com.lowagie.text.pdf.parser.MarkedUpTextAssembler Maven / Gradle / Ivy
/**
* Copyright 2014 by Tizra Inc.
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999-2008 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000-2008 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
* details.
*/
package com.lowagie.text.pdf.parser;
import com.lowagie.text.pdf.PdfReader;
import javax.annotation.Nullable;
import java.util.ArrayList;
import java.util.List;
/**
* We'll get called on a variety of marked section content (perhaps including
* the results of nested sections), and will assemble it into an order as we
* can.
*
* @author dgd
*
*/
public class MarkedUpTextAssembler implements TextAssembler {
/**
* our result may be partially processed already, in which case we'll just
* add things to it, once ready.
*/
List result = new ArrayList<>();
private PdfReader reader;
@Nullable
private ParsedTextImpl inProgress = null;
private int page;
private int wordIdCounter = 1;
private boolean usePdfMarkupElements = false;
/**
* as we get new content (final or not), we accumulate it until we reach the
* end of a parsing unit
*
* Each parsing unit may have a tag name that should wrap its content
*/
private List partialWords = new ArrayList<>();
MarkedUpTextAssembler(PdfReader reader) {
this.reader = reader;
}
MarkedUpTextAssembler(PdfReader reader, boolean usePdfMarkupElements) {
this.reader = reader;
this.usePdfMarkupElements = usePdfMarkupElements;
}
/**
* Remember an unassembled chunk until we hit the end of this element, or we
* hit an assembled chunk, and need to pull things together.
*
* @param unassembled
* chunk of text rendering instruction to contribute to final
* text
*/
@Override
public void process(ParsedText unassembled, String contextName) {
partialWords.addAll(unassembled.getAsPartialWords());
}
/**
* Slot fully-assembled chunk into our result at the current location. If
* there are unassembled chunks waiting, assemble them first.
*
* @param completed
* This is a chunk from a nested element
*/
@Override
public void process(FinalText completed, String contextName) {
clearAccumulator();
result.add(completed);
}
/**
* {@inheritDoc}
* @see com.lowagie.text.pdf.parser.TextAssembler#process(Word, String)
*/
@Override
public void process(Word completed, String contextName) {
partialWords.add(completed);
}
/**
*
*/
private void clearAccumulator() {
for (TextAssemblyBuffer partialWord : partialWords) {
// Visit each partialWord, calling renderText
partialWord.assemble(this);
}
partialWords.clear();
if (inProgress != null) {
result.add(inProgress.getFinalText(reader, page, this, usePdfMarkupElements));
inProgress = null;
}
}
private FinalText concatenateResult(@Nullable String containingElementName) {
// null element means that this is a formatting artifact, not content.
if (containingElementName == null) {
// at some point, we may want to extract alternate text for some
// artifacts.
return null;
}
StringBuilder res = new StringBuilder();
if (usePdfMarkupElements && !containingElementName.isEmpty()) {
res.append('<').append(containingElementName).append('>');
}
for (FinalText item : result) {
res.append(item.getText());
}
// important, as the stuff buffered in the result is now used up!
result.clear();
if (usePdfMarkupElements && !containingElementName.isEmpty()) {
res.append("= 0) {
containingElementName = containingElementName.substring(0, spacePos);
}
res.append(containingElementName).append('>');
}
return new FinalText(res.toString());
}
/**
* {@inheritDoc}
* @see com.lowagie.text.pdf.parser.TextAssembler#endParsingContext(String)
*/
@Override
public FinalText endParsingContext(@Nullable String containingElementName) {
clearAccumulator();
return concatenateResult(containingElementName);
}
/**
*
* @see com.lowagie.text.pdf.parser.TextAssembler#reset()
*/
@Override
public void reset() {
result.clear();
partialWords.clear();
inProgress = null;
}
@Override
public void renderText(FinalText finalText) {
result.add(finalText);
}
/**
* Captures text using a simplified algorithm for inserting hard returns and
* spaces
*
* @see com.lowagie.text.pdf.parser.GraphicsState
* @see com.lowagie.text.pdf.parser.Matrix
*/
@Override
public void renderText(ParsedTextImpl partialWord) {
boolean firstRender = inProgress == null;
boolean hardReturn = false;
if (firstRender) {
inProgress = partialWord;
return;
}
Vector start = partialWord.getStartPoint();
Vector lastStart = inProgress.getStartPoint();
Vector lastEnd = inProgress.getEndPoint();
// see
// http://mathworld.wolfram.com/Point-LineDistance2-Dimensional.html
float dist = inProgress.getBaseline()
.subtract(lastStart)
.cross(lastStart.subtract(start))
.lengthSquared() / inProgress.getBaseline().subtract(lastStart).lengthSquared();
float sameLineThreshold = partialWord.getAscent() * 0.5f;
// let's try using 25% of current leading for vertical slop.
if (dist > sameLineThreshold || Float.isNaN(dist)) {
hardReturn = true;
}
/*
* Note: Technically, we should check both the start and end positions,
* in case the angle of the text changed without any displacement but
* this sort of thing probably doesn't happen much in reality, so we'll
* leave it alone for now
*/
float spacing = lastEnd.subtract(start).length();
if (hardReturn || partialWord.breakBefore()) {
result.add(inProgress.getFinalText(reader, page, this, usePdfMarkupElements));
if (hardReturn) {
result.add(new FinalText("\n"));
if (usePdfMarkupElements) {
result.add(new FinalText("
"));
}
}
inProgress = partialWord;
// System.out.println("<< Hard Return >>");
} else if (spacing < partialWord.getSingleSpaceWidth() / 2.3 || inProgress.shouldNotSplit()) {
inProgress = new Word(inProgress.getText() + partialWord.getText().trim(),
partialWord.getAscent(),
partialWord.getDescent(),
lastStart,
partialWord.getEndPoint(),
inProgress.getBaseline(),
partialWord.getSingleSpaceWidth(),
inProgress.shouldNotSplit(),
inProgress.breakBefore());
} else {
result.add(inProgress.getFinalText(reader, page, this, usePdfMarkupElements));
inProgress = partialWord;
}
}
/**
* Getter.
*
* @return reader
*/
protected PdfReader getReader() {
return reader;
}
/**
* {@inheritDoc}
* @see com.lowagie.text.pdf.parser.TextAssembler#setPage(int)
*/
@Override
public void setPage(int page) {
this.page = page;
}
/**
* {@inheritDoc}
* @see com.lowagie.text.pdf.parser.TextAssembler#getWordId()
*/
@Override
public String getWordId() {
return "word" + wordIdCounter++;
}
}