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/*
* 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 "SkPDFDevice.h"
#include "SkPDFDocument.h"
#include "SkPDFPage.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);
}
}
}
SkPDFDocument::SkPDFDocument() : fXRefFileOffset(0) {
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();
}
bool SkPDFDocument::emitPDF(SkWStream* stream) {
if (fPages.isEmpty())
return false;
// We haven't emitted the document before if fPageTree is empty.
if (fPageTree.count() == 0) {
SkPDFDict* pageTreeRoot;
SkPDFPage::generatePageTree(fPages, &fCatalog, &fPageTree,
&pageTreeRoot);
SkRefPtr<SkPDFObjRef> pageTreeRootRef = new SkPDFObjRef(pageTreeRoot);
pageTreeRootRef->unref(); // SkRefPtr and new both took a reference.
fDocCatalog->insert("Pages", pageTreeRootRef.get());
/* TODO(vandebo) output intent
SkRefPtr<SkPDFDict> outputIntent = new SkPDFDict("OutputIntent");
outputIntent->unref(); // SkRefPtr and new both took a reference.
SkRefPtr<SkPDFName> intentSubtype = new SkPDFName("GTS_PDFA1");
intentSubtype->unref(); // SkRefPtr and new both took a reference.
outputIntent->insert("S", intentSubtype.get());
SkRefPtr<SkPDFString> intentIdentifier = new SkPDFString("sRGB");
intentIdentifier->unref(); // SkRefPtr and new both took a reference.
outputIntent->insert("OutputConditionIdentifier",
intentIdentifier.get());
SkRefPtr<SkPDFArray> intentArray = new SkPDFArray;
intentArray->unref(); // SkRefPtr and new both took a reference.
intentArray->append(outputIntent.get());
fDocCatalog->insert("OutputIntent", intentArray.get());
*/
bool first_page = true;
for (int i = 0; i < fPages.count(); i++) {
int resourceCount = fPageResources.count();
fPages[i]->finalizePage(&fCatalog, first_page, &fPageResources);
addResourcesToCatalog(resourceCount, first_page, &fPageResources,
&fCatalog);
if (i == 0) {
first_page = false;
fSecondPageFirstResourceIndex = fPageResources.count();
}
}
// 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, fileOffset);
for (int i = 0; i < fSecondPageFirstResourceIndex; i++)
fileOffset += fCatalog.setFileOffset(fPageResources[i], fileOffset);
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, fileOffset);
for (int i = fSecondPageFirstResourceIndex;
i < fPageResources.count();
i++)
fileOffset += fCatalog.setFileOffset(fPageResources[i], fileOffset);
fXRefFileOffset = fileOffset;
}
emitHeader(stream);
fDocCatalog->emitObject(stream, &fCatalog, true);
fPages[0]->emitObject(stream, &fCatalog, true);
fPages[0]->emitPage(stream, &fCatalog);
for (int i = 0; i < fSecondPageFirstResourceIndex; i++)
fPageResources[i]->emitObject(stream, &fCatalog, 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, true);
for (int i = 1; i < fPages.count(); i++)
fPages[i]->emitPage(stream, &fCatalog);
for (int i = fSecondPageFirstResourceIndex; i < fPageResources.count(); i++)
fPageResources[i]->emitObject(stream, &fCatalog, true);
int64_t objCount = fCatalog.emitXrefTable(stream, fPages.count() > 1);
emitFooter(stream, objCount);
return true;
}
bool SkPDFDocument::appendPage(const SkRefPtr<SkPDFDevice>& pdfDevice) {
if (fPageTree.count() != 0)
return false;
SkPDFPage* page = new SkPDFPage(pdfDevice);
fPages.push(page); // Reference from new passed to fPages.
// The rest of the pages will be added to the catalog along with the rest
// of the page tree. But the first page has to be marked as such, so we
// handle it here.
if (fPages.count() == 1)
fCatalog.addObject(page, true);
return true;
}
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.
SkPDFInt* objCountInt = new SkPDFInt(objCount);
fTrailerDict->insert("Size", objCountInt);
objCountInt->unref(); // insert took a ref and we're done with it.
// TODO(vandebo) Linearized format will take a Prev entry too.
SkPDFObjRef* docCatalogRef = new SkPDFObjRef(fDocCatalog.get());
fTrailerDict->insert("Root", docCatalogRef);
docCatalogRef->unref(); // insert took a ref and we're done with it.
// TODO(vandebo) PDF/A requires an ID entry.
}
stream->writeText("trailer\n");
fTrailerDict->emitObject(stream, &fCatalog, false);
stream->writeText("\nstartxref\n");
stream->writeBigDecAsText(fXRefFileOffset);
stream->writeText("\n%%EOF");
}
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