src/pdf/SkPDFDocument.cpp - platform/external/skqp - Gitiles

 /*
  * Copyright (C) 2011 Google Inc.
  *
  * Licensed 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.
  */

 #include "SkPDFCatalog.h"
 #include "SkPDFDevice.h"
 #include "SkPDFDocument.h"
 #include "SkPDFPage.h"
 #include "SkPDFFont.h"
 #include "SkStream.h"

 // Add the resources, starting at firstIndex to the catalog, removing any dupes.
 // A hash table would be really nice here.
 void addResourcesToCatalog(int firstIndex, bool firstPage,
                           SkTDArray<SkPDFObject*>* resourceList,
                           SkPDFCatalog* catalog) {
     for (int i = firstIndex; i < resourceList->count(); i++) {
         int index = resourceList->find((*resourceList)[i]);
         if (index != i) {
             (*resourceList)[i]->unref();
             resourceList->removeShuffle(i);
             i--;
         } else {
             catalog->addObject((*resourceList)[i], firstPage);
         }
     }
 }

 static void perform_font_subsetting(SkPDFCatalog* catalog,
                                     const SkTDArray<SkPDFPage*>& pages,
                                     SkTDArray<SkPDFObject*>* substitutes) {
     SkASSERT(catalog);
     SkASSERT(substitutes);

     SkPDFGlyphSetMap usage;
     for (int i = 0; i < pages.count(); ++i) {
         usage.merge(pages[i]->getFontGlyphUsage());
     }
     SkPDFGlyphSetMap::F2BIter iterator(usage);
     SkPDFGlyphSetMap::FontGlyphSetPair* entry = iterator.next();
     while (entry) {
         SkPDFFont* subsetFont =
             entry->fFont->getFontSubset(entry->fGlyphSet);
         if (subsetFont) {
             catalog->setSubstitute(entry->fFont, subsetFont);
             substitutes->push(subsetFont);  // Transfer ownership to substitutes
         }
         entry = iterator.next();
     }
 }

 SkPDFDocument::SkPDFDocument(Flags flags)
         : fXRefFileOffset(0),
           fSecondPageFirstResourceIndex(0) {
     fCatalog.reset(new SkPDFCatalog(flags));
     fDocCatalog = new SkPDFDict("Catalog");
     fDocCatalog->unref();  // SkRefPtr and new both took a reference.
     fCatalog->addObject(fDocCatalog.get(), true);
 }

 SkPDFDocument::~SkPDFDocument() {
     fPages.safeUnrefAll();

     // The page tree has both child and parent pointers, so it creates a
     // reference cycle.  We must clear that cycle to properly reclaim memory.
     for (int i = 0; i < fPageTree.count(); i++)
         fPageTree[i]->clear();
     fPageTree.safeUnrefAll();
     fPageResources.safeUnrefAll();
     fSubstitutes.safeUnrefAll();
 }

 bool SkPDFDocument::emitPDF(SkWStream* stream) {
     if (fPages.isEmpty()) {
         return false;
     }
     for (int i = 0; i < fPages.count(); i++) {
         if (fPages[i] == NULL) {
             return false;
         }
     }

     // We haven't emitted the document before if fPageTree is empty.
     if (fPageTree.count() == 0) {
         SkPDFDict* pageTreeRoot;
         SkPDFPage::GeneratePageTree(fPages, fCatalog.get(), &fPageTree,
                                     &pageTreeRoot);
         fDocCatalog->insert("Pages", new SkPDFObjRef(pageTreeRoot))->unref();

         /* TODO(vandebo) output intent
         SkRefPtr<SkPDFDict> outputIntent = new SkPDFDict("OutputIntent");
         outputIntent->unref();  // SkRefPtr and new both took a reference.
         outputIntent->insert("S", new SkPDFName("GTS_PDFA1"))->unref();
         outputIntent->insert("OutputConditionIdentifier",
                              new SkPDFString("sRGB"))->unref();
         SkRefPtr<SkPDFArray> intentArray = new SkPDFArray;
         intentArray->unref();  // SkRefPtr and new both took a reference.
         intentArray->append(outputIntent.get());
         fDocCatalog->insert("OutputIntent", intentArray.get());
         */

         bool firstPage = true;
         for (int i = 0; i < fPages.count(); i++) {
             int resourceCount = fPageResources.count();
             fPages[i]->finalizePage(fCatalog.get(), firstPage, &fPageResources);
             addResourcesToCatalog(resourceCount, firstPage, &fPageResources,
                                   fCatalog.get());
             if (i == 0) {
                 firstPage = false;
                 fSecondPageFirstResourceIndex = fPageResources.count();
             }
         }

         // Build font subsetting info before proceeding.
         perform_font_subsetting(fCatalog.get(), fPages, &fSubstitutes);

         // Figure out the size of things and inform the catalog of file offsets.
         off_t fileOffset = headerSize();
         fileOffset += fCatalog->setFileOffset(fDocCatalog.get(), fileOffset);
         fileOffset += fCatalog->setFileOffset(fPages[0], fileOffset);
         fileOffset += fPages[0]->getPageSize(fCatalog.get(), fileOffset);
         for (int i = 0; i < fSecondPageFirstResourceIndex; i++) {
             fileOffset += fCatalog->setFileOffset(fPageResources[i],
                                                   fileOffset);
         }
         // Add the size of resources of substitute objects used on page 1.
         fileOffset += fCatalog->setSubstituteResourcesOffsets(fileOffset, true);
         if (fPages.count() > 1) {
             // TODO(vandebo) For linearized format, save the start of the
             // first page xref table and calculate the size.
         }

         for (int i = 0; i < fPageTree.count(); i++)
             fileOffset += fCatalog->setFileOffset(fPageTree[i], fileOffset);

         for (int i = 1; i < fPages.count(); i++)
             fileOffset += fPages[i]->getPageSize(fCatalog.get(), fileOffset);

         for (int i = fSecondPageFirstResourceIndex;
                  i < fPageResources.count();
                  i++)
             fileOffset += fCatalog->setFileOffset(fPageResources[i],
                                                   fileOffset);

         fileOffset += fCatalog->setSubstituteResourcesOffsets(fileOffset,
                                                               false);
         fXRefFileOffset = fileOffset;
     }

     emitHeader(stream);
     fDocCatalog->emitObject(stream, fCatalog.get(), true);
     fPages[0]->emitObject(stream, fCatalog.get(), true);
     fPages[0]->emitPage(stream, fCatalog.get());
     for (int i = 0; i < fSecondPageFirstResourceIndex; i++) {
         fPageResources[i]->emit(stream, fCatalog.get(), true);
     }
     fCatalog->emitSubstituteResources(stream, true);
     // TODO(vandebo) support linearized format
     //if (fPages.size() > 1) {
     //    // TODO(vandebo) save the file offset for the first page xref table.
     //    fCatalog->emitXrefTable(stream, true);
     //}

     for (int i = 0; i < fPageTree.count(); i++) {
         fPageTree[i]->emitObject(stream, fCatalog.get(), true);
     }

     for (int i = 1; i < fPages.count(); i++) {
         fPages[i]->emitPage(stream, fCatalog.get());
     }

     for (int i = fSecondPageFirstResourceIndex;
             i < fPageResources.count();
             i++) {
         fPageResources[i]->emit(stream, fCatalog.get(), true);
     }

     fCatalog->emitSubstituteResources(stream, false);
     int64_t objCount = fCatalog->emitXrefTable(stream, fPages.count() > 1);
     emitFooter(stream, objCount);
     return true;
 }

 bool SkPDFDocument::setPage(int pageNumber, SkPDFDevice* pdfDevice) {
     if (fPageTree.count() != 0) {
         return false;
     }

     pageNumber--;
     SkASSERT(pageNumber >= 0);

     if (pageNumber >= fPages.count()) {
         int oldSize = fPages.count();
         fPages.setCount(pageNumber + 1);
         for (int i = oldSize; i <= pageNumber; i++) {
             fPages[i] = NULL;
         }
     }

     SkPDFPage* page = new SkPDFPage(pdfDevice);
     SkSafeUnref(fPages[pageNumber]);
     fPages[pageNumber] = page; // Reference from new passed to fPages.
     return true;
 }

 bool SkPDFDocument::appendPage(SkPDFDevice* pdfDevice) {
     if (fPageTree.count() != 0) {
         return false;
     }

     SkPDFPage* page = new SkPDFPage(pdfDevice);
     fPages.push(page);  // Reference from new passed to fPages.
     return true;
 }

 const SkTDArray<SkPDFPage*>& SkPDFDocument::getPages() {
     return fPages;
 }

 void SkPDFDocument::emitHeader(SkWStream* stream) {
     stream->writeText("%PDF-1.4\n%");
     // The PDF spec recommends including a comment with four bytes, all
     // with their high bits set.  This is "Skia" with the high bits set.
     stream->write32(0xD3EBE9E1);
     stream->writeText("\n");
 }

 size_t SkPDFDocument::headerSize() {
     SkDynamicMemoryWStream buffer;
     emitHeader(&buffer);
     return buffer.getOffset();
 }

 void SkPDFDocument::emitFooter(SkWStream* stream, int64_t objCount) {
     if (fTrailerDict.get() == NULL) {
         fTrailerDict = new SkPDFDict();
         fTrailerDict->unref();  // SkRefPtr and new both took a reference.

         // TODO(vandebo) Linearized format will take a Prev entry too.
         // TODO(vandebo) PDF/A requires an ID entry.
         fTrailerDict->insertInt("Size", objCount);
         fTrailerDict->insert("Root",
                              new SkPDFObjRef(fDocCatalog.get()))->unref();
     }

     stream->writeText("trailer\n");
     fTrailerDict->emitObject(stream, fCatalog.get(), false);
     stream->writeText("\nstartxref\n");
     stream->writeBigDecAsText(fXRefFileOffset);
     stream->writeText("\n%%EOF");
 }
	/*
	* Copyright (C) 2011 Google Inc.
	*
	* Licensed 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.
	*/

	#include "SkPDFCatalog.h"
	#include "SkPDFDevice.h"
	#include "SkPDFDocument.h"
	#include "SkPDFPage.h"
	#include "SkPDFFont.h"
	#include "SkStream.h"

	// Add the resources, starting at firstIndex to the catalog, removing any dupes.
	// A hash table would be really nice here.
	void addResourcesToCatalog(int firstIndex, bool firstPage,
	SkTDArray<SkPDFObject> resourceList,
	SkPDFCatalog* catalog) {
	for (int i = firstIndex; i < resourceList->count(); i++) {
	int index = resourceList->find((*resourceList)[i]);
	if (index != i) {
	(*resourceList)[i]->unref();
	resourceList->removeShuffle(i);
	i--;
	} else {
	catalog->addObject((*resourceList)[i], firstPage);
	}
	}
	}

	static void perform_font_subsetting(SkPDFCatalog* catalog,
	const SkTDArray<SkPDFPage*>& pages,
	SkTDArray<SkPDFObject> substitutes) {
	SkASSERT(catalog);
	SkASSERT(substitutes);

	SkPDFGlyphSetMap usage;
	for (int i = 0; i < pages.count(); ++i) {
	usage.merge(pages[i]->getFontGlyphUsage());
	}
	SkPDFGlyphSetMap::F2BIter iterator(usage);
	SkPDFGlyphSetMap::FontGlyphSetPair* entry = iterator.next();
	while (entry) {
	SkPDFFont* subsetFont =
	entry->fFont->getFontSubset(entry->fGlyphSet);
	if (subsetFont) {
	catalog->setSubstitute(entry->fFont, subsetFont);
	substitutes->push(subsetFont); // Transfer ownership to substitutes
	}
	entry = iterator.next();
	}
	}

	SkPDFDocument::SkPDFDocument(Flags flags)
	: fXRefFileOffset(0),
	fSecondPageFirstResourceIndex(0) {
	fCatalog.reset(new SkPDFCatalog(flags));
	fDocCatalog = new SkPDFDict("Catalog");
	fDocCatalog->unref(); // SkRefPtr and new both took a reference.
	fCatalog->addObject(fDocCatalog.get(), true);
	}

	SkPDFDocument::~SkPDFDocument() {
	fPages.safeUnrefAll();

	// The page tree has both child and parent pointers, so it creates a
	// reference cycle. We must clear that cycle to properly reclaim memory.
	for (int i = 0; i < fPageTree.count(); i++)
	fPageTree[i]->clear();
	fPageTree.safeUnrefAll();
	fPageResources.safeUnrefAll();
	fSubstitutes.safeUnrefAll();
	}

	bool SkPDFDocument::emitPDF(SkWStream* stream) {
	if (fPages.isEmpty()) {
	return false;
	}
	for (int i = 0; i < fPages.count(); i++) {
	if (fPages[i] == NULL) {
	return false;
	}
	}

	// We haven't emitted the document before if fPageTree is empty.
	if (fPageTree.count() == 0) {
	SkPDFDict* pageTreeRoot;
	SkPDFPage::GeneratePageTree(fPages, fCatalog.get(), &fPageTree,
	&pageTreeRoot);
	fDocCatalog->insert("Pages", new SkPDFObjRef(pageTreeRoot))->unref();

	/* TODO(vandebo) output intent
	SkRefPtr<SkPDFDict> outputIntent = new SkPDFDict("OutputIntent");
	outputIntent->unref(); // SkRefPtr and new both took a reference.
	outputIntent->insert("S", new SkPDFName("GTS_PDFA1"))->unref();
	outputIntent->insert("OutputConditionIdentifier",
	new SkPDFString("sRGB"))->unref();
	SkRefPtr<SkPDFArray> intentArray = new SkPDFArray;
	intentArray->unref(); // SkRefPtr and new both took a reference.
	intentArray->append(outputIntent.get());
	fDocCatalog->insert("OutputIntent", intentArray.get());
	*/

	bool firstPage = true;
	for (int i = 0; i < fPages.count(); i++) {
	int resourceCount = fPageResources.count();
	fPages[i]->finalizePage(fCatalog.get(), firstPage, &fPageResources);
	addResourcesToCatalog(resourceCount, firstPage, &fPageResources,
	fCatalog.get());
	if (i == 0) {
	firstPage = false;
	fSecondPageFirstResourceIndex = fPageResources.count();
	}
	}

	// Build font subsetting info before proceeding.
	perform_font_subsetting(fCatalog.get(), fPages, &fSubstitutes);

	// Figure out the size of things and inform the catalog of file offsets.
	off_t fileOffset = headerSize();
	fileOffset += fCatalog->setFileOffset(fDocCatalog.get(), fileOffset);
	fileOffset += fCatalog->setFileOffset(fPages[0], fileOffset);
	fileOffset += fPages[0]->getPageSize(fCatalog.get(), fileOffset);
	for (int i = 0; i < fSecondPageFirstResourceIndex; i++) {
	fileOffset += fCatalog->setFileOffset(fPageResources[i],
	fileOffset);
	}
	// Add the size of resources of substitute objects used on page 1.
	fileOffset += fCatalog->setSubstituteResourcesOffsets(fileOffset, true);
	if (fPages.count() > 1) {
	// TODO(vandebo) For linearized format, save the start of the
	// first page xref table and calculate the size.
	}

	for (int i = 0; i < fPageTree.count(); i++)
	fileOffset += fCatalog->setFileOffset(fPageTree[i], fileOffset);

	for (int i = 1; i < fPages.count(); i++)
	fileOffset += fPages[i]->getPageSize(fCatalog.get(), fileOffset);

	for (int i = fSecondPageFirstResourceIndex;
	i < fPageResources.count();
	i++)
	fileOffset += fCatalog->setFileOffset(fPageResources[i],
	fileOffset);

	fileOffset += fCatalog->setSubstituteResourcesOffsets(fileOffset,
	false);
	fXRefFileOffset = fileOffset;
	}

	emitHeader(stream);
	fDocCatalog->emitObject(stream, fCatalog.get(), true);
	fPages[0]->emitObject(stream, fCatalog.get(), true);
	fPages[0]->emitPage(stream, fCatalog.get());
	for (int i = 0; i < fSecondPageFirstResourceIndex; i++) {
	fPageResources[i]->emit(stream, fCatalog.get(), true);
	}
	fCatalog->emitSubstituteResources(stream, true);
	// TODO(vandebo) support linearized format
	//if (fPages.size() > 1) {
	// // TODO(vandebo) save the file offset for the first page xref table.
	// fCatalog->emitXrefTable(stream, true);
	//}

	for (int i = 0; i < fPageTree.count(); i++) {
	fPageTree[i]->emitObject(stream, fCatalog.get(), true);
	}

	for (int i = 1; i < fPages.count(); i++) {
	fPages[i]->emitPage(stream, fCatalog.get());
	}

	for (int i = fSecondPageFirstResourceIndex;
	i < fPageResources.count();
	i++) {
	fPageResources[i]->emit(stream, fCatalog.get(), true);
	}

	fCatalog->emitSubstituteResources(stream, false);
	int64_t objCount = fCatalog->emitXrefTable(stream, fPages.count() > 1);
	emitFooter(stream, objCount);
	return true;
	}

	bool SkPDFDocument::setPage(int pageNumber, SkPDFDevice* pdfDevice) {
	if (fPageTree.count() != 0) {
	return false;
	}

	pageNumber--;
	SkASSERT(pageNumber >= 0);

	if (pageNumber >= fPages.count()) {
	int oldSize = fPages.count();
	fPages.setCount(pageNumber + 1);
	for (int i = oldSize; i <= pageNumber; i++) {
	fPages[i] = NULL;
	}
	}

	SkPDFPage* page = new SkPDFPage(pdfDevice);
	SkSafeUnref(fPages[pageNumber]);
	fPages[pageNumber] = page; // Reference from new passed to fPages.
	return true;
	}

	bool SkPDFDocument::appendPage(SkPDFDevice* pdfDevice) {
	if (fPageTree.count() != 0) {
	return false;
	}

	SkPDFPage* page = new SkPDFPage(pdfDevice);
	fPages.push(page); // Reference from new passed to fPages.
	return true;
	}

	const SkTDArray<SkPDFPage*>& SkPDFDocument::getPages() {
	return fPages;
	}

	void SkPDFDocument::emitHeader(SkWStream* stream) {
	stream->writeText("%PDF-1.4\n%");
	// The PDF spec recommends including a comment with four bytes, all
	// with their high bits set. This is "Skia" with the high bits set.
	stream->write32(0xD3EBE9E1);
	stream->writeText("\n");
	}

	size_t SkPDFDocument::headerSize() {
	SkDynamicMemoryWStream buffer;
	emitHeader(&buffer);
	return buffer.getOffset();
	}

	void SkPDFDocument::emitFooter(SkWStream* stream, int64_t objCount) {
	if (fTrailerDict.get() == NULL) {
	fTrailerDict = new SkPDFDict();
	fTrailerDict->unref(); // SkRefPtr and new both took a reference.

	// TODO(vandebo) Linearized format will take a Prev entry too.
	// TODO(vandebo) PDF/A requires an ID entry.
	fTrailerDict->insertInt("Size", objCount);
	fTrailerDict->insert("Root",
	new SkPDFObjRef(fDocCatalog.get()))->unref();
	}

	stream->writeText("trailer\n");
	fTrailerDict->emitObject(stream, fCatalog.get(), false);
	stream->writeText("\nstartxref\n");
	stream->writeBigDecAsText(fXRefFileOffset);
	stream->writeText("\n%%EOF");
	}