package com.tom_roush.pdfbox.multipdf;
import com.tom_roush.fontbox.util.BoundingBox;
import com.tom_roush.pdfbox.cos.COSArray;
import com.tom_roush.pdfbox.cos.COSBase;
import com.tom_roush.pdfbox.cos.COSDictionary;
import com.tom_roush.pdfbox.cos.COSName;
import com.tom_roush.pdfbox.cos.COSStream;
import com.tom_roush.pdfbox.pdmodel.PDDocument;
import com.tom_roush.pdfbox.pdmodel.PDDocumentCatalog;
import com.tom_roush.pdfbox.pdmodel.PDPage;
import com.tom_roush.pdfbox.pdmodel.PDPageContentStream;
import com.tom_roush.pdfbox.pdmodel.PDResources;
import com.tom_roush.pdfbox.pdmodel.common.PDRectangle;
import com.tom_roush.pdfbox.pdmodel.common.PDStream;
import com.tom_roush.pdfbox.pdmodel.graphics.form.PDFormXObject;
import com.tom_roush.pdfbox.pdmodel.graphics.optionalcontent.PDOptionalContentGroup;
import com.tom_roush.pdfbox.pdmodel.graphics.optionalcontent.PDOptionalContentProperties;
import com.tom_roush.pdfbox.util.Matrix;
import com.tom_roush.pdfbox.util.awt.AffineTransform;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Map;
import java.util.Set;
/**
* This class allows to import pages as Form XObjects into a PDF file and use them to create
* layers (optional content groups).
*/
public class LayerUtility
{
private static final boolean DEBUG = true;
private final PDDocument targetDoc;
private final PDFCloneUtility cloner;
/**
* Creates a new instance.
* @param document the PDF document to modify
*/
public LayerUtility(PDDocument document)
{
this.targetDoc = document;
this.cloner = new PDFCloneUtility(document);
}
/**
* Returns the PDF document we work on.
* @return the PDF document
*/
public PDDocument getDocument()
{
return this.targetDoc;
}
/**
* Some applications may not wrap their page content in a save/restore (q/Q) pair which can
* lead to problems with coordinate system transformations when content is appended. This
* method lets you add a q/Q pair around the existing page's content.
* @param page the page
* @throws IOException if an I/O error occurs
*/
public void wrapInSaveRestore(PDPage page) throws IOException
{
COSStream saveGraphicsStateStream = getDocument().getDocument().createCOSStream();
OutputStream saveStream = saveGraphicsStateStream.createOutputStream();
saveStream.write("q\n".getBytes("ISO-8859-1"));
saveStream.close();
COSStream restoreGraphicsStateStream = getDocument().getDocument().createCOSStream();
OutputStream restoreStream = restoreGraphicsStateStream.createOutputStream();
restoreStream.write("Q\n".getBytes("ISO-8859-1"));
restoreStream.close();
//Wrap the existing page's content in a save/restore pair (q/Q) to have a controlled
//environment to add additional content.
COSDictionary pageDictionary = page.getCOSObject();
COSBase contents = pageDictionary.getDictionaryObject(COSName.CONTENTS);
if (contents instanceof COSStream)
{
COSStream contentsStream = (COSStream)contents;
COSArray array = new COSArray();
array.add(saveGraphicsStateStream);
array.add(contentsStream);
array.add(restoreGraphicsStateStream);
pageDictionary.setItem(COSName.CONTENTS, array);
}
else if( contents instanceof COSArray )
{
COSArray contentsArray = (COSArray)contents;
contentsArray.add(0, saveGraphicsStateStream);
contentsArray.add(restoreGraphicsStateStream);
}
else
{
throw new IOException("Contents are unknown type: " + contents.getClass().getName());
}
}
/**
* Imports a page from some PDF file as a Form XObject so it can be placed on another page
* in the target document.
* @param sourceDoc the source PDF document that contains the page to be copied
* @param pageNumber the page number of the page to be copied
* @return a Form XObject containing the original page's content
* @throws IOException if an I/O error occurs
*/
public PDFormXObject importPageAsForm(PDDocument sourceDoc, int pageNumber) throws IOException
{
PDPage page = sourceDoc.getPage(pageNumber);
return importPageAsForm(sourceDoc, page);
}
private static final Set<String> PAGE_TO_FORM_FILTER = new java.util.HashSet<String>(
Arrays.asList(new String[] {"Group", "LastModified", "Metadata"}));
/**
* Imports a page from some PDF file as a Form XObject so it can be placed on another page
* in the target document.
* @param sourceDoc the source PDF document that contains the page to be copied
* @param page the page in the source PDF document to be copied
* @return a Form XObject containing the original page's content
* @throws IOException if an I/O error occurs
*/
public PDFormXObject importPageAsForm(PDDocument sourceDoc, PDPage page) throws IOException
{
PDStream newStream = new PDStream(targetDoc, page.getContents(), COSName.FLATE_DECODE);
PDFormXObject form = new PDFormXObject(newStream);
//Copy resources
PDResources pageRes = page.getResources();
PDResources formRes = new PDResources();
cloner.cloneMerge(pageRes, formRes);
form.setResources(formRes);
//Transfer some values from page to form
transferDict(page.getCOSObject(), form.getCOSStream(), PAGE_TO_FORM_FILTER, true);
Matrix matrix = form.getMatrix();
AffineTransform at = matrix.createAffineTransform();
PDRectangle mediaBox = page.getMediaBox();
PDRectangle cropBox = page.getCropBox();
PDRectangle viewBox = (cropBox != null ? cropBox : mediaBox);
//Handle the /Rotation entry on the page dict
int rotation = page.getRotation();
//Transform to FOP's user space
//at.scale(1 / viewBox.getWidth(), 1 / viewBox.getHeight());
at.translate(mediaBox.getLowerLeftX() - viewBox.getLowerLeftX(),
mediaBox.getLowerLeftY() - viewBox.getLowerLeftY());
switch (rotation)
{
case 90:
at.scale(viewBox.getWidth() / viewBox.getHeight(), viewBox.getHeight() / viewBox.getWidth());
at.translate(0, viewBox.getWidth());
at.rotate((float)(-Math.PI / 2.0));
break;
case 180:
at.translate(viewBox.getWidth(), viewBox.getHeight());
at.rotate((float)-Math.PI);
break;
case 270:
at.scale(viewBox.getWidth() / viewBox.getHeight(), viewBox.getHeight() / viewBox.getWidth());
at.translate(viewBox.getHeight(), 0);
at.rotate((float)(-Math.PI * 1.5));
default:
//no additional transformations necessary
}
//Compensate for Crop Boxes not starting at 0,0
at.translate(-viewBox.getLowerLeftX(), -viewBox.getLowerLeftY());
if (!at.isIdentity())
{
form.setMatrix(at);
}
BoundingBox bbox = new BoundingBox();
bbox.setLowerLeftX(viewBox.getLowerLeftX());
bbox.setLowerLeftY(viewBox.getLowerLeftY());
bbox.setUpperRightX(viewBox.getUpperRightX());
bbox.setUpperRightY(viewBox.getUpperRightY());
form.setBBox(new PDRectangle(bbox));
return form;
}
/**
* Places the given form over the existing content of the indicated page (like an overlay).
* The form is enveloped in a marked content section to indicate that it's part of an
* optional content group (OCG), here used as a layer. This optional group is returned and
* can be enabled and disabled through methods on {@link PDOptionalContentProperties}.
* @param targetPage the target page
* @param form the form to place
* @param transform the transformation matrix that controls the placement
* @param layerName the name for the layer/OCG to produce
* @return the optional content group that was generated for the form usage
* @throws IOException if an I/O error occurs
*/
public PDOptionalContentGroup appendFormAsLayer(PDPage targetPage,
PDFormXObject form, AffineTransform transform,
String layerName) throws IOException
{
PDDocumentCatalog catalog = targetDoc.getDocumentCatalog();
PDOptionalContentProperties ocprops = catalog.getOCProperties();
if (ocprops == null)
{
ocprops = new PDOptionalContentProperties();
catalog.setOCProperties(ocprops);
}
if (ocprops.hasGroup(layerName))
{
throw new IllegalArgumentException("Optional group (layer) already exists: " + layerName);
}
PDOptionalContentGroup layer = new PDOptionalContentGroup(layerName);
ocprops.addGroup(layer);
PDPageContentStream contentStream = new PDPageContentStream(
targetDoc, targetPage, true, !DEBUG);
contentStream.beginMarkedContent(COSName.OC, layer);
contentStream.saveGraphicsState();
contentStream.transform(new Matrix(transform));
contentStream.drawForm(form);
contentStream.restoreGraphicsState();
contentStream.endMarkedContent();
contentStream.close();
return layer;
}
private void transferDict(COSDictionary orgDict, COSDictionary targetDict,
Set<String> filter, boolean inclusive) throws IOException
{
for (Map.Entry<COSName, COSBase> entry : orgDict.entrySet())
{
COSName key = entry.getKey();
if (inclusive && !filter.contains(key.getName()))
{
continue;
}
else if (!inclusive && filter.contains(key.getName()))
{
continue;
}
targetDict.setItem(key,
cloner.cloneForNewDocument(entry.getValue()));
}
}
}