/*
* 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: BlockLayoutManager.java 453310 2006-10-05 18:44:15Z spepping $ */
package org.apache.fop.layoutmgr;
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.area.LineArea;
import org.apache.fop.datatypes.Length;
import org.apache.fop.fonts.Font;
import org.apache.fop.layoutmgr.inline.InlineLayoutManager;
import org.apache.fop.layoutmgr.inline.InlineLevelLayoutManager;
import org.apache.fop.layoutmgr.inline.LineLayoutManager;
import org.apache.fop.traits.MinOptMax;
import org.apache.fop.traits.SpaceVal;
/**
* LayoutManager for a block FO.
*/
public class BlockLayoutManager extends BlockStackingLayoutManager
implements ConditionalElementListener {
/**
* logging instance
*/
private static Log log = LogFactory.getLog(BlockLayoutManager.class);
private Block curBlockArea;
/** Iterator over the child layout managers. */
protected ListIterator proxyLMiter;
private int lead = 12000;
private Length lineHeight;
private int follow = 2000;
private int middleShift = 0;
private boolean discardBorderBefore;
private boolean discardBorderAfter;
private boolean discardPaddingBefore;
private boolean discardPaddingAfter;
private MinOptMax effSpaceBefore;
private MinOptMax effSpaceAfter;
/** The list of child BreakPoss instances. */
protected List childBreaks = new java.util.ArrayList();
/**
* Creates a new BlockLayoutManager.
* @param inBlock the block FO object to create the layout manager for.
*/
public BlockLayoutManager(org.apache.fop.fo.flow.Block inBlock) {
super(inBlock);
proxyLMiter = new ProxyLMiter();
}
public void initialize() {
super.initialize();
Font fs = getBlockFO().getCommonFont().getFontState(
getBlockFO().getFOEventHandler().getFontInfo(), this);
lead = fs.getAscender();
follow = -fs.getDescender();
middleShift = -fs.getXHeight() / 2;
lineHeight = getBlockFO().getLineHeight().getOptimum(this).getLength();
startIndent = getBlockFO().getCommonMarginBlock().startIndent.getValue(this);
endIndent = getBlockFO().getCommonMarginBlock().endIndent.getValue(this);
foSpaceBefore = new SpaceVal(getBlockFO().getCommonMarginBlock().spaceBefore, this)
.getSpace();
foSpaceAfter = new SpaceVal(getBlockFO().getCommonMarginBlock().spaceAfter, this)
.getSpace();
bpUnit = 0; // non-standard extension
if (bpUnit == 0) {
// use optimum space values
adjustedSpaceBefore = getBlockFO().getCommonMarginBlock().spaceBefore.getSpace()
.getOptimum(this).getLength().getValue(this);
adjustedSpaceAfter = getBlockFO().getCommonMarginBlock().spaceAfter.getSpace()
.getOptimum(this).getLength().getValue(this);
} else {
// use minimum space values
adjustedSpaceBefore = getBlockFO().getCommonMarginBlock().spaceBefore.getSpace()
.getMinimum(this).getLength().getValue(this);
adjustedSpaceAfter = getBlockFO().getCommonMarginBlock().spaceAfter.getSpace()
.getMinimum(this).getLength().getValue(this);
}
}
/** @see org.apache.fop.layoutmgr.BlockStackingLayoutManager */
public LinkedList getNextKnuthElements(LayoutContext context, int alignment) {
resetSpaces();
return super.getNextKnuthElements(context, alignment);
}
private void resetSpaces() {
this.discardBorderBefore = false;
this.discardBorderAfter = false;
this.discardPaddingBefore = false;
this.discardPaddingAfter = false;
this.effSpaceBefore = null;
this.effSpaceAfter = null;
}
/**
* Proxy iterator for Block LM.
* This iterator creates and holds the complete list
* of child LMs.
* It uses fobjIter as its base iterator.
* Block LM's createNextChildLMs uses this iterator
* as its base iterator.
*/
protected class ProxyLMiter extends LMiter {
/*
* Constructs a proxy iterator for Block LM.
*/
public ProxyLMiter() {
super(BlockLayoutManager.this);
listLMs = new java.util.ArrayList(10);
}
/**
* @return true if there are more child lms
*/
public boolean hasNext() {
return (curPos < listLMs.size()) ? true : createNextChildLMs(curPos);
}
/**
* @return true if new child lms were added
*/
protected boolean createNextChildLMs(int pos) {
List newLMs = createChildLMs(pos + 1 - listLMs.size());
if (newLMs != null) {
listLMs.addAll(newLMs);
}
return pos < listLMs.size();
}
}
/**
* @see org.apache.fop.layoutmgr.LayoutManager#createNextChildLMs
*/
public boolean createNextChildLMs(int pos) {
while (proxyLMiter.hasNext()) {
LayoutManager lm = (LayoutManager) proxyLMiter.next();
if (lm instanceof InlineLevelLayoutManager) {
LineLayoutManager lineLM = createLineManager(lm);
addChildLM(lineLM);
} else {
addChildLM(lm);
}
if (pos < childLMs.size()) {
return true;
}
}
return false;
}
/**
* Create a new LineLM, and collect all consecutive
* inline generating LMs as its child LMs.
* @param firstlm First LM in new LineLM
* @return the newly created LineLM
*/
private LineLayoutManager createLineManager(LayoutManager firstlm) {
LineLayoutManager llm;
llm = new LineLayoutManager(getBlockFO(), lineHeight, lead, follow);
List inlines = new java.util.ArrayList();
inlines.add(firstlm);
while (proxyLMiter.hasNext()) {
LayoutManager lm = (LayoutManager) proxyLMiter.next();
if (lm instanceof InlineLevelLayoutManager) {
inlines.add(lm);
} else {
proxyLMiter.previous();
break;
}
}
llm.addChildLMs(inlines);
return llm;
}
/**
* @see org.apache.fop.layoutmgr.BlockLevelLayoutManager#mustKeepTogether()
*/
public boolean mustKeepTogether() {
// TODO Keeps will have to be more sophisticated sooner or later
// TODO This is a quick fix for the fact that the parent is not always a BlockLevelLM;
// eventually mustKeepTogether() must be moved up to the LM interface
return (!getBlockFO().getKeepTogether().getWithinPage().isAuto()
|| !getBlockFO().getKeepTogether().getWithinColumn().isAuto()
|| (getParent() instanceof BlockLevelLayoutManager
&& ((BlockLevelLayoutManager) getParent()).mustKeepTogether())
|| (getParent() instanceof InlineLayoutManager
&& ((InlineLayoutManager) getParent()).mustKeepTogether()));
}
/**
* @see org.apache.fop.layoutmgr.BlockLevelLayoutManager#mustKeepWithPrevious()
*/
public boolean mustKeepWithPrevious() {
return !getBlockFO().getKeepWithPrevious().getWithinPage().isAuto()
|| !getBlockFO().getKeepWithPrevious().getWithinColumn().isAuto();
}
/**
* @see org.apache.fop.layoutmgr.BlockLevelLayoutManager#mustKeepWithNext()
*/
public boolean mustKeepWithNext() {
return !getBlockFO().getKeepWithNext().getWithinPage().isAuto()
|| !getBlockFO().getKeepWithNext().getWithinColumn().isAuto();
}
/**
* @see org.apache.fop.layoutmgr.LayoutManager#addAreas(org.apache.fop.layoutmgr.PositionIterator, org.apache.fop.layoutmgr.LayoutContext)
*/
public void addAreas(PositionIterator parentIter,
LayoutContext layoutContext) {
getParentArea(null);
// if this will create the first block area in a page
// and display-align is after or center, add space before
if (layoutContext.getSpaceBefore() > 0) {
addBlockSpacing(0.0, new MinOptMax(layoutContext.getSpaceBefore()));
}
LayoutManager childLM = null;
LayoutManager lastLM = null;
LayoutContext lc = new LayoutContext(0);
lc.setSpaceAdjust(layoutContext.getSpaceAdjust());
// set space after in the LayoutContext for children
if (layoutContext.getSpaceAfter() > 0) {
lc.setSpaceAfter(layoutContext.getSpaceAfter());
}
PositionIterator childPosIter;
// "unwrap" the NonLeafPositions stored in parentIter
// and put them in a new list;
LinkedList positionList = new LinkedList();
Position pos;
boolean bSpaceBefore = false;
boolean bSpaceAfter = false;
Position firstPos = null;
Position lastPos = null;
while (parentIter.hasNext()) {
pos = (Position) parentIter.next();
//log.trace("pos = " + pos.getClass().getName() + "; " + pos);
if (pos.getIndex() >= 0) {
if (firstPos == null) {
firstPos = pos;
}
lastPos = pos;
}
Position innerPosition = pos;
if (pos instanceof NonLeafPosition) {
//Not all elements are wrapped
innerPosition = ((NonLeafPosition) pos).getPosition();
}
if (innerPosition == null) {
// pos was created by this BlockLM and was inside an element
// representing space before or after
// this means the space was not discarded
if (positionList.size() == 0) {
// pos was in the element representing space-before
bSpaceBefore = true;
//log.trace(" space before");
} else {
// pos was in the element representing space-after
bSpaceAfter = true;
//log.trace(" space-after");
}
} else if (innerPosition.getLM() == this
&& !(innerPosition instanceof MappingPosition)) {
// pos was created by this BlockLM and was inside a penalty
// allowing or forbidding a page break
// nothing to do
//log.trace(" penalty");
} else {
// innerPosition was created by another LM
positionList.add(innerPosition);
lastLM = innerPosition.getLM();
//log.trace(" " + innerPosition.getClass().getName());
}
}
getPSLM().addIDToPage(getBlockFO().getId());
if (markers != null) {
getCurrentPV().addMarkers(markers, true, isFirst(firstPos), isLast(lastPos));
}
if (bpUnit == 0) {
// the Positions in positionList were inside the elements
// created by the LineLM
childPosIter = new StackingIter(positionList.listIterator());
} else {
// the Positions in positionList were inside the elements
// created by the BlockLM in the createUnitElements() method
//if (((Position) positionList.getLast()) instanceof
// LeafPosition) {
// // the last item inside positionList is a LeafPosition
// // (a LineBreakPosition, more precisely); this means that
// // the whole paragraph is on the same page
// childPosIter = new KnuthPossPosIter(storedList, 0,
// storedList.size());
//} else {
// // the last item inside positionList is a Position;
// // this means that the paragraph has been split
// // between consecutive pages
LinkedList splitList = new LinkedList();
int splitLength = 0;
int iFirst = ((MappingPosition) positionList.getFirst()).getFirstIndex();
int iLast = ((MappingPosition) positionList.getLast()).getLastIndex();
// copy from storedList to splitList all the elements from
// iFirst to iLast
ListIterator storedListIterator = storedList.listIterator(iFirst);
while (storedListIterator.nextIndex() <= iLast) {
KnuthElement element = (KnuthElement) storedListIterator
.next();
// some elements in storedList (i.e. penalty items) were created
// by this BlockLM, and must be ignored
if (element.getLayoutManager() != this) {
splitList.add(element);
splitLength += element.getW();
lastLM = element.getLayoutManager();
}
}
//log.debug("Adding areas from " + iFirst + " to " + iLast);
//log.debug("splitLength= " + splitLength
// + " (" + neededUnits(splitLength) + " units') "
// + (neededUnits(splitLength) * bpUnit - splitLength)
// + " spacing");
// add space before and / or after the paragraph
// to reach a multiple of bpUnit
if (bSpaceBefore && bSpaceAfter) {
foSpaceBefore = new SpaceVal(getBlockFO()
.getCommonMarginBlock().spaceBefore, this).getSpace();
foSpaceAfter = new SpaceVal(getBlockFO()
.getCommonMarginBlock().spaceAfter, this).getSpace();
adjustedSpaceBefore = (neededUnits(splitLength
+ foSpaceBefore.min
+ foSpaceAfter.min)
* bpUnit - splitLength) / 2;
adjustedSpaceAfter = neededUnits(splitLength
+ foSpaceBefore.min
+ foSpaceAfter.min)
* bpUnit - splitLength - adjustedSpaceBefore;
} else if (bSpaceBefore) {
adjustedSpaceBefore = neededUnits(splitLength
+ foSpaceBefore.min)
* bpUnit - splitLength;
} else {
adjustedSpaceAfter = neededUnits(splitLength
+ foSpaceAfter.min)
* bpUnit - splitLength;
}
//log.debug("spazio prima = " + adjustedSpaceBefore
// + " spazio dopo = " + adjustedSpaceAfter + " totale = " +
// (adjustedSpaceBefore + adjustedSpaceAfter + splitLength));
childPosIter = new KnuthPossPosIter(splitList, 0, splitList
.size());
//}
}
while ((childLM = childPosIter.getNextChildLM()) != null) {
// set last area flag
lc.setFlags(LayoutContext.LAST_AREA,
(layoutContext.isLastArea() && childLM == lastLM));
lc.setStackLimit(layoutContext.getStackLimit());
// Add the line areas to Area
childLM.addAreas(childPosIter, lc);
}
if (markers != null) {
getCurrentPV().addMarkers(markers, false, isFirst(firstPos), isLast(lastPos));
}
TraitSetter.addSpaceBeforeAfter(curBlockArea, layoutContext.getSpaceAdjust(),
effSpaceBefore, effSpaceAfter);
flush();
curBlockArea = null;
resetSpaces();
// Notify end of block layout manager to the PSLM
getPSLM().notifyEndOfLayout(getBlockFO().getId());
}
/**
* 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 area to get the parent area for
* @return the parent area
*/
public Area getParentArea(Area childArea) {
if (curBlockArea == null) {
curBlockArea = new Block();
curBlockArea.setIPD(super.getContentAreaIPD());
TraitSetter.addBreaks(curBlockArea,
getBlockFO().getBreakBefore(), getBlockFO().getBreakAfter());
// Must get dimensions from parent area
//Don't optimize this line away. It can have ugly side-effects.
/*Area parentArea =*/ parentLM.getParentArea(curBlockArea);
// set traits
TraitSetter.setProducerID(curBlockArea, getBlockFO().getId());
TraitSetter.addBorders(curBlockArea,
getBlockFO().getCommonBorderPaddingBackground(),
discardBorderBefore, discardBorderAfter, false, false, this);
TraitSetter.addPadding(curBlockArea,
getBlockFO().getCommonBorderPaddingBackground(),
discardPaddingBefore, discardPaddingAfter, false, false, this);
TraitSetter.addMargins(curBlockArea,
getBlockFO().getCommonBorderPaddingBackground(),
startIndent, endIndent,
this);
setCurrentArea(curBlockArea); // ??? for generic operations
}
return curBlockArea;
}
/**
* @see org.apache.fop.layoutmgr.LayoutManager#addChildArea(Area)
*/
public void addChildArea(Area childArea) {
if (curBlockArea != null) {
if (childArea instanceof LineArea) {
curBlockArea.addLineArea((LineArea) childArea);
} else {
curBlockArea.addBlock((Block) childArea);
}
}
}
/**
* Force current area to be added to parent area.
* @see org.apache.fop.layoutmgr.BlockStackingLayoutManager#flush()
*/
protected void flush() {
if (curBlockArea != null) {
TraitSetter.addBackground(curBlockArea,
getBlockFO().getCommonBorderPaddingBackground(),
this);
super.flush();
}
}
/**
* @see org.apache.fop.layoutmgr.LayoutManager#resetPosition(org.apache.fop.layoutmgr.Position)
*/
public void resetPosition(Position resetPos) {
if (resetPos == null) {
reset(null);
childBreaks.clear();
} else {
//reset(resetPos);
LayoutManager lm = resetPos.getLM();
}
}
/**
* convenience method that returns the Block node
* @return the block node
*/
protected org.apache.fop.fo.flow.Block getBlockFO() {
return (org.apache.fop.fo.flow.Block) fobj;
}
// --------- Property Resolution related functions --------- //
/**
* Returns the IPD of the content area
* @return the IPD of the content area
*/
public int getContentAreaIPD() {
if (curBlockArea != null) {
return curBlockArea.getIPD();
}
return super.getContentAreaIPD();
}
/**
* Returns the BPD of the content area
* @return the BPD of the content area
*/
public int getContentAreaBPD() {
if (curBlockArea != null) {
return curBlockArea.getBPD();
}
return -1;
}
/**
* @see org.apache.fop.layoutmgr.LayoutManager#getGeneratesBlockArea
*/
public boolean getGeneratesBlockArea() {
return true;
}
/** @see org.apache.fop.layoutmgr.ConditionalElementListener */
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;
}
}
/** @see org.apache.fop.layoutmgr.ConditionalElementListener */
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);
}
}
/** @see org.apache.fop.layoutmgr.ConditionalElementListener */
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);
}
}
}