
        getChangedKnuthElements in interface LayoutManager
        Overrides:
        getChangedKnuthElements in class AbstractLayoutManager
        Parameters:
        oldList - the elements to replace
        alignment - the desired text alignment
        Returns:
        the updated list of KnuthElements
      • getParentKeepTogether

        protected Keep getParentKeepTogether()
        Retrieves and returns the keep-together strength from the parent element.
        Returns:
        the keep-together strength
      • getKeepTogetherProperty

        public KeepProperty getKeepTogetherProperty()
        Returns the keep-together property specified on the FObj. Default implementation throws a IllegalStateException. Must be implemented by the subclass, if applicable.
        Specified by:
        getKeepTogetherProperty in interface BlockLevelLayoutManager
        Returns:
        the keep-together property
      • getKeepWithPreviousProperty

        public KeepProperty getKeepWithPreviousProperty()
        Returns the keep-with-previous property specified on the FObj. Default implementation throws a IllegalStateException. Must be implemented by the subclass, if applicable.
        Specified by:
        getKeepWithPreviousProperty in interface BlockLevelLayoutManager
        Returns:
        the keep-together property
      • getKeepWithNextProperty

        public KeepProperty getKeepWithNextProperty()
        Returns the keep-with-next property specified on the FObj. Default implementation throws a IllegalStateException. Must be implemented by the subclass, if applicable.
        Specified by:
        getKeepWithNextProperty in interface BlockLevelLayoutManager
        Returns:
        the keep-together property
      • addPendingMarks

        protected void addPendingMarks​(LayoutContext context)
        Adds the unresolved elements for border and padding to a layout context so break possibilities can be properly constructed.
        Parameters:
        context - the layout context
      • getSpaceBeforeProperty

        protected SpaceProperty getSpaceBeforeProperty()
        Returns:
        the space-before property
      • getSpaceAfterProperty

        protected SpaceProperty getSpaceAfterProperty()
        Returns:
        the space-after property
      • addKnuthElementsForBorderPaddingBefore

        protected void addKnuthElementsForBorderPaddingBefore​(java.util.List returnList,
                                                              boolean isFirst)
        Creates Knuth elements for before border padding and adds them to the return list.
        Parameters:
        returnList - return list to add the additional elements to
        isFirst - true if this is the first time a layout manager instance needs to generate border and padding
      • addKnuthElementsForBorderPaddingAfter

        protected void addKnuthElementsForBorderPaddingAfter​(java.util.List returnList,
                                                             boolean isLast)
        Creates Knuth elements for after border padding and adds them to the return list.
        Parameters:
        returnList - return list to add the additional elements to
        isLast - true if this is the last time a layout manager instance needs to generate border and padding
      • addKnuthElementsForBreakBefore

        protected boolean addKnuthElementsForBreakBefore​(java.util.List returnList,
                                                         LayoutContext context)
        Creates Knuth elements for break-before and adds them to the return list.
        Parameters:
        returnList - return list to add the additional elements to
        context - the layout context
        Returns:
        true if an element has been added due to a break-before.
      • getBreakBefore

        public int getBreakBefore()
        Returns the highest priority break-before value on this layout manager or its relevant descendants.
        Returns:
        the break-before value (Constants.EN_*)
        See Also:
        BreakOpportunity.getBreakBefore()
      • addKnuthElementsForBreakAfter

        protected boolean addKnuthElementsForBreakAfter​(java.util.List returnList,
                                                        LayoutContext context)
        Creates Knuth elements for break-after and adds them to the return list.
        Parameters:
        returnList - return list to add the additional elements to
        context - the layout context
        Returns:
        true if an element has been added due to a break-after.
      • addKnuthElementsForSpaceBefore

        protected void addKnuthElementsForSpaceBefore​(java.util.List returnList,
                                                      int alignment)
        Creates Knuth elements for space-before and adds them to the return list.
        Parameters:
        returnList - return list to add the additional elements to
        alignment - vertical alignment
      • addKnuthElementsForSpaceAfter

        protected void addKnuthElementsForSpaceAfter​(java.util.List returnList,
                                                     int alignment)
        Creates Knuth elements for space-after and adds them to the return list.
        Parameters:
        returnList - return list to add the additional elements to
        alignment - vertical alignment
      • wrapPositionElements

        protected void wrapPositionElements​(java.util.List sourceList,
                                            java.util.List targetList)
        "wrap" the Position inside each element moving the elements from SourceList to targetList
        Parameters:
        sourceList - source list
        targetList - target list receiving the wrapped position elements
      • wrapPositionElements

        protected void wrapPositionElements​(java.util.List sourceList,
                                            java.util.List targetList,
                                            boolean force)
        "wrap" the Position inside each element moving the elements from SourceList to targetList
        Parameters:
        sourceList - source list
        targetList - target list receiving the wrapped position elements
        force - if true, every Position is wrapped regardless of its LM of origin
      • wrapPositionElement

        protected void wrapPositionElement​(ListElement el,
                                           java.util.List targetList,
                                           boolean force)
        "wrap" the Position inside the given element and add it to the target list.
        Parameters:
        el - the list element
        targetList - target list receiving the wrapped position elements
        force - if true, every Position is wrapped regardless of its LM of origin
      • getIPIndents

        protected int getIPIndents()
        Returns:
        the sum of start-indent and end-indent
      • setContentAreaIPD

        protected void setContentAreaIPD​(int contentAreaIPD)
        Sets the IPD of the content area
        Parameters:
        contentAreaIPD - the IPD of the content area
      • reset

        public void reset()
        Re-initializes this layout manager in order to re-generate its Knuth elements according to a new IPD value.
        Specified by:
        reset in interface LayoutManager
        Overrides:
        reset in class AbstractLayoutManager
      • handleOverflow

        public boolean handleOverflow​(int milliPoints)
        Whether this LM can handle horizontal overflow error messages (only a BlockContainerLayoutManager can).
        Parameters:
        milliPoints - horizontal overflow
        Returns:
        true if handled by a BlockContainerLayoutManager