/**
* PDFDomTree.java
* (c) Radek Burget, 2011
*
* Pdf2Dom is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Pdf2Dom 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with CSSBox. If not, see <http://www.gnu.org/licenses/>.
*
* Created on 13.9.2011, 14:17:24 by burgetr
*/
package org.fit.pdfdom;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.fit.pdfdom.resource.IgnoreResourceHandler;
import org.fit.pdfdom.resource.ImageResource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.Text;
import org.w3c.dom.bootstrap.DOMImplementationRegistry;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSOutput;
import org.w3c.dom.ls.LSSerializer;
/**
* A DOM representation of a PDF file.
*
* @author burgetr
*/
public class PDFDomTree extends PDFBoxTree
{
private static Logger log = LoggerFactory.getLogger(PDFDomTree.class);
/** Default style placed in the begining of the resulting document */
protected String defaultStyle = ".page{position:relative; border:1px solid blue;margin:0.5em}\n" +
".p,.r{position:absolute;}\n" +
// disable text-shadow fallback for text stroke if stroke supported by browser
"@supports(-webkit-text-stroke: 1px black) {" +
".p{text-shadow:none !important;}" +
"}";
/** The resulting document representing the PDF file. */
protected Document doc;
/** The head element of the resulting document. */
protected Element head;
/** The body element of the resulting document. */
protected Element body;
/** The title element of the resulting document. */
protected Element title;
/** The global style element of the resulting document. */
protected Element globalStyle;
/** The element representing the page currently being created in the resulting document. */
protected Element curpage;
/** Text element counter for assigning IDs to the text elements. */
protected int textcnt;
/** Page counter for assigning IDs to the pages. */
protected int pagecnt;
protected PDFDomTreeConfig config;
/**
* Creates a new PDF DOM parser.
* @throws IOException
* @throws ParserConfigurationException
*/
public PDFDomTree() throws IOException, ParserConfigurationException
{
super();
init();
}
/**
* Creates a new PDF DOM parser.
* @throws IOException
* @throws ParserConfigurationException
*/
public PDFDomTree(PDFDomTreeConfig config) throws IOException, ParserConfigurationException
{
this();
if (config != null)
this.config = config;
}
/**
* Internal initialization.
* @throws ParserConfigurationException
*/
private void init() throws ParserConfigurationException
{
pagecnt = 0;
textcnt = 0;
this.config = PDFDomTreeConfig.createDefaultConfig();
}
/**
* Creates a new empty HTML document tree.
* @throws ParserConfigurationException
*/
protected void createDocument() throws ParserConfigurationException
{
DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = builderFactory.newDocumentBuilder();
DocumentType doctype = builder.getDOMImplementation().createDocumentType("html", "-//W3C//DTD XHTML 1.1//EN", "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd");
doc = builder.getDOMImplementation().createDocument("http://www.w3.org/1999/xhtml", "html", doctype);
head = doc.createElement("head");
Element meta = doc.createElement("meta");
meta.setAttribute("http-equiv", "content-type");
meta.setAttribute("content", "text/html;charset=utf-8");
head.appendChild(meta);
title = doc.createElement("title");
title.setTextContent("PDF Document");
head.appendChild(title);
globalStyle = doc.createElement("style");
globalStyle.setAttribute("type", "text/css");
//globalStyle.setTextContent(createGlobalStyle());
head.appendChild(globalStyle);
body = doc.createElement("body");
Element root = doc.getDocumentElement();
root.appendChild(head);
root.appendChild(body);
}
/**
* Obtains the resulting document tree.
* @return The DOM root element.
*/
public Document getDocument()
{
return doc;
}
@Override
public void startDocument(PDDocument document)
throws IOException
{
try {
createDocument();
} catch (ParserConfigurationException e) {
throw new IOException("Error: parser configuration error", e);
}
}
@Override
protected void endDocument(PDDocument document) throws IOException
{
//use the PDF title
String doctitle = document.getDocumentInformation().getTitle();
if (doctitle != null && doctitle.trim().length() > 0)
title.setTextContent(doctitle);
//set the main style
globalStyle.setTextContent(createGlobalStyle());
}
/**
* Parses a PDF document and serializes the resulting DOM tree to an output. This requires
* a DOM Level 3 capable implementation to be available.
*/
@Override
public void writeText(PDDocument doc, Writer outputStream) throws IOException
{
try
{
DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
DOMImplementationLS impl = (DOMImplementationLS)registry.getDOMImplementation("LS");
LSSerializer writer = impl.createLSSerializer();
LSOutput output = impl.createLSOutput();
writer.getDomConfig().setParameter("format-pretty-print", true);
output.setCharacterStream(outputStream);
createDOM(doc);
writer.write(getDocument(), output);
} catch (ClassCastException e) {
throw new IOException("Error: cannot initialize the DOM serializer", e);
} catch (ClassNotFoundException e) {
throw new IOException("Error: cannot initialize the DOM serializer", e);
} catch (InstantiationException e) {
throw new IOException("Error: cannot initialize the DOM serializer", e);
} catch (IllegalAccessException e) {
throw new IOException("Error: cannot initialize the DOM serializer", e);
}
}
/**
* Loads a PDF document and creates a DOM tree from it.
* @param doc the source document
* @return a DOM Document representing the DOM tree
* @throws IOException
*/
public Document createDOM(PDDocument doc) throws IOException
{
/* We call the original PDFTextStripper.writeText but nothing should
be printed actually because our processing methods produce no output.
They create the DOM structures instead */
super.writeText(doc, new OutputStreamWriter(System.out));
return this.doc;
}
//===========================================================================================
@Override
protected void startNewPage()
{
curpage = createPageElement();
body.appendChild(curpage);
}
@Override
protected void renderText(String data, TextMetrics metrics)
{
curpage.appendChild(createTextElement(data, metrics.getWidth()));
}
@Override
protected void renderPath(List<PathSegment> path, boolean stroke, boolean fill) throws IOException
{
float[] rect = toRectangle(path);
if (rect != null)
{
curpage.appendChild(createRectangleElement(rect[0], rect[1], rect[2]-rect[0], rect[3]-rect[1], stroke, fill));
}
else if (stroke)
{
for (PathSegment segm : path)
curpage.appendChild(createLineElement(segm.getX1(), segm.getY1(), segm.getX2(), segm.getY2()));
}
else {
Element pathImage = createPathImage(path);
if (pathImage != null)
curpage.appendChild(pathImage);
}
}
@Override
protected void renderImage(float x, float y, float width, float height, ImageResource resource) throws IOException
{
curpage.appendChild(createImageElement(x, y, width, height, resource));
}
//===========================================================================================
/**
* Creates an element that represents a single page.
* @return the resulting DOM element
*/
protected Element createPageElement()
{
String pstyle = "";
PDRectangle layout = getCurrentMediaBox();
if (layout != null)
{
/*System.out.println("x1 " + layout.getLowerLeftX());
System.out.println("y1 " + layout.getLowerLeftY());
System.out.println("x2 " + layout.getUpperRightX());
System.out.println("y2 " + layout.getUpperRightY());
System.out.println("rot " + pdpage.findRotation());*/
float w = layout.getWidth();
float h = layout.getHeight();
final int rot = pdpage.getRotation();
if (rot == 90 || rot == 270)
{
float x = w; w = h; h = x;
}
pstyle = "width:" + w + UNIT + ";" + "height:" + h + UNIT + ";";
pstyle += "overflow:hidden;";
}
else
log.warn("No media box found");
Element el = doc.createElement("div");
el.setAttribute("id", "page_" + (pagecnt++));
el.setAttribute("class", "page");
el.setAttribute("style", pstyle);
return el;
}
/**
* Creates an element that represents a single positioned box with no content.
* @return the resulting DOM element
*/
protected Element createTextElement(float width)
{
Element el = doc.createElement("div");
el.setAttribute("id", "p" + (textcnt++));
el.setAttribute("class", "p");
String style = curstyle.toString();
style += "width:" + width + UNIT + ";";
el.setAttribute("style", style);
return el;
}
/**
* Creates an element that represents a single positioned box containing the specified text string.
* @param data the text string to be contained in the created box.
* @return the resulting DOM element
*/
protected Element createTextElement(String data, float width)
{
Element el = createTextElement(width);
Text text = doc.createTextNode(data);
el.appendChild(text);
return el;
}
/**
* Creates an element that represents a rectangle drawn at the specified coordinates in the page.
* @param x the X coordinate of the rectangle
* @param y the Y coordinate of the rectangle
* @param width the width of the rectangle
* @param height the height of the rectangle
* @param stroke should there be a stroke around?
* @param fill should the rectangle be filled?
* @return the resulting DOM element
*/
protected Element createRectangleElement(float x, float y, float width, float height, boolean stroke, boolean fill)
{
float lineWidth = transformWidth(getGraphicsState().getLineWidth());
float wcor = stroke ? lineWidth : 0.0f;
float strokeOffset = wcor == 0 ? 0 : wcor / 2;
width = width - wcor < 0 ? 1 : width - wcor;
height = height - wcor < 0 ? 1 : height - wcor;
StringBuilder pstyle = new StringBuilder(50);
pstyle.append("left:").append(style.formatLength(x - strokeOffset)).append(';');
pstyle.append("top:").append(style.formatLength(y - strokeOffset)).append(';');
pstyle.append("width:").append(style.formatLength(width)).append(';');
pstyle.append("height:").append(style.formatLength(height)).append(';');
if (stroke)
{
String color = colorString(getGraphicsState().getStrokingColor());
pstyle.append("border:").append(style.formatLength(lineWidth)).append(" solid ").append(color).append(';');
}
if (fill)
{
String fcolor = colorString(getGraphicsState().getNonStrokingColor());
pstyle.append("background-color:").append(fcolor).append(';');
}
Element el = doc.createElement("div");
el.setAttribute("class", "r");
el.setAttribute("style", pstyle.toString());
el.appendChild(doc.createEntityReference("nbsp"));
return el;
}
/**
* Create an element that represents a horizntal or vertical line.
* @param x1
* @param y1
* @param x2
* @param y2
* @return the created DOM element
*/
protected Element createLineElement(float x1, float y1, float x2, float y2)
{
HtmlDivLine line = new HtmlDivLine(x1, y1, x2, y2);
String color = colorString(getGraphicsState().getStrokingColor());
StringBuilder pstyle = new StringBuilder(50);
pstyle.append("left:").append(style.formatLength(line.getLeft())).append(';');
pstyle.append("top:").append(style.formatLength(line.getTop())).append(';');
pstyle.append("width:").append(style.formatLength(line.getWidth())).append(';');
pstyle.append("height:").append(style.formatLength(line.getHeight())).append(';');
pstyle.append(line.getBorderSide()).append(':').append(style.formatLength(line.getLineStrokeWidth())).append(" solid ").append(color).append(';');
if (line.getAngleDegrees() != 0)
pstyle.append("transform:").append("rotate(").append(line.getAngleDegrees()).append("deg);");
Element el = doc.createElement("div");
el.setAttribute("class", "r");
el.setAttribute("style", pstyle.toString());
el.appendChild(doc.createEntityReference("nbsp"));
return el;
}
protected Element createPathImage(List<PathSegment> path) throws IOException
{
PathDrawer drawer = new PathDrawer(getGraphicsState());
ImageResource renderedPath = drawer.drawPath(path);
if (renderedPath != null)
return createImageElement((float) renderedPath.getX(), (float) renderedPath.getY(),
renderedPath.getWidth(), renderedPath.getHeight(), renderedPath);
else
return null;
}
/**
* Creates an element that represents an image drawn at the specified coordinates in the page.
* @param x the X coordinate of the image
* @param y the Y coordinate of the image
* @param width the width coordinate of the image
* @param height the height coordinate of the image
* @param type the image type: <code>"png"</code> or <code>"jpeg"</code>
* @param resource the image data depending on the specified type
* @return
*/
protected Element createImageElement(float x, float y, float width, float height, ImageResource resource) throws IOException
{
StringBuilder pstyle = new StringBuilder("position:absolute;");
pstyle.append("left:").append(x).append(UNIT).append(';');
pstyle.append("top:").append(y).append(UNIT).append(';');
pstyle.append("width:").append(width).append(UNIT).append(';');
pstyle.append("height:").append(height).append(UNIT).append(';');
//pstyle.append("border:1px solid red;");
Element el = doc.createElement("img");
el.setAttribute("style", pstyle.toString());
String imgSrc = config.getImageHandler().handleResource(resource);
if (!disableImageData && !imgSrc.isEmpty())
el.setAttribute("src", imgSrc);
else
el.setAttribute("src", "");
return el;
}
/**
* Maps input line to an HTML div rectangle, since HTML does not support standard lines
*/
protected class HtmlDivLine
{
private final float x1;
private final float y1;
private final float x2;
private final float y2;
private final float width;
private final float height;
//horizontal or vertical lines are treated separately (no rotations used)
private final boolean horizontal;
private final boolean vertical;
public HtmlDivLine(float x1, float y1, float x2, float y2)
{
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
this.width = Math.abs(x2 - x1);
this.height = Math.abs(y2 - y1);
this.horizontal = (height < 0.5f);
this.vertical = (width < 0.5f);
}
public float getHeight()
{
return vertical ? height : 0;
}
public float getWidth()
{
if (vertical)
return 0;
else if (horizontal)
return width;
else
return distanceFormula(x1, y1, x2, y2);
}
public float getLeft()
{
if (horizontal || vertical)
return Math.min(x1, x2);
else
return Math.abs((x2 + x1) / 2) - getWidth() / 2;
}
public float getTop()
{
if (horizontal || vertical)
return Math.min(y1, y2);
else
// after rotation top left will be center of line so find the midpoint and correct for the line to border transform
return Math.abs((y2 + y1) / 2) - (getLineStrokeWidth() + getHeight()) / 2;
}
public double getAngleDegrees()
{
if (horizontal || vertical)
return 0;
else
return Math.toDegrees(Math.atan((y2 - y1) / (x2 - x1)));
}
public float getLineStrokeWidth()
{
float lineWidth = transformWidth(getGraphicsState().getLineWidth());
if (lineWidth < 0.5f)
lineWidth = 0.5f;
return lineWidth;
}
public String getBorderSide()
{
return vertical ? "border-right" : "border-bottom";
}
private float distanceFormula(float x1, float y1, float x2, float y2)
{
return (float) Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
}
}
/**
* Generate the global CSS style for the whole document.
* @return the CSS code used in the generated document header
*/
protected String createGlobalStyle()
{
StringBuilder ret = new StringBuilder();
ret.append(createFontFaces());
ret.append("\n");
ret.append(defaultStyle);
return ret.toString();
}
@Override
protected void updateFontTable()
{
// skip font processing completley if ignore fonts mode to optimize processing speed
if (!(config.getFontHandler() instanceof IgnoreResourceHandler))
super.updateFontTable();
}
protected String createFontFaces()
{
StringBuilder ret = new StringBuilder();
for (FontTable.Entry font : fontTable.getEntries())
createFontFace(ret, font);
return ret.toString();
}
private void createFontFace(StringBuilder ret, FontTable.Entry font)
{
ret.append("@font-face {");
ret.append("font-family:\"").append(font.usedName).append("\";");
ret.append("src:url('");
try
{
String src = config.getFontHandler().handleResource(font);
ret.append(src);
} catch (IOException e)
{
log.error("Error writing font face data for font: " + font.getName()
+ "Exception: {} {}", e.getMessage(), e.getClass());
}
ret.append("');");
ret.append("}\n");
}
}
