3 * Copyright 2011 Google Inc.
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
11 #ifndef SkTypefaceCache_DEFINED
12 #define SkTypefaceCache_DEFINED
14 #include "SkTypeface.h"
15 #include "SkTDArray.h"
18 * Provide std way to cache name+requestedStyle aliases to the same typeface.
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)
24 class SkTypefaceCache {
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.
34 typedef bool(*FindProc)(SkTypeface*, const SkFontStyle&, void* context);
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
42 void add(SkTypeface*, const SkFontStyle& requested);
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.
50 SkTypeface* findByID(SkFontID findID) const;
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.
57 SkTypeface* findByProcAndRef(FindProc proc, void* ctx) const;
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).
68 * Helper: returns a unique fontID to pass to the constructor of
69 * your subclass of SkTypeface
71 static SkFontID NewFontID();
73 // These are static wrappers around a global instance of a cache.
75 static void Add(SkTypeface*, const SkFontStyle& requested);
76 static SkTypeface* FindByID(SkFontID fontID);
77 static SkTypeface* FindByProcAndRef(FindProc proc, void* ctx);
78 static void PurgeAll();
81 * Debugging only: dumps the status of the typefaces in the cache
86 static SkTypefaceCache& Get();
88 void purge(int count);
92 SkFontStyle fRequestedStyle;
94 SkTDArray<Rec> fArray;