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Pdf2Dom is a PDF parser that converts the documents to a HTML DOM representation. The obtained DOM tree may be then serialized to a HTML file or further processed. The inline CSS definitions contained in the resulting document are used for making the HTML page as similar as possible to the PDF input. A command-line utility for converting the PDF documents to HTML is included in the distribution package. Pdf2Dom may be also used as an independent Java library with a standard DOM interface for your DOM-based applications or as an alternative parser for the CSSBox rendering engine in order to add the PDF processing capability to CSSBox.
/**
* PDFBoxTree.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 true, the graphics in the PDF file will be ignored. */
protected boolean disableGraphics = false;
/** When set to true, the embedded images will be ignored. */
protected boolean disableImages = false;
/** When set to true, the image data will not be transferred to the HTML data: url. */
protected boolean disableImageData = false;
/** First page to be processed */
protected int startPage;
/** Last page to be processed */
protected int endPage;
/** Table of embedded fonts */
protected FontTable fontTable;
/** The PDF page currently being processed */
protected PDPage pdpage;
/** Current text coordinates (the coordinates of the last encountered text box). */
protected float cur_x;
/** Current text coordinates (the coordinates of the last encountered text box). */
protected float cur_y;
/** Current path construction position */
protected float path_x;
/** Current path construction position */
protected float path_y;
/** Starting path construction position */
protected float path_start_x;
/** Starting path construction position */
protected float path_start_y;
/** Previous positioned text. */
protected TextPosition lastText = null;
/** Last diacritic if any */
protected TextPosition lastDia = null;
/** The text box currently being created. */
protected StringBuilder textLine;
/** Current text line metrics */
protected TextMetrics textMetrics;
/** Current graphics path */
protected Vector graphicsPath;
/** The style of the future box being modified by the operators */
protected BoxStyle style;
/** The style of the text line being created */
protected BoxStyle curstyle;
public PDFBoxTree() throws IOException
{
super();
super.setSortByPosition(true);
super.setSuppressDuplicateOverlappingText(true);
//add operators for tracking the graphic state
addOperator(new SetStrokingColorSpace());
addOperator(new SetNonStrokingColorSpace());
addOperator(new SetLineDashPattern());
addOperator(new SetStrokingDeviceGrayColor());
addOperator(new SetNonStrokingDeviceGrayColor());
addOperator(new SetFlatness());
addOperator(new SetLineJoinStyle());
addOperator(new SetLineCapStyle());
addOperator(new SetStrokingDeviceCMYKColor());
addOperator(new SetNonStrokingDeviceCMYKColor());
addOperator(new SetLineMiterLimit());
addOperator(new SetStrokingDeviceRGBColor());
addOperator(new SetNonStrokingDeviceRGBColor());
addOperator(new SetRenderingIntent());
addOperator(new SetStrokingColor());
addOperator(new SetNonStrokingColor());
addOperator(new SetStrokingColorN());
addOperator(new SetNonStrokingColorN());
addOperator(new SetFontAndSize());
addOperator(new SetLineWidth());
init();
}
/**
* Internal initialization.
* @throws ParserConfigurationException
*/
private void init()
{
style = new BoxStyle(UNIT);
textLine = new StringBuilder();
textMetrics = null;
graphicsPath = new Vector();
startPage = 0;
endPage = Integer.MAX_VALUE;
fontTable = new FontTable();
}
public void processPage(PDPage page) throws IOException
{
if (getCurrentPageNo() >= startPage && getCurrentPageNo() <= endPage)
{
pdpage = page;
updateFontTable();
startNewPage();
super.processPage(page);
finishBox();
}
}
/**
* Checks whether the graphics processing is disabled.
* @return true when the graphics processing is disabled in the parser configuration.
*/
public boolean getDisableGraphics()
{
return disableGraphics;
}
/**
* Disables the processing of the graphic operators in the PDF files.
* @param disableGraphics when set to true the graphics is ignored in the source file.
*/
public void setDisableGraphics(boolean disableGraphics)
{
this.disableGraphics = disableGraphics;
}
/**
* Checks whether processing of embedded images is disabled.
* @return true when the processing of embedded images is disabled in the parser configuration.
*/
public boolean getDisableImages()
{
return disableImages;
}
/**
* Disables the processing of images contained in the PDF files.
* @param disableImages when set to true the images are ignored in the source file.
*/
public void setDisableImages(boolean disableImages)
{
this.disableImages = disableImages;
}
/**
* Checks whether the copying of image data is disabled.
* @return true when the copying of image data is disabled in the parser configuration.
*/
public boolean getDisableImageData()
{
return disableImageData;
}
/**
* Disables the copying the image data to the resulting DOM tree.
* @param disableImageData when set to true the image data is not copied to the document tree.
* The eventual img elements will have an empty src attribute.
*/
public void setDisableImageData(boolean disableImageData)
{
this.disableImageData = disableImageData;
}
@Override
public int getStartPage()
{
return startPage;
}
@Override
public void setStartPage(int startPage)
{
this.startPage = startPage;
}
@Override
public int getEndPage()
{
return endPage;
}
@Override
public void setEndPage(int endPage)
{
this.endPage = endPage;
}
//===========================================================================================
/**
* Adds a new page to the resulting document and makes it a current (active) page.
*/
protected abstract void startNewPage();
/**
* Creates a new text box in the current page. The style and position of the text are contained
* in the {@link PDFBoxTree#curstyle} property.
* @param data The text contents.
*/
protected abstract void renderText(String data, TextMetrics metrics);
/**
* Adds a rectangle to the current page on the specified position.
* @param rect the rectangle to be rendered
* @param stroke should there be a stroke around?
* @param fill should the rectangle be filled?
*/
protected abstract void renderPath(List path, boolean stroke, boolean fill) throws IOException;
/**
* Adds an image to the current page.
* @param type the image type: "png" or "jpeg"
* @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 data the image data depending on the specified type
* @return
*/
protected abstract void renderImage(float x, float y, float width, float height, ImageResource data) throws IOException;
protected float[] toRectangle(List path)
{
if (path.size() == 4)
{
Set xc = new HashSet();
Set yc = new HashSet();
//find x/y 1/2
for (PathSegment line : path)
{
xc.add(line.getX1());
xc.add(line.getX2());
yc.add(line.getY1());
yc.add(line.getY2());
}
if (xc.size() == 2 && yc.size() == 2)
{
return new float[]{Collections.min(xc), Collections.min(yc), Collections.max(xc), Collections.max(yc)};
}
else
return null; //two different X and Y coordinates required
}
else
return null; //four segments required
}
/**
* Updates the font table by adding new fonts used at the current page.
*/
protected void updateFontTable()
{
PDResources resources = pdpage.getResources();
if (resources != null)
{
try
{
processFontResources(resources, fontTable);
} catch (IOException e) {
log.error("Error processing font resources: "
+ "Exception: {} {}", e.getMessage(), e.getClass());
}
}
}
private void processFontResources(PDResources resources, FontTable table) throws IOException
{
String fontNotSupportedMessage = "Font: {} skipped because type '{}' is not supported.";
for (COSName key : resources.getFontNames())
{
PDFont font = resources.getFont(key);
if (font instanceof PDTrueTypeFont)
{
table.addEntry( font);
log.debug("Font: " + font.getName() + " TTF");
}
else if (font instanceof PDType0Font)
{
PDCIDFont descendantFont = ((PDType0Font) font).getDescendantFont();
if (descendantFont instanceof PDCIDFontType2)
table.addEntry(font);
else
log.warn(fontNotSupportedMessage, font.getName(), font.getClass().getSimpleName());
}
else if (font instanceof PDType1CFont)
table.addEntry(font);
else
log.warn(fontNotSupportedMessage, font.getName(), font.getClass().getSimpleName());
}
for (COSName name : resources.getXObjectNames())
{
PDXObject xobject = resources.getXObject(name);
if (xobject instanceof PDFormXObject)
{
PDFormXObject xObjectForm = (PDFormXObject) xobject;
PDResources formResources = xObjectForm.getResources();
if (formResources != null && formResources != resources && formResources.getCOSObject() != resources.getCOSObject())
processFontResources(formResources, table);
}
}
}
//===========================================================================================
@Override
protected void processOperator(Operator operator, List arguments)
throws IOException
{
String operation = operator.getName();
/*System.out.println("Operator: " + operation + ":" + arguments.size());
if (operation.equals("sc") || operation.equals("cs"))
{
System.out.print(" ");
for (int i = 0; i < arguments.size(); i++)
System.out.print(arguments.get(i) + " ");
System.out.println();
}*/
//word spacing
if (operation.equals("Tw"))
{
style.setWordSpacing(getLength(arguments.get(0)));
}
//letter spacing
else if (operation.equals("Tc"))
{
style.setLetterSpacing(getLength(arguments.get(0)));
}
//graphics
else if (operation.equals("m")) //move
{
if (!disableGraphics)
{
if (arguments.size() == 2)
{
float[] pos = transformPosition(getLength(arguments.get(0)), getLength(arguments.get(1)));
path_x = pos[0];
path_y = pos[1];
path_start_x = pos[0];
path_start_y = pos[1];
}
}
}
else if (operation.equals("l")) //line
{
if (!disableGraphics)
{
if (arguments.size() == 2)
{
float[] pos = transformPosition(getLength(arguments.get(0)), getLength(arguments.get(1)));
graphicsPath.add(new PathSegment(path_x, path_y, pos[0], pos[1]));
path_x = pos[0];
path_y = pos[1];
}
}
}
else if (operation.equals("h")) //end subpath
{
if (!disableGraphics)
{
graphicsPath.add(new PathSegment(path_x, path_y, path_start_x, path_start_y));
}
}
//rectangle
else if (operation.equals("re"))
{
if (!disableGraphics)
{
if (arguments.size() == 4)
{
float x = getLength(arguments.get(0));
float y = getLength(arguments.get(1));
float width = getLength(arguments.get(2));
float height = getLength(arguments.get(3));
float[] p1 = transformPosition(x, y);
float[] p2 = transformPosition(x + width, y + height);
graphicsPath.add(new PathSegment(p1[0], p1[1], p2[0], p1[1]));
graphicsPath.add(new PathSegment(p2[0], p1[1], p2[0], p2[1]));
graphicsPath.add(new PathSegment(p2[0], p2[1], p1[0], p2[1]));
graphicsPath.add(new PathSegment(p1[0], p2[1], p1[0], p1[1]));
}
}
}
//fill
else if (operation.equals("f") || operation.equals("F") || operation.equals("f*"))
{
renderPath(graphicsPath, false, true);
graphicsPath.removeAllElements();
}
//stroke
else if (operation.equals("S"))
{
renderPath(graphicsPath, true, false);
graphicsPath.removeAllElements();
}
else if (operation.equals("s"))
{
graphicsPath.add(new PathSegment(path_x, path_y, path_start_x, path_start_y));
renderPath(graphicsPath, true, false);
graphicsPath.removeAllElements();
}
//stroke and fill
else if (operation.equals("B") || operation.equals("B*"))
{
renderPath(graphicsPath, true, true);
graphicsPath.removeAllElements();
}
else if (operation.equals("b") || operation.equals("b*"))
{
graphicsPath.add(new PathSegment(path_x, path_y, path_start_x, path_start_y));
renderPath(graphicsPath, true, true);
graphicsPath.removeAllElements();
}
//cancel path
else if (operation.equals("n"))
{
graphicsPath.removeAllElements();
}
//invoke named object - images
else if (operation.equals("Do"))
{
if (!disableImages)
processImageOperation(arguments);
}
super.processOperator(operator, arguments);
}
protected void processImageOperation(List arguments) throws IOException
{
COSName objectName = (COSName)arguments.get( 0 );
PDXObject xobject = getResources().getXObject( objectName );
if (xobject instanceof PDImageXObject)
{
PDImageXObject pdfImage = (PDImageXObject) xobject;
BufferedImage outputImage = pdfImage.getImage();
outputImage = rotateImage(outputImage);
ImageResource imageData = new ImageResource(getTitle(), outputImage);
Rectangle2D bounds = calculateImagePosition(pdfImage);
float x = (float) bounds.getX();
float y = (float) bounds.getY();
renderImage(x, y, (float) bounds.getWidth(), (float) bounds.getHeight(), imageData);
}
}
private BufferedImage rotateImage(BufferedImage outputImage)
{
// x, y and size are handled by css attributes but still need to rotate the image so pulling
// only rotation out of the matrix so no giant whitespace offset from translations
Matrix ctm = getGraphicsState().getCurrentTransformationMatrix();
AffineTransform tr = ctm.createAffineTransform();
double rotate = Math.atan2(tr.getShearY(), tr.getScaleY()) - Math.toRadians(pdpage.getRotation());
outputImage = ImageUtils.rotateImage(outputImage, rotate);
return outputImage;
}
private Rectangle2D calculateImagePosition(PDImageXObject pdfImage) throws IOException
{
Matrix ctm = getGraphicsState().getCurrentTransformationMatrix();
Rectangle2D imageBounds = pdfImage.getImage().getRaster().getBounds();
AffineTransform imageTransform = new AffineTransform(ctm.createAffineTransform());
imageTransform.scale(1.0 / pdfImage.getWidth(), -1.0 / pdfImage.getHeight());
imageTransform.translate(0, -pdfImage.getHeight());
AffineTransform pageTransform = createCurrentPageTransformation();
pageTransform.concatenate(imageTransform);
return pageTransform.createTransformedShape(imageBounds).getBounds2D();
}
@Override
protected void processTextPosition(TextPosition text)
{
if (text.isDiacritic())
{
lastDia = text;
}
else if (!text.getUnicode().trim().isEmpty())
{
if (lastDia != null)
{
if (text.contains(lastDia))
text.mergeDiacritic(lastDia);
lastDia = null;
}
/*float[] c = transformPosition(text.getX(), text.getY());
cur_x = c[0];
cur_y = c[1];*/
cur_x = text.getX();
cur_y = text.getY();
/*System.out.println("Text: " + text.getCharacter());
System.out.println(" Font size: " + text.getFontSize() + " " + text.getFontSizeInPt() + "pt");
System.out.println(" Width: " + text.getWidth());
System.out.println(" Width adj: " + text.getWidthDirAdj());
System.out.println(" Height: " + text.getHeight());
System.out.println(" Height dir: " + text.getHeightDir());
System.out.println(" XScale: " + text.getXScale());
System.out.println(" YScale: " + text.getYScale());*/
float distx = 0;
float disty = 0;
if (lastText != null)
{
distx = text.getX() - (lastText.getX() + lastText.getWidth());
disty = text.getY() - lastText.getY();
}
//should we split the boxes?
boolean split = lastText == null || distx > 1.0f || distx < -6.0f || Math.abs(disty) > 1.0f
|| isReversed(getTextDirectionality(text)) != isReversed(getTextDirectionality(lastText));
//if the style changed, we should split the boxes
updateStyle(style, text);
if (!style.equals(curstyle))
split = true;
if (split) //start of a new box
{
//finish current box (if any)
if (lastText != null)
{
finishBox();
}
//start a new box
curstyle = new BoxStyle(style);
}
textLine.append(text.getUnicode());
if (textMetrics == null)
textMetrics = new TextMetrics(text);
else
textMetrics.append(text);
lastText = text;
}
}
/**
* Finishes the current box - empties the text line buffer and creates a DOM element from it.
*/
protected void finishBox()
{
if (textLine.length() > 0)
{
String s;
if (isReversed(Character.getDirectionality(textLine.charAt(0))))
s = textLine.reverse().toString();
else
s = textLine.toString();
curstyle.setLeft(textMetrics.getX());
curstyle.setTop(textMetrics.getTop());
curstyle.setLineHeight(textMetrics.getHeight());
renderText(s, textMetrics);
textLine = new StringBuilder();
textMetrics = null;
}
}
/**
* Checks whether the text directionality corresponds to reversed text (very rough)
* @param directionality the Character.directionality
* @return
*/
protected boolean isReversed(byte directionality)
{
switch (directionality)
{
case Character.DIRECTIONALITY_RIGHT_TO_LEFT:
case Character.DIRECTIONALITY_RIGHT_TO_LEFT_ARABIC:
case Character.DIRECTIONALITY_RIGHT_TO_LEFT_EMBEDDING:
case Character.DIRECTIONALITY_RIGHT_TO_LEFT_OVERRIDE:
return true;
default:
return false;
}
}
/**
* Updates the text style according to a new text position
* @param bstyle the style to be updated
* @param text the text position
*/
protected void updateStyle(BoxStyle bstyle, TextPosition text)
{
String font = text.getFont().getName();
String family = null;
String weight = null;
String fstyle = null;
bstyle.setFontSize(text.getFontSizeInPt());
bstyle.setLineHeight(text.getHeight());
if (font != null)
{
//font style and weight
for (int i = 0; i < pdFontType.length; i++)
{
if (font.toLowerCase().lastIndexOf(pdFontType[i]) >= 0)
{
weight = cssFontWeight[i];
fstyle = cssFontStyle[i];
break;
}
}
if (weight != null)
bstyle.setFontWeight(weight);
else
bstyle.setFontWeight(cssFontWeight[0]);
if (fstyle != null)
bstyle.setFontStyle(fstyle);
else
bstyle.setFontStyle(cssFontStyle[0]);
//font family
//If it's a known common font don't embed in html output to save space
String knownFontFamily = findKnownFontFamily(font);
if (!knownFontFamily.equals(""))
family = knownFontFamily;
else
{
family = fontTable.getUsedName(text.getFont());
if (family == null)
family = font;
}
if (family != null)
bstyle.setFontFamily(family);
}
updateStyleForRenderingMode();
}
private String findKnownFontFamily(String font) {
for (String fontFamilyOn : cssFontFamily)
{
if (font.toLowerCase().lastIndexOf(fontFamilyOn.toLowerCase().replaceAll("\\s+","")) >= 0)
return fontFamilyOn;
}
return "";
}
private void updateStyleForRenderingMode()
{
String fillColor = colorString(getGraphicsState().getNonStrokingColor());
String strokeColor = colorString(getGraphicsState().getStrokingColor());
if (isTextFillEnabled())
style.setColor(fillColor);
else
style.setColor(BoxStyle.transparentColor);
if (isTextStrokeEnabled())
style.setStrokeColor(strokeColor);
else
style.setStrokeColor(BoxStyle.transparentColor);
}
private boolean isTextStrokeEnabled()
{
RenderingMode mode = getGraphicsState().getTextState().getRenderingMode();
return mode == STROKE || mode == STROKE_CLIP || mode == FILL_STROKE || mode == FILL_STROKE_CLIP;
}
private boolean isTextFillEnabled()
{
RenderingMode mode = getGraphicsState().getTextState().getRenderingMode();
return mode == FILL || mode == FILL_CLIP || mode == FILL_STROKE || mode == FILL_STROKE_CLIP;
}
/**
* Obtains the media box valid for the current page.
* @return the media box rectangle
*/
protected PDRectangle getCurrentMediaBox()
{
PDRectangle layout = pdpage.getCropBox();
return layout;
}
//===========================================================================================
/**
* Transforms a length according to the current transformation matrix.
*/
protected float transformLength(float w)
{
Matrix ctm = getGraphicsState().getCurrentTransformationMatrix();
Matrix m = new Matrix();
m.setValue(2, 0, w);
return m.multiply(ctm).getTranslateX();
}
/**
* Transforms a position according to the current transformation matrix and current page transformation.
* @param x
* @param y
* @return
*/
protected float[] transformPosition(float x, float y)
{
Point2D.Float point = super.transformedPoint(x, y);
AffineTransform pageTransform = createCurrentPageTransformation();
Point2D.Float transformedPoint = (Point2D.Float) pageTransform.transform(point, null);
return new float[]{(float) transformedPoint.getX(), (float) transformedPoint.getY()};
}
protected AffineTransform createCurrentPageTransformation()
{
PDRectangle cb = pdpage.getCropBox();
AffineTransform pageTransform = new AffineTransform();
switch (pdpage.getRotation())
{
case 90:
pageTransform.translate(cb.getHeight(), 0);
break;
case 180:
pageTransform.translate(cb.getWidth(), cb.getHeight());
break;
case 270:
pageTransform.translate(0, cb.getWidth());
break;
}
pageTransform.rotate(Math.toRadians(pdpage.getRotation()));
pageTransform.translate(0, cb.getHeight());
pageTransform.scale(1, -1);
pageTransform.translate(-cb.getLowerLeftX(), -cb.getLowerLeftY());
return pageTransform;
}
/**
* Obtains a number from a PDF number value
* @param value the PDF value of the Integer or Fload type
* @return the corresponging numeric value
*/
protected int intValue(COSBase value)
{
if (value instanceof COSNumber)
return ((COSNumber) value).intValue();
else
return 0;
}
/**
* Obtains a number from a PDF number value
* @param value the PDF value of the Integer or Float type
* @return the corresponging numeric value
*/
protected float floatValue(COSBase value)
{
if (value instanceof COSNumber)
return ((COSNumber) value).floatValue();
else
return 0;
}
/**
* Obtains a length in points from a PDF number value
* @param value the PDF value of the Integer or Fload type
* @return the resulting length in points
*/
protected float getLength(COSBase value)
{
return floatValue(value); //no conversion is done right now, we count in PDF units
}
/**
* Obtains a string from a PDF value
* @param value the PDF value of the String, Integer or Float type
* @return the corresponging string value
*/
protected String stringValue(COSBase value)
{
if (value instanceof COSString)
return ((COSString) value).getString();
else if (value instanceof COSNumber)
return String.valueOf(((COSNumber) value).floatValue());
else
return "";
}
/**
* Creates a CSS rgb() specification from the color component values.
* @param ir red value (0..255)
* @param ig green value (0..255)
* @param ib blue value (0..255)
* @return the rgb() string
*/
protected String colorString(int ir, int ig, int ib)
{
return String.format("#%02x%02x%02x", ir, ig, ib);
}
/**
* Creates a CSS rgb() specification from the color component values.
* @param r red value (0..1)
* @param g green value (0..1)
* @param b blue value (0..1)
* @return the rgb() string
*/
protected String colorString(float r, float g, float b)
{
return colorString((int) (r * 255), (int) (g * 255), (int) (b * 255));
}
/**
* Creates a CSS rgb specification from a PDF color
* @param pdcolor
* @return the rgb() string
*/
protected String colorString(PDColor pdcolor)
{
String color = null;
try
{
float[] rgb = pdcolor.getColorSpace().toRGB(pdcolor.getComponents());
color = colorString(rgb[0], rgb[1], rgb[2]);
} catch (IOException e) {
log.error("colorString: IOException: {}", e.getMessage());
} catch (UnsupportedOperationException e) {
log.error("colorString: UnsupportedOperationException: {}", e.getMessage());
}
return color;
}
protected String getTitle() {
String title = document.getDocumentInformation().getTitle();
if (title == null || title.isEmpty())
title = "PDF Document";
return title;
}
protected byte getTextDirectionality(TextPosition text)
{
return getTextDirectionality(text.getUnicode());
}
protected byte getTextDirectionality(String s)
{
if (s.length() > 0)
return Character.getDirectionality(s.charAt(0));
else
return Character.DIRECTIONALITY_UNDEFINED;
}
}