/*
* 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: ListItemLayoutManager.java 893238 2009-12-22 17:20:51Z vhennebert $ */
package org.apache.fop.layoutmgr.list;
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.area.Area;
import org.apache.fop.area.Block;
import org.apache.fop.fo.flow.ListItem;
import org.apache.fop.fo.flow.ListItemBody;
import org.apache.fop.fo.flow.ListItemLabel;
import org.apache.fop.fo.properties.KeepProperty;
import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
import org.apache.fop.layoutmgr.BreakElement;
import org.apache.fop.layoutmgr.ConditionalElementListener;
import org.apache.fop.layoutmgr.ElementListObserver;
import org.apache.fop.layoutmgr.ElementListUtils;
import org.apache.fop.layoutmgr.Keep;
import org.apache.fop.layoutmgr.KnuthBlockBox;
import org.apache.fop.layoutmgr.KnuthBox;
import org.apache.fop.layoutmgr.KnuthElement;
import org.apache.fop.layoutmgr.KnuthPenalty;
import org.apache.fop.layoutmgr.KnuthPossPosIter;
import org.apache.fop.layoutmgr.LayoutContext;
import org.apache.fop.layoutmgr.LayoutManager;
import org.apache.fop.layoutmgr.ListElement;
import org.apache.fop.layoutmgr.NonLeafPosition;
import org.apache.fop.layoutmgr.Position;
import org.apache.fop.layoutmgr.PositionIterator;
import org.apache.fop.layoutmgr.RelSide;
import org.apache.fop.layoutmgr.SpaceResolver;
import org.apache.fop.layoutmgr.TraitSetter;
import org.apache.fop.traits.MinOptMax;
import org.apache.fop.traits.SpaceVal;
/**
* LayoutManager for a list-item FO.
* The list item contains a list item label and a list item body.
*/
public class ListItemLayoutManager extends BlockStackingLayoutManager
implements ConditionalElementListener {
/**
* logging instance
*/
private static Log log = LogFactory.getLog(ListItemLayoutManager.class);
private ListItemContentLayoutManager label;
private ListItemContentLayoutManager body;
private Block curBlockArea = null;
private List labelList = null;
private List bodyList = null;
private boolean discardBorderBefore;
private boolean discardBorderAfter;
private boolean discardPaddingBefore;
private boolean discardPaddingAfter;
private MinOptMax effSpaceBefore;
private MinOptMax effSpaceAfter;
private Keep keepWithNextPendingOnLabel;
private Keep keepWithNextPendingOnBody;
private int listItemHeight;
private class ListItemPosition extends Position {
private int iLabelFirstIndex;
private int iLabelLastIndex;
private int iBodyFirstIndex;
private int iBodyLastIndex;
public ListItemPosition(LayoutManager lm, int labelFirst, int labelLast,
int bodyFirst, int bodyLast) {
super(lm);
iLabelFirstIndex = labelFirst;
iLabelLastIndex = labelLast;
iBodyFirstIndex = bodyFirst;
iBodyLastIndex = bodyLast;
}
public int getLabelFirstIndex() {
return iLabelFirstIndex;
}
public int getLabelLastIndex() {
return iLabelLastIndex;
}
public int getBodyFirstIndex() {
return iBodyFirstIndex;
}
public int getBodyLastIndex() {
return iBodyLastIndex;
}
/** {@inheritDoc} */
public boolean generatesAreas() {
return true;
}
/** {@inheritDoc} */
public String toString() {
StringBuffer sb = new StringBuffer("ListItemPosition:");
sb.append(getIndex()).append("(");
sb.append("label:").append(iLabelFirstIndex).append("-").append(iLabelLastIndex);
sb.append(" body:").append(iBodyFirstIndex).append("-").append(iBodyLastIndex);
sb.append(")");
return sb.toString();
}
}
/**
* Create a new list item layout manager.
* @param node list-item to create the layout manager for
*/
public ListItemLayoutManager(ListItem node) {
super(node);
setLabel(node.getLabel());
setBody(node.getBody());
}
/**
* Convenience method.
* @return the ListBlock node
*/
protected ListItem getListItemFO() {
return (ListItem)fobj;
}
/**
* Create a LM for the fo:list-item-label object
* @param node the fo:list-item-label FO
*/
public void setLabel(ListItemLabel node) {
label = new ListItemContentLayoutManager(node);
label.setParent(this);
}
/**
* Create a LM for the fo:list-item-body object
* @param node the fo:list-item-body FO
*/
public void setBody(ListItemBody node) {
body = new ListItemContentLayoutManager(node);
body.setParent(this);
}
/** {@inheritDoc} */
public void initialize() {
foSpaceBefore = new SpaceVal(
getListItemFO().getCommonMarginBlock().spaceBefore, this).getSpace();
foSpaceAfter = new SpaceVal(
getListItemFO().getCommonMarginBlock().spaceAfter, this).getSpace();
startIndent = getListItemFO().getCommonMarginBlock().startIndent.getValue(this);
endIndent = getListItemFO().getCommonMarginBlock().endIndent.getValue(this);
}
private void resetSpaces() {
this.discardBorderBefore = false;
this.discardBorderAfter = false;
this.discardPaddingBefore = false;
this.discardPaddingAfter = false;
this.effSpaceBefore = null;
this.effSpaceAfter = null;
}
/** {@inheritDoc} */
public List getNextKnuthElements(LayoutContext context, int alignment) {
referenceIPD = context.getRefIPD();
LayoutContext childLC;
List returnList = new LinkedList();
if (!breakBeforeServed) {
breakBeforeServed = true;
if (!context.suppressBreakBefore()) {
if (addKnuthElementsForBreakBefore(returnList, context)) {
return returnList;
}
}
}
addKnuthElementsForSpaceBefore(returnList, alignment);
addKnuthElementsForBorderPaddingBefore(returnList, !firstVisibleMarkServed);
firstVisibleMarkServed = true;
//Spaces, border and padding to be repeated at each break
addPendingMarks(context);
// label
childLC = new LayoutContext(0);
childLC.setRefIPD(context.getRefIPD());
label.initialize();
labelList = label.getNextKnuthElements(childLC, alignment);
//Space resolution as if the contents were placed in a new reference area
//(see 6.8.3, XSL 1.0, section on Constraints, last paragraph)
SpaceResolver.resolveElementList(labelList);
ElementListObserver.observe(labelList, "list-item-label", label.getPartFO().getId());
context.updateKeepWithPreviousPending(childLC.getKeepWithPreviousPending());
this.keepWithNextPendingOnLabel = childLC.getKeepWithNextPending();
// body
childLC = new LayoutContext(0);
childLC.setRefIPD(context.getRefIPD());
body.initialize();
bodyList = body.getNextKnuthElements(childLC, alignment);
//Space resolution as if the contents were placed in a new reference area
//(see 6.8.3, XSL 1.0, section on Constraints, last paragraph)
SpaceResolver.resolveElementList(bodyList);
ElementListObserver.observe(bodyList, "list-item-body", body.getPartFO().getId());
context.updateKeepWithPreviousPending(childLC.getKeepWithPreviousPending());
this.keepWithNextPendingOnBody = childLC.getKeepWithNextPending();
// create a combined list
List returnedList = getCombinedKnuthElementsForListItem(labelList, bodyList, context);
// "wrap" the Position inside each element
wrapPositionElements(returnedList, returnList, true);
addKnuthElementsForBorderPaddingAfter(returnList, true);
addKnuthElementsForSpaceAfter(returnList, alignment);
addKnuthElementsForBreakAfter(returnList, context);
context.updateKeepWithNextPending(this.keepWithNextPendingOnLabel);
context.updateKeepWithNextPending(this.keepWithNextPendingOnBody);
context.updateKeepWithNextPending(getKeepWithNext());
context.updateKeepWithPreviousPending(getKeepWithPrevious());
setFinished(true);
resetSpaces();
return returnList;
}
private List getCombinedKnuthElementsForListItem(List labelElements,
List bodyElements, LayoutContext context) {
// Copy elements to array lists to improve element access performance
List[] elementLists = {new ArrayList(labelElements),
new ArrayList(bodyElements)};
int[] fullHeights = {ElementListUtils.calcContentLength(elementLists[0]),
ElementListUtils.calcContentLength(elementLists[1])};
int[] partialHeights = {0, 0};
int[] start = {-1, -1};
int[] end = {-1, -1};
int totalHeight = Math.max(fullHeights[0], fullHeights[1]);
int step;
int addedBoxHeight = 0;
Keep keepWithNextActive = Keep.KEEP_AUTO;
LinkedList returnList = new LinkedList();
while ((step = getNextStep(elementLists, start, end, partialHeights)) > 0) {
if (end[0] + 1 == elementLists[0].size()) {
keepWithNextActive = keepWithNextActive.compare(keepWithNextPendingOnLabel);
}
if (end[1] + 1 == elementLists[1].size()) {
keepWithNextActive = keepWithNextActive.compare(keepWithNextPendingOnBody);
}
// compute penalty height and box height
int penaltyHeight = step
+ getMaxRemainingHeight(fullHeights, partialHeights)
- totalHeight;
//Additional penalty height from penalties in the source lists
int additionalPenaltyHeight = 0;
int stepPenalty = 0;
KnuthElement endEl = (KnuthElement)elementLists[0].get(end[0]);
if (endEl instanceof KnuthPenalty) {
additionalPenaltyHeight = endEl.getWidth();
stepPenalty = Math.max(stepPenalty, endEl.getPenalty());
}
endEl = (KnuthElement)elementLists[1].get(end[1]);
if (endEl instanceof KnuthPenalty) {
additionalPenaltyHeight = Math.max(
additionalPenaltyHeight, endEl.getWidth());
stepPenalty = Math.max(stepPenalty, endEl.getPenalty());
}
int boxHeight = step - addedBoxHeight - penaltyHeight;
penaltyHeight += additionalPenaltyHeight; //Add AFTER calculating boxHeight!
// collect footnote information
// TODO this should really not be done like this. ListItemLM should remain as
// footnote-agnostic as possible
LinkedList footnoteList = null;
ListElement el;
for (int i = 0; i < elementLists.length; i++) {
for (int j = start[i]; j <= end[i]; j++) {
el = (ListElement) elementLists[i].get(j);
if (el instanceof KnuthBlockBox && ((KnuthBlockBox) el).hasAnchors()) {
if (footnoteList == null) {
footnoteList = new LinkedList();
}
footnoteList.addAll(((KnuthBlockBox) el).getFootnoteBodyLMs());
}
}
}
// add the new elements
addedBoxHeight += boxHeight;
ListItemPosition stepPosition = new ListItemPosition(this,
start[0], end[0], start[1], end[1]);
if (footnoteList == null) {
returnList.add(new KnuthBox(boxHeight, stepPosition, false));
} else {
returnList.add(new KnuthBlockBox(boxHeight, footnoteList, stepPosition, false));
}
if (addedBoxHeight < totalHeight) {
Keep keep = keepWithNextActive.compare(getKeepTogether());
int p = stepPenalty;
if (p > -KnuthElement.INFINITE) {
p = Math.max(p, keep.getPenalty());
}
returnList.add(new BreakElement(stepPosition, penaltyHeight, p, keep.getContext(),
context));
}
}
return returnList;
}
private int getNextStep(List[] elementLists, int[] start, int[] end, int[] partialHeights) {
// backup of partial heights
int[] backupHeights = {partialHeights[0], partialHeights[1]};
// set starting points
start[0] = end[0] + 1;
start[1] = end[1] + 1;
// get next possible sequence for label and body
int seqCount = 0;
for (int i = 0; i < start.length; i++) {
while (end[i] + 1 < elementLists[i].size()) {
end[i]++;
KnuthElement el = (KnuthElement)elementLists[i].get(end[i]);
if (el.isPenalty()) {
if (el.getPenalty() < KnuthElement.INFINITE) {
//First legal break point
break;
}
} else if (el.isGlue()) {
if (end[i] > 0) {
KnuthElement prev = (KnuthElement)elementLists[i].get(end[i] - 1);
if (prev.isBox()) {
//Second legal break point
break;
}
}
partialHeights[i] += el.getWidth();
} else {
partialHeights[i] += el.getWidth();
}
}
if (end[i] < start[i]) {
partialHeights[i] = backupHeights[i];
} else {
seqCount++;
}
}
if (seqCount == 0) {
return 0;
}
// determine next step
int step;
if (backupHeights[0] == 0 && backupHeights[1] == 0) {
// this is the first step: choose the maximum increase, so that
// the smallest area in the first page will contain at least
// a label area and a body area
step = Math.max((end[0] >= start[0] ? partialHeights[0] : Integer.MIN_VALUE),
(end[1] >= start[1] ? partialHeights[1] : Integer.MIN_VALUE));
} else {
// this is not the first step: choose the minimum increase
step = Math.min((end[0] >= start[0] ? partialHeights[0] : Integer.MAX_VALUE),
(end[1] >= start[1] ? partialHeights[1] : Integer.MAX_VALUE));
}
// reset bigger-than-step sequences
for (int i = 0; i < partialHeights.length; i++) {
if (partialHeights[i] > step) {
partialHeights[i] = backupHeights[i];
end[i] = start[i] - 1;
}
}
return step;
}
private int getMaxRemainingHeight(int[] fullHeights, int[] partialHeights) {
return Math.max(fullHeights[0] - partialHeights[0],
fullHeights[1] - partialHeights[1]);
}
/**
* {@inheritDoc}
*/
public List getChangedKnuthElements(List oldList, int alignment) {
//log.debug(" LILM.getChanged> label");
// label
labelList = label.getChangedKnuthElements(labelList, alignment);
//log.debug(" LILM.getChanged> body");
// body
// "unwrap" the Positions stored in the elements
ListIterator oldListIterator = oldList.listIterator();
KnuthElement oldElement;
while (oldListIterator.hasNext()) {
oldElement = (KnuthElement)oldListIterator.next();
Position innerPosition = oldElement.getPosition().getPosition();
//log.debug(" BLM> unwrapping: " + (oldElement.isBox()
// ? "box " : (oldElement.isGlue() ? "glue " : "penalty"))
// + " creato da " + oldElement.getLayoutManager().getClass().getName());
//log.debug(" BLM> unwrapping: "
// + oldElement.getPosition().getClass().getName());
if (innerPosition != null) {
// oldElement was created by a descendant of this BlockLM
oldElement.setPosition(innerPosition);
} else {
// thisElement was created by this BlockLM
// modify its position in order to recognize it was not created
// by a child
oldElement.setPosition(new Position(this));
}
}
List returnedList = body.getChangedKnuthElements(oldList, alignment);
// "wrap" the Position inside each element
List tempList = returnedList;
KnuthElement tempElement;
returnedList = new LinkedList();
ListIterator listIter = tempList.listIterator();
while (listIter.hasNext()) {
tempElement = (KnuthElement)listIter.next();
tempElement.setPosition(new NonLeafPosition(this, tempElement.getPosition()));
returnedList.add(tempElement);
}
return returnedList;
}
/**
* Add the areas for the break points.
* This sets the offset of each cell as it is added.
*
* @param parentIter the position iterator
* @param layoutContext the layout context for adding areas
*/
public void addAreas(PositionIterator parentIter,
LayoutContext layoutContext) {
getParentArea(null);
addId();
LayoutContext lc = new LayoutContext(0);
Position firstPos = null;
Position lastPos = null;
// "unwrap" the NonLeafPositions stored in parentIter
LinkedList positionList = new LinkedList();
Position pos;
while (parentIter.hasNext()) {
pos = (Position) parentIter.next();
if (pos.getIndex() >= 0) {
if (firstPos == null) {
firstPos = pos;
}
lastPos = pos;
}
if (pos instanceof NonLeafPosition && pos.getPosition() != null) {
// pos contains a ListItemPosition created by this ListBlockLM
positionList.add(pos.getPosition());
}
}
addMarkersToPage(true, isFirst(firstPos), isLast(lastPos));
// use the first and the last ListItemPosition to determine the
// corresponding indexes in the original labelList and bodyList
int labelFirstIndex = ((ListItemPosition) positionList.getFirst()).getLabelFirstIndex();
int labelLastIndex = ((ListItemPosition) positionList.getLast()).getLabelLastIndex();
int bodyFirstIndex = ((ListItemPosition) positionList.getFirst()).getBodyFirstIndex();
int bodyLastIndex = ((ListItemPosition) positionList.getLast()).getBodyLastIndex();
//Determine previous break if any
int previousBreak = ElementListUtils.determinePreviousBreak(labelList, labelFirstIndex);
SpaceResolver.performConditionalsNotification(labelList,
labelFirstIndex, labelLastIndex, previousBreak);
//Determine previous break if any
previousBreak = ElementListUtils.determinePreviousBreak(bodyList, bodyFirstIndex);
SpaceResolver.performConditionalsNotification(bodyList,
bodyFirstIndex, bodyLastIndex, previousBreak);
// add label areas
if (labelFirstIndex <= labelLastIndex) {
KnuthPossPosIter labelIter = new KnuthPossPosIter(labelList,
labelFirstIndex, labelLastIndex + 1);
lc.setFlags(LayoutContext.FIRST_AREA, layoutContext.isFirstArea());
lc.setFlags(LayoutContext.LAST_AREA, layoutContext.isLastArea());
// set the space adjustment ratio
lc.setSpaceAdjust(layoutContext.getSpaceAdjust());
// TO DO: use the right stack limit for the label
lc.setStackLimitBP(layoutContext.getStackLimitBP());
label.addAreas(labelIter, lc);
}
// add body areas
if (bodyFirstIndex <= bodyLastIndex) {
KnuthPossPosIter bodyIter = new KnuthPossPosIter(bodyList,
bodyFirstIndex, bodyLastIndex + 1);
lc.setFlags(LayoutContext.FIRST_AREA, layoutContext.isFirstArea());
lc.setFlags(LayoutContext.LAST_AREA, layoutContext.isLastArea());
// set the space adjustment ratio
lc.setSpaceAdjust(layoutContext.getSpaceAdjust());
// TO DO: use the right stack limit for the body
lc.setStackLimitBP(layoutContext.getStackLimitBP());
body.addAreas(bodyIter, lc);
}
// after adding body areas, set the maximum area bpd
int childCount = curBlockArea.getChildAreas().size();
assert childCount >= 1 && childCount <= 2;
int itemBPD = ((Block)curBlockArea.getChildAreas().get(0)).getAllocBPD();
if (childCount == 2) {
itemBPD = Math.max(itemBPD, ((Block)curBlockArea.getChildAreas().get(1)).getAllocBPD());
}
curBlockArea.setBPD(itemBPD);
addMarkersToPage(false, isFirst(firstPos), isLast(lastPos));
// We are done with this area add the background
TraitSetter.addBackground(curBlockArea,
getListItemFO().getCommonBorderPaddingBackground(),
this);
TraitSetter.addSpaceBeforeAfter(curBlockArea, layoutContext.getSpaceAdjust(),
effSpaceBefore, effSpaceAfter);
flush();
curBlockArea = null;
resetSpaces();
checkEndOfLayout(lastPos);
}
/**
* Get the height of the list item after adjusting.
* Should only be called after adding the list item areas.
*
* @return the height of this list item after adjustment
*/
public int getListItemHeight() {
return listItemHeight;
}
/**
* Return an Area which can contain the passed childArea. The childArea
* may not yet have any content, but it has essential traits set.
* In general, if the LayoutManager already has an Area it simply returns
* it. Otherwise, it makes a new Area of the appropriate class.
* It gets a parent area for its area by calling its parent LM.
* Finally, based on the dimensions of the parent area, it initializes
* its own area. This includes setting the content IPD and the maximum
* BPD.
*
* @param childArea the child area
* @return the parent are for the child
*/
public Area getParentArea(Area childArea) {
if (curBlockArea == null) {
curBlockArea = new Block();
// Set up dimensions
/*Area parentArea =*/ parentLayoutManager.getParentArea(curBlockArea);
// set traits
TraitSetter.setProducerID(curBlockArea, getListItemFO().getId());
TraitSetter.addBorders(curBlockArea,
getListItemFO().getCommonBorderPaddingBackground(),
discardBorderBefore, discardBorderAfter, false, false, this);
TraitSetter.addPadding(curBlockArea,
getListItemFO().getCommonBorderPaddingBackground(),
discardPaddingBefore, discardPaddingAfter, false, false, this);
TraitSetter.addMargins(curBlockArea,
getListItemFO().getCommonBorderPaddingBackground(),
getListItemFO().getCommonMarginBlock(), this);
TraitSetter.addBreaks(curBlockArea,
getListItemFO().getBreakBefore(),
getListItemFO().getBreakAfter());
int contentIPD = referenceIPD - getIPIndents();
curBlockArea.setIPD(contentIPD);
setCurrentArea(curBlockArea);
}
return curBlockArea;
}
/**
* Add the child.
* Rows return the areas returned by the child elements.
* This simply adds the area to the parent layout manager.
*
* @param childArea the child area
*/
public void addChildArea(Area childArea) {
if (curBlockArea != null) {
curBlockArea.addBlock((Block) childArea);
}
}
/** {@inheritDoc} */
public KeepProperty getKeepTogetherProperty() {
return getListItemFO().getKeepTogether();
}
/** {@inheritDoc} */
public KeepProperty getKeepWithPreviousProperty() {
return getListItemFO().getKeepWithPrevious();
}
/** {@inheritDoc} */
public KeepProperty getKeepWithNextProperty() {
return getListItemFO().getKeepWithNext();
}
/** {@inheritDoc} */
public void notifySpace(RelSide side, MinOptMax effectiveLength) {
if (RelSide.BEFORE == side) {
if (log.isDebugEnabled()) {
log.debug(this + ": Space " + side + ", "
+ this.effSpaceBefore + "-> " + effectiveLength);
}
this.effSpaceBefore = effectiveLength;
} else {
if (log.isDebugEnabled()) {
log.debug(this + ": Space " + side + ", "
+ this.effSpaceAfter + "-> " + effectiveLength);
}
this.effSpaceAfter = effectiveLength;
}
}
/** {@inheritDoc} */
public void notifyBorder(RelSide side, MinOptMax effectiveLength) {
if (effectiveLength == null) {
if (RelSide.BEFORE == side) {
this.discardBorderBefore = true;
} else {
this.discardBorderAfter = true;
}
}
if (log.isDebugEnabled()) {
log.debug(this + ": Border " + side + " -> " + effectiveLength);
}
}
/** {@inheritDoc} */
public void notifyPadding(RelSide side, MinOptMax effectiveLength) {
if (effectiveLength == null) {
if (RelSide.BEFORE == side) {
this.discardPaddingBefore = true;
} else {
this.discardPaddingAfter = true;
}
}
if (log.isDebugEnabled()) {
log.debug(this + ": Padding " + side + " -> " + effectiveLength);
}
}
/** {@inheritDoc} */
public void reset() {
super.reset();
label.reset();
body.reset();
}
}