ContentLayoutManager (Apache FOP 2.7 API)
Date: 2022-01-12

org.apache.fop.layoutmgr.inline

## Class ContentLayoutManager

- java.lang.Object
- - org.apache.fop.layoutmgr.AbstractBaseLayoutManager
  - - org.apache.fop.layoutmgr.inline.ContentLayoutManager

- All Implemented Interfaces:
    PercentBaseContext, InlineLevelLayoutManager, LayoutManager

      public class ContentLayoutManager
      extends AbstractBaseLayoutManager
      implements InlineLevelLayoutManager

  Content Layout Manager. For use with objects that contain inline areas such as leader use-content and title.

- - ### Field Summary

    - ### Fields inherited from class org.apache.fop.layoutmgr.AbstractBaseLayoutManager

      `fobj, generatesBlockArea, generatesReferenceArea`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `ContentLayoutManager(Area area, LayoutManager parentLM)` Constructs a new ContentLayoutManager
    `ContentLayoutManager(PageSequenceLayoutManager pslm, Title foTitle)` Constructor using a fo:title formatting object and its PageSequenceLayoutManager parent.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `java.util.List` | `addALetterSpaceTo(java.util.List oldList)` Tell the LM to modify its data, adding a letter space to the word fragment represented by the given elements, and returning the corrected elements
    `java.util.List` | `addALetterSpaceTo(java.util.List oldList, int depth)` Tell the LM to modify its data, adding a letter space to the word fragment represented by the given elements, and returning the corrected elements
    `void` | `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` | `addChildLM(LayoutManager lm)` Add the LM in the argument to the list of child LMs; set this LM as the parent; initialize the LM.
    `void` | `addChildLMs(java.util.List newLMs)` Add the LMs in the argument to the list of child LMs;
    `boolean` | `applyChanges(java.util.List oldList)` Tell the LM to apply the changes due to hyphenation
    `boolean` | `applyChanges(java.util.List oldList, int depth)` Tell the LM to apply the changes due to hyphenation
    `boolean` | `createNextChildLMs(int pos)` Create more child LMs of the parent, up to child LM index pos
    `int` | `getBaselineOffset()` Returns the position of the dominant-baseline of this FO's first descendant line-area.
    `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.
    `java.util.List` | `getChangedKnuthElements(java.util.List oldList, int alignment, int depth)` Get a sequence of KnuthElements representing the content of the node assigned to the LM, after changes have been applied
    `java.util.List` | `getChildLMs()`
    `int` | `getContentAreaBPD()` Returns the BPD of the content area
    `int` | `getContentAreaIPD()` Returns the IPD of the content area
    `boolean` | `getGeneratesBlockArea()` Returns an indication if the layout manager generates a block area.
    `boolean` | `getGeneratesLineArea()` Returns an indication if the layout manager generates a line area.
    `boolean` | `getGeneratesReferenceArea()` Returns an indication if the layout manager generates a reference area.
    `java.util.List` | `getNextKnuthElements(LayoutContext context, int alignment)` Get a sequence of KnuthElements representing the content of the node assigned to the LM.
    `LayoutManager` | `getParent()` Get the parent layout manager.
    `Area` | `getParentArea(Area childArea)` Get the parent area for an area.
    `PageSequenceLayoutManager` | `getPSLM()` Get the active PageSequenceLayoutManager instance for this layout process.
    `int` | `getStackingSize()`
    `java.lang.String` | `getWordChars(Position pos)` Get the word chars corresponding to the given position.
    `boolean` | `hasLineAreaDescendant()` Whether the FO handled by this layout manager has a descendant (including itself) that will generate a line-area.
    `void` | `hyphenate(Position pos, HyphContext hc)` Tell the LM to hyphenate a word
    `void` | `initialize()` initialize the layout manager.
    `boolean` | `isFinished()` Return a value indicating whether this LayoutManager has laid out all its content (or generated BreakPossibilities for all content.)
    `Position` | `notifyPos(Position pos)` Adds a Position to the Position participating in the first|last determination by assigning it a unique position index.
    `void` | `setFinished(boolean isFinished)` Set a flag indicating whether the LayoutManager has laid out all its content.
    `void` | `setParent(LayoutManager lm)` Set the parent layout manager.

    - ### Methods inherited from class org.apache.fop.layoutmgr.AbstractBaseLayoutManager

      `getAncestorBlockAreaBPD, getAncestorBlockAreaIPD, getBaseLength, getChangeBarList, getFObj, getNextKnuthElements, getParentAreaBPD, getParentAreaIPD, getReferenceAreaBPD, getReferenceAreaIPD, isRestartable, preserveChildrenAtEndOfLayout, recreateChildrenLMs, reset, setGeneratesBlockArea, setGeneratesReferenceArea`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

    - ### Methods inherited from interface org.apache.fop.layoutmgr.LayoutManager

      `getFObj, getNextKnuthElements, isRestartable, reset`

    - ### Methods inherited from interface org.apache.fop.datatypes.PercentBaseContext

      `getBaseLength`

- - ### Constructor Detail

    - #### ContentLayoutManager

          public ContentLayoutManager(Area area,
                                      LayoutManager parentLM)

      Constructs a new ContentLayoutManager
      Parameters:
        `area` - The parent area
        `parentLM` - the parent layout manager

    - #### ContentLayoutManager

          public ContentLayoutManager(PageSequenceLayoutManager pslm,
                                      Title foTitle)

      Constructor using a fo:title formatting object and its PageSequenceLayoutManager parent. throws IllegalStateException if the foTitle has no children. TODO: convert IllegalStateException to FOPException; also in makeLayoutManager and makeContentLayoutManager and callers.
      Parameters:
        `pslm` - the PageSequenceLayoutManager parent of this LM
        `foTitle` - the Title FO for which this LM is made

  - ### Method Detail

    - #### initialize

          public void initialize()

      initialize the layout manager. Allows each layout manager to calculate often used values.
      Specified by:
        `initialize` in interface `LayoutManager`

    - #### addAreas

          public void 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.
      Specified by:
        `addAreas` in interface `LayoutManager`
      Parameters:
        `posIter` - the position iterator
        `context` - the context

    - #### getStackingSize

          public int getStackingSize()

      Returns:
        stack size

    - #### getParentArea

          public Area getParentArea(Area childArea)

      Get the parent area for an area. This should get the parent depending on the class of the area passed in.
      Specified by:
        `getParentArea` in interface `LayoutManager`
      Parameters:
        `childArea` - the child area to get the parent for
      Returns:
        the parent Area

    - #### addChildArea

          public void addChildArea(Area childArea)

      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.
      Specified by:
        `addChildArea` in interface `LayoutManager`
      Parameters:
        `childArea` - the child area to add

    - #### setParent

          public void setParent(LayoutManager lm)

      Set the parent layout manager. The parent layout manager is required for adding areas.
      Specified by:
        `setParent` in interface `LayoutManager`
      Parameters:
        `lm` - the parent layout manager

    - #### getParent

          public LayoutManager getParent()

      Get the parent layout manager.
      Specified by:
        `getParent` in interface `LayoutManager`
      Returns:
        the parent layout manager.

    - #### isFinished

          public boolean isFinished()

      Return a value indicating whether this LayoutManager has laid out all its content (or generated BreakPossibilities for all content.)
      Specified by:
        `isFinished` in interface `LayoutManager`
      Returns:
        true if this layout manager is finished

    - #### setFinished

          public 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.
      Specified by:
        `setFinished` in interface `LayoutManager`
      Parameters:
        `isFinished` - the value to set the finished flag to

    - #### createNextChildLMs

          public boolean createNextChildLMs(int pos)

      Create more child LMs of the parent, up to child LM index pos
      Specified by:
        `createNextChildLMs` in interface `LayoutManager`
      Parameters:
        `pos` - index up to which child LMs are requested
      Returns:
        true if requested index does exist

    - #### getChildLMs

          public java.util.List getChildLMs()

      Specified by:
        `getChildLMs` in interface `LayoutManager`
      Returns:
        the list of child LMs

    - #### addChildLM

          public void addChildLM(LayoutManager lm)

      Add the LM in the argument to the list of child LMs; set this LM as the parent; initialize the LM.
      Specified by:
        `addChildLM` in interface `LayoutManager`
      Parameters:
        `lm` - the LM to be added

    - #### addChildLMs

          public void addChildLMs(java.util.List newLMs)

      Add the LMs in the argument to the list of child LMs;
      Specified by:
        `addChildLMs` in interface `LayoutManager`
      Parameters:
        `newLMs` - the list of LMs to be added

    - #### 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`
      Parameters:
        `context` - the LayoutContext used to store layout information
        `alignment` - the desired text alignment
      Returns:
        the list of KnuthElements

    - #### addALetterSpaceTo

          public java.util.List addALetterSpaceTo(java.util.List oldList)

      Tell the LM to modify its data, adding a letter space to the word fragment represented by the given elements, and returning the corrected elements
      Specified by:
        `addALetterSpaceTo` in interface `InlineLevelLayoutManager`
      Parameters:
        `oldList` - the elements which must be given one more letter space
      Returns:
        the new elements replacing the old ones

    - #### addALetterSpaceTo

          public java.util.List addALetterSpaceTo(java.util.List oldList,
                                                  int depth)

      Tell the LM to modify its data, adding a letter space to the word fragment represented by the given elements, and returning the corrected elements
      Specified by:
        `addALetterSpaceTo` in interface `InlineLevelLayoutManager`
      Parameters:
        `oldList` - the elements which must be given one more letter space
        `depth` - the depth at which the Positions for this LM in oldList are found
      Returns:
        the new elements replacing the old ones

    - #### getWordChars

          public java.lang.String getWordChars(Position pos)

      Get the word chars corresponding to the given position.
      Specified by:
        `getWordChars` in interface `InlineLevelLayoutManager`
      Parameters:
        `pos` - the position referring to the needed word chars.
      Returns:
        the word chars

    - #### hyphenate

          public void hyphenate(Position pos,
                                HyphContext hc)

      Tell the LM to hyphenate a word
      Specified by:
        `hyphenate` in interface `InlineLevelLayoutManager`
      Parameters:
        `pos` - the Position referring to the word
        `hc` - the HyphContext storing hyphenation information

    - #### applyChanges

          public boolean applyChanges(java.util.List oldList)

      Tell the LM to apply the changes due to hyphenation
      Specified by:
        `applyChanges` in interface `InlineLevelLayoutManager`
      Parameters:
        `oldList` - the list of the old elements the changes refer to
      Returns:
        true if the LM had to change its data, false otherwise

    - #### applyChanges

          public boolean applyChanges(java.util.List oldList,
                                      int depth)

      Tell the LM to apply the changes due to hyphenation
      Specified by:
        `applyChanges` in interface `InlineLevelLayoutManager`
      Parameters:
        `oldList` - the list of the old elements the changes refer to
        `depth` - the depth at which the Positions for this LM in oldList are found
      Returns:
        true if the LM had to change its data, false otherwise

    - #### 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`
      Parameters:
        `oldList` - the elements to replace
        `alignment` - the desired text alignment
      Returns:
        the updated list of KnuthElements

    - #### getChangedKnuthElements

          public java.util.List getChangedKnuthElements(java.util.List oldList,
                                                        int alignment,
                                                        int depth)

      Get a sequence of KnuthElements representing the content of the node assigned to the LM, after changes have been applied
      Specified by:
        `getChangedKnuthElements` in interface `InlineLevelLayoutManager`
      Parameters:
        `oldList` - the elements to replace
        `alignment` - the desired text alignment
        `depth` - the depth at which the Positions for this LM in oldList are found
      Returns:
        the updated list of KnuthElements

    - #### getPSLM

          public PageSequenceLayoutManager getPSLM()

      Get the active PageSequenceLayoutManager instance for this layout process.
      Specified by:
        `getPSLM` in interface `LayoutManager`
      Returns:
        the PageSequenceLayoutManager

    - #### hasLineAreaDescendant

          public boolean hasLineAreaDescendant()

      Description copied from interface: `LayoutManager`
      Whether the FO handled by this layout manager has a descendant (including itself) that will generate a line-area.
      Specified by:
        `hasLineAreaDescendant` in interface `LayoutManager`
      Returns:
        `true` if a descendant line-area will be generated, `false` otherwise

    - #### getBaselineOffset

          public int getBaselineOffset()

      Description copied from interface: `LayoutManager`
      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 `LayoutManager.hasLineAreaDescendant()`

      Specified by:
        `getBaselineOffset` in interface `LayoutManager`
      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:
        `LayoutManager.hasLineAreaDescendant()`

    - #### getContentAreaIPD

          public int getContentAreaIPD()

      Returns the IPD of the content area
      Specified by:
        `getContentAreaIPD` in interface `LayoutManager`
      Overrides:
        `getContentAreaIPD` in class `AbstractBaseLayoutManager`
      Returns:
        the IPD of the content area

    - #### getContentAreaBPD

          public int getContentAreaBPD()

      Returns the BPD of the content area
      Specified by:
        `getContentAreaBPD` in interface `LayoutManager`
      Overrides:
        `getContentAreaBPD` in class `AbstractBaseLayoutManager`
      Returns:
        the BPD of the content area

    - #### getGeneratesReferenceArea

          public boolean getGeneratesReferenceArea()

      Returns an indication if the layout manager generates a reference area.
      Specified by:
        `getGeneratesReferenceArea` in interface `LayoutManager`
      Overrides:
        `getGeneratesReferenceArea` in class `AbstractBaseLayoutManager`
      Returns:
        True if the layout manager generates a reference area

    - #### getGeneratesBlockArea

          public boolean getGeneratesBlockArea()

      Returns an indication if the layout manager generates a block area.
      Specified by:
        `getGeneratesBlockArea` in interface `LayoutManager`
      Overrides:
        `getGeneratesBlockArea` in class `AbstractBaseLayoutManager`
      Returns:
        True if the layout manager generates a block area

    - #### getGeneratesLineArea

          public boolean getGeneratesLineArea()

      Returns an indication if the layout manager generates a line area.
      Specified by:
        `getGeneratesLineArea` in interface `LayoutManager`
      Overrides:
        `getGeneratesLineArea` in class `AbstractBaseLayoutManager`
      Returns:
        True if the layout manager generates a line area

    - #### notifyPos

          public Position notifyPos(Position pos)

      Adds a Position to the Position participating in the first|last determination by assigning it a unique position index.
      Specified by:
        `notifyPos` in interface `LayoutManager`
      Parameters:
        `pos` - the Position
      Returns:
        the same Position but with a position index

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