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      1 
      2 /*
      3  * Copyright 2010 The Android Open Source Project
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 #ifndef SkPDFGraphicState_DEFINED
     11 #define SkPDFGraphicState_DEFINED
     12 
     13 #include "SkPaint.h"
     14 #include "SkPDFTypes.h"
     15 #include "SkTemplates.h"
     16 #include "SkThread.h"
     17 
     18 class SkPDFFormXObject;
     19 
     20 /** \class SkPDFGraphicState
     21     SkPaint objects roughly correspond to graphic state dictionaries that can
     22     be installed. So that a given dictionary is only output to the pdf file
     23     once, we want to canonicalize them. Static methods in this class manage
     24     a weakly referenced set of SkPDFGraphicState objects: when the last
     25     reference to a SkPDFGraphicState is removed, it removes itself from the
     26     static set of objects.
     27 
     28 */
     29 class SkPDFGraphicState : public SkPDFDict {
     30     SK_DECLARE_INST_COUNT(SkPDFGraphicState)
     31 public:
     32     enum SkPDFSMaskMode {
     33         kAlpha_SMaskMode,
     34         kLuminosity_SMaskMode
     35     };
     36 
     37     virtual ~SkPDFGraphicState();
     38 
     39     virtual void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
     40                               SkTSet<SkPDFObject*>* newResourceObjects);
     41 
     42     // Override emitObject and getOutputSize so that we can populate
     43     // the dictionary on demand.
     44     virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog,
     45                             bool indirect);
     46     virtual size_t getOutputSize(SkPDFCatalog* catalog, bool indirect);
     47 
     48     /** Get the graphic state for the passed SkPaint. The reference count of
     49      *  the object is incremented and it is the caller's responsibility to
     50      *  unreference it when done. This is needed to accommodate the weak
     51      *  reference pattern used when the returned object is new and has no
     52      *  other references.
     53      *  @param paint  The SkPaint to emulate.
     54      */
     55     static SkPDFGraphicState* GetGraphicStateForPaint(const SkPaint& paint);
     56 
     57     /** Make a graphic state that only sets the passed soft mask. The
     58      *  reference count of the object is incremented and it is the caller's
     59      *  responsibility to unreference it when done.
     60      *  @param sMask     The form xobject to use as a soft mask.
     61      *  @param invert    Indicates if the alpha of the sMask should be inverted.
     62      *  @param sMaskMode Whether to use alpha or luminosity for the sMask.
     63      */
     64     static SkPDFGraphicState* GetSMaskGraphicState(SkPDFFormXObject* sMask,
     65                                                    bool invert,
     66                                                    SkPDFSMaskMode sMaskMode);
     67 
     68     /** Get a graphic state that only unsets the soft mask. The reference
     69      *  count of the object is incremented and it is the caller's responsibility
     70      *  to unreference it when done. This is needed to accommodate the weak
     71      *  reference pattern used when the returned object is new and has no
     72      *  other references.
     73      */
     74     static SkPDFGraphicState* GetNoSMaskGraphicState();
     75 
     76 private:
     77     const SkPaint fPaint;
     78     SkTDArray<SkPDFObject*> fResources;
     79     bool fPopulated;
     80     bool fSMask;
     81 
     82     class GSCanonicalEntry {
     83     public:
     84         SkPDFGraphicState* fGraphicState;
     85         const SkPaint* fPaint;
     86 
     87         bool operator==(const GSCanonicalEntry& b) const;
     88         explicit GSCanonicalEntry(SkPDFGraphicState* gs)
     89             : fGraphicState(gs),
     90               fPaint(&gs->fPaint) {}
     91         explicit GSCanonicalEntry(const SkPaint* paint)
     92             : fGraphicState(NULL),
     93               fPaint(paint) {}
     94     };
     95 
     96     // This should be made a hash table if performance is a problem.
     97     static SkTDArray<GSCanonicalEntry>& CanonicalPaints();
     98     static SkBaseMutex& CanonicalPaintsMutex();
     99 
    100     SkPDFGraphicState();
    101     explicit SkPDFGraphicState(const SkPaint& paint);
    102 
    103     void populateDict();
    104 
    105     static SkPDFObject* GetInvertFunction();
    106 
    107     static int Find(const SkPaint& paint);
    108     typedef SkPDFDict INHERITED;
    109 };
    110 
    111 #endif
    112