1 // 2 // Copyright 2016 The Android Open Source Project 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 <atomic> 20 #include <functional> 21 #include <map> 22 #include <mutex> 23 24 #include <base/macros.h> 25 #include <bluetooth/uuid.h> 26 27 #include "service/bluetooth_instance.h" 28 #include "service/common/bluetooth/advertise_data.h" 29 #include "service/common/bluetooth/advertise_settings.h" 30 #include "service/common/bluetooth/low_energy_constants.h" 31 #include "service/common/bluetooth/scan_filter.h" 32 #include "service/common/bluetooth/scan_result.h" 33 #include "service/common/bluetooth/scan_settings.h" 34 #include "service/hal/bluetooth_gatt_interface.h" 35 36 namespace bluetooth { 37 38 class Adapter; 39 40 // A LowEnergyScanner represents an application's handle to perform various 41 // Bluetooth Low Energy GAP operations. Instances cannot be created directly and 42 // should be obtained through the factory. 43 class LowEnergyScanner : private hal::BluetoothGattInterface::ScannerObserver, 44 public BluetoothInstance { 45 public: 46 // The Delegate interface is used to notify asynchronous events related to LE 47 // scan. 48 class Delegate { 49 public: 50 Delegate() = default; 51 virtual ~Delegate() = default; 52 53 // Called asynchronously to notify the delegate of nearby BLE advertisers 54 // found during a device scan. 55 virtual void OnScanResult(LowEnergyScanner* client, 56 const ScanResult& scan_result) = 0; 57 58 private: 59 DISALLOW_COPY_AND_ASSIGN(Delegate); 60 }; 61 62 // The destructor automatically unregisters this client instance from the 63 // stack. 64 ~LowEnergyScanner() override; 65 66 // Assigns a delegate to this instance. |delegate| must out-live this 67 // LowEnergyClient instance. 68 void SetDelegate(Delegate* delegate); 69 70 // Initiates a BLE device scan for this client using the given |settings| and 71 // |filters|. See the documentation for ScanSettings and ScanFilter for how 72 // these parameters can be configured. Return true on success, false 73 // otherwise. Please see logs for details in case of error. 74 bool StartScan(const ScanSettings& settings, 75 const std::vector<ScanFilter>& filters); 76 77 // Stops an ongoing BLE device scan for this client. 78 bool StopScan(); 79 80 // Returns the current scan settings. scan_settings()81 const ScanSettings& scan_settings() const { return scan_settings_; } 82 83 // BluetoothInstace overrides: 84 const Uuid& GetAppIdentifier() const override; 85 int GetInstanceId() const override; 86 87 void ScanResultCallback(hal::BluetoothGattInterface* gatt_iface, 88 const RawAddress& bda, int rssi, 89 std::vector<uint8_t> adv_data) override; 90 91 private: 92 friend class LowEnergyScannerFactory; 93 94 // Constructor shouldn't be called directly as instances are meant to be 95 // obtained from the factory. 96 LowEnergyScanner(Adapter& adapter, const Uuid& uuid, int scanner_id); 97 98 // Calls and clears the pending callbacks. 99 void InvokeAndClearStartCallback(BLEStatus status); 100 void InvokeAndClearStopCallback(BLEStatus status); 101 102 // Raw pointer to the Bluetooth Adapter. 103 Adapter& adapter_; 104 105 // See getters above for documentation. 106 Uuid app_identifier_; 107 int scanner_id_; 108 109 // Protects device scan related members below. 110 std::mutex scan_fields_lock_; 111 112 // Current scan settings. 113 ScanSettings scan_settings_; 114 115 // If true, then this client have a BLE device scan in progress. 116 std::atomic_bool scan_started_; 117 118 // Raw handle to the Delegate, which must outlive this LowEnergyScanner 119 // instance. 120 std::mutex delegate_mutex_; 121 Delegate* delegate_; 122 123 DISALLOW_COPY_AND_ASSIGN(LowEnergyScanner); 124 }; 125 126 // LowEnergyScannerFactory is used to register and obtain a per-application 127 // LowEnergyScanner instance. Users should call RegisterInstance to obtain their 128 // own unique LowEnergyScanner instance that has been registered with the 129 // Bluetooth stack. 130 class LowEnergyScannerFactory 131 : private hal::BluetoothGattInterface::ScannerObserver, 132 public BluetoothInstanceFactory { 133 public: 134 // Don't construct/destruct directly except in tests. Instead, obtain a handle 135 // from an Adapter instance. 136 explicit LowEnergyScannerFactory(Adapter& adapter); 137 ~LowEnergyScannerFactory() override; 138 139 // BluetoothInstanceFactory override: 140 bool RegisterInstance(const Uuid& app_uuid, 141 const RegisterCallback& callback) override; 142 143 private: 144 friend class LowEnergyScanner; 145 146 // BluetoothGattInterface::ScannerObserver overrides: 147 void RegisterScannerCallback(const RegisterCallback& callback, 148 const Uuid& app_uuid, uint8_t scanner_id, 149 uint8_t status); 150 151 // Map of pending calls to register. 152 std::mutex pending_calls_lock_; 153 std::unordered_set<Uuid> pending_calls_; 154 155 // Raw pointer to the Adapter that owns this factory. 156 Adapter& adapter_; 157 158 DISALLOW_COPY_AND_ASSIGN(LowEnergyScannerFactory); 159 }; 160 161 } // namespace bluetooth 162