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 SkFontConfigInterface_DEFINED 9 #define SkFontConfigInterface_DEFINED 10 11 #include "SkDataTable.h" 12 #include "SkFontStyle.h" 13 #include "SkRefCnt.h" 14 #include "SkTArray.h" 15 #include "SkTypeface.h" 16 17 struct SkBaseMutex; 18 19 /** 20 * \class SkFontConfigInterface 21 * 22 * Provides SkFontHost clients with access to fontconfig services. They will 23 * access the global instance found in RefGlobal(). 24 */ 25 class SK_API SkFontConfigInterface : public SkRefCnt { 26 public: 27 SK_DECLARE_INST_COUNT(SkFontConfigInterface) 28 29 /** 30 * Returns the global SkFontConfigInterface instance, and if it is not 31 * NULL, calls ref() on it. The caller must balance this with a call to 32 * unref(). 33 */ 34 static SkFontConfigInterface* RefGlobal(); 35 36 /** 37 * Replace the current global instance with the specified one, safely 38 * ref'ing the new instance, and unref'ing the previous. Returns its 39 * parameter (the new global instance). 40 */ 41 static SkFontConfigInterface* SetGlobal(SkFontConfigInterface*); 42 43 /** 44 * This should be treated as private to the impl of SkFontConfigInterface. 45 * Callers should not change or expect any particular values. It is meant 46 * to be a union of possible storage types to aid the impl. 47 */ 48 struct FontIdentity { 49 FontIdentity() : fID(0), fTTCIndex(0) {} 50 51 bool operator==(const FontIdentity& other) const { 52 return fID == other.fID && 53 fTTCIndex == other.fTTCIndex && 54 fString == other.fString; 55 } 56 bool operator!=(const FontIdentity& other) const { 57 return !(*this == other); 58 } 59 60 uint32_t fID; 61 int32_t fTTCIndex; 62 SkString fString; 63 SkFontStyle fStyle; 64 65 // If buffer is NULL, just return the number of bytes that would have 66 // been written. Will pad contents to a multiple of 4. 67 size_t writeToMemory(void* buffer = NULL) const; 68 69 // Recreate from a flattened buffer, returning the number of bytes read. 70 size_t readFromMemory(const void* buffer, size_t length); 71 }; 72 73 /** 74 * Given a familyName and style, find the best match. 75 * 76 * If a match is found, return true and set its outFontIdentifier. 77 * If outFamilyName is not null, assign the found familyName to it 78 * (which may differ from the requested familyName). 79 * If outStyle is not null, assign the found style to it 80 * (which may differ from the requested style). 81 * 82 * If a match is not found, return false, and ignore all out parameters. 83 */ 84 virtual bool matchFamilyName(const char familyName[], 85 SkTypeface::Style requested, 86 FontIdentity* outFontIdentifier, 87 SkString* outFamilyName, 88 SkTypeface::Style* outStyle) = 0; 89 90 /** 91 * Given a FontRef, open a stream to access its data, or return null 92 * if the FontRef's data is not available. The caller is responsible for 93 * calling stream->unref() when it is done accessing the data. 94 */ 95 virtual SkStream* openStream(const FontIdentity&) = 0; 96 97 /** 98 * Return a singleton instance of a direct subclass that calls into 99 * libfontconfig. This does not affect the refcnt of the returned instance. 100 * The mutex may be used to guarantee the singleton is only constructed once. 101 */ 102 static SkFontConfigInterface* GetSingletonDirectInterface 103 (SkBaseMutex* mutex = NULL); 104 105 // New APIS, which have default impls for now (which do nothing) 106 107 virtual SkDataTable* getFamilyNames() { return SkDataTable::NewEmpty(); } 108 virtual bool matchFamilySet(const char inFamilyName[], 109 SkString* outFamilyName, 110 SkTArray<FontIdentity>*) { 111 return false; 112 } 113 typedef SkRefCnt INHERITED; 114 }; 115 116 #endif 117
