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The Adobe Experience Manager SDK
/*
* 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.
*/
package org.apache.tika.parser.microsoft.ooxml.xps;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TikaCoreProperties;
import org.apache.tika.sax.XHTMLContentHandler;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Stack;
/**
* Handles an individual page. For now, this marks up
* canvas entities in a <div> tag. Based on the spec,
* it currently relies on order within the xml for order of output
* of text to xhtml. We could do more complex processing of coordinates
* for bidi-languages, but the spec implies that we should be able
* to rely on storage order.
*
* As with our PDFParser, this currently dumps urls at the bottom of the page
* and does not attempt to calculate the correct anchor text.
*
* TODO: integrate table markup
*/
class XPSPageContentHandler extends DefaultHandler {
private static final String GLYPHS = "Glyphs";
private static final String CANVAS = "Canvas";
private static final String CLIP = "Clip";
private static final String NULL_CLIP = "NULL_CLIP";
private static final String UNICODE_STRING = "UnicodeString";
private static final String ORIGIN_X = "OriginX";
private static final String ORIGIN_Y = "OriginY";
private static final String BIDI_LEVEL = "BidiLevel";
private static final String INDICES = "Indices";
private static final String NAME = "Name";
private static final String PATH = "Path";
private static final String NAVIGATE_URI = "FixedPage.NavigateUri";
private static final String IMAGE_SOURCE = "ImageSource";
private static final String IMAGE_BRUSH = "ImageBrush";
private static final String AUTOMATION_PROPERITES_HELP_TEXT = "AutomationProperties.HelpText";
private static final String URL_DIV = "urls";
private static final String DIV = "div";
private static final String CLASS = "class";
private static final String PAGE = "page";
private static final String CANVAS_SAX = "canvas";
private static final String P = "p";
private static final String HREF = "href";
private static final String A = "a";
private final XHTMLContentHandler xhml;
//path in zip file for an image rendered on this page
private String imageSourcePathInZip = null;
//embedded images sometimes include full path info of original image
private String originalLocationOnDrive = null;
//buffer for the glyph runs within a given canvas
//in insertion order
private Map> canvases = new LinkedHashMap<>();
private Set urls = new LinkedHashSet();
private Stack canvasStack = new Stack<>();
private final Map embeddedInfos;
//sort based on y coordinate of first element in each row
//this requires every row to have at least one element
private static Comparator> ROW_SORTER = new Comparator>() {
@Override
public int compare(List o1, List o2) {
if (o1.get(0).originY < o2.get(0).originY) {
return -1;
} else if (o1.get(0).originY > o2.get(0).originY) {
return 1;
}
return 0;
}
};
public XPSPageContentHandler(XHTMLContentHandler xhtml, Map embeddedInfos) {
this.xhml = xhtml;
this.embeddedInfos = embeddedInfos;
}
@Override
public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
if (CANVAS.equals(localName)) {
String clip = getVal(CLIP, atts);
if (clip == null) {
canvasStack.push(NULL_CLIP);
} else {
canvasStack.push(clip);
}
return;
} else if (PATH.equals(localName)) {
//for now just grab them and dump them at the end of the page.
String url = getVal(NAVIGATE_URI, atts);
if (url != null) {
urls.add(url);
}
originalLocationOnDrive = getVal(AUTOMATION_PROPERITES_HELP_TEXT, atts);
} else if (IMAGE_BRUSH.equals(localName)) {
imageSourcePathInZip = getVal(IMAGE_SOURCE, atts);
}
if (!GLYPHS.equals(localName)) {
return;
}
String name = null;
Float originX = null;
Float originY = null;
String unicodeString = null;
Integer bidilevel = 1;
String indicesString = null;
for (int i = 0; i < atts.getLength(); i++) {
String lName = atts.getLocalName(i);
String value = atts.getValue(i);
value = (value == null) ? "" : value.trim();
if (ORIGIN_X.equals(lName) && value.length() > 0) {
try {
originX = Float.parseFloat(atts.getValue(i));
} catch (NumberFormatException e) {
throw new SAXException(e);
}
} else if (ORIGIN_Y.equals(lName) && value.length() > 0) {
try {
originY = Float.parseFloat(atts.getValue(i));
} catch (NumberFormatException e) {
throw new SAXException(e);
}
} else if (UNICODE_STRING.equals(lName)) {
unicodeString = atts.getValue(i);
} else if (BIDI_LEVEL.equals(lName) && value.length() > 0) {
try {
bidilevel = Integer.parseInt(atts.getValue(i));
} catch (NumberFormatException e) {
throw new SAXException(e);
}
} else if (INDICES.equals(lName)) {
indicesString = atts.getValue(i);
} else if (NAME.equals(lName)) {
name = value;
}
}
if (unicodeString != null) {
originX = (originX == null) ? Integer.MIN_VALUE : originX;
originY = (originY == null) ? Integer.MAX_VALUE : originY;
String currentCanvasClip = (canvasStack.size() > 0) ? canvasStack.peek() : NULL_CLIP;
List runs = canvases.get(currentCanvasClip);
if (runs == null) {
runs = new ArrayList<>();
}
runs.add(new GlyphRun(name, originY, originX, unicodeString, bidilevel, indicesString));
canvases.put(currentCanvasClip, runs);
}
}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
if (CANVAS.equals(localName)) {
if (! canvasStack.isEmpty()) {
canvasStack.pop();
}
} else if (PATH.equals(localName)) {
//this assumes that there cannot be a path within a path
//not sure if this is true or if we need to track path depth
if (imageSourcePathInZip != null) {
Metadata m = embeddedInfos.get(imageSourcePathInZip);
if (m == null) {
m = new Metadata();
}
if (originalLocationOnDrive != null) {
String val = m.get(TikaCoreProperties.ORIGINAL_RESOURCE_NAME);
if (val == null) {
m.set(TikaCoreProperties.ORIGINAL_RESOURCE_NAME, originalLocationOnDrive);
}
}
m.set(TikaCoreProperties.EMBEDDED_RESOURCE_TYPE,
TikaCoreProperties.EmbeddedResourceType.INLINE.toString());
embeddedInfos.put(imageSourcePathInZip, m);
}
//reset
imageSourcePathInZip = null;
originalLocationOnDrive = null;
}
}
@Override
public void startDocument() throws SAXException {
xhml.startElement(DIV, CLASS, PAGE);
}
@Override
public void endDocument() throws SAXException {
writePage();
xhml.endElement(DIV);
}
private final void writePage() throws SAXException {
if (canvases.size() == 0) {
return;
}
for (Map.Entry> e : canvases.entrySet()) {
String clip = e.getKey();
List runs = e.getValue();
if (runs.size() == 0) {
continue;
}
xhml.startElement(DIV, CLASS, CANVAS_SAX);
//a list of rows sorted by the y of the first element in each row
List> rows = buildRows(runs);
for (List row : rows) {
writeRow(row);
}
xhml.endElement(DIV);
}
//for now just dump the urls at the end of the page
//At some point, we could link them back up to their
//true anchor text.
if (urls.size() > 0) {
xhml.startElement(DIV, CLASS, URL_DIV);
for (String u : urls) {
xhml.startElement(A, HREF, u);
xhml.characters(u);
xhml.endElement(A);
}
xhml.endElement(DIV);
}
canvases.clear();
}
private void writeRow(List row) throws SAXException {
/*
int rtl = 0;
int ltr = 0;
//if the row is entirely rtl, sort all as rtl
//otherwise sort ltr
for (GlyphRun r : row) {
//ignore directionality of pure spaces
if (r.unicodeString == null || r.unicodeString.trim().length() == 0) {
continue;
}
if (r.direction == GlyphRun.DIRECTION.RTL) {
rtl++;
} else {
ltr++;
}
}
if (rtl > 0 && ltr == 0) {
Collections.sort(row, GlyphRun.RTL_COMPARATOR);
} else {
Collections.sort(row, GlyphRun.LTR_COMPARATOR);
}*/
xhml.startElement(P);
for (GlyphRun run : row) {
//figure out if you need to add a space
xhml.characters(run.unicodeString);
}
xhml.endElement(P);
}
//returns a List of rows (where a row is a list of glyphruns)
//the List is sorted in increasing order of the first y of each row
private List> buildRows(List glyphRuns) {
List> rows = new ArrayList<>();
float maxY = -1.0f;
for (GlyphRun glyphRun : glyphRuns) {
if (rows.size() == 0) {
List row = new ArrayList<>();
row.add(glyphRun);
rows.add(row);
continue;
} else {
boolean addedNewRow = false;
//can rely on the last row having the highest y
List row = rows.get(rows.size()-1);
//0.5 is a purely heuristic/magical number that should be derived
//from the data, not made up. TODO: fix this
if (Math.abs(glyphRun.originY -row.get(0).originY) < 0.5) {
row.add(glyphRun);
} else {
row = new ArrayList<>();
row.add(glyphRun);
rows.add(row);
addedNewRow = true;
}
//sort rows so that they are in ascending order of y
//in most xps files in our test corpus, this is never triggered
//because the runs are already ordered correctly
if (maxY > -1.0f && addedNewRow && glyphRun.originY < maxY) {
Collections.sort(rows, ROW_SORTER);
}
if (glyphRun.originY > maxY) {
maxY = glyphRun.originY;
}
}
}
return rows;
}
private static String getVal(String localName, Attributes atts) {
for (int i = 0; i < atts.getLength(); i++) {
if (localName.equals(atts.getLocalName(i))) {
return atts.getValue(i);
}
}
return null;
}
final static class GlyphRun {
private enum DIRECTION {
LTR,
RTL
}
//TODO: use name in conjunction with Frag information
//to do a better job of extracting paragraph and table structure
private final String name;
private final float originY;
private final float originX;//not currently used, but could be used for bidi text calculations
private final String unicodeString;
private final String indicesString;//not currently used, but could be used for width calculations
//not used yet
private final DIRECTION direction;
private GlyphRun(String name, float originY, float originX, String unicodeString, Integer bidiLevel, String indicesString) {
this.name = name;
this.unicodeString = unicodeString;
this.originY = originY;
this.originX = originX;
if (bidiLevel == null) {
direction = DIRECTION.LTR;
} else {
if (bidiLevel % 2 == 0) {
direction = DIRECTION.LTR;
} else {
direction = DIRECTION.RTL;
}
}
this.indicesString = indicesString;
}
}
}
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