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      1 /*
      2  * Copyright 2016 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 #ifndef SkPDFDocumentPriv_DEFINED
      8 #define SkPDFDocumentPriv_DEFINED
      9 
     10 #include "SkCanvas.h"
     11 #include "SkMutex.h"
     12 #include "SkPDFDocument.h"
     13 #include "SkPDFMetadata.h"
     14 #include "SkPDFTag.h"
     15 #include "SkStream.h"
     16 #include "SkTHash.h"
     17 
     18 #include <atomic>
     19 #include <vector>
     20 #include <memory>
     21 
     22 class SkExecutor;
     23 class SkPDFDevice;
     24 class SkPDFFont;
     25 struct SkAdvancedTypefaceMetrics;
     26 struct SkBitmapKey;
     27 struct SkPDFFillGraphicState;
     28 struct SkPDFImageShaderKey;
     29 struct SkPDFStrokeGraphicState;
     30 
     31 namespace SkPDFGradientShader {
     32 struct Key;
     33 struct KeyHash;
     34 }
     35 
     36 const char* SkPDFGetNodeIdKey();
     37 
     38 // Logically part of SkPDFDocument, but separate to keep similar functionality together.
     39 class SkPDFOffsetMap {
     40 public:
     41     void markStartOfDocument(const SkWStream*);
     42     void markStartOfObject(int referenceNumber, const SkWStream*);
     43     int objectCount() const;
     44     int emitCrossReferenceTable(SkWStream* s) const;
     45 private:
     46     std::vector<int> fOffsets;
     47     size_t fBaseOffset = SIZE_MAX;
     48 };
     49 
     50 /** Concrete implementation of SkDocument that creates PDF files. This
     51     class does not produced linearized or optimized PDFs; instead it
     52     it attempts to use a minimum amount of RAM. */
     53 class SkPDFDocument : public SkDocument {
     54 public:
     55     SkPDFDocument(SkWStream*, SkPDF::Metadata);
     56     ~SkPDFDocument() override;
     57     SkCanvas* onBeginPage(SkScalar, SkScalar) override;
     58     void onEndPage() override;
     59     void onClose(SkWStream*) override;
     60     void onAbort() override;
     61 
     62     /**
     63        Serialize the object, as well as any other objects it
     64        indirectly refers to.  If any any other objects have been added
     65        to the SkPDFObjNumMap without serializing them, they will be
     66        serialized as well.
     67 
     68        It might go without saying that objects should not be changed
     69        after calling serialize, since those changes will be too late.
     70      */
     71     SkPDFIndirectReference emit(const SkPDFObject&, SkPDFIndirectReference);
     72     SkPDFIndirectReference emit(const SkPDFObject& o) { return this->emit(o, this->reserveRef()); }
     73 
     74     template <typename T>
     75     void emitStream(const SkPDFDict& dict, T writeStream, SkPDFIndirectReference ref) {
     76         SkWStream* stream = this->beginObject(ref);
     77         dict.emitObject(stream);
     78         stream->writeText(" stream\n");
     79         writeStream(stream);
     80         stream->writeText("\nendstream");
     81         this->endObject();
     82     }
     83 
     84     const SkPDF::Metadata& metadata() const { return fMetadata; }
     85 
     86     SkPDFIndirectReference getPage(size_t pageIndex) const;
     87     // Returns -1 if no mark ID.
     88     int getMarkIdForNodeId(int nodeId);
     89 
     90     SkPDFIndirectReference reserveRef() { return SkPDFIndirectReference{fNextObjectNumber++}; }
     91 
     92     SkExecutor* executor() const { return fExecutor; }
     93     void incrementJobCount();
     94     void signalJobComplete();
     95     size_t currentPageIndex() { return fPages.size(); }
     96     size_t pageCount() { return fPageRefs.size(); }
     97 
     98     // Canonicalized objects
     99     SkTHashMap<SkPDFImageShaderKey, SkPDFIndirectReference> fImageShaderMap;
    100     SkTHashMap<SkPDFGradientShader::Key, SkPDFIndirectReference, SkPDFGradientShader::KeyHash>
    101         fGradientPatternMap;
    102     SkTHashMap<SkBitmapKey, SkPDFIndirectReference> fPDFBitmapMap;
    103     SkTHashMap<uint32_t, std::unique_ptr<SkAdvancedTypefaceMetrics>> fTypefaceMetrics;
    104     SkTHashMap<uint32_t, std::vector<SkString>> fType1GlyphNames;
    105     SkTHashMap<uint32_t, std::vector<SkUnichar>> fToUnicodeMap;
    106     SkTHashMap<uint32_t, SkPDFIndirectReference> fFontDescriptors;
    107     SkTHashMap<uint32_t, SkPDFIndirectReference> fType3FontDescriptors;
    108     SkTHashMap<uint64_t, SkPDFFont> fFontMap;
    109     SkTHashMap<SkPDFStrokeGraphicState, SkPDFIndirectReference> fStrokeGSMap;
    110     SkTHashMap<SkPDFFillGraphicState, SkPDFIndirectReference> fFillGSMap;
    111     SkPDFIndirectReference fInvertFunction;
    112     SkPDFIndirectReference fNoSmaskGraphicState;
    113 
    114 private:
    115     SkPDFOffsetMap fOffsetMap;
    116     SkCanvas fCanvas;
    117     std::vector<std::unique_ptr<SkPDFDict>> fPages;
    118     std::vector<SkPDFIndirectReference> fPageRefs;
    119     SkPDFDict fDests;
    120     sk_sp<SkPDFDevice> fPageDevice;
    121     std::atomic<int> fNextObjectNumber = {1};
    122     std::atomic<int> fJobCount = {0};
    123     SkUUID fUUID;
    124     SkPDFIndirectReference fInfoDict;
    125     SkPDFIndirectReference fXMP;
    126     SkPDF::Metadata fMetadata;
    127     SkScalar fRasterScale = 1;
    128     SkScalar fInverseRasterScale = 1;
    129     SkExecutor* fExecutor = nullptr;
    130 
    131     // For tagged PDFs.
    132     SkPDFTagTree fTagTree;
    133 
    134     SkMutex fMutex;
    135     SkSemaphore fSemaphore;
    136 
    137     void waitForJobs();
    138     SkWStream* beginObject(SkPDFIndirectReference);
    139     void endObject();
    140 };
    141 
    142 #endif  // SkPDFDocumentPriv_DEFINED
    143