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      1 //
      2 //  Copyright 2015 Google, Inc.
      3 //
      4 //  Licensed under the Apache License, Version 2.0 (the "License");
      5 //  you may not use this file except in compliance with the License.
      6 //  You may obtain a copy of the License at:
      7 //
      8 //  http://www.apache.org/licenses/LICENSE-2.0
      9 //
     10 //  Unless required by applicable law or agreed to in writing, software
     11 //  distributed under the License is distributed on an "AS IS" BASIS,
     12 //  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13 //  See the License for the specific language governing permissions and
     14 //  limitations under the License.
     15 //
     16 
     17 #pragma once
     18 
     19 #include <base/macros.h>
     20 #include <hardware/bluetooth.h>
     21 
     22 namespace bluetooth {
     23 namespace hal {
     24 
     25 // This class represents the HAL Bluetooth adapter interface, wrapping around
     26 // the underlying bt_interface_t structure, its methods, and callbacks. A single
     27 // instance of this class exists per application and it allows multiple classes
     28 // to interface with the global HAL interface by multiplexing callbacks among
     29 // registered clients.
     30 //
     31 // This is declared as an abstract interface so that a fake implementation can
     32 // be injected for testing the upper layer.
     33 //
     34 // TODO: (expose callback types directly but via redirection) methods for
     35 // initialize, clean up, and set for testing.
     36 class BluetoothInterface {
     37  public:
     38   // The standard Bluetooth adapter management callback interface. The HAL
     39   // interface doesn't allow registering "user data" that carries context beyond
     40   // the callback parameters, forcing implementations to deal with global
     41   // variables. The Observer interface is to redirect these events to interested
     42   // parties in an object-oriented manner.
     43   //
     44   // TODO(armansito): We should fix this in the HAL.
     45   class Observer {
     46    public:
     47     virtual ~Observer() = default;
     48 
     49     // All of the events below correspond to callbacks defined in
     50     // "bt_callbacks_t" in the HAL API definitions.
     51 
     52     virtual void AdapterStateChangedCallback(bt_state_t state);
     53     virtual void AdapterPropertiesCallback(bt_status_t status,
     54                                            int num_properties,
     55                                            bt_property_t* properties);
     56     virtual void RemoteDevicePropertiesCallback(bt_status_t status,
     57                                                 RawAddress* remote_bd_addr,
     58                                                 int num_properties,
     59                                                 bt_property_t* properties);
     60     virtual void DiscoveryStateChangedCallback(bt_discovery_state_t state);
     61     virtual void PinRequestCallback(RawAddress* remote_bd_addr,
     62                                     bt_bdname_t* bd_name, uint32_t cod,
     63                                     bool min_16_digit);
     64     virtual void SSPRequestCallback(RawAddress* remote_bd_addr,
     65                                     bt_bdname_t* bd_name, uint32_t cod,
     66                                     bt_ssp_variant_t pairing_variant,
     67                                     uint32_t pass_key);
     68     virtual void BondStateChangedCallback(bt_status_t status,
     69                                           RawAddress* remote_bd_addr,
     70                                           bt_bond_state_t state);
     71     virtual void AclStateChangedCallback(bt_status_t status,
     72                                          const RawAddress& remote_bdaddr,
     73                                          bt_acl_state_t state);
     74 
     75     // TODO(armansito): Complete the list of callbacks.
     76   };
     77 
     78   // Initialize and clean up the BluetoothInterface singleton. Returns false if
     79   // the underlying HAL interface failed to initialize, and true on success.
     80   static bool Initialize();
     81 
     82   // Shuts down and cleans up the interface. CleanUp must be called on the same
     83   // thread that called Initialize.
     84   static void CleanUp();
     85 
     86   // Returns true if the interface was initialized and a global singleton has
     87   // been created.
     88   static bool IsInitialized();
     89 
     90   // Initialize for testing. Use this to inject a test version of
     91   // BlueoothInterface. To be used from unit tests only.
     92   static void InitializeForTesting(BluetoothInterface* test_instance);
     93 
     94   // Returns the BluetoothInterface singleton. If the interface has not been
     95   // initialized, returns nullptr.
     96   static BluetoothInterface* Get();
     97 
     98   // Add or remove an observer that is interested in notifications from us.
     99   virtual void AddObserver(Observer* observer) = 0;
    100   virtual void RemoveObserver(Observer* observer) = 0;
    101 
    102   // The HAL module pointer that represents the standard Bluetooth adapter
    103   // management interface. This is implemented in and provided by the shared
    104   // Bluetooth library, so this isn't owned by us.
    105   //
    106   // Upper layers can make bt_interface_t API calls through this structure.
    107   // However, DO NOT call the "init" function as this is called and managed by
    108   // us. The behavior is undefined if "init" is called directly by upper layers.
    109   virtual const bt_interface_t* GetHALInterface() const = 0;
    110 
    111   // Returns the HAL callbacks that have been initialized previously.
    112   virtual bt_callbacks_t* GetHALCallbacks() const = 0;
    113 
    114  protected:
    115   BluetoothInterface() = default;
    116   virtual ~BluetoothInterface() = default;
    117 
    118  private:
    119   DISALLOW_COPY_AND_ASSIGN(BluetoothInterface);
    120 };
    121 
    122 }  // namespace hal
    123 }  // namespace bluetooth
    124