Index: core/fxcrt/include/cfx_observable.h |
diff --git a/core/fxcrt/include/cfx_observable.h b/core/fxcrt/include/cfx_observable.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..1f447bcaf19de44800cb855da5f6a22933e01249 |
--- /dev/null |
+++ b/core/fxcrt/include/cfx_observable.h |
@@ -0,0 +1,63 @@ |
+// 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_INCLUDE_CFX_OBSERVABLE_H_ |
+#define CORE_FXCRT_INCLUDE_CFX_OBSERVABLE_H_ |
+ |
+#include <set> |
+ |
+#include "core/fxcrt/include/fx_system.h" |
+#include "third_party/base/stl_util.h" |
+ |
+template <class T> |
+class CFX_Observable { |
+ public: |
+ class Observer { |
Tom Sepez
2016/09/07 17:10:16
An Observable<>::Observer that observes observable
|
+ public: |
+ Observer() : m_pWatchedPtr(nullptr) {} |
+ Observer(T** pWatchedPtr) : m_pWatchedPtr(pWatchedPtr) {} |
+ Observer(const Observer& that) = delete; |
+ ~Observer() { |
+ if (m_pWatchedPtr) |
+ (*m_pWatchedPtr)->RemoveObserver(this); |
+ } |
+ void SetWatchedPtr(T** pWatchedPtr) { |
+ if (m_pWatchedPtr) |
+ (*m_pWatchedPtr)->RemoveObserver(this); |
+ m_pWatchedPtr = pWatchedPtr; |
+ if (m_pWatchedPtr) |
+ (*m_pWatchedPtr)->AddObserver(this); |
+ } |
+ void OnDestroy() { |
+ ASSERT(m_pWatchedPtr); |
+ *m_pWatchedPtr = nullptr; |
+ m_pWatchedPtr = nullptr; |
+ } |
+ Observer& operator=(const Observer& that) = delete; |
+ |
+ private: |
+ T** m_pWatchedPtr; |
+ }; |
+ |
+ CFX_Observable() {} |
+ CFX_Observable(const CFX_Observable& that) = delete; |
+ ~CFX_Observable() { |
+ for (auto* pObserver : m_Observers) |
+ pObserver->OnDestroy(); |
+ } |
+ void AddObserver(Observer* pObserver) { |
+ ASSERT(!pdfium::ContainsKey(m_Observers, pObserver)); |
+ m_Observers.insert(pObserver); |
+ } |
+ void RemoveObserver(Observer* pObserver) { |
+ ASSERT(pdfium::ContainsKey(m_Observers, pObserver)); |
+ m_Observers.erase(pObserver); |
+ } |
+ CFX_Observable& operator=(const CFX_Observable& that) = delete; |
+ |
+ private: |
+ std::set<Observer*> m_Observers; |
+}; |
+ |
+#endif // CORE_FXCRT_INCLUDE_CFX_OBSERVABLE_H_ |