Package org.apache.fop.layoutmgr

Class BalancingColumnBreakingAlgorithm

java.lang.Object

org.apache.fop.layoutmgr.BreakingAlgorithm

org.apache.fop.layoutmgr.PageBreakingAlgorithm

org.apache.fop.layoutmgr.BalancingColumnBreakingAlgorithm

public class BalancingColumnBreakingAlgorithm
extends PageBreakingAlgorithm

This is a the breaking algorithm that is responsible for balancing columns in multi-column layout.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	BalancingColumnBreakingAlgorithm.ColumnContent

Nested classes/interfaces inherited from class org.apache.fop.layoutmgr.PageBreakingAlgorithm

PageBreakingAlgorithm.BestPageRecords, PageBreakingAlgorithm.KnuthPageNode, PageBreakingAlgorithm.PageBreakingLayoutListener

Nested classes/interfaces inherited from class org.apache.fop.layoutmgr.BreakingAlgorithm

BreakingAlgorithm.BestRecords, BreakingAlgorithm.FitnessClasses, BreakingAlgorithm.KnuthNode

Field Summary

Fields

Modifier and Type	Field	Description
private int	columnCount
private java.util.List<java.lang.Integer>	idealBreaks

Fields inherited from class org.apache.fop.layoutmgr.PageBreakingAlgorithm

bestNodeForLastPage

Fields inherited from class org.apache.fop.layoutmgr.BreakingAlgorithm

activeLines, activeNodeCount, alignment, alignmentLast, ALL_BREAKS, best, considerTooShort, endLine, incompatibleFitnessDemerit, indentFirstPart, INFINITE_RATIO, lineWidth, maxFlaggedPenaltiesCount, NO_FLAGGED_PENALTIES, ONLY_FORCED_BREAKS, par, repeatedFlaggedDemerit, startLine, totalShrink, totalStretch, totalWidth

Constructor Summary

Constructors

Constructor	Description
BalancingColumnBreakingAlgorithm(LayoutManager topLevelLM, PageProvider pageProvider, PageBreakingAlgorithm.PageBreakingLayoutListener layoutListener, int alignment, int alignmentLast, MinOptMax footnoteSeparatorLength, boolean partOverflowRecovery, int columnCount)

Method Summary

Modifier and Type	Method	Description
private int	calcContentLength(KnuthSequence par, int startIndex, int endIndex)
private java.util.List<java.lang.Integer>	calculateIdealBreaks(int startPos)
protected double	computeDemerits(BreakingAlgorithm.KnuthNode activeNode, KnuthElement element, int fitnessClass, double r)	Computes the demerits of the current breaking (that is, up to the given element), if the next-to-last chosen breakpoint is the given active node.
private int	getAverageColumnLength(java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> columns)
private java.util.List<java.lang.Integer>	getElementIdBreaks(java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> breaks, int startPos)
private java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent>	getInitialBreaks(int startIndex, int averageColLength)
private int	getNextStartIndex(int breakIndex)
private int	getPenaltyWidth(int index)
private java.util.LinkedList<java.lang.Integer>	getPossibilityTrail(BreakingAlgorithm.KnuthNode activeNode)
private boolean	isLegalBreak(int index, boolean prevIsBox)
private java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent>	sortElementsForBreaks(java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> breaks)

Methods inherited from class org.apache.fop.layoutmgr.PageBreakingAlgorithm

addNode, compareNodes, computeAdjustmentRatio, computeDifference, considerLegalBreak, createForcedNodes, createNode, createNode, deactivateNode, disableFloatHandling, elementCanEndLine, filterActiveNodes, finish, getBestFloatEdgeNode, getBestNodeBeforeIPDChange, getBestNodeForLastPage, getFloatHeight, getFloatPosition, getFObj, getFootnoteList, getIPDdifference, getLineWidth, getPageBreaks, handleBox, handleFloat, handleIpdChange, handlePenaltyAt, handlingEndOfFloat, handlingFloat, handlingStartOfFloat, initialize, insertPageBreakAsFirst, loadFootnotes, recoverFromOverflow, recoverFromTooLong, relayFootnotes, removeAllPageBreaks, restartFrom, updateData1, updateData2

Methods inherited from class org.apache.fop.layoutmgr.BreakingAlgorithm

activateNode, calculateBreakPoints, findBreakingPoints, findBreakingPoints, forceNode, getAlignment, getAlignmentLast, getElement, getLastTooLong, getLastTooShort, getLineWidth, getMaxRecoveryAttempts, getNode, handleElementAt, handleGlueAt, isPartOverflowRecoveryActivated, removeNode, replaceLastDeactivated, setConstantLineWidth, toString

Methods inherited from class java.lang.Object

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

Field Detail

columnCount

private int columnCount

idealBreaks

private java.util.List<java.lang.Integer> idealBreaks

Constructor Detail

BalancingColumnBreakingAlgorithm

public BalancingColumnBreakingAlgorithm(LayoutManager topLevelLM,
                                        PageProvider pageProvider,
                                        PageBreakingAlgorithm.PageBreakingLayoutListener layoutListener,
                                        int alignment,
                                        int alignmentLast,
                                        MinOptMax footnoteSeparatorLength,
                                        boolean partOverflowRecovery,
                                        int columnCount)

Method Detail

computeDemerits

protected double computeDemerits(BreakingAlgorithm.KnuthNode activeNode,
                                 KnuthElement element,
                                 int fitnessClass,
                                 double r)

Computes the demerits of the current breaking (that is, up to the given element), if the next-to-last chosen breakpoint is the given active node. This adds to the total demerits of the given active node, the demerits of a line starting at this node and ending at the given element.

Overrides:

computeDemerits in class PageBreakingAlgorithm

Parameters:

activeNode - considered preceding line break

element - considered current line break

fitnessClass - fitness of the current line

r - adjustment ratio for the current line

Returns:

the demerit of the current line

calculateIdealBreaks

private java.util.List<java.lang.Integer> calculateIdealBreaks(int startPos)

getAverageColumnLength

private int getAverageColumnLength(java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> columns)

getInitialBreaks

private java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> getInitialBreaks(int startIndex,
                                                                                        int averageColLength)

getNextStartIndex

private int getNextStartIndex(int breakIndex)

sortElementsForBreaks

private java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> sortElementsForBreaks(java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> breaks)

isLegalBreak

private boolean isLegalBreak(int index,
                             boolean prevIsBox)

calcContentLength

private int calcContentLength(KnuthSequence par,
                              int startIndex,
                              int endIndex)

getPenaltyWidth

private int getPenaltyWidth(int index)

getElementIdBreaks

private java.util.List<java.lang.Integer> getElementIdBreaks(java.util.List<BalancingColumnBreakingAlgorithm.ColumnContent> breaks,
                                                             int startPos)

getPossibilityTrail

private java.util.LinkedList<java.lang.Integer> getPossibilityTrail(BreakingAlgorithm.KnuthNode activeNode)