SkPDF: merge skdocument_pdf and skpdfdocument

src/doc/SkDocument_PDF.cpp

 /*
- * Copyright 2013 Google Inc.
+ * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDocument.h"
 #include "SkPDFCanon.h"
-#include "SkPDFDocument.h"
+#include "SkPDFCatalog.h"
 #include "SkPDFDevice.h"
+#include "SkPDFFont.h"
+#include "SkPDFPage.h"
+#include "SkPDFTypes.h"
+#include "SkStream.h"
+
+static void emit_pdf_header(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");
+}
+
+static void emit_pdf_footer(SkWStream* stream,
+                            SkPDFCatalog* catalog,
+                            SkPDFObject* docCatalog,
+                            int64_t objCount,
+                            int32_t xRefFileOffset) {
+    SkPDFDict trailerDict;
+    // TODO(vandebo): Linearized format will take a Prev entry too.
+    // TODO(vandebo): PDF/A requires an ID entry.
+    trailerDict.insertInt("Size", int(objCount));
+    trailerDict.insert("Root", new SkPDFObjRef(docCatalog))->unref();
+
+    stream->writeText("trailer\n");
+    trailerDict.emitObject(stream, catalog);
+    stream->writeText("\nstartxref\n");
+    stream->writeBigDecAsText(xRefFileOffset);
+    stream->writeText("\n%%EOF");
+}
+
+static void perform_font_subsetting(SkPDFCatalog* catalog,
+                                    const SkTDArray<SkPDFPage*>& pages) {
+    SkASSERT(catalog);
+
+    SkPDFGlyphSetMap usage;
+    for (int i = 0; i < pages.count(); ++i) {
+        usage.merge(pages[i]->getFontGlyphUsage());
+    }
+    SkPDFGlyphSetMap::F2BIter iterator(usage);
+    const SkPDFGlyphSetMap::FontGlyphSetPair* entry = iterator.next();
+    while (entry) {
+        SkAutoTUnref<SkPDFFont> subsetFont(
+                entry->fFont->getFontSubset(entry->fGlyphSet));
+        if (subsetFont) {
+            catalog->setSubstitute(entry->fFont, subsetFont.get());
+        }
+        entry = iterator.next();
+    }
+}
+
+static bool emit_pdf_document(const SkTDArray<const SkPDFDevice*>& pageDevices,
+                              SkWStream* stream) {
+    if (pageDevices.isEmpty()) {
+        return false;
+    }
+
+    SkTDArray<SkPDFPage*> pages;
+    SkAutoTUnref<SkPDFDict> dests(SkNEW(SkPDFDict));
+
+    for (int i = 0; i < pageDevices.count(); i++) {
+        SkASSERT(pageDevices[i]);
+        SkASSERT(i == 0 ||
+                 pageDevices[i - 1]->getCanon() == pageDevices[i]->getCanon());
+        // Reference from new passed to pages.
+        SkAutoTUnref<SkPDFPage> page(SkNEW_ARGS(SkPDFPage, (pageDevices[i])));
+        page->finalizePage();
+        page->appendDestinations(dests);
+        pages.push(page.detach());
+    }
+    SkPDFCatalog catalog;
+
+    SkTDArray<SkPDFDict*> pageTree;
+    SkAutoTUnref<SkPDFDict> docCatalog(SkNEW_ARGS(SkPDFDict, ("Catalog")));
+
+    SkPDFDict* pageTreeRoot;
+    SkPDFPage::GeneratePageTree(pages, &pageTree, &pageTreeRoot);
+
+    docCatalog->insert("Pages", new SkPDFObjRef(pageTreeRoot))->unref();
+
+    /* TODO(vandebo): output intent
+    SkAutoTUnref<SkPDFDict> outputIntent = new SkPDFDict("OutputIntent");
+    outputIntent->insert("S", new SkPDFName("GTS_PDFA1"))->unref();
+    outputIntent->insert("OutputConditionIdentifier",
+                         new SkPDFString("sRGB"))->unref();
+    SkAutoTUnref<SkPDFArray> intentArray = new SkPDFArray;
+    intentArray->append(outputIntent.get());
+    docCatalog->insert("OutputIntent", intentArray.get());
+    */
+
+    if (dests->size() > 0) {
+        docCatalog->insert("Dests", SkNEW_ARGS(SkPDFObjRef, (dests.get())))
+                ->unref();
+    }
+
+    // Build font subsetting info before proceeding.
+    perform_font_subsetting(&catalog, pages);
+
+    SkTSet<SkPDFObject*> resourceSet;
+    if (resourceSet.add(docCatalog.get())) {
+        docCatalog->addResources(&resourceSet, &catalog);
+    }
+    for (int i = 0; i < resourceSet.count(); ++i) {
+        SkAssertResult(catalog.addObject(resourceSet[i]));
+    }
+
+    size_t baseOffset = SkToOffT(stream->bytesWritten());
+    emit_pdf_header(stream);
+    SkTDArray<int32_t> offsets;
+    for (int i = 0; i < resourceSet.count(); ++i) {
+        SkPDFObject* object = resourceSet[i];
+        offsets.push(SkToS32(stream->bytesWritten() - baseOffset));
+        SkASSERT(object == catalog.getSubstituteObject(object));
+        SkASSERT(catalog.getObjectNumber(object) == i + 1);
+        stream->writeDecAsText(i + 1);
+        stream->writeText(" 0 obj\n");  // Generation number is always 0.
+        object->emitObject(stream, &catalog);
+        stream->writeText("\nendobj\n");
+    }
+    int32_t xRefFileOffset = SkToS32(stream->bytesWritten() - baseOffset);
+
+    int32_t objCount = SkToS32(offsets.count() + 1);
+
+    stream->writeText("xref\n0 ");
+    stream->writeDecAsText(objCount + 1);
+    stream->writeText("\n0000000000 65535 f \n");
+    for (int i = 0; i < offsets.count(); i++) {
+        SkASSERT(offsets[i] > 0);
+        stream->writeBigDecAsText(offsets[i], 10);
+        stream->writeText(" 00000 n \n");
+    }
+    emit_pdf_footer(stream, &catalog, docCatalog.get(), objCount,
+                    xRefFileOffset);
+
+    // 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 < pageTree.count(); i++) {
+        pageTree[i]->clear();
+    }
+    pageTree.safeUnrefAll();
+    pages.unrefAll();
+    return true;
+}
+
+#if 0
+// TODO(halcanary): expose notEmbeddableCount in SkDocument
+void GetCountOfFontTypes(
+        const SkTDArray<SkPDFDevice*>& pageDevices,
+        int counts[SkAdvancedTypefaceMetrics::kOther_Font + 1],
+        int* notSubsettableCount,
+        int* notEmbeddableCount) {
+    sk_bzero(counts, sizeof(int) *
+                     (SkAdvancedTypefaceMetrics::kOther_Font + 1));
+    SkTDArray<SkFontID> seenFonts;
+    int notSubsettable = 0;
+    int notEmbeddable = 0;
+
+    for (int pageNumber = 0; pageNumber < pageDevices.count(); pageNumber++) {
+        const SkTDArray<SkPDFFont*>& fontResources =
+                pageDevices[pageNumber]->getFontResources();
+        for (int font = 0; font < fontResources.count(); font++) {
+            SkFontID fontID = fontResources[font]->typeface()->uniqueID();
+            if (seenFonts.find(fontID) == -1) {
+                counts[fontResources[font]->getType()]++;
+                seenFonts.push(fontID);
+                if (!fontResources[font]->canSubset()) {
+                    notSubsettable++;
+                }
+                if (!fontResources[font]->canEmbed()) {
+                    notEmbeddable++;
+                }
+            }
+        }
+    }
+    if (notSubsettableCount) {
+        *notSubsettableCount = notSubsettable;
+
+    }
+    if (notEmbeddableCount) {
+        *notEmbeddableCount = notEmbeddable;
+    }
+}
+#endif
+////////////////////////////////////////////////////////////////////////////////
 
 namespace {
 class SkDocument_PDF : public SkDocument {
 public:
     SkDocument_PDF(SkWStream* stream,
                    void (*doneProc)(SkWStream*, bool),
                    SkScalar rasterDpi)
         : SkDocument(stream, doneProc)
         , fRasterDpi(rasterDpi) {}
 
@@ skipping 20 matching lines @@
 
     void onEndPage() SK_OVERRIDE {
         SkASSERT(fCanvas.get());
         fCanvas->flush();
         fCanvas.reset(NULL);
     }
 
     bool onClose(SkWStream* stream) SK_OVERRIDE {
         SkASSERT(!fCanvas.get());
 
-        bool success = SkPDFDocument::EmitPDF(fPageDevices, stream);
+        bool success = emit_pdf_document(fPageDevices, stream);
         fPageDevices.unrefAll();
         fCanon.reset();
         return success;
     }
 
     void onAbort() SK_OVERRIDE {
         fPageDevices.unrefAll();
         fCanon.reset();
     }
 
 private:
     SkPDFCanon fCanon;
     SkTDArray<const SkPDFDevice*> fPageDevices;
     SkAutoTUnref<SkCanvas> fCanvas;
     SkScalar fRasterDpi;
 };
 }  // namespace
 ///////////////////////////////////////////////////////////////////////////////
 
 SkDocument* SkDocument::CreatePDF(SkWStream* stream, SkScalar dpi) {
     return stream ? SkNEW_ARGS(SkDocument_PDF, (stream, NULL, dpi)) : NULL;
 }
 
-static void delete_wstream(SkWStream* stream, bool aborted) {
-    SkDELETE(stream);
-}
-
 SkDocument* SkDocument::CreatePDF(const char path[], SkScalar dpi) {
     SkFILEWStream* stream = SkNEW_ARGS(SkFILEWStream, (path));
     if (!stream->isValid()) {
         SkDELETE(stream);
         return NULL;
     }
+    auto delete_wstream = [](SkWStream* stream, bool) { SkDELETE(stream); };
     return SkNEW_ARGS(SkDocument_PDF, (stream, delete_wstream, dpi));
 }