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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 public:
     31     virtual ~SkPDFGraphicState();
     32 
     33     virtual void getResources(SkTDArray<SkPDFObject*>* resourceList);
     34 
     35     // Override emitObject and getOutputSize so that we can populate
     36     // the dictionary on demand.
     37     virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog,
     38                             bool indirect);
     39     virtual size_t getOutputSize(SkPDFCatalog* catalog, bool indirect);
     40 
     41     /** Get the graphic state for the passed SkPaint. The reference count of
     42      *  the object is incremented and it is the caller's responsibility to
     43      *  unreference it when done. This is needed to accommodate the weak
     44      *  reference pattern used when the returned object is new and has no
     45      *  other references.
     46      *  @param paint  The SkPaint to emulate.
     47      */
     48     static SkPDFGraphicState* GetGraphicStateForPaint(const SkPaint& paint);
     49 
     50     /** Make a graphic state that only sets the passed soft mask. The
     51      *  reference count of the object is incremented and it is the caller's
     52      *  responsibility to unreference it when done.
     53      *  @param sMask  The form xobject to use as a soft mask.
     54      *  @param invert Indicates if the alpha of the sMask should be inverted.
     55      */
     56     static SkPDFGraphicState* GetSMaskGraphicState(SkPDFFormXObject* sMask,
     57                                                    bool invert);
     58 
     59     /** Get a graphic state that only unsets the soft mask. The reference
     60      *  count of the object is incremented and it is the caller's responsibility
     61      *  to unreference it when done. This is needed to accommodate the weak
     62      *  reference pattern used when the returned object is new and has no
     63      *  other references.
     64      */
     65     static SkPDFGraphicState* GetNoSMaskGraphicState();
     66 
     67 private:
     68     const SkPaint fPaint;
     69     SkTDArray<SkPDFObject*> fResources;
     70     bool fPopulated;
     71     bool fSMask;
     72 
     73     class GSCanonicalEntry {
     74     public:
     75         SkPDFGraphicState* fGraphicState;
     76         const SkPaint* fPaint;
     77 
     78         bool operator==(const GSCanonicalEntry& b) const;
     79         explicit GSCanonicalEntry(SkPDFGraphicState* gs)
     80             : fGraphicState(gs),
     81               fPaint(&gs->fPaint) {}
     82         explicit GSCanonicalEntry(const SkPaint* paint)
     83             : fGraphicState(NULL),
     84               fPaint(paint) {}
     85     };
     86 
     87     // This should be made a hash table if performance is a problem.
     88     static SkTDArray<GSCanonicalEntry>& CanonicalPaints();
     89     static SkBaseMutex& CanonicalPaintsMutex();
     90 
     91     SkPDFGraphicState();
     92     explicit SkPDFGraphicState(const SkPaint& paint);
     93 
     94     void populateDict();
     95 
     96     static SkPDFObject* GetInvertFunction();
     97 
     98     static int Find(const SkPaint& paint);
     99 };
    100 
    101 #endif
    102