org.apache.fop.layoutmgr
Class BreakingAlgorithm

java.lang.Object
  org.apache.fop.layoutmgr.BreakingAlgorithm

Direct Known Subclasses:

BalancingColumnBreakingAlgorithm

public abstract class BreakingAlgorithm
extends java.lang.Object

The set of nodes is sorted into lines indexed into activeLines. The nodes in each line are linked together in a single linked list by the BreakingAlgorithm.KnuthNode.next field. The activeLines array contains a link to the head of the linked list in index 'line*2' and a link to the tail at index 'line*2+1'.

The set of active nodes can be traversed by

 for (int line = startLine; line < endLine; line++) {
     for (KnuthNode node = getNode(line); node != null; node = node.next) {
         // Do something with 'node'
     }
 }
 

Nested Class Summary

protected class	BreakingAlgorithm.BestRecords Class that stores, for each fitness class, the best active node that could start a line of the corresponding fitness ending at the current element.
class	BreakingAlgorithm.KnuthNode Class recording all the informations of a feasible breaking point.

Field Summary

protected BreakingAlgorithm.KnuthNode[]	activeLines The set of active nodes in ascending line order.
protected int	activeNodeCount The number of active nodes.
protected int	alignment Alignment of the paragraph/page.
protected int	alignmentLast Alignment of the paragraph's last line.
static int	ALL_BREAKS All feasible breaks are ok.
protected BreakingAlgorithm.BestRecords	best Best records.
protected boolean	considerTooShort If set to true, doesn't ignore break possibilities which are definitely too short.
protected int	endLine The highest + 1 available line in the set of active nodes.
protected int	incompatibleFitnessDemerit Demerit for consecutive lines belonging to incompatible fitness classes .
protected boolean	indentFirstPart Used to handle the text-indent property (indent the first line of a paragraph).
protected static int	INFINITE_RATIO Maximum adjustment ration
protected int	lineWidth The width of a line (or height of a column in page-breaking mode).
protected static org.apache.commons.logging.Log	log the logger for the class
protected int	maxFlaggedPenaltiesCount Maximum number of consecutive lines ending with a flagged penalty.
static int	NO_FLAGGED_PENALTIES This forbids hyphenation.
static int	ONLY_FORCED_BREAKS wrap-option = "no-wrap".
protected KnuthSequence	par The paragraph of KnuthElements.
protected int	repeatedFlaggedDemerit Demerit for consecutive lines ending at flagged penalties.
protected int	startLine The lowest available line in the set of active nodes.
protected int	totalShrink The total shrink of all elements handled so far.
protected int	totalStretch The total stretch of all elements handled so far.
protected int	totalWidth The total width of all elements handled so far.

Constructor Summary

BreakingAlgorithm(int align, int alignLast, boolean first, boolean partOverflowRecovery, int maxFlagCount)
Create a new instance.

Method Summary

protected void	activateNode(BreakingAlgorithm.KnuthNode node, int difference, double r, double demerits, int fitnessClass, int availableShrink, int availableStretch) Activate the given node.
protected void	addNode(int line, BreakingAlgorithm.KnuthNode node) Add a node at the end of the given line's existing active nodes.
protected void	calculateBreakPoints(BreakingAlgorithm.KnuthNode node, KnuthSequence par, int total) Determines the set of optimal breakpoints corresponding to the given active node.
protected BreakingAlgorithm.KnuthNode	compareNodes(BreakingAlgorithm.KnuthNode node1, BreakingAlgorithm.KnuthNode node2) Compare two KnuthNodes and return the node with the least demerit.
protected double	computeAdjustmentRatio(BreakingAlgorithm.KnuthNode activeNode, int difference) Return the adjustment ratio needed to make up for the difference.
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.
protected int	computeDifference(BreakingAlgorithm.KnuthNode activeNode, KnuthElement element, int elementIndex) Return the difference between the natural width of a line that would be made between the given active node and the given element, and the available width of the real line.
protected void	considerLegalBreak(KnuthElement element, int elementIdx) Determines if the given breakpoint is a feasible breakpoint.
protected void	createForcedNodes(BreakingAlgorithm.KnuthNode node, int line, int elementIdx, int difference, double r, double demerits, int fitnessClass, int availableShrink, int availableStretch, int newWidth, int newStretch, int newShrink)
protected BreakingAlgorithm.KnuthNode	createNode(int position, int line, int fitness, int totalWidth, int totalStretch, int totalShrink) Creates a new active node for a break from the best active node of the given fitness class to the element at the given position.
protected BreakingAlgorithm.KnuthNode	createNode(int position, int line, int fitness, int totalWidth, int totalStretch, int totalShrink, double adjustRatio, int availableShrink, int availableStretch, int difference, double totalDemerits, BreakingAlgorithm.KnuthNode previous) Creates a new active node for a feasible breakpoint at the given position.
protected void	deactivateNode(BreakingAlgorithm.KnuthNode node, int line) Deactivate the given node
protected void	disableFloatHandling()
protected boolean	elementCanEndLine(KnuthElement element, int line, int difference) Check if the given KnuthElement can end the line with the given number.
protected abstract int	filterActiveNodes() Filter active nodes.
int	findBreakingPoints(KnuthSequence par, double threshold, boolean force, int allowedBreaks)
int	findBreakingPoints(KnuthSequence par, int startIndex, double threshold, boolean force, int allowedBreaks) Finds an optimal set of breakpoints for the given paragraph.
protected void	finish() Hook for subclasses to trigger special behavior after ending the main loop in findBreakingPoints(KnuthSequence,int,double,boolean,int)
protected void	forceNode(BreakingAlgorithm.KnuthNode node, int line, int elementIdx, int difference, double r, double demerits, int fitnessClass, int availableShrink, int availableStretch) Force the given BreakingAlgorithm.KnuthNode, and register it.
int	getAlignment()
int	getAlignmentLast()
protected KnuthElement	getElement(int idx) Return the element at index idx in the paragraph.
protected int	getIPDdifference() obtain ipd difference
protected BreakingAlgorithm.KnuthNode	getLastTooLong()
protected BreakingAlgorithm.KnuthNode	getLastTooShort() Return the last node that yielded a too short line.
protected int	getLineWidth()
protected int	getLineWidth(int line) Returns the line/part width of a given line/part.
protected int	getMaxRecoveryAttempts()
protected BreakingAlgorithm.KnuthNode	getNode(int line) Returns the first active node for the given line.
protected void	handleBox(KnuthBox box) Handle a KnuthBox.
protected KnuthElement	handleElementAt(int position, boolean previousIsBox, int allowedBreaks) Generic handler for a KnuthElement at the given position, taking into account whether the preceding element was a box, and which type(s) of breaks are allowed.
protected int	handleFloat()
protected void	handleGlueAt(KnuthGlue glue, int position, boolean previousIsBox, int allowedBreaks) Handle a KnuthGlue at the given position, taking into account the additional parameters.
protected int	handleIpdChange() handle ipd change
protected void	handlePenaltyAt(KnuthPenalty penalty, int position, int allowedBreaks) Handle a KnuthPenalty at the given position, taking into account the type of breaks allowed.
protected boolean	handlingFloat()
protected void	initialize() Initializes the algorithm's variables.
protected boolean	isPartOverflowRecoveryActivated() Controls the behaviour of the algorithm in cases where the first element of a part overflows a line/page.
protected BreakingAlgorithm.KnuthNode	recoverFromOverflow() Recover from an overflow condition.
protected BreakingAlgorithm.KnuthNode	recoverFromTooLong(BreakingAlgorithm.KnuthNode lastTooLong) Recover from a BreakingAlgorithm.KnuthNode leading to a line that is too long.
protected void	removeNode(int line, BreakingAlgorithm.KnuthNode node) Remove the given active node registered for the given line.
protected void	replaceLastDeactivated() Replace the last too-long or too-short node by the last deactivated node, if applicable.
protected int	restartFrom(BreakingAlgorithm.KnuthNode restartingNode, int currentIndex) Restart from the given node at the given index.
void	setConstantLineWidth(int lineWidth)
java.lang.String	toString(java.lang.String prepend) Creates a string representation of the active nodes.
abstract void	updateData1(int total, double demerits) Empty method, hook for subclasses.
abstract void	updateData2(BreakingAlgorithm.KnuthNode bestActiveNode, KnuthSequence sequence, int total) Empty method, hook for subclasses.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.commons.logging.Log log

the logger for the class

INFINITE_RATIO

protected static final int INFINITE_RATIO

Maximum adjustment ration

See Also:

Constant Field Values

ALL_BREAKS

public static final int ALL_BREAKS

All feasible breaks are ok.

See Also:

Constant Field Values

NO_FLAGGED_PENALTIES

public static final int NO_FLAGGED_PENALTIES

This forbids hyphenation.

See Also:

Constant Field Values

ONLY_FORCED_BREAKS

public static final int ONLY_FORCED_BREAKS

wrap-option = "no-wrap".

See Also:

Constant Field Values

repeatedFlaggedDemerit

protected int repeatedFlaggedDemerit

Demerit for consecutive lines ending at flagged penalties.

incompatibleFitnessDemerit

protected int incompatibleFitnessDemerit

Demerit for consecutive lines belonging to incompatible fitness classes .

maxFlaggedPenaltiesCount

protected int maxFlaggedPenaltiesCount

Maximum number of consecutive lines ending with a flagged penalty. Only a value >= 1 is a significant limit.

par

protected KnuthSequence par

The paragraph of KnuthElements.

lineWidth

protected int lineWidth

The width of a line (or height of a column in page-breaking mode). -1 indicates that the line widths are different for each line.

considerTooShort

protected boolean considerTooShort

If set to true, doesn't ignore break possibilities which are definitely too short.

alignment

protected int alignment

Alignment of the paragraph/page. One of EN_START, EN_JUSTIFY, etc.

alignmentLast

protected int alignmentLast

Alignment of the paragraph's last line.

indentFirstPart

protected boolean indentFirstPart

Used to handle the text-indent property (indent the first line of a paragraph).

activeLines

protected BreakingAlgorithm.KnuthNode[] activeLines

The set of active nodes in ascending line order. For each line l, activeLines[2l] contains a link to l's first active node, and activeLines[2l+1] a link to l's last active node. The line number l corresponds to the number of the line ending at the node's breakpoint.

activeNodeCount

protected int activeNodeCount

The number of active nodes.

startLine

protected int startLine

The lowest available line in the set of active nodes.

endLine

protected int endLine

The highest + 1 available line in the set of active nodes.

totalWidth

protected int totalWidth

The total width of all elements handled so far.

totalStretch

protected int totalStretch

The total stretch of all elements handled so far.

totalShrink

protected int totalShrink

The total shrink of all elements handled so far.

best

protected BreakingAlgorithm.BestRecords best

Best records.

Constructor Detail

BreakingAlgorithm

public BreakingAlgorithm(int align,
                         int alignLast,
                         boolean first,
                         boolean partOverflowRecovery,
                         int maxFlagCount)

Create a new instance.

Parameters:

align - alignment of the paragraph/page. One of Constants.EN_START, Constants.EN_JUSTIFY, Constants.EN_CENTER, Constants.EN_END. For pages, Constants.EN_BEFORE and Constants.EN_AFTER are mapped to the corresponding inline properties, Constants.EN_START and Constants.EN_END.

alignLast - alignment of the paragraph's last line

first - for the text-indent property (true if the first line of a paragraph should be indented)

partOverflowRecovery - true if too long elements should be moved to the next line/part

maxFlagCount - maximum allowed number of consecutive lines ending at a flagged penalty item

Method Detail

getMaxRecoveryAttempts

protected int getMaxRecoveryAttempts()

Returns:

the number of times the algorithm should try to move overflowing content to the next line/page.

isPartOverflowRecoveryActivated

protected boolean isPartOverflowRecoveryActivated()

Controls the behaviour of the algorithm in cases where the first element of a part overflows a line/page.

Returns:

true if the algorithm should try to send the element to the next line/page.

getLastTooLong

protected BreakingAlgorithm.KnuthNode getLastTooLong()

updateData1

public abstract void updateData1(int total,
                                 double demerits)

Empty method, hook for subclasses. Called before determining the optimal breakpoints corresponding to a given active node.

Parameters:

total - number of lines for the active node

demerits - total demerits of the paragraph for the active node

updateData2

public abstract void updateData2(BreakingAlgorithm.KnuthNode bestActiveNode,
                                 KnuthSequence sequence,
                                 int total)

Empty method, hook for subclasses. Called when determining the optimal breakpoints for a given active node.

Parameters:

bestActiveNode - a node in the chain of best active nodes, corresponding to one of the optimal breakpoints

sequence - the corresponding paragraph

total - the number of lines into which the paragraph will be broken

setConstantLineWidth

public void setConstantLineWidth(int lineWidth)

Parameters:

lineWidth - the line width

findBreakingPoints

public int findBreakingPoints(KnuthSequence par,
                              double threshold,
                              boolean force,
                              int allowedBreaks)

Parameters:

par - the paragraph to break

threshold - upper bound of the adjustment ratio

force - true if a set of breakpoints must be found, even if there are no feasible ones

allowedBreaks - the type(s) of breaks allowed. One of ONLY_FORCED_BREAKS, NO_FLAGGED_PENALTIES or ALL_BREAKS.

Returns:

the number of effective breaks

See Also:

findBreakingPoints(KnuthSequence, int, double, boolean, int)

findBreakingPoints

public int findBreakingPoints(KnuthSequence par,
                              int startIndex,
                              double threshold,
                              boolean force,
                              int allowedBreaks)

Finds an optimal set of breakpoints for the given paragraph.

Parameters:

par - the paragraph to break

startIndex - index of the Knuth element at which the breaking must start

threshold - upper bound of the adjustment ratio

force - true if a set of breakpoints must be found, even if there are no feasible ones

allowedBreaks - the type(s) of breaks allowed. One of ONLY_FORCED_BREAKS, NO_FLAGGED_PENALTIES or ALL_BREAKS.

Returns:

the number of effective breaks

getIPDdifference

protected int getIPDdifference()

obtain ipd difference

Returns:

an integer

handleIpdChange

protected int handleIpdChange()

handle ipd change

Returns:

an integer

recoverFromTooLong

protected BreakingAlgorithm.KnuthNode recoverFromTooLong(BreakingAlgorithm.KnuthNode lastTooLong)

Recover from a BreakingAlgorithm.KnuthNode leading to a line that is too long. The default implementation creates a new node corresponding to a break point after the previous node that led to a line that was too short.

Parameters:

lastTooLong - the node that leads to a "too long" line

Returns:

node corresponding to a breakpoint after the previous "too short" line

initialize

protected void initialize()

Initializes the algorithm's variables.

createNode

protected BreakingAlgorithm.KnuthNode createNode(int position,
                                                 int line,
                                                 int fitness,
                                                 int totalWidth,
                                                 int totalStretch,
                                                 int totalShrink,
                                                 double adjustRatio,
                                                 int availableShrink,
                                                 int availableStretch,
                                                 int difference,
                                                 double totalDemerits,
                                                 BreakingAlgorithm.KnuthNode previous)

Creates a new active node for a feasible breakpoint at the given position. Only called in forced mode.

Parameters:

position - index of the element in the Knuth sequence

line - number of the line ending at the breakpoint

fitness - fitness class of the line ending at the breakpoint. One of 0, 1, 2, 3.

totalWidth - accumulated width of the KnuthElements up to after the breakpoint

totalStretch - accumulated stretchability of the KnuthElements up to after the breakpoint

totalShrink - accumulated shrinkability of the KnuthElements up to after the breakpoint

adjustRatio - adjustment ratio if the line ends at this breakpoint

availableShrink - available stretch of the line ending at this breakpoint

availableStretch - available shrink of the line ending at this breakpoint

difference - difference between target and actual line width

totalDemerits - minimum total demerits up to the breakpoint

previous - active node for the preceding breakpoint

Returns:

a new node

createNode

protected BreakingAlgorithm.KnuthNode createNode(int position,
                                                 int line,
                                                 int fitness,
                                                 int totalWidth,
                                                 int totalStretch,
                                                 int totalShrink)

Creates a new active node for a break from the best active node of the given fitness class to the element at the given position.

Parameters:

position - index of the element in the Knuth sequence

line - number of the line ending at the breakpoint

fitness - fitness class of the line ending at the breakpoint. One of 0, 1, 2, 3.

totalWidth - accumulated width of the KnuthElements up to after the breakpoint

totalStretch - accumulated stretchability of the KnuthElements up to after the breakpoint

totalShrink - accumulated shrinkability of the KnuthElements up to after the breakpoint

Returns:

a new node

See Also:

createNode(int, int, int, int, int, int, double, int, int, int, double, org.apache.fop.layoutmgr.BreakingAlgorithm.KnuthNode), BreakingAlgorithm.BestRecords

getLastTooShort

protected final BreakingAlgorithm.KnuthNode getLastTooShort()

Return the last node that yielded a too short line.

Returns:

the node corresponding to the last too short line

handleElementAt

protected final KnuthElement handleElementAt(int position,
                                             boolean previousIsBox,
                                             int allowedBreaks)

Generic handler for a KnuthElement at the given position, taking into account whether the preceding element was a box, and which type(s) of breaks are allowed. Non-overridable. This method simply serves to route the call to one of the more specific handlers (handleBox(KnuthBox), handleGlueAt(KnuthGlue,int,boolean,int) or handlePenaltyAt(KnuthPenalty,int,int). The specialized handlers can be overridden by subclasses to add to or modify the default behavior for the different types of elements.

Parameters:

position - the position index of the element in the paragraph

previousIsBox - true if the previous element is a box

allowedBreaks - the type(s) of breaks allowed; should be one of ALL_BREAKS, NO_FLAGGED_PENALTIES or ONLY_FORCED_BREAKS

Returns:

the handled element

handleBox

protected void handleBox(KnuthBox box)

Handle a KnuthBox.
Note: default implementation just adds the box's width to the total content width. Subclasses that do not keep track of this themselves, but override this method, should remember to call super.handleBox(box) to avoid unwanted side-effects.

Parameters:

box - the KnuthBox to handle

handleGlueAt

protected void handleGlueAt(KnuthGlue glue,
                            int position,
                            boolean previousIsBox,
                            int allowedBreaks)

Handle a KnuthGlue at the given position, taking into account the additional parameters.

Parameters:

glue - the KnuthGlue to handle

position - the position of the glue in the list

previousIsBox - true if the preceding element is a box

allowedBreaks - the type of breaks that are allowed

handlePenaltyAt

protected void handlePenaltyAt(KnuthPenalty penalty,
                               int position,
                               int allowedBreaks)

Handle a KnuthPenalty at the given position, taking into account the type of breaks allowed.

Parameters:

penalty - the KnuthPenalty to handle

position - the position of the penalty in the list

allowedBreaks - the type of breaks that are allowed

replaceLastDeactivated

protected final void replaceLastDeactivated()

Replace the last too-long or too-short node by the last deactivated node, if applicable.

recoverFromOverflow

protected BreakingAlgorithm.KnuthNode recoverFromOverflow()

Recover from an overflow condition.

Returns:

the new lastForced node

restartFrom

protected int restartFrom(BreakingAlgorithm.KnuthNode restartingNode,
                          int currentIndex)

Restart from the given node at the given index.

Parameters:

restartingNode - the BreakingAlgorithm.KnuthNode to restart from

currentIndex - the current position index

Returns:

the index of the restart point

considerLegalBreak

protected void considerLegalBreak(KnuthElement element,
                                  int elementIdx)

Determines if the given breakpoint is a feasible breakpoint. That is, if a decent line may be built between one of the currently active nodes and this breakpoint.

Parameters:

element - the paragraph's element to consider

elementIdx - the element's index inside the paragraph

elementCanEndLine

protected boolean elementCanEndLine(KnuthElement element,
                                    int line,
                                    int difference)

Check if the given KnuthElement can end the line with the given number.

Parameters:

element - the element

line - the line number

difference - an integer

Returns:

true if the element can end the line

forceNode

protected void forceNode(BreakingAlgorithm.KnuthNode node,
                         int line,
                         int elementIdx,
                         int difference,
                         double r,
                         double demerits,
                         int fitnessClass,
                         int availableShrink,
                         int availableStretch)

Force the given BreakingAlgorithm.KnuthNode, and register it.

Parameters:

node - the node

line - the line number

elementIdx - the position index of the element

difference - the difference between content-length and available width

r - the adjustment ratio

demerits - demerits produced by the node

fitnessClass - the fitness class

availableShrink - the available amount of shrink

availableStretch - tha available amount of stretch

createForcedNodes

protected void createForcedNodes(BreakingAlgorithm.KnuthNode node,
                                 int line,
                                 int elementIdx,
                                 int difference,
                                 double r,
                                 double demerits,
                                 int fitnessClass,
                                 int availableShrink,
                                 int availableStretch,
                                 int newWidth,
                                 int newStretch,
                                 int newShrink)

activateNode

protected void activateNode(BreakingAlgorithm.KnuthNode node,
                            int difference,
                            double r,
                            double demerits,
                            int fitnessClass,
                            int availableShrink,
                            int availableStretch)

Activate the given node. Will result in the given BreakingAlgorithm.KnuthNode being registered as a feasible breakpoint, if the demerits are better than that of the best node registered for the given fitnessClass.

Parameters:

node - the node

difference - the difference between content-length and available width

r - the adjustment ratio

demerits - demerits produced by the node

fitnessClass - the fitness class

availableShrink - the available amount of shrink

availableStretch - the available amount of stretch

deactivateNode

protected void deactivateNode(BreakingAlgorithm.KnuthNode node,
                              int line)

Deactivate the given node

Parameters:

node - the node

line - the line number

computeDifference

protected int computeDifference(BreakingAlgorithm.KnuthNode activeNode,
                                KnuthElement element,
                                int elementIndex)

Return the difference between the natural width of a line that would be made between the given active node and the given element, and the available width of the real line.

Parameters:

activeNode - node for the previous breakpoint

element - currently considered breakpoint

elementIndex - index of the element that is considered as a breakpoint

Returns:

The difference in width. Positive numbers mean extra space in the line, negative number that the line overflows.

computeAdjustmentRatio

protected double computeAdjustmentRatio(BreakingAlgorithm.KnuthNode activeNode,
                                        int difference)

Return the adjustment ratio needed to make up for the difference. A ratio of

• 0 means that the break has the exact right width
• >= -1 && < 0 means that the break is wider than the line, but within the minimim values of the glues.
• >0 && < 1 means that the break is smaller than the line width, but within the maximum values of the glues.
• > 1 means that the break is too small to make up for the glues.

Parameters:

activeNode - the currently active node

difference - the difference between content-length and available width

Returns:

The adjustment ratio.

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.

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

finish

protected void finish()

Hook for subclasses to trigger special behavior after ending the main loop in findBreakingPoints(KnuthSequence,int,double,boolean,int)

getElement

protected KnuthElement getElement(int idx)

Return the element at index idx in the paragraph.

Parameters:

idx - index of the element.

Returns:

the element at index idx in the paragraph.

compareNodes

protected BreakingAlgorithm.KnuthNode compareNodes(BreakingAlgorithm.KnuthNode node1,
                                                   BreakingAlgorithm.KnuthNode node2)

Compare two KnuthNodes and return the node with the least demerit.

Parameters:

node1 - The first knuth node.

node2 - The other knuth node.

Returns:

the node with the least demerit.

addNode

protected void addNode(int line,
                       BreakingAlgorithm.KnuthNode node)

Add a node at the end of the given line's existing active nodes. If this is the first node in the line, adjust endLine accordingly.

Parameters:

line - number of the line ending at the node's corresponding breakpoint

node - the active node to add

removeNode

protected void removeNode(int line,
                          BreakingAlgorithm.KnuthNode node)

Remove the given active node registered for the given line. If there are no more active nodes for this line, adjust the startLine accordingly.

Parameters:

line - number of the line ending at the node's corresponding breakpoint

node - the node to deactivate

getNode

protected BreakingAlgorithm.KnuthNode getNode(int line)

Returns the first active node for the given line.

Parameters:

line - the line/part number

Returns:

the requested active node

getLineWidth

protected int getLineWidth(int line)

Returns the line/part width of a given line/part.

Parameters:

line - the line/part number

Returns:

the width/length in millipoints

getLineWidth

protected int getLineWidth()

Returns:

the constant line/part width or -1 if there is no such value

toString

public java.lang.String toString(java.lang.String prepend)

Creates a string representation of the active nodes. Used for debugging.

Parameters:

prepend - a string to prepend on each entry

Returns:

the requested string

filterActiveNodes

protected abstract int filterActiveNodes()

Filter active nodes.

Returns:

an integer

calculateBreakPoints

protected void calculateBreakPoints(BreakingAlgorithm.KnuthNode node,
                                    KnuthSequence par,
                                    int total)

Determines the set of optimal breakpoints corresponding to the given active node.

Parameters:

node - the active node

par - the corresponding paragraph

total - the number of lines into which the paragraph will be broken

getAlignment

public int getAlignment()

Returns:

the alignment for normal lines/parts

getAlignmentLast

public int getAlignmentLast()

Returns:

the alignment for the last line/part

handlingFloat

protected boolean handlingFloat()

handleFloat

protected int handleFloat()

disableFloatHandling

protected void disableFloatHandling()