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// Copyright 2015 The Chromium 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 IOS_CHROME_BROWSER_TAB_PARENTING_GLOBAL_OBSERVER_H_
#define IOS_CHROME_BROWSER_TAB_PARENTING_GLOBAL_OBSERVER_H_
#include <memory>
#include "base/callback_list.h"
#include "base/macros.h"
namespace base {
template <typename T>
struct DefaultSingletonTraits;
} // namespace base
namespace web {
class WebState;
}
// Allows clients to observe every tab (i.e., WebState) that is parented.
// NOTE: Should be used only to correspond to //chrome flows that listen for
// the TAB_PARENTED notification from all sources.
class TabParentingGlobalObserver {
public:
typedef base::Callback<void(web::WebState*)> OnTabParentedCallback;
// Returns the instance of TabParentingGlobalObserver.
static TabParentingGlobalObserver* GetInstance();
// Registers |cb| to be invoked when a tab is parented.
std::unique_ptr<base::CallbackList<void(web::WebState*)>::Subscription>
RegisterCallback(const OnTabParentedCallback& cb);
// Called to notify all registered callbacks that |web_state| was parented.
void OnTabParented(web::WebState* web_state);
private:
friend struct base::DefaultSingletonTraits<TabParentingGlobalObserver>;
TabParentingGlobalObserver();
~TabParentingGlobalObserver();
base::CallbackList<void(web::WebState*)> on_tab_parented_callback_list_;
DISALLOW_COPY_AND_ASSIGN(TabParentingGlobalObserver);
};
#endif // IOS_CHROME_BROWSER_TAB_PARENTING_GLOBAL_OBSERVER_H_