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// 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.
#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 {
// 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);
BluetoothDiscoverySession(); // Called by mock.
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_;
} // namespace device