1 2 /* 3 * Copyright 2011 Google Inc. 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 11 #ifndef SkTypefaceCache_DEFINED 12 #define SkTypefaceCache_DEFINED 13 14 #include "SkTypeface.h" 15 #include "SkTDArray.h" 16 17 /* TODO 18 * Provide std way to cache name+requestedStyle aliases to the same typeface. 19 * 20 * The current mechanism ends up create a diff typeface for each one, even if 21 * they map to the same internal obj (e.g. CTFontRef on the mac) 22 */ 23 24 class SkTypefaceCache { 25 public: 26 SkTypefaceCache(); 27 ~SkTypefaceCache(); 28 29 /** 30 * Callback for FindByProc. Returns true if the given typeface is a match 31 * for the given context. The passed typeface is owned by the cache and is 32 * not additionally ref()ed. The typeface may be in the disposed state. 33 */ 34 typedef bool(*FindProc)(SkTypeface*, const SkFontStyle&, void* context); 35 36 /** 37 * Add a typeface to the cache. This ref()s the typeface, so that the 38 * cache is also an owner. Later, if we need to purge the cache, typefaces 39 * whose refcnt is 1 (meaning only the cache is an owner) will be 40 * unref()ed. 41 */ 42 void add(SkTypeface*, const SkFontStyle& requested); 43 44 /** 45 * Iterate through the cache, calling proc(typeface, ctx) with each 46 * typeface. If proc returns true, then we return that typeface (this 47 * ref()s the typeface). If it never returns true, we return nullptr. 48 */ 49 SkTypeface* findByProcAndRef(FindProc proc, void* ctx) const; 50 51 /** 52 * This will unref all of the typefaces in the cache for which the cache 53 * is the only owner. Normally this is handled automatically as needed. 54 * This function is exposed for clients that explicitly want to purge the 55 * cache (e.g. to look for leaks). 56 */ 57 void purgeAll(); 58 59 /** 60 * Helper: returns a unique fontID to pass to the constructor of 61 * your subclass of SkTypeface 62 */ 63 static SkFontID NewFontID(); 64 65 // These are static wrappers around a global instance of a cache. 66 67 static void Add(SkTypeface*, const SkFontStyle& requested); 68 static SkTypeface* FindByProcAndRef(FindProc proc, void* ctx); 69 static void PurgeAll(); 70 71 /** 72 * Debugging only: dumps the status of the typefaces in the cache 73 */ 74 static void Dump(); 75 76 private: 77 static SkTypefaceCache& Get(); 78 79 void purge(int count); 80 81 struct Rec { 82 SkTypeface* fFace; 83 SkFontStyle fRequestedStyle; 84 }; 85 SkTDArray<Rec> fArray; 86 }; 87 88 #endif 89