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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkTypefaceCache_DEFINED
#define SkTypefaceCache_DEFINED
#include "SkTypeface.h"
#include "SkTDArray.h"
/* TODO
* Provide std way to cache name+requestedStyle aliases to the same typeface.
*
* The current mechanism ends up create a diff typeface for each one, even if
* they map to the same internal obj (e.g. CTFontRef on the mac)
*/
class SkTypefaceCache {
public:
SkTypefaceCache();
~SkTypefaceCache();
/**
* Callback for FindByProc. Returns true if the given typeface is a match
* for the given context. The passed typeface is owned by the cache and is
* not additionally ref()ed. The typeface may be in the disposed state.
*/
typedef bool(*FindProc)(SkTypeface*, const SkFontStyle&, void* context);
/**
* Add a typeface to the cache. This ref()s the typeface, so that the
* cache is also an owner. Later, if we need to purge the cache, typefaces
* whose refcnt is 1 (meaning only the cache is an owner) will be
* unref()ed.
*/
void add(SkTypeface*, const SkFontStyle& requested);
/**
* Iterate through the cache, calling proc(typeface, ctx) with each
* typeface. If proc returns true, then we return that typeface (this
* ref()s the typeface). If it never returns true, we return nullptr.
*/
SkTypeface* findByProcAndRef(FindProc proc, void* ctx) const;
/**
* This will unref all of the typefaces in the cache for which the cache
* is the only owner. Normally this is handled automatically as needed.
* This function is exposed for clients that explicitly want to purge the
* cache (e.g. to look for leaks).
*/
void purgeAll();
/**
* Helper: returns a unique fontID to pass to the constructor of
* your subclass of SkTypeface
*/
static SkFontID NewFontID();
// These are static wrappers around a global instance of a cache.
static void Add(SkTypeface*, const SkFontStyle& requested);
static SkTypeface* FindByProcAndRef(FindProc proc, void* ctx);
static void PurgeAll();
/**
* Debugging only: dumps the status of the typefaces in the cache
*/
static void Dump();
private:
static SkTypefaceCache& Get();
void purge(int count);
struct Rec {
SkTypeface* fFace;
SkFontStyle fRequestedStyle;
};
SkTDArray<Rec> fArray;
};
#endif
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