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 Summary

Fields

Modifier and Type	Field and Description
protected FObj	fobj The formatting object for this LM.
protected boolean	generatesBlockArea Indicator if this LM generates block areas.
protected boolean	generatesReferenceArea Indicator if this LM generates reference areas.

Constructor Summary

Constructors

Constructor and Description
AbstractBaseLayoutManager() Abstract base layout manager.
AbstractBaseLayoutManager(FObj fo) Abstract base layout manager.

Method Summary

Modifier and Type	Method and Description
protected int	getAncestorBlockAreaBPD() Find the first ancestor area that is a block area and returns its BPD.
protected int	getAncestorBlockAreaIPD() Find the first ancestor area that is a block area and returns its IPD.
int	getBaseLength(int lengthBase, FObj fobjx) Returns the base length for the given length base.
List<ChangeBar>	getChangeBarList() Returns the active change bar list.
int	getContentAreaBPD() Returns the BPD of the content area
int	getContentAreaIPD() Returns the IPD of the content area
FObj	getFObj() Returns the fo this layout manager is associated with.
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.
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.
protected int	getParentAreaBPD() Find the parent area and returns its BPD.
protected int	getParentAreaIPD() Find the parent area and returns its IPD.
protected int	getReferenceAreaBPD() Find the first ancestor area that is a reference area and returns its BPD.
int	getReferenceAreaIPD() Find the first ancestor area that is a reference area and returns its IPD.
boolean	isRestartable() Returns true if this layout manager is able to re-generate its Knuth elements after an IPD change.
void	preserveChildrenAtEndOfLayout()
void	recreateChildrenLMs()
void	reset() Re-initializes this layout manager in order to re-generate its Knuth elements according to a new IPD value.
protected void	setGeneratesBlockArea(boolean generatesBlockArea) Lets implementing LM set the flag indicating if they generate block areas.
protected void	setGeneratesReferenceArea(boolean generatesReferenceArea) Lets implementing LM set the flag indicating if they generate reference areas.

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

addAreas, addChildArea, addChildLM, addChildLMs, createNextChildLMs, getBaselineOffset, getChangedKnuthElements, getChildLMs, getNextKnuthElements, getParent, getParentArea, getPSLM, hasLineAreaDescendant, initialize, isFinished, notifyPos, setFinished, setParent

Field Detail

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 Detail

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 Detail

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()