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      1 /*
      2  * Copyright 2013 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 
      8 #ifndef SkFontMgr_DEFINED
      9 #define SkFontMgr_DEFINED
     10 
     11 #include "SkRefCnt.h"
     12 #include "SkFontStyle.h"
     13 
     14 class SkData;
     15 class SkStream;
     16 class SkString;
     17 class SkTypeface;
     18 
     19 class SK_API SkFontStyleSet : public SkRefCnt {
     20 public:
     21     SK_DECLARE_INST_COUNT(SkFontStyleSet)
     22 
     23     virtual int count() = 0;
     24     virtual void getStyle(int index, SkFontStyle*, SkString* style) = 0;
     25     virtual SkTypeface* createTypeface(int index) = 0;
     26     virtual SkTypeface* matchStyle(const SkFontStyle& pattern) = 0;
     27 
     28     static SkFontStyleSet* CreateEmpty();
     29 
     30 private:
     31     typedef SkRefCnt INHERITED;
     32 };
     33 
     34 class SkTypeface;
     35 
     36 class SK_API SkFontMgr : public SkRefCnt {
     37 public:
     38     SK_DECLARE_INST_COUNT(SkFontMgr)
     39 
     40     int countFamilies() const;
     41     void getFamilyName(int index, SkString* familyName) const;
     42     SkFontStyleSet* createStyleSet(int index) const;
     43 
     44     /**
     45      *  The caller must call unref() on the returned object.
     46      *  Never returns NULL; will return an empty set if the name is not found.
     47      *
     48      *  It is possible that this will return a style set not accessible from
     49      *  createStyleSet(int) due to hidden or auto-activated fonts.
     50      */
     51     SkFontStyleSet* matchFamily(const char familyName[]) const;
     52 
     53     /**
     54      *  Find the closest matching typeface to the specified familyName and style
     55      *  and return a ref to it. The caller must call unref() on the returned
     56      *  object. Will never return NULL, as it will return the default font if
     57      *  no matching font is found.
     58      *
     59      *  It is possible that this will return a style set not accessible from
     60      *  createStyleSet(int) or matchFamily(const char[]) due to hidden or
     61      *  auto-activated fonts.
     62      */
     63     SkTypeface* matchFamilyStyle(const char familyName[], const SkFontStyle&) const;
     64 
     65     /**
     66      *  Use the system fallback to find a typeface for the given character.
     67      *  Note that bpc47 is a combination of ISO 639, 15924, and 3166-1 codes,
     68      *  so it is fine to just pass a ISO 639 here.
     69      *
     70      *  Will return NULL if no family can be found for the character
     71      *  in the system fallback.
     72      */
     73     SkTypeface* matchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
     74                                           const char bpc47[], uint32_t character) const;
     75 
     76     SkTypeface* matchFaceStyle(const SkTypeface*, const SkFontStyle&) const;
     77 
     78     /**
     79      *  Create a typeface for the specified data and TTC index (pass 0 for none)
     80      *  or NULL if the data is not recognized. The caller must call unref() on
     81      *  the returned object if it is not null.
     82      */
     83     SkTypeface* createFromData(SkData*, int ttcIndex = 0) const;
     84 
     85     /**
     86      *  Create a typeface for the specified stream and TTC index
     87      *  (pass 0 for none) or NULL if the stream is not recognized. The caller
     88      *  must call unref() on the returned object if it is not null.
     89      */
     90     SkTypeface* createFromStream(SkStream*, int ttcIndex = 0) const;
     91 
     92     /**
     93      *  Create a typeface for the specified fileName and TTC index
     94      *  (pass 0 for none) or NULL if the file is not found, or its contents are
     95      *  not recognized. The caller must call unref() on the returned object
     96      *  if it is not null.
     97      */
     98     SkTypeface* createFromFile(const char path[], int ttcIndex = 0) const;
     99 
    100     SkTypeface* legacyCreateTypeface(const char familyName[],
    101                                      unsigned typefaceStyleBits) const;
    102 
    103     /**
    104      *  Return a ref to the default fontmgr. The caller must call unref() on
    105      *  the returned object.
    106      */
    107     static SkFontMgr* RefDefault();
    108 
    109 protected:
    110     virtual int onCountFamilies() const = 0;
    111     virtual void onGetFamilyName(int index, SkString* familyName) const = 0;
    112     virtual SkFontStyleSet* onCreateStyleSet(int index)const  = 0;
    113 
    114     /** May return NULL if the name is not found. */
    115     virtual SkFontStyleSet* onMatchFamily(const char familyName[]) const = 0;
    116 
    117     virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
    118                                            const SkFontStyle&) const = 0;
    119     // TODO: pure virtual, implement on all impls.
    120     virtual SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
    121                                                     const char bpc47[], uint32_t character) const
    122     { return NULL; }
    123     virtual SkTypeface* onMatchFaceStyle(const SkTypeface*,
    124                                          const SkFontStyle&) const = 0;
    125 
    126     virtual SkTypeface* onCreateFromData(SkData*, int ttcIndex) const = 0;
    127     virtual SkTypeface* onCreateFromStream(SkStream*, int ttcIndex) const = 0;
    128     virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const = 0;
    129 
    130     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[],
    131                                                unsigned styleBits) const = 0;
    132 private:
    133     static SkFontMgr* Factory();    // implemented by porting layer
    134     static SkFontMgr* CreateDefault();
    135 
    136     typedef SkRefCnt INHERITED;
    137 };
    138 
    139 #endif
    140