// Copyright 2014 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 DEVICE_BLUETOOTH_BLUETOOTH_DISCOVERY_SESSION_H_ #define DEVICE_BLUETOOTH_BLUETOOTH_DISCOVERY_SESSION_H_ #include "base/callback.h" #include "base/memory/ref_counted.h" #include "base/memory/weak_ptr.h" namespace device { class BluetoothAdapter; // BluetoothDiscoverySession represents a current active or inactive device // discovery session. Instances of this class are obtained by calling // BluetoothAdapter::StartDiscoverySession. The Bluetooth adapter will be // constantly searching for nearby devices, as long as at least one instance // of an active BluetoothDiscoverySession exists. A BluetoothDiscoverySession is // considered active, as long as the adapter is discovering AND the owner of the // instance has not called BluetoothDiscoverySession::Stop. A // BluetoothDiscoverySession might unexpectedly become inactive, if the adapter // unexpectedly stops discovery. Users can implement the // AdapterDiscoveringChanged method of the BluetoothAdapter::Observer interface // to be notified of such a change and promptly request a new // BluetoothDiscoverySession if their existing sessions have become inactive. class BluetoothDiscoverySession { public: // The ErrorCallback is used by methods to asynchronously report errors. typedef base::Closure ErrorCallback; // Destructor automatically terminates the discovery session. If this // results in a call to the underlying system to stop device discovery // (i.e. this instance represents the last active discovery session), // the call may not always succeed. To be notified of such failures, // users are highly encouraged to call BluetoothDiscoverySession::Stop, // instead of relying on the destructor. virtual ~BluetoothDiscoverySession(); // Returns true if the session is active, false otherwise. If false, the // adapter might still be discovering as there might still be other active // sessions; this just means that this instance no longer has a say in // whether or not discovery should continue. In this case, the application // should request a new BluetoothDiscoverySession to make sure that device // discovery continues. virtual bool IsActive() const; // Requests this discovery session instance to stop. If this instance is // active, the session will stop. On success, |callback| is called and // on error |error_callback| is called. After a successful invocation, the // adapter may or may not stop device discovery, depending on whether or not // other active discovery sessions are present. Users are highly encouraged // to call this method to end a discovery session, instead of relying on the // destructor, so that they can be notified of the result via the callback // arguments. virtual void Stop(const base::Closure& callback, const ErrorCallback& error_callback); protected: BluetoothDiscoverySession(); // Called by mock. private: friend class BluetoothAdapter; explicit BluetoothDiscoverySession(scoped_refptr<BluetoothAdapter> adapter); // Internal callback invoked when a call to Stop has succeeded. void OnStop(const base::Closure& callback); // Marks this instance as inactive. Called by BluetoothAdapter to mark a // session as inactive in the case of an unexpected change to the adapter // discovery state. void MarkAsInactive(); // Whether or not this instance represents an active discovery session. bool active_; // The adapter that created this instance. scoped_refptr<BluetoothAdapter> adapter_; // Note: This should remain the last member so it'll be destroyed and // invalidate its weak pointers before any other members are destroyed. base::WeakPtrFactory<BluetoothDiscoverySession> weak_ptr_factory_; DISALLOW_COPY_AND_ASSIGN(BluetoothDiscoverySession); }; } // namespace device #endif // DEVICE_BLUETOOTH_BLUETOOTH_DISCOVERY_SESSION_H_