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authordsinclair <dsinclair@chromium.org>2016-09-29 13:59:29 -0700
committerCommit bot <commit-bot@chromium.org>2016-09-29 13:59:29 -0700
commita52ab741019342fbca0468e43a01deb44fa5f1bd (patch)
tree9b1deef3b8deb23d65bf56348b220fe59dcd3169 /core/fxcrt/cfx_observable.h
parent8a4e286e686c3027f382afb07d3ddcec4610fdd9 (diff)
downloadpdfium-a52ab741019342fbca0468e43a01deb44fa5f1bd.tar.xz
Move core/fxcrt/include to core/fxcrt
BUG=pdfium:611 Review-Url: https://codereview.chromium.org/2382723003
Diffstat (limited to 'core/fxcrt/cfx_observable.h')
-rw-r--r--core/fxcrt/cfx_observable.h78
1 files changed, 78 insertions, 0 deletions
diff --git a/core/fxcrt/cfx_observable.h b/core/fxcrt/cfx_observable.h
new file mode 100644
index 0000000000..dc869b1766
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+++ b/core/fxcrt/cfx_observable.h
@@ -0,0 +1,78 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CORE_FXCRT_CFX_OBSERVABLE_H_
+#define CORE_FXCRT_CFX_OBSERVABLE_H_
+
+#include <set>
+
+#include "core/fxcrt/fx_system.h"
+#include "third_party/base/stl_util.h"
+
+template <class T>
+class CFX_Observable {
+ public:
+ class ObservedPtr {
+ public:
+ ObservedPtr() : m_pObservedPtr(nullptr) {}
+ explicit ObservedPtr(T* pObservedPtr) : m_pObservedPtr(pObservedPtr) {
+ if (m_pObservedPtr)
+ m_pObservedPtr->AddObservedPtr(this);
+ }
+ ObservedPtr(const ObservedPtr& that) = delete;
+ ~ObservedPtr() {
+ if (m_pObservedPtr)
+ m_pObservedPtr->RemoveObservedPtr(this);
+ }
+ void Reset(T* pObservedPtr = nullptr) {
+ if (m_pObservedPtr)
+ m_pObservedPtr->RemoveObservedPtr(this);
+ m_pObservedPtr = pObservedPtr;
+ if (m_pObservedPtr)
+ m_pObservedPtr->AddObservedPtr(this);
+ }
+ void OnDestroy() {
+ ASSERT(m_pObservedPtr);
+ m_pObservedPtr = nullptr;
+ }
+ ObservedPtr& operator=(const ObservedPtr& that) = delete;
+ bool operator==(const ObservedPtr& that) const {
+ return m_pObservedPtr == that.m_pObservedPtr;
+ }
+ bool operator!=(const ObservedPtr& that) const { return !(*this == that); }
+ explicit operator bool() const { return !!m_pObservedPtr; }
+ T* Get() const { return m_pObservedPtr; }
+ T& operator*() const { return *m_pObservedPtr; }
+ T* operator->() const { return m_pObservedPtr; }
+
+ private:
+ T* m_pObservedPtr;
+ };
+
+ CFX_Observable() {}
+ CFX_Observable(const CFX_Observable& that) = delete;
+ ~CFX_Observable() { NotifyObservedPtrs(); }
+ void AddObservedPtr(ObservedPtr* pObservedPtr) {
+ ASSERT(!pdfium::ContainsKey(m_ObservedPtrs, pObservedPtr));
+ m_ObservedPtrs.insert(pObservedPtr);
+ }
+ void RemoveObservedPtr(ObservedPtr* pObservedPtr) {
+ ASSERT(pdfium::ContainsKey(m_ObservedPtrs, pObservedPtr));
+ m_ObservedPtrs.erase(pObservedPtr);
+ }
+ void NotifyObservedPtrs() {
+ for (auto* pObservedPtr : m_ObservedPtrs)
+ pObservedPtr->OnDestroy();
+ m_ObservedPtrs.clear();
+ }
+ CFX_Observable& operator=(const CFX_Observable& that) = delete;
+
+ protected:
+ size_t ActiveObservedPtrsForTesting() const { return m_ObservedPtrs.size(); }
+
+ private:
+ std::set<ObservedPtr*> m_ObservedPtrs;
+};
+
+#endif // CORE_FXCRT_CFX_OBSERVABLE_H_