Package org.apache.fop.layoutmgr
Interface LayoutManager
- All Superinterfaces:
PercentBaseContext
- All Known Subinterfaces:
BlockLevelLayoutManager
,InlineLevelLayoutManager
- All Known Implementing Classes:
AbstractBaseLayoutManager
,AbstractGraphicsLayoutManager
,AbstractLayoutManager
,AbstractPageNumberCitationLayoutManager
,AbstractPageSequenceLayoutManager
,BasicLinkLayoutManager
,BidiLayoutManager
,BlockContainerLayoutManager
,BlockLayoutManager
,BlockStackingLayoutManager
,CharacterLayoutManager
,ContentLayoutManager
,ExternalDocumentLayoutManager
,ExternalGraphicLayoutManager
,FloatContentLayoutManager
,FloatLayoutManager
,FlowLayoutManager
,FootnoteBodyLayoutManager
,FootnoteLayoutManager
,InlineContainerLayoutManager
,InlineLayoutManager
,InlineStackingLayoutManager
,InstreamForeignObjectLM
,LeaderLayoutManager
,LeafNodeLayoutManager
,LineLayoutManager
,ListBlockLayoutManager
,ListItemContentLayoutManager
,ListItemLayoutManager
,MultiCaseLayoutManager
,MultiSwitchLayoutManager
,PageNumberCitationLastLayoutManager
,PageNumberCitationLayoutManager
,PageNumberLayoutManager
,PageSequenceLayoutManager
,RetrieveTableMarkerLayoutManager
,SpacedBorderedPaddedBlockLayoutManager
,StaticContentLayoutManager
,TableAndCaptionLayoutManager
,TableCaptionLayoutManager
,TableCellLayoutManager
,TableLayoutManager
,TextLayoutManager
,WrapperLayoutManager
The interface for all LayoutManagers.
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Method Summary
Modifier and TypeMethodDescriptionvoid
addAreas
(PositionIterator posIter, LayoutContext context) Tell the layout manager to add all the child areas implied by Position objects which will be returned by the Iterator.void
addChildArea
(Area childArea) Add the area as a child of the current area.void
Add the LM in the argument to the list of child LMs; set this LM as the parent; initialize the LM.void
addChildLMs
(List newLMs) Add the LMs in the argument to the list of child LMs;boolean
createNextChildLMs
(int pos) Create more child LMs of the parent, up to child LM index posint
Returns the position of the dominant-baseline of this FO's first descendant line-area.getChangedKnuthElements
(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.int
Returns the BPD of the content areaint
Returns the IPD of the content areagetFObj()
Returns the fo this layout manager is associated with.boolean
Returns an indication if the layout manager generates a block area.boolean
Returns an indication if the layout manager generates a line area.boolean
Returns an indication if the layout manager generates a reference area.getNextKnuthElements
(LayoutContext context, int alignment) Get a sequence of KnuthElements representing the content of the node assigned to the LM.getNextKnuthElements
(LayoutContext context, int alignment, Stack lmStack, Position positionAtIPDChange, LayoutManager restartAtLM) Returns an updated list of Knuth elements corresponding to this layout manager, after a change of IPD has been detected.Get the parent layout manager.getParentArea
(Area childArea) Get the parent area for an area.getPSLM()
Get the active PageSequenceLayoutManager instance for this layout process.boolean
Whether the FO handled by this layout manager has a descendant (including itself) that will generate a line-area.void
initialize the layout manager.boolean
Return a value indicating whether this LayoutManager has laid out all its content (or generated BreakPossibilities for all content.)boolean
Returnstrue
if this layout manager is able to re-generate its Knuth elements after an IPD change.Adds a Position to the Position participating in the first|last determination by assigning it a unique position index.void
reset()
Re-initializes this layout manager in order to re-generate its Knuth elements according to a new IPD value.void
setFinished
(boolean isFinished) Set a flag indicating whether the LayoutManager has laid out all its content.void
Set the parent layout manager.Methods inherited from interface org.apache.fop.datatypes.PercentBaseContext
getBaseLength
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Method Details
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setParent
Set the parent layout manager. The parent layout manager is required for adding areas.- Parameters:
lm
- the parent layout manager
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getParent
LayoutManager getParent()Get the parent layout manager.- Returns:
- the parent layout manager.
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initialize
void initialize()initialize the layout manager. Allows each layout manager to calculate often used values. -
getPSLM
PageSequenceLayoutManager getPSLM()Get the active PageSequenceLayoutManager instance for this layout process.- Returns:
- the PageSequenceLayoutManager
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isFinished
boolean isFinished()Return a value indicating whether this LayoutManager has laid out all its content (or generated BreakPossibilities for all content.)- Returns:
- true if this layout manager is finished
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setFinished
void setFinished(boolean isFinished) Set a flag indicating whether the LayoutManager has laid out all its content. This is generally called by the LM itself, but can be called by a parentLM when backtracking.- Parameters:
isFinished
- the value to set the finished flag to
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getParentArea
Get the parent area for an area. This should get the parent depending on the class of the area passed in.- Parameters:
childArea
- the child area to get the parent for- Returns:
- the parent Area
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addChildArea
Add the area as a child of the current area. This is called by child layout managers to add their areas as children of the current area.- Parameters:
childArea
- the child area to add
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addAreas
Tell the layout manager to add all the child areas implied by Position objects which will be returned by the Iterator.- Parameters:
posIter
- the position iteratorcontext
- the context
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createNextChildLMs
boolean createNextChildLMs(int pos) Create more child LMs of the parent, up to child LM index pos- Parameters:
pos
- index up to which child LMs are requested- Returns:
- true if requested index does exist
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getChildLMs
List getChildLMs()- Returns:
- the list of child LMs
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addChildLM
Add the LM in the argument to the list of child LMs; set this LM as the parent; initialize the LM.- Parameters:
lm
- the LM to be added
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addChildLMs
Add the LMs in the argument to the list of child LMs;- Parameters:
newLMs
- the list of LMs to be added
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getNextKnuthElements
Get a sequence of KnuthElements representing the content of the node assigned to the LM.- Parameters:
context
- the LayoutContext used to store layout informationalignment
- the desired text alignment- Returns:
- the list of KnuthElements
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getChangedKnuthElements
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.- Parameters:
oldList
- the elements to replacealignment
- the desired text alignment- Returns:
- the updated list of KnuthElements
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hasLineAreaDescendant
boolean hasLineAreaDescendant()Whether the FO handled by this layout manager has a descendant (including itself) that will generate a line-area.- Returns:
true
if a descendant line-area will be generated,false
otherwise
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getBaselineOffset
int getBaselineOffset()Returns the position of the dominant-baseline of this FO's first descendant line-area.The behavior of this method is undefined if this FO has no descendant line-area, and an exception may be thrown. See
hasLineAreaDescendant()
- Returns:
- this FO's space-before plus the distance from the before-edge of its allocation-rectangle to the dominant-baseline of the first line-area descendant
- See Also:
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getContentAreaIPD
int getContentAreaIPD()Returns the IPD of the content area- Returns:
- the IPD of the content area
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getContentAreaBPD
int getContentAreaBPD()Returns the BPD of the content area- Returns:
- the BPD of the content area
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getGeneratesReferenceArea
boolean getGeneratesReferenceArea()Returns an indication if the layout manager generates a reference area.- Returns:
- True if the layout manager generates a reference area
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getGeneratesBlockArea
boolean getGeneratesBlockArea()Returns an indication if the layout manager generates a block area.- Returns:
- True if the layout manager generates a block area
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getGeneratesLineArea
boolean getGeneratesLineArea()Returns an indication if the layout manager generates a line area.- Returns:
- True if the layout manager generates a line area
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getFObj
FObj getFObj()Returns the fo this layout manager is associated with.- Returns:
- The fo for this layout manager or null.
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notifyPos
Adds a Position to the Position participating in the first|last determination by assigning it a unique position index.- Parameters:
pos
- the Position- Returns:
- the same Position but with a position index
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reset
void reset()Re-initializes this layout manager in order to re-generate its Knuth elements according to a new IPD value. -
isRestartable
boolean isRestartable()Returnstrue
if this layout manager is able to re-generate its Knuth elements after an IPD change.- Returns:
true
if this layout manager can be restarted after an IPD change
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getNextKnuthElements
List getNextKnuthElements(LayoutContext context, int alignment, Stack lmStack, Position positionAtIPDChange, LayoutManager restartAtLM) Returns an updated list of Knuth elements corresponding to this layout manager, after a change of IPD has been detected.- Parameters:
context
- the layout contextalignment
- the alignmentlmStack
- the stack of LMs that are active at the IPD changepositionAtIPDChange
- the position corresponding to the element finishing the page before the IPD changerestartAtLM
- 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
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