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authortsepez <tsepez@chromium.org>2016-09-12 09:47:52 -0700
committerCommit bot <commit-bot@chromium.org>2016-09-12 09:47:52 -0700
commit1c62054a42cf0759148501a36c541de5d5769d32 (patch)
treeed2e53f26474dff1149ce83d3f175c3c36b31631 /core/fxcrt/include/cfx_observable.h
parent75f84a56fed36111ece82d0ac96e87289622b093 (diff)
downloadpdfium-1c62054a42cf0759148501a36c541de5d5769d32.tar.xz
Make CFX_Obeservable::Observer into a pointer-ish type;
This may be a better design because it avoids having a level of indirection that the Observer required. Review-Url: https://codereview.chromium.org/2326763002
Diffstat (limited to 'core/fxcrt/include/cfx_observable.h')
-rw-r--r--core/fxcrt/include/cfx_observable.h74
1 files changed, 42 insertions, 32 deletions
diff --git a/core/fxcrt/include/cfx_observable.h b/core/fxcrt/include/cfx_observable.h
index 99a9951284..a5053f3952 100644
--- a/core/fxcrt/include/cfx_observable.h
+++ b/core/fxcrt/include/cfx_observable.h
@@ -13,56 +13,66 @@
template <class T>
class CFX_Observable {
public:
- class Observer {
+ class ObservedPtr {
public:
- Observer() : m_pWatchedPtr(nullptr) {}
- Observer(T** pWatchedPtr) : m_pWatchedPtr(pWatchedPtr) {
- if (m_pWatchedPtr)
- (*m_pWatchedPtr)->AddObserver(this);
+ ObservedPtr() : m_pObservedPtr(nullptr) {}
+ explicit ObservedPtr(T* pObservedPtr) : m_pObservedPtr(pObservedPtr) {
+ if (m_pObservedPtr)
+ m_pObservedPtr->AddObservedPtr(this);
}
- Observer(const Observer& that) = delete;
- ~Observer() {
- if (m_pWatchedPtr)
- (*m_pWatchedPtr)->RemoveObserver(this);
+ ObservedPtr(const ObservedPtr& that) = delete;
+ ~ObservedPtr() {
+ if (m_pObservedPtr)
+ m_pObservedPtr->RemoveObservedPtr(this);
}
- void SetWatchedPtr(T** pWatchedPtr) {
- if (m_pWatchedPtr)
- (*m_pWatchedPtr)->RemoveObserver(this);
- m_pWatchedPtr = pWatchedPtr;
- if (m_pWatchedPtr)
- (*m_pWatchedPtr)->AddObserver(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_pWatchedPtr);
- *m_pWatchedPtr = nullptr;
- m_pWatchedPtr = nullptr;
+ ASSERT(m_pObservedPtr);
+ m_pObservedPtr = nullptr;
}
- Observer& operator=(const Observer& that) = delete;
+ 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_pWatchedPtr;
+ T* m_pObservedPtr;
};
CFX_Observable() {}
CFX_Observable(const CFX_Observable& that) = delete;
- ~CFX_Observable() { NotifyObservers(); }
- void AddObserver(Observer* pObserver) {
- ASSERT(!pdfium::ContainsKey(m_Observers, pObserver));
- m_Observers.insert(pObserver);
+ ~CFX_Observable() { NotifyObservedPtrs(); }
+ void AddObservedPtr(ObservedPtr* pObservedPtr) {
+ ASSERT(!pdfium::ContainsKey(m_ObservedPtrs, pObservedPtr));
+ m_ObservedPtrs.insert(pObservedPtr);
}
- void RemoveObserver(Observer* pObserver) {
- ASSERT(pdfium::ContainsKey(m_Observers, pObserver));
- m_Observers.erase(pObserver);
+ void RemoveObservedPtr(ObservedPtr* pObservedPtr) {
+ ASSERT(pdfium::ContainsKey(m_ObservedPtrs, pObservedPtr));
+ m_ObservedPtrs.erase(pObservedPtr);
}
- void NotifyObservers() {
- for (auto* pObserver : m_Observers)
- pObserver->OnDestroy();
- m_Observers.clear();
+ 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<Observer*> m_Observers;
+ std::set<ObservedPtr*> m_ObservedPtrs;
};
#endif // CORE_FXCRT_INCLUDE_CFX_OBSERVABLE_H_