2 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 #ifndef CachedResourceHandle_h
27 #define CachedResourceHandle_h
29 #include "CachedResource.h"
33 class CachedResourceHandleBase {
35 ~CachedResourceHandleBase() { if (m_resource) m_resource->unregisterHandle(this); }
36 CachedResource* get() const { return m_resource; }
38 bool operator!() const { return !m_resource; }
40 // This conversion operator allows implicit conversion to bool but not to other integer types.
41 typedef CachedResource* CachedResourceHandleBase::*UnspecifiedBoolType;
42 operator UnspecifiedBoolType() const { return m_resource ? &CachedResourceHandleBase::m_resource : 0; }
45 CachedResourceHandleBase() : m_resource(0) {}
46 CachedResourceHandleBase(CachedResource* res) { m_resource = res; if (m_resource) m_resource->registerHandle(this); }
47 CachedResourceHandleBase(const CachedResourceHandleBase& o) : m_resource(o.m_resource) { if (m_resource) m_resource->registerHandle(this); }
49 void setResource(CachedResource*);
52 CachedResourceHandleBase& operator=(const CachedResourceHandleBase&) { return *this; }
54 friend class CachedResource;
56 CachedResource* m_resource;
59 template <class R> class CachedResourceHandle : public CachedResourceHandleBase {
61 CachedResourceHandle() { }
62 CachedResourceHandle(R* res) : CachedResourceHandleBase(res) { }
63 CachedResourceHandle(const CachedResourceHandle<R>& o) : CachedResourceHandleBase(o) { }
65 R* get() const { return reinterpret_cast<R*>(CachedResourceHandleBase::get()); }
66 R* operator->() const { return get(); }
68 CachedResourceHandle& operator=(R* res) { setResource(res); return *this; }
69 CachedResourceHandle& operator=(const CachedResourceHandle& o) { setResource(o.get()); return *this; }
70 bool operator==(const CachedResourceHandleBase& o) const { return get() == o.get(); }
71 bool operator!=(const CachedResourceHandleBase& o) const { return get() != o.get(); }
74 template <class R, class RR> bool operator==(const CachedResourceHandle<R>& h, const RR* res)
76 return h.get() == res;
78 template <class R, class RR> bool operator==(const RR* res, const CachedResourceHandle<R>& h)
80 return h.get() == res;
82 template <class R, class RR> bool operator!=(const CachedResourceHandle<R>& h, const RR* res)
84 return h.get() != res;
86 template <class R, class RR> bool operator!=(const RR* res, const CachedResourceHandle<R>& h)
88 return h.get() != res;