Package org.apache.fop.layoutmgr

Class AbstractBaseLayoutManager

java.lang.Object
org.apache.fop.layoutmgr.AbstractBaseLayoutManager
All Implemented Interfaces:
PercentBaseContext, LayoutManager
Direct Known Subclasses:
AbstractLayoutManager, ContentLayoutManager
public abstract class AbstractBaseLayoutManager extends Object implements LayoutManager, PercentBaseContext
The base class for nearly all LayoutManagers. Provides the functionality for merging the LayoutManager and the PercentBaseContext interfaces into a common base class for all higher LayoutManagers.

  • Field Details

    • generatesReferenceArea

      protected boolean generatesReferenceArea
      Indicator if this LM generates reference areas.

    • generatesBlockArea

      protected boolean generatesBlockArea
      Indicator if this LM generates block areas.

    • fobj

      protected final FObj fobj
      The formatting object for this LM.

  • Constructor Details

    • AbstractBaseLayoutManager

      public AbstractBaseLayoutManager()
      Abstract base layout manager.

    • AbstractBaseLayoutManager

      public AbstractBaseLayoutManager(FObj fo)
      Abstract base layout manager.
      Parameters:
      fo - the formatting object for this layout manager

  • Method Details

    • getBaseLength

      public int getBaseLength(int lengthBase, FObj fobjx)
      Returns the base length for the given length base. Length base should be one of the constants defined in LengthBase.
      Specified by:
      getBaseLength in interface PercentBaseContext
      Parameters:
      lengthBase - Indicates which type of the base length value is to be returned
      fobjx - The FO object against which the percentage should be evaluated
      Returns:
      The base length value of the given kind

    • getAncestorBlockAreaIPD

      protected int getAncestorBlockAreaIPD()
      Find the first ancestor area that is a block area and returns its IPD.
      Returns:
      the ipd of the ancestor block area

    • getAncestorBlockAreaBPD

      protected int getAncestorBlockAreaBPD()
      Find the first ancestor area that is a block area and returns its BPD.
      Returns:
      the bpd of the ancestor block area

    • getParentAreaIPD

      protected int getParentAreaIPD()
      Find the parent area and returns its IPD.
      Returns:
      the ipd of the parent area

    • getParentAreaBPD

      protected int getParentAreaBPD()
      Find the parent area and returns its BPD.
      Returns:
      the bpd of the parent area

    • getReferenceAreaIPD

      public int getReferenceAreaIPD()
      Find the first ancestor area that is a reference area and returns its IPD.
      Returns:
      the ipd of the ancestor reference area

    • getReferenceAreaBPD

      protected int getReferenceAreaBPD()
      Find the first ancestor area that is a reference area and returns its BPD.
      Returns:
      the bpd of the ancestor reference area

    • getContentAreaIPD

      public int getContentAreaIPD()
      Returns the IPD of the content area NOTE: Should be overridden by subclasses. Default implementation throws an UnsupportedOperationException.
      Specified by:
      getContentAreaIPD in interface LayoutManager
      Returns:
      the IPD of the content area

    • getContentAreaBPD

      public int getContentAreaBPD()
      Returns the BPD of the content area NOTE: Should be overridden by subclasses. Default implementation throws an UnsupportedOperationException.
      Specified by:
      getContentAreaBPD in interface LayoutManager
      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
      Returns:
      True if the layout manager generates a reference area

    • setGeneratesReferenceArea

      protected void setGeneratesReferenceArea(boolean generatesReferenceArea)
      Lets implementing LM set the flag indicating if they generate reference areas.
      Parameters:
      generatesReferenceArea - if true the areas generates by this LM are reference areas.

    • getGeneratesBlockArea

      public boolean getGeneratesBlockArea()
      Returns an indication if the layout manager generates a block area.
      Specified by:
      getGeneratesBlockArea in interface LayoutManager
      Returns:
      True if the layout manager generates a block area

    • setGeneratesBlockArea

      protected void setGeneratesBlockArea(boolean generatesBlockArea)
      Lets implementing LM set the flag indicating if they generate block areas.
      Parameters:
      generatesBlockArea - if true the areas generates by this LM are block areas.

    • getGeneratesLineArea

      public boolean getGeneratesLineArea()
      Returns an indication if the layout manager generates a line area.
      Specified by:
      getGeneratesLineArea in interface LayoutManager
      Returns:
      True if the layout manager generates a line area

    • getFObj

      public FObj getFObj()
      Returns the fo this layout manager is associated with.
      Specified by:
      getFObj in interface LayoutManager
      Returns:
      The fo for this layout manager or null.

    • getChangeBarList

      public List<ChangeBar> getChangeBarList()
      Returns the active change bar list.
      Returns:
      The active change bar list

    • 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

    • isRestartable

      public boolean isRestartable()
      Returns true if this layout manager is able to re-generate its Knuth elements after an IPD change.
      Specified by:
      isRestartable in interface LayoutManager
      Returns:
      true if this layout manager can be restarted after an IPD change

    • getNextKnuthElements

      public 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.
      Specified by:
      getNextKnuthElements in interface LayoutManager
      Parameters:
      context - the layout context
      alignment - the alignment
      lmStack - the stack of LMs that are active at the IPD change
      positionAtIPDChange - 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

    • preserveChildrenAtEndOfLayout

      public void preserveChildrenAtEndOfLayout()

    • recreateChildrenLMs

      public void recreateChildrenLMs()