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content / public / renderer / render_frame_observer_tracker.h [blame]
// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Helper class used to find the RenderFrameObservers for a given RenderFrame.
//
// Example usage:
//
// class MyRFO : public RenderFrameObserver,
// public RenderFrameObserverTracker<MyRFO> {
// ...
// };
//
// MyRFO::MyRFO(RenderFrame* render_frame)
// : RenderFrameObserver(render_frame),
// RenderFrameObserverTracker<MyRFO>(render_frame) {
// ...
// }
//
// void SomeFunction(RenderFrame* rf) {
// MyRFO* my_rfo = new MyRFO(rf);
// MyRFO* my_rfo_tracked = MyRFO::Get(rf);
// // my_rfo == my_rfo_tracked
// }
#ifndef CONTENT_PUBLIC_RENDERER_RENDER_FRAME_OBSERVER_TRACKER_H_
#define CONTENT_PUBLIC_RENDERER_RENDER_FRAME_OBSERVER_TRACKER_H_
#include <map>
#include "base/lazy_instance.h"
#include "base/memory/raw_ptr.h"
namespace content {
class RenderFrame;
template <class T>
class RenderFrameObserverTracker {
public:
static T* Get(const RenderFrame* render_frame) {
return static_cast<T*>(render_frame_map_.Get()[render_frame]);
}
explicit RenderFrameObserverTracker(const RenderFrame* render_frame)
: render_frame_(render_frame) {
render_frame_map_.Get()[render_frame] = this;
}
RenderFrameObserverTracker(const RenderFrameObserverTracker<T>&) = delete;
RenderFrameObserverTracker<T>& operator=(
const RenderFrameObserverTracker<T>&) = delete;
~RenderFrameObserverTracker() {
render_frame_map_.Get().erase(render_frame_);
}
private:
raw_ptr<const RenderFrame, DanglingUntriaged> render_frame_;
static typename base::LazyInstance<
std::map<const RenderFrame*, RenderFrameObserverTracker<T>*>>::
DestructorAtExit render_frame_map_;
};
template <class T>
typename base::LazyInstance<
std::map<const RenderFrame*, RenderFrameObserverTracker<T>*>>::
DestructorAtExit RenderFrameObserverTracker<T>::render_frame_map_ =
LAZY_INSTANCE_INITIALIZER;
} // namespace content
#endif // CONTENT_PUBLIC_RENDERER_RENDER_FRAME_OBSERVER_TRACKER_H_