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Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF.
/*
* 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: LineArea.java 1761020 2016-09-16 11:17:35Z ssteiner $ */
package org.apache.fop.area;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.apache.fop.area.inline.InlineArea;
import static org.apache.fop.fo.Constants.EN_CENTER;
import static org.apache.fop.fo.Constants.EN_END;
import static org.apache.fop.fo.Constants.EN_JUSTIFY;
import static org.apache.fop.fo.Constants.EN_START;
/**
* The line area.
* This is a line area that contains inline areas.
*/
public class LineArea extends Area {
private static final long serialVersionUID = 7670235908329290684L;
/**
* this class stores information about line width and potential adjustments
* that can be used in order to re-compute adjustement and / or indents when a
* page-number or a page-number-citation is resolved
*/
// @SuppressFBWarnings("SE_INNER_CLASS")
private final class LineAdjustingInfo implements Serializable {
private static final long serialVersionUID = -6103629976229458273L;
private int lineAlignment;
private int difference;
private int availableStretch;
private int availableShrink;
private double variationFactor;
private boolean bAddedToAreaTree;
private LineAdjustingInfo(int alignment, int diff,
int stretch, int shrink) {
lineAlignment = alignment;
difference = diff;
availableStretch = stretch;
availableShrink = shrink;
variationFactor = 1.0;
bAddedToAreaTree = false;
}
/** {@inheritDoc} */
public String toString() {
return getClass().getSimpleName()
+ ": diff=" + difference
+ ", variation=" + variationFactor
+ ", stretch=" + availableStretch
+ ", shrink=" + availableShrink;
}
}
private LineAdjustingInfo adjustingInfo;
// this class can contain the dominant char styling info
// this means that many renderers can optimise a bit
private List inlineAreas = new ArrayList();
/**
* default constructor:
* nothing to do
*/
public LineArea() {
}
/**
* constructor with extra parameters:
* a new LineAdjustingInfo object is created
* @param alignment alignment of this line
* @param diff difference between content width and line width
* @param stretch the available stretch for any adjustments
* @param shrink the available shrink for any adjustments
*/
public LineArea(int alignment, int diff,
int stretch, int shrink) {
adjustingInfo = new LineAdjustingInfo(alignment, diff, stretch, shrink);
}
/**
* Add a child area to this line area.
*
* @param childArea the inline child area to add
*/
@Override
public void addChildArea(Area childArea) {
if (childArea instanceof InlineArea) {
addInlineArea((InlineArea)childArea);
// set the parent area for the child area
((InlineArea)childArea).setParentArea(this);
}
}
/**
* Add an inline child area to this line area.
*
* @param area the inline child area to add
*/
public void addInlineArea(InlineArea area) {
inlineAreas.add(area);
}
/**
* Set (en masse) the inline child areas of this line area.
* Used by bidirectional processing after line area consituent reordering.
* @param inlineAreas the list of inline areas
*/
public void setInlineAreas(List inlineAreas) {
for (InlineArea ia : (Iterable) inlineAreas) {
Area pa = ia.getParentArea();
if (pa == null) {
ia.setParentArea(this);
} else {
assert pa == this;
}
}
this.inlineAreas = inlineAreas;
}
/**
* Get the inline child areas of this line area.
*
* @return the list of inline areas
*/
public List getInlineAreas() {
return inlineAreas;
}
/**
* Get the start indent of this line area.
* The start indent is used for offsetting the start of
* the inline areas for alignment or other indents.
*
* @return the start indent value
*/
public int getStartIndent() {
if (hasTrait(Trait.START_INDENT)) {
return getTraitAsInteger(Trait.START_INDENT);
} else {
return 0;
}
}
/**
* Get the end indent of this line area.
* The end indent is used for offsetting the end of
* the inline areas for alignment or other indents.
*
* @return the end indent value
*/
public int getEndIndent() {
if (hasTrait(Trait.END_INDENT)) {
return getTraitAsInteger(Trait.END_INDENT);
} else {
return 0;
}
}
/**
* Updates the extents of the line area from its children.
*/
public void updateExtentsFromChildren() {
int ipd = 0;
int bpd = 0;
for (InlineArea inlineArea : inlineAreas) {
ipd = Math.max(ipd, inlineArea.getAllocIPD());
bpd += inlineArea.getAllocBPD();
}
setIPD(ipd);
setBPD(bpd);
}
/**
* receive notification about the ipd variation of a descendant area
* and perform the needed adjustment, according to the alignment;
* in particular:
*
* - left-aligned text needs no adjustement;
* - right-aligned text and centered text are handled locally,
* adjusting the indent of this LineArea;
* - justified text requires a more complex adjustment, as the
* variation factor computed on the basis of the total
* stretch and shrink of the line must be applied in every
* descendant leaf areas (text areas and leader areas).
*
* @param ipdVariation the difference between old and new ipd
*/
public void handleIPDVariation(int ipdVariation) {
int si = getStartIndent();
int ei = getEndIndent();
switch (adjustingInfo.lineAlignment) {
case EN_START:
// adjust end indent
addTrait(Trait.END_INDENT, ei - ipdVariation);
break;
case EN_CENTER:
// adjust start and end indents
addTrait(Trait.START_INDENT, si - ipdVariation / 2);
addTrait(Trait.END_INDENT, ei - ipdVariation / 2);
break;
case EN_END:
// adjust start indent
addTrait(Trait.START_INDENT, si - ipdVariation);
break;
case EN_JUSTIFY:
// compute variation factor
adjustingInfo.variationFactor *= (float) (adjustingInfo.difference - ipdVariation)
/ adjustingInfo.difference;
adjustingInfo.difference -= ipdVariation;
// if the LineArea has already been added to the area tree,
// call finalize(); otherwise, wait for the LineLM to call it
if (adjustingInfo.bAddedToAreaTree) {
finish();
}
break;
default:
throw new RuntimeException();
}
}
/**
* apply the variation factor to all descendant areas
* and destroy the AdjustingInfo object if there are
* no UnresolvedAreas left
*/
public void finish() {
if (adjustingInfo.lineAlignment == EN_JUSTIFY) {
if (log.isTraceEnabled()) {
log.trace("Applying variation factor to justified line: " + adjustingInfo);
}
// justified line: apply the variation factor
boolean bUnresolvedAreasPresent = false;
// recursively apply variation factor to descendant areas
for (InlineArea inlineArea : inlineAreas) {
bUnresolvedAreasPresent |= inlineArea
.applyVariationFactor(adjustingInfo.variationFactor,
adjustingInfo.availableStretch,
adjustingInfo.availableShrink);
}
if (!bUnresolvedAreasPresent) {
// there are no more UnresolvedAreas:
// destroy the AdjustingInfo instance
adjustingInfo = null;
} else {
// this method will be called again later:
// the first time, it is called by the LineLM,
// afterwards it must be called by the LineArea itself
if (!adjustingInfo.bAddedToAreaTree) {
adjustingInfo.bAddedToAreaTree = true;
}
// reset the variation factor
adjustingInfo.variationFactor = 1.0;
}
} else {
// the line is not justified: the ipd variation has already
// been handled, modifying the line indent
}
}
public int getEffectiveIPD() {
int maxIPD = 0;
if (inlineAreas != null) {
for (Area area : inlineAreas) {
int effectiveIPD = area.getEffectiveIPD();
if (effectiveIPD > maxIPD) {
maxIPD = effectiveIPD;
}
}
}
return maxIPD;
}
}