| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /* $Id$ */ |
| |
| package org.apache.fop.layoutmgr; |
| |
| import java.util.ArrayList; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.ListIterator; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import org.apache.fop.fo.Constants; |
| import org.apache.fop.fo.FObj; |
| import org.apache.fop.layoutmgr.AbstractBreaker.PageBreakPosition; |
| import org.apache.fop.traits.MinOptMax; |
| import org.apache.fop.util.ListUtil; |
| |
| class PageBreakingAlgorithm extends BreakingAlgorithm { |
| |
| /** the logger for the class */ |
| private static Log log = LogFactory.getLog(PageBreakingAlgorithm.class); |
| |
| private LayoutManager topLevelLM; |
| private PageProvider pageProvider; |
| private PageBreakingLayoutListener layoutListener; |
| /** List of PageBreakPosition elements. */ |
| private LinkedList<PageBreakPosition> pageBreaks = null; |
| |
| /** Footnotes which are cited between the currently considered active node (previous |
| * break) and the current considered break. Its type is |
| * List<List<KnuthElement>>, it contains the sequences of KnuthElement |
| * representing the footnotes bodies. |
| */ |
| private List<List<KnuthElement>> footnotesList = null; |
| /** Cumulated bpd of unhandled footnotes. */ |
| private List<Integer> lengthList = null; |
| /** Length of all the footnotes which will be put on the current page. */ |
| private int totalFootnotesLength = 0; |
| /** |
| * Length of all the footnotes which have already been inserted, up to the currently |
| * considered element. That is, footnotes from the currently considered page plus |
| * footnotes from its preceding pages. |
| */ |
| private int insertedFootnotesLength = 0; |
| |
| /** True if footnote citations have been met since the beginning of the page sequence. */ |
| private boolean footnotesPending = false; |
| /** True if the elements met after the previous break point contain footnote citations. */ |
| private boolean newFootnotes = false; |
| /** Index of the first footnote met after the previous break point. */ |
| private int firstNewFootnoteIndex = 0; |
| /** Index of the last footnote inserted on the current page. */ |
| private int footnoteListIndex = 0; |
| /** Index of the last element of the last footnote inserted on the current page. */ |
| private int footnoteElementIndex = -1; |
| |
| // demerits for a page break that splits a footnote |
| private int splitFootnoteDemerits = 5000; |
| // demerits for a page break that defers a whole footnote to the following page |
| private int deferredFootnoteDemerits = 10000; |
| private MinOptMax footnoteSeparatorLength = null; |
| |
| // the method noBreakBetween(int, int) uses these variables |
| // to store parameters and result of the last call, in order |
| // to reuse them and take less time |
| private int storedPrevBreakIndex = -1; |
| private int storedBreakIndex = -1; |
| private boolean storedValue = false; |
| |
| //Controls whether overflows should be warned about or not |
| private boolean autoHeight = false; |
| |
| //Controls whether a single part should be forced if possible (ex. block-container) |
| private boolean favorSinglePart = false; |
| |
| private int ipdDifference; |
| private KnuthNode bestNodeForIPDChange; |
| |
| //Used to keep track of switches in keep-context |
| private int currentKeepContext = Constants.EN_AUTO; |
| private KnuthNode lastBeforeKeepContextSwitch; |
| |
| /** |
| * Construct a page breaking algorithm. |
| * @param topLevelLM the top level layout manager |
| * @param pageProvider the page provider |
| * @param layoutListener the layout listener |
| * @param alignment alignment of the paragraph/page. One of {@link Constants#EN_START}, |
| * {@link Constants#EN_JUSTIFY}, {@link Constants#EN_CENTER}, |
| * {@link Constants#EN_END}. |
| * For pages, {@link Constants#EN_BEFORE} and {@link Constants#EN_AFTER} |
| * are mapped to the corresponding inline properties, |
| * {@link Constants#EN_START} and {@link Constants#EN_END}. |
| * @param alignmentLast alignment of the paragraph's last line |
| * @param footnoteSeparatorLength length of footnote separator |
| * @param partOverflowRecovery {@code true} if too long elements should be moved to |
| * the next line/part |
| * @param autoHeight true if auto height |
| * @param favorSinglePart true if favoring single part |
| * @see BreakingAlgorithm |
| */ |
| public PageBreakingAlgorithm(LayoutManager topLevelLM, // CSOK: ParameterNumber |
| PageProvider pageProvider, |
| PageBreakingLayoutListener layoutListener, |
| int alignment, int alignmentLast, |
| MinOptMax footnoteSeparatorLength, |
| boolean partOverflowRecovery, boolean autoHeight, |
| boolean favorSinglePart) { |
| super(alignment, alignmentLast, true, partOverflowRecovery, 0); |
| this.topLevelLM = topLevelLM; |
| this.pageProvider = pageProvider; |
| this.layoutListener = layoutListener; |
| best = new BestPageRecords(); |
| this.footnoteSeparatorLength = footnoteSeparatorLength; |
| this.autoHeight = autoHeight; |
| this.favorSinglePart = favorSinglePart; |
| } |
| |
| /** |
| * This class represents a feasible breaking point |
| * with extra information about footnotes. |
| */ |
| protected class KnuthPageNode extends KnuthNode { |
| |
| /** Additional length due to footnotes. */ |
| public int totalFootnotes; // CSOK: VisibilityModifier |
| |
| /** Index of the last inserted footnote. */ |
| public int footnoteListIndex; // CSOK: VisibilityModifier |
| |
| /** Index of the last inserted element of the last inserted footnote. */ |
| public int footnoteElementIndex; // CSOK: VisibilityModifier |
| |
| public KnuthPageNode(int position, // CSOK: ParameterNumber |
| int line, int fitness, |
| int totalWidth, int totalStretch, int totalShrink, |
| int totalFootnotes, int footnoteListIndex, int footnoteElementIndex, |
| double adjustRatio, int availableShrink, int availableStretch, |
| int difference, double totalDemerits, KnuthNode previous) { |
| super(position, line, fitness, |
| totalWidth, totalStretch, totalShrink, |
| adjustRatio, availableShrink, availableStretch, |
| difference, totalDemerits, previous); |
| this.totalFootnotes = totalFootnotes; |
| this.footnoteListIndex = footnoteListIndex; |
| this.footnoteElementIndex = footnoteElementIndex; |
| } |
| |
| } |
| |
| /** |
| * this class stores information about how the nodes |
| * which could start a line ending at the current element |
| */ |
| protected class BestPageRecords extends BestRecords { |
| |
| private int[] bestFootnotesLength = new int[4]; |
| private int[] bestFootnoteListIndex = new int[4]; |
| private int[] bestFootnoteElementIndex = new int[4]; |
| |
| public void addRecord(double demerits, KnuthNode node, double adjust, |
| int availableShrink, int availableStretch, |
| int difference, int fitness) { |
| super.addRecord(demerits, node, adjust, |
| availableShrink, availableStretch, |
| difference, fitness); |
| bestFootnotesLength[fitness] = insertedFootnotesLength; |
| bestFootnoteListIndex[fitness] = footnoteListIndex; |
| bestFootnoteElementIndex[fitness] = footnoteElementIndex; |
| } |
| |
| public int getFootnotesLength(int fitness) { |
| return bestFootnotesLength[fitness]; |
| } |
| |
| public int getFootnoteListIndex(int fitness) { |
| return bestFootnoteListIndex[fitness]; |
| } |
| |
| public int getFootnoteElementIndex(int fitness) { |
| return bestFootnoteElementIndex[fitness]; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected void initialize() { |
| super.initialize(); |
| insertedFootnotesLength = 0; |
| footnoteListIndex = 0; |
| footnoteElementIndex = -1; |
| } |
| |
| /** |
| * Overridden to defer a part to the next page, if it |
| * must be kept within one page, but is too large to fit in |
| * the last column. |
| * {@inheritDoc} |
| */ |
| @Override |
| protected KnuthNode recoverFromTooLong(KnuthNode lastTooLong) { |
| |
| if (log.isDebugEnabled()) { |
| log.debug("Recovering from too long: " + lastTooLong); |
| log.debug("\tlastTooShort = " + getLastTooShort()); |
| log.debug("\tlastBeforeKeepContextSwitch = " + lastBeforeKeepContextSwitch); |
| log.debug("\tcurrentKeepContext = " |
| + AbstractBreaker.getBreakClassName(currentKeepContext)); |
| } |
| |
| if (lastBeforeKeepContextSwitch == null |
| || currentKeepContext == Constants.EN_AUTO) { |
| return super.recoverFromTooLong(lastTooLong); |
| } |
| |
| KnuthNode node = lastBeforeKeepContextSwitch; |
| lastBeforeKeepContextSwitch = null; |
| // content would overflow, insert empty page/column(s) and try again |
| while (!pageProvider.endPage(node.line - 1)) { |
| log.trace("Adding node for empty column"); |
| node = createNode( |
| node.position, |
| node.line + 1, 1, |
| 0, 0, 0, |
| 0, 0, 0, |
| 0, 0, node); |
| } |
| return node; |
| } |
| |
| /** |
| * Compare two KnuthNodes and return the node with the least demerit. |
| * |
| * @param node1 The first knuth node. |
| * @param node2 The other knuth node. |
| * @return the node with the least demerit. |
| */ |
| @Override |
| protected KnuthNode compareNodes(KnuthNode node1, KnuthNode node2) { |
| |
| /* if either node is null, return the other one */ |
| if (node1 == null || node2 == null) { |
| return (node1 == null) ? node2 : node1; |
| } |
| |
| /* if either one of the nodes corresponds to a mere column-break, |
| * and the other one corresponds to a page-break, return the page-break node |
| */ |
| if (pageProvider != null) { |
| if (pageProvider.endPage(node1.line - 1) |
| && !pageProvider.endPage(node2.line - 1)) { |
| return node1; |
| } else if (pageProvider.endPage(node2.line - 1) |
| && !pageProvider.endPage(node1.line - 1)) { |
| return node2; |
| } |
| } |
| |
| /* all other cases: use superclass implementation */ |
| return super.compareNodes(node1, node2); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected KnuthNode createNode(int position, // CSOK: ParameterNumber |
| int line, int fitness, |
| int totalWidth, int totalStretch, int totalShrink, |
| double adjustRatio, int availableShrink, int availableStretch, |
| int difference, double totalDemerits, KnuthNode previous) { |
| return new KnuthPageNode(position, line, fitness, |
| totalWidth, totalStretch, totalShrink, |
| insertedFootnotesLength, footnoteListIndex, footnoteElementIndex, |
| adjustRatio, availableShrink, availableStretch, |
| difference, totalDemerits, previous); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected KnuthNode createNode(int position, int line, int fitness, |
| int totalWidth, int totalStretch, int totalShrink) { |
| return new KnuthPageNode(position, line, fitness, |
| totalWidth, totalStretch, totalShrink, |
| ((BestPageRecords) best).getFootnotesLength(fitness), |
| ((BestPageRecords) best).getFootnoteListIndex(fitness), |
| ((BestPageRecords) best).getFootnoteElementIndex(fitness), |
| best.getAdjust(fitness), best.getAvailableShrink(fitness), |
| best.getAvailableStretch(fitness), best.getDifference(fitness), |
| best.getDemerits(fitness), best.getNode(fitness)); |
| } |
| |
| /** |
| * Page-breaking specific handling of the given box. Currently it adds the footnotes |
| * cited in the given box to the list of to-be-handled footnotes. |
| * {@inheritDoc} |
| */ |
| @Override |
| protected void handleBox(KnuthBox box) { |
| super.handleBox(box); |
| if (box instanceof KnuthBlockBox |
| && ((KnuthBlockBox) box).hasAnchors()) { |
| handleFootnotes(((KnuthBlockBox) box).getElementLists()); |
| if (!newFootnotes) { |
| newFootnotes = true; |
| firstNewFootnoteIndex = footnotesList.size() - 1; |
| } |
| } |
| } |
| |
| /** |
| * Overridden to consider penalties with value {@link KnuthElement#INFINITE} |
| * as legal break-points, if the current keep-context allows this |
| * (a keep-*.within-page="always" constraint still permits column-breaks) |
| * {@inheritDoc} |
| */ |
| @Override |
| protected void handlePenaltyAt(KnuthPenalty penalty, int position, |
| int allowedBreaks) { |
| super.handlePenaltyAt(penalty, position, allowedBreaks); |
| /* if the penalty had value INFINITE, default implementation |
| * will not have considered it a legal break, but it could still |
| * be one. |
| */ |
| if (penalty.getPenalty() == KnuthPenalty.INFINITE) { |
| int breakClass = penalty.getBreakClass(); |
| if (breakClass == Constants.EN_PAGE |
| || breakClass == Constants.EN_COLUMN) { |
| considerLegalBreak(penalty, position); |
| } |
| } |
| } |
| |
| /** |
| * Handles the footnotes cited inside a block-level box. Updates footnotesList and the |
| * value of totalFootnotesLength with the lengths of the given footnotes. |
| * @param elementLists list of KnuthElement sequences corresponding to the footnotes |
| * bodies |
| */ |
| private void handleFootnotes(List<List<KnuthElement>> elementLists) { |
| // initialization |
| if (!footnotesPending) { |
| footnotesPending = true; |
| footnotesList = new ArrayList<List<KnuthElement>>(); |
| lengthList = new ArrayList<Integer>(); |
| totalFootnotesLength = 0; |
| } |
| if (!newFootnotes) { |
| newFootnotes = true; |
| firstNewFootnoteIndex = footnotesList.size(); |
| } |
| |
| // compute the total length of the footnotes |
| for (List<KnuthElement> noteList : elementLists) { |
| |
| //Space resolution (Note: this does not respect possible stacking constraints |
| //between footnotes!) |
| SpaceResolver.resolveElementList(noteList); |
| |
| int noteLength = 0; |
| footnotesList.add(noteList); |
| for (KnuthElement element : noteList) { |
| if (element.isBox() || element.isGlue()) { |
| noteLength += element.getWidth(); |
| } |
| } |
| int prevLength = (lengthList == null || lengthList.isEmpty()) |
| ? 0 |
| : ListUtil.getLast(lengthList); |
| if (lengthList != null) { |
| lengthList.add(prevLength + noteLength); |
| } |
| totalFootnotesLength += noteLength; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected int restartFrom(KnuthNode restartingNode, int currentIndex) { |
| int returnValue = super.restartFrom(restartingNode, currentIndex); |
| newFootnotes = false; |
| if (footnotesPending) { |
| // remove from footnotesList the note lists that will be met |
| // after the restarting point |
| for (int j = currentIndex; j >= restartingNode.position; j--) { |
| final KnuthElement resetElement = getElement(j); |
| if (resetElement instanceof KnuthBlockBox |
| && ((KnuthBlockBox) resetElement).hasAnchors()) { |
| resetFootnotes(((KnuthBlockBox) resetElement).getElementLists()); |
| } |
| } |
| } |
| return returnValue; |
| } |
| |
| private void resetFootnotes(List<List<KnuthElement>> elementLists) { |
| for (int i = 0; i < elementLists.size(); i++) { |
| ListUtil.removeLast(footnotesList); |
| ListUtil.removeLast(lengthList); |
| |
| // update totalFootnotesLength |
| if (!lengthList.isEmpty()) { |
| totalFootnotesLength = ListUtil.getLast(lengthList); |
| } else { |
| totalFootnotesLength = 0; |
| } |
| } |
| // update footnotesPending; |
| if (footnotesList.size() == 0) { |
| footnotesPending = false; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected void considerLegalBreak(KnuthElement element, int elementIdx) { |
| if (element.isPenalty()) { |
| int breakClass = ((KnuthPenalty) element).getBreakClass(); |
| switch (breakClass) { |
| case Constants.EN_PAGE: |
| if (this.currentKeepContext != breakClass) { |
| this.lastBeforeKeepContextSwitch = getLastTooShort(); |
| } |
| this.currentKeepContext = breakClass; |
| break; |
| case Constants.EN_COLUMN: |
| if (this.currentKeepContext != breakClass) { |
| this.lastBeforeKeepContextSwitch = getLastTooShort(); |
| } |
| this.currentKeepContext = breakClass; |
| break; |
| case Constants.EN_AUTO: |
| this.currentKeepContext = breakClass; |
| break; |
| default: |
| //nop |
| } |
| } |
| super.considerLegalBreak(element, elementIdx); |
| newFootnotes = false; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected boolean elementCanEndLine(KnuthElement element, int line, int difference) { |
| if (!(element.isPenalty()) || pageProvider == null) { |
| return true; |
| } else { |
| KnuthPenalty p = (KnuthPenalty) element; |
| if (p.getPenalty() <= 0) { |
| return true; |
| } else { |
| int context = p.getBreakClass(); |
| switch (context) { |
| case Constants.EN_LINE: |
| case Constants.EN_COLUMN: |
| return p.getPenalty() < KnuthPenalty.INFINITE; |
| case Constants.EN_PAGE: |
| return p.getPenalty() < KnuthPenalty.INFINITE |
| || !pageProvider.endPage(line - 1); |
| case Constants.EN_AUTO: |
| log.debug("keep is not auto but context is"); |
| return true; |
| default: |
| if (p.getPenalty() < KnuthPenalty.INFINITE) { |
| log.debug("Non recognized keep context:" + context); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| } |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected int computeDifference(KnuthNode activeNode, KnuthElement element, |
| int elementIndex) { |
| KnuthPageNode pageNode = (KnuthPageNode) activeNode; |
| int actualWidth = totalWidth - pageNode.totalWidth; |
| int footnoteSplit; |
| boolean canDeferOldFN; |
| if (element.isPenalty()) { |
| actualWidth += element.getWidth(); |
| } |
| if (footnotesPending) { |
| // compute the total length of the footnotes not yet inserted |
| int allFootnotes = totalFootnotesLength - pageNode.totalFootnotes; |
| if (allFootnotes > 0) { |
| // this page contains some footnote citations |
| // add the footnote separator width |
| actualWidth += footnoteSeparatorLength.getOpt(); |
| if (actualWidth + allFootnotes <= getLineWidth(activeNode.line)) { |
| // there is enough space to insert all footnotes: |
| // add the whole allFootnotes length |
| actualWidth += allFootnotes; |
| insertedFootnotesLength = pageNode.totalFootnotes + allFootnotes; |
| footnoteListIndex = footnotesList.size() - 1; |
| footnoteElementIndex |
| = getFootnoteList(footnoteListIndex).size() - 1; |
| } else if (((canDeferOldFN = canDeferOldFootnotes // CSOK: InnerAssignment |
| (pageNode, elementIndex)) |
| || newFootnotes) |
| && (footnoteSplit = getFootnoteSplit // CSOK: InnerAssignment |
| (pageNode, getLineWidth(activeNode.line) - actualWidth, |
| canDeferOldFN)) > 0) { |
| // it is allowed to break or even defer footnotes if either: |
| // - there are new footnotes in the last piece of content, and |
| // there is space to add at least a piece of the first one |
| // - or the previous page break deferred some footnote lines, and |
| // this is the first feasible break; in this case it is allowed |
| // to break and defer, if necessary, old and new footnotes |
| actualWidth += footnoteSplit; |
| insertedFootnotesLength = pageNode.totalFootnotes + footnoteSplit; |
| // footnoteListIndex has been set in getFootnoteSplit() |
| // footnoteElementIndex has been set in getFootnoteSplit() |
| } else { |
| // there is no space to add the smallest piece of footnote, |
| // or we are trying to add a piece of content with no footnotes and |
| // it does not fit in the page, because of previous footnote bodies |
| // that cannot be broken: |
| // add the whole allFootnotes length, so this breakpoint will be discarded |
| actualWidth += allFootnotes; |
| insertedFootnotesLength = pageNode.totalFootnotes + allFootnotes; |
| footnoteListIndex = footnotesList.size() - 1; |
| footnoteElementIndex |
| = getFootnoteList(footnoteListIndex).size() - 1; |
| } |
| } else { |
| // all footnotes have already been placed on previous pages |
| } |
| } else { |
| // there are no footnotes |
| } |
| int diff = getLineWidth(activeNode.line) - actualWidth; |
| if (autoHeight && diff < 0) { |
| //getLineWidth() for auto-height parts return 0 so the diff will be negative |
| return 0; //...but we don't want to shrink in this case. Stick to optimum. |
| } else { |
| return diff; |
| } |
| } |
| |
| /** |
| * Checks whether footnotes from preceding pages may be deferred to the page after |
| * the given element. |
| * @param node active node for the preceding page break |
| * @param contentElementIndex index of the Knuth element considered for the |
| * current page break |
| * @return true if footnotes can be deferred |
| */ |
| private boolean canDeferOldFootnotes(KnuthPageNode node, int contentElementIndex) { |
| return (noBreakBetween(node.position, contentElementIndex) |
| && deferredFootnotes(node.footnoteListIndex, |
| node.footnoteElementIndex, node.totalFootnotes)); |
| } |
| |
| /** |
| * Returns true if there may be no breakpoint between the two given elements. |
| * @param prevBreakIndex index of the element from the currently considered active |
| * node |
| * @param breakIndex index of the currently considered breakpoint |
| * @return true if no element between the two can be a breakpoint |
| */ |
| private boolean noBreakBetween(int prevBreakIndex, int breakIndex) { |
| // this method stores the parameters and the return value from previous calls |
| // in order to avoid scanning the element list unnecessarily: |
| // - if there is no break between element #i and element #j |
| // there will not be a break between #(i+h) and #j too |
| // - if there is a break between element #i and element #j |
| // there will be a break between #(i-h) and #(j+k) too |
| if (storedPrevBreakIndex != -1 |
| && ((prevBreakIndex >= storedPrevBreakIndex |
| && breakIndex == storedBreakIndex |
| && storedValue) |
| || (prevBreakIndex <= storedPrevBreakIndex |
| && breakIndex >= storedBreakIndex |
| && !storedValue))) { |
| // use the stored value, do nothing |
| } else { |
| // compute the new value |
| int index; |
| // ignore suppressed elements |
| for (index = prevBreakIndex + 1; |
| !par.getElement(index).isBox(); |
| index++) { |
| //nop |
| } |
| // find the next break |
| for (; |
| index < breakIndex; |
| index++) { |
| if (par.getElement(index).isGlue() && par.getElement(index - 1).isBox() |
| || par.getElement(index).isPenalty() |
| && ((KnuthElement) par |
| .getElement(index)).getPenalty() < KnuthElement.INFINITE) { |
| // break found |
| break; |
| } |
| } |
| // update stored parameters and value |
| storedPrevBreakIndex = prevBreakIndex; |
| storedBreakIndex = breakIndex; |
| storedValue = (index == breakIndex); |
| } |
| return storedValue; |
| } |
| |
| /** |
| * Returns true if their are (pieces of) footnotes to be typeset on the current page. |
| * @param listIndex index of the last inserted footnote for the currently considered |
| * active node |
| * @param elementIndex index of the last element of the last inserted footnote |
| * @param length total length of all footnotes inserted so far |
| */ |
| private boolean deferredFootnotes(int listIndex, int elementIndex, int length) { |
| return ((newFootnotes |
| && firstNewFootnoteIndex != 0 |
| && (listIndex < firstNewFootnoteIndex - 1 |
| || elementIndex < getFootnoteList(listIndex).size() - 1)) |
| || length < totalFootnotesLength); |
| } |
| |
| /** |
| * Tries to split the flow of footnotes to put one part on the current page. |
| * @param activeNode currently considered previous page break |
| * @param availableLength available space for footnotes |
| * @param canDeferOldFootnotes |
| * @return ... |
| */ |
| private int getFootnoteSplit(KnuthPageNode activeNode, int availableLength, |
| boolean canDeferOldFootnotes) { |
| return getFootnoteSplit(activeNode.footnoteListIndex, |
| activeNode.footnoteElementIndex, |
| activeNode.totalFootnotes, |
| availableLength, canDeferOldFootnotes); |
| } |
| |
| /** |
| * Tries to split the flow of footnotes to put one part on the current page. |
| * @param prevListIndex index of the last footnote on the previous page |
| * @param prevElementIndex index of the last element of the last footnote |
| * @param prevLength total length of footnotes inserted so far |
| * @param availableLength available space for footnotes on this page |
| * @param canDeferOldFootnotes |
| * @return ... |
| */ |
| private int getFootnoteSplit(int prevListIndex, int prevElementIndex, int prevLength, |
| int availableLength, boolean canDeferOldFootnotes) { |
| if (availableLength <= 0) { |
| return 0; |
| } else { |
| // the split should contain a piece of the last footnote |
| // together with all previous, not yet inserted footnotes; |
| // but if this is not possible, try adding as much content as possible |
| int splitLength = 0; |
| ListIterator<KnuthElement> noteListIterator; |
| KnuthElement element; |
| boolean somethingAdded = false; |
| |
| // prevListIndex and prevElementIndex points to the last footnote element |
| // already placed in a page: advance to the next element |
| int listIndex = prevListIndex; |
| int elementIndex = prevElementIndex; |
| if (elementIndex == getFootnoteList(listIndex).size() - 1) { |
| listIndex++; |
| elementIndex = 0; |
| } else { |
| elementIndex++; |
| } |
| |
| // try adding whole notes |
| if (footnotesList.size() - 1 > listIndex) { |
| // add the previous footnotes: these cannot be broken or deferred |
| if (!canDeferOldFootnotes && newFootnotes && firstNewFootnoteIndex > 0) { |
| splitLength = lengthList.get(firstNewFootnoteIndex - 1) - prevLength; |
| listIndex = firstNewFootnoteIndex; |
| elementIndex = 0; |
| } |
| // try adding the new footnotes |
| while (lengthList.get(listIndex) - prevLength |
| <= availableLength) { |
| splitLength = lengthList.get(listIndex) - prevLength; |
| somethingAdded = true; |
| listIndex++; |
| elementIndex = 0; |
| } |
| // as this method is called only if it is not possible to insert |
| // all footnotes, at this point listIndex and elementIndex points to |
| // an existing element, the next one we will try to insert |
| } |
| |
| // try adding a split of the next note |
| noteListIterator = getFootnoteList(listIndex).listIterator(elementIndex); |
| |
| int prevSplitLength = 0; |
| int prevIndex = -1; |
| int index = -1; |
| |
| while (!(somethingAdded && splitLength > availableLength)) { |
| if (!somethingAdded) { |
| somethingAdded = true; |
| } else { |
| prevSplitLength = splitLength; |
| prevIndex = index; |
| } |
| // get a sub-sequence from the note element list |
| boolean boxPreceding = false; |
| while (noteListIterator.hasNext()) { |
| // as this method is called only if it is not possible to insert |
| // all footnotes, and we have already tried (and failed) to insert |
| // this whole footnote, the while loop will never reach the end |
| // of the note sequence |
| element = noteListIterator.next(); |
| if (element.isBox()) { |
| // element is a box |
| splitLength += element.getWidth(); |
| boxPreceding = true; |
| } else if (element.isGlue()) { |
| // element is a glue |
| if (boxPreceding) { |
| // end of the sub-sequence |
| index = noteListIterator.previousIndex(); |
| break; |
| } |
| boxPreceding = false; |
| splitLength += element.getWidth(); |
| } else { |
| // element is a penalty |
| if (element.getPenalty() < KnuthElement.INFINITE) { |
| // end of the sub-sequence |
| index = noteListIterator.previousIndex(); |
| break; |
| } |
| } |
| } |
| } |
| |
| // if prevSplitLength is 0, this means that the available length isn't enough |
| // to insert even the smallest split of the last footnote, so we cannot end a |
| // page here |
| // if prevSplitLength is > 0 we can insert some footnote content in this page |
| // and insert the remaining in the following one |
| //TODO: check this conditional, as the first one is always false...? |
| if (!somethingAdded) { |
| // there was not enough space to add a piece of the first new footnote |
| // this is not a good break |
| prevSplitLength = 0; |
| } else if (prevSplitLength > 0) { |
| // prevIndex is -1 if we have added only some whole footnotes |
| footnoteListIndex = (prevIndex != -1) ? listIndex : listIndex - 1; |
| footnoteElementIndex = (prevIndex != -1) |
| ? prevIndex |
| : getFootnoteList(footnoteListIndex).size() - 1; |
| } |
| return prevSplitLength; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected double computeAdjustmentRatio(KnuthNode activeNode, int difference) { |
| // compute the adjustment ratio |
| if (difference > 0) { |
| int maxAdjustment = totalStretch - activeNode.totalStretch; |
| // add the footnote separator stretch if some footnote content will be added |
| if (((KnuthPageNode) activeNode).totalFootnotes < totalFootnotesLength) { |
| maxAdjustment += footnoteSeparatorLength.getStretch(); |
| } |
| if (maxAdjustment > 0) { |
| return (double) difference / maxAdjustment; |
| } else { |
| return INFINITE_RATIO; |
| } |
| } else if (difference < 0) { |
| int maxAdjustment = totalShrink - activeNode.totalShrink; |
| // add the footnote separator shrink if some footnote content will be added |
| if (((KnuthPageNode) activeNode).totalFootnotes < totalFootnotesLength) { |
| maxAdjustment += footnoteSeparatorLength.getShrink(); |
| } |
| if (maxAdjustment > 0) { |
| return (double) difference / maxAdjustment; |
| } else { |
| return -INFINITE_RATIO; |
| } |
| } else { |
| return 0; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected double computeDemerits(KnuthNode activeNode, KnuthElement element, |
| int fitnessClass, double r) { |
| double demerits = 0; |
| // compute demerits |
| double f = Math.abs(r); |
| f = 1 + 100 * f * f * f; |
| if (element.isPenalty()) { |
| double penalty = element.getPenalty(); |
| if (penalty >= 0) { |
| f += penalty; |
| demerits = f * f; |
| } else if (!element.isForcedBreak()) { |
| demerits = f * f - penalty * penalty; |
| } else { |
| demerits = f * f; |
| } |
| } else { |
| demerits = f * f; |
| } |
| |
| if (element.isPenalty() && ((KnuthPenalty) element).isPenaltyFlagged() |
| && getElement(activeNode.position).isPenalty() |
| && ((KnuthPenalty) getElement(activeNode.position)).isPenaltyFlagged()) { |
| // add demerit for consecutive breaks at flagged penalties |
| demerits += repeatedFlaggedDemerit; |
| } |
| if (Math.abs(fitnessClass - activeNode.fitness) > 1) { |
| // add demerit for consecutive breaks |
| // with very different fitness classes |
| demerits += incompatibleFitnessDemerit; |
| } |
| |
| if (footnotesPending) { |
| if (footnoteListIndex < footnotesList.size() - 1) { |
| // add demerits for the deferred footnotes |
| demerits += (footnotesList.size() - 1 - footnoteListIndex) |
| * deferredFootnoteDemerits; |
| } |
| if (footnoteListIndex < footnotesList.size()) { |
| if (footnoteElementIndex |
| < getFootnoteList(footnoteListIndex).size() - 1) { |
| // add demerits for the footnote split between pages |
| demerits += splitFootnoteDemerits; |
| } |
| } else { |
| //TODO Why can this happen in the first place? Does anybody know? See #44160 |
| } |
| } |
| demerits += activeNode.totalDemerits; |
| return demerits; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected void finish() { |
| for (int i = startLine; i < endLine; i++) { |
| for (KnuthPageNode node = (KnuthPageNode) getNode(i); |
| node != null; |
| node = (KnuthPageNode) node.next) { |
| if (node.totalFootnotes < totalFootnotesLength) { |
| // layout remaining footnote bodies |
| createFootnotePages(node); |
| } |
| } |
| } |
| } |
| |
| private void createFootnotePages(KnuthPageNode lastNode) { |
| |
| insertedFootnotesLength = lastNode.totalFootnotes; |
| footnoteListIndex = lastNode.footnoteListIndex; |
| footnoteElementIndex = lastNode.footnoteElementIndex; |
| int availableBPD = getLineWidth(lastNode.line); |
| int split = 0; |
| KnuthPageNode prevNode = lastNode; |
| |
| // create pages containing the remaining footnote bodies |
| while (insertedFootnotesLength < totalFootnotesLength) { |
| final int tmpLength = lengthList.get(footnoteListIndex); |
| // try adding some more content |
| if ((tmpLength - insertedFootnotesLength) <= availableBPD) { |
| // add a whole footnote |
| availableBPD -= tmpLength - insertedFootnotesLength; |
| insertedFootnotesLength = tmpLength; |
| footnoteElementIndex |
| = getFootnoteList(footnoteListIndex).size() - 1; |
| } else if ((split = getFootnoteSplit // CSOK: InnerAssignment |
| (footnoteListIndex, footnoteElementIndex, |
| insertedFootnotesLength, availableBPD, true)) > 0) { |
| // add a piece of a footnote |
| availableBPD -= split; |
| insertedFootnotesLength += split; |
| // footnoteListIndex has already been set in getFootnoteSplit() |
| // footnoteElementIndex has already been set in getFootnoteSplit() |
| } else { |
| // cannot add any content: create a new node and start again |
| KnuthPageNode node = (KnuthPageNode) |
| createNode(lastNode.position, prevNode.line + 1, 1, |
| insertedFootnotesLength - prevNode.totalFootnotes, |
| 0, 0, |
| 0, 0, 0, |
| 0, 0, prevNode); |
| addNode(node.line, node); |
| removeNode(prevNode.line, prevNode); |
| |
| prevNode = node; |
| availableBPD = getLineWidth(node.line); |
| } |
| } |
| // create the last node |
| KnuthPageNode node = (KnuthPageNode) |
| createNode(lastNode.position, prevNode.line + 1, 1, |
| totalFootnotesLength - prevNode.totalFootnotes, 0, 0, |
| 0, 0, 0, |
| 0, 0, prevNode); |
| addNode(node.line, node); |
| removeNode(prevNode.line, prevNode); |
| } |
| |
| /** |
| * @return a list of {@link PageBreakPosition} elements |
| * corresponding to the computed page- and column-breaks |
| */ |
| public LinkedList<PageBreakPosition> getPageBreaks() { |
| return pageBreaks; |
| } |
| |
| /** |
| * Insert the given {@link PageBreakPosition} as the first |
| * element in the list of page-breaks |
| * |
| * @param pageBreak the position to insert |
| */ |
| public void insertPageBreakAsFirst(PageBreakPosition pageBreak) { |
| if (pageBreaks == null) { |
| pageBreaks = new LinkedList<PageBreakPosition>(); |
| } |
| pageBreaks.addFirst(pageBreak); |
| } |
| |
| /** |
| * Removes all page breaks from the result list. This is used by block-containers and |
| * static-content when it is only desired to know where there is an overflow but later the |
| * whole content should be painted as one part. |
| */ |
| public void removeAllPageBreaks() { |
| if (pageBreaks == null || pageBreaks.isEmpty()) { |
| return; |
| } |
| pageBreaks.subList(0, pageBreaks.size() - 1).clear(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void updateData1(int total, double demerits) { |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void updateData2(KnuthNode bestActiveNode, |
| KnuthSequence sequence, |
| int total) { |
| //int difference = (bestActiveNode.line < total) |
| // ? bestActiveNode.difference : bestActiveNode.difference + fillerMinWidth; |
| int difference = bestActiveNode.difference; |
| if (difference + bestActiveNode.availableShrink < 0) { |
| if (!autoHeight) { |
| if (layoutListener != null) { |
| layoutListener.notifyOverflow(bestActiveNode.line - 1, -difference, getFObj()); |
| } |
| } |
| } |
| boolean isNonLastPage = (bestActiveNode.line < total); |
| int blockAlignment = isNonLastPage ? alignment : alignmentLast; |
| // it is always allowed to adjust space, so the ratio must be set regardless of |
| // the value of the property display-align; the ratio must be <= 1 |
| double ratio = bestActiveNode.adjustRatio; |
| if (ratio < 0) { |
| // page break with a negative difference: |
| // spaces always have enough shrink |
| difference = 0; |
| } else if (ratio <= 1 && isNonLastPage) { |
| // not-last page break with a positive difference smaller than the available stretch: |
| // spaces can stretch to fill the whole difference |
| difference = 0; |
| } else if (ratio > 1) { |
| // not-last page with a positive difference greater than the available stretch |
| // spaces can stretch to fill the difference only partially |
| ratio = 1; |
| difference -= bestActiveNode.availableStretch; |
| } else { |
| // last page with a positive difference: |
| // spaces do not need to stretch |
| if (blockAlignment != Constants.EN_JUSTIFY) { |
| ratio = 0; |
| } else { |
| //Stretch as much as possible on last page |
| difference = 0; |
| } |
| } |
| // compute the indexes of the first footnote list and the first element in that list |
| int firstListIndex = ((KnuthPageNode) bestActiveNode.previous).footnoteListIndex; |
| int firstElementIndex = ((KnuthPageNode) bestActiveNode.previous).footnoteElementIndex; |
| if (footnotesList != null |
| && firstElementIndex == getFootnoteList(firstListIndex).size() - 1) { |
| // advance to the next list |
| firstListIndex++; |
| firstElementIndex = 0; |
| } else { |
| firstElementIndex++; |
| } |
| |
| // add nodes at the beginning of the list, as they are found |
| // backwards, from the last one to the first one |
| if (log.isDebugEnabled()) { |
| log.debug("BBA> difference=" + difference + " ratio=" + ratio |
| + " position=" + bestActiveNode.position); |
| } |
| insertPageBreakAsFirst(new PageBreakPosition(this.topLevelLM, |
| bestActiveNode.position, |
| firstListIndex, firstElementIndex, |
| ((KnuthPageNode) bestActiveNode).footnoteListIndex, |
| ((KnuthPageNode) bestActiveNode).footnoteElementIndex, |
| ratio, difference)); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected int filterActiveNodes() { |
| // leave only the active node with fewest total demerits |
| KnuthNode bestActiveNode = null; |
| for (int i = startLine; i < endLine; i++) { |
| for (KnuthNode node = getNode(i); node != null; node = node.next) { |
| if (favorSinglePart |
| && node.line > 1 |
| && bestActiveNode != null |
| && Math.abs(bestActiveNode.difference) < bestActiveNode.availableShrink) { |
| //favor current best node, so just skip the current node because it would |
| //result in more than one part |
| } else { |
| bestActiveNode = compareNodes(bestActiveNode, node); |
| } |
| if (node != bestActiveNode) { |
| removeNode(i, node); |
| } |
| } |
| } |
| assert (bestActiveNode != null); |
| return bestActiveNode.line; |
| } |
| |
| /** |
| * Obtain the element-list corresponding to the footnote at the given index. |
| * |
| * @param index the index in the list of footnotes |
| * @return the element-list |
| */ |
| protected final List<KnuthElement> getFootnoteList(int index) { |
| return footnotesList.get(index); |
| } |
| |
| /** @return the associated top-level formatting object. */ |
| public FObj getFObj() { |
| return topLevelLM.getFObj(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected int getLineWidth(int line) { |
| int bpd; |
| if (pageProvider != null) { |
| bpd = pageProvider.getAvailableBPD(line); |
| } else { |
| bpd = super.getLineWidth(line); |
| } |
| if (log.isTraceEnabled()) { |
| log.trace("getLineWidth(" + line + ") -> " + bpd); |
| } |
| return bpd; |
| } |
| |
| /** |
| * Interface to notify about layout events during page breaking. |
| */ |
| public interface PageBreakingLayoutListener { |
| |
| /** |
| * Issued when an overflow is detected |
| * @param part the number of the part (page) this happens on |
| * @param amount the amount by which the area overflows (in mpt) |
| * @param obj the root FO object where this happens |
| */ |
| void notifyOverflow(int part, int amount, FObj obj); |
| |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected int getIPDdifference() { |
| return ipdDifference; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected int handleIpdChange() { |
| log.trace("Best node for ipd change:" + bestNodeForIPDChange); |
| // TODO finish() |
| /* |
| * The third parameter is used to determine if this is the last page, so |
| * if the content must be vertically justified or not. If we are here |
| * this means that there is further content and the next page has a |
| * different ipd. So tweak the parameter to fall into the non-last-page |
| * case. |
| */ |
| calculateBreakPoints(bestNodeForIPDChange, par, bestNodeForIPDChange.line + 1); |
| activeLines = null; |
| return bestNodeForIPDChange.line; |
| } |
| |
| /** |
| * 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. |
| * @param line number of the line ending at the node's corresponding breakpoint |
| * @param node the active node to add |
| */ |
| @Override |
| protected void addNode(int line, KnuthNode node) { |
| if (node.position < par.size() - 1 && line > 0 |
| && (ipdDifference = compareIPDs(line - 1)) != 0) { // CSOK: InnerAssignment |
| log.trace("IPD changes at page " + line); |
| if (bestNodeForIPDChange == null |
| || node.totalDemerits < bestNodeForIPDChange.totalDemerits) { |
| bestNodeForIPDChange = node; |
| } |
| } else { |
| if (node.position == par.size() - 1) { |
| /* |
| * The whole sequence could actually fit on the last page before |
| * the IPD change. No need to do any special handling. |
| */ |
| ipdDifference = 0; |
| } |
| super.addNode(line, node); |
| } |
| } |
| |
| KnuthNode getBestNodeBeforeIPDChange() { |
| return bestNodeForIPDChange; |
| } |
| |
| private int compareIPDs(int line) { |
| if (pageProvider == null) { |
| return 0; |
| } |
| return pageProvider.compareIPDs(line); |
| } |
| } |
