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*, SkTypeface::Style, 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*, SkTypeface::Style requested, bool strong = true); 43 44 /** 45 * Search the cache for a typeface with the specified fontID (uniqueID). 46 * If one is found, return it (its reference count is unmodified). If none 47 * is found, return NULL. The reference count is unmodified as it is 48 * assumed that the stack will contain a ref to the typeface. 49 */ 50 SkTypeface* findByID(SkFontID findID) const; 51 52 /** 53 * Iterate through the cache, calling proc(typeface, ctx) with each 54 * typeface. If proc returns true, then we return that typeface (this 55 * ref()s the typeface). If it never returns true, we return NULL. 56 */ 57 SkTypeface* findByProcAndRef(FindProc proc, void* ctx) const; 58 59 /** 60 * This will unref all of the typefaces in the cache for which the cache 61 * is the only owner. Normally this is handled automatically as needed. 62 * This function is exposed for clients that explicitly want to purge the 63 * cache (e.g. to look for leaks). 64 */ 65 void purgeAll(); 66 67 /** 68 * Helper: returns a unique fontID to pass to the constructor of 69 * your subclass of SkTypeface 70 */ 71 static SkFontID NewFontID(); 72 73 // These are static wrappers around a global instance of a cache. 74 75 static void Add(SkTypeface*, 76 SkTypeface::Style requested, 77 bool strong = true); 78 static SkTypeface* FindByID(SkFontID fontID); 79 static SkTypeface* FindByProcAndRef(FindProc proc, void* ctx); 80 static void PurgeAll(); 81 82 /** 83 * Debugging only: dumps the status of the typefaces in the cache 84 */ 85 static void Dump(); 86 87 private: 88 static SkTypefaceCache& Get(); 89 90 void purge(int count); 91 92 struct Rec { 93 SkTypeface* fFace; 94 bool fStrong; 95 SkTypeface::Style fRequestedStyle; 96 }; 97 SkTDArray<Rec> fArray; 98 }; 99 100 #endif 101
