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 <bluetooth/uuid.h> 20 21 #include <atomic> 22 #include <functional> 23 #include <map> 24 #include <mutex> 25 26 #include "service/bluetooth_instance.h" 27 #include "service/common/bluetooth/advertise_data.h" 28 #include "service/common/bluetooth/advertise_settings.h" 29 #include "service/common/bluetooth/low_energy_constants.h" 30 #include "service/common/bluetooth/scan_filter.h" 31 #include "service/common/bluetooth/scan_result.h" 32 #include "service/common/bluetooth/scan_settings.h" 33 #include "service/hal/bluetooth_gatt_interface.h" 34 #include "types/raw_address.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 Delegate(const Delegate&) = delete; 52 Delegate& operator=(const Delegate&) = delete; 53 54 virtual ~Delegate() = default; 55 56 // Called asynchronously to notify the delegate of nearby BLE advertisers 57 // found during a device scan. 58 virtual void OnScanResult(LowEnergyScanner* client, 59 const ScanResult& scan_result) = 0; 60 }; 61 62 LowEnergyScanner(const LowEnergyScanner&) = delete; 63 LowEnergyScanner& operator=(const LowEnergyScanner&) = delete; 64 65 // The destructor automatically unregisters this client instance from the 66 // stack. 67 ~LowEnergyScanner() override; 68 69 // Assigns a delegate to this instance. |delegate| must out-live this 70 // LowEnergyClient instance. 71 void SetDelegate(Delegate* delegate); 72 73 // Initiates a BLE device scan for this client using the given |settings| and 74 // |filters|. See the documentation for ScanSettings and ScanFilter for how 75 // these parameters can be configured. Return true on success, false 76 // otherwise. Please see logs for details in case of error. 77 bool StartScan(const ScanSettings& settings, 78 const std::vector<ScanFilter>& filters); 79 80 // Stops an ongoing BLE device scan for this client. 81 bool StopScan(); 82 83 // Returns the current scan settings. scan_settings()84 const ScanSettings& scan_settings() const { return scan_settings_; } 85 86 // BluetoothInstace overrides: 87 const Uuid& GetAppIdentifier() const override; 88 int GetInstanceId() const override; 89 90 void ScanResultCallback(hal::BluetoothGattInterface* gatt_iface, 91 const RawAddress& bda, int rssi, 92 std::vector<uint8_t> adv_data) override; 93 94 private: 95 friend class LowEnergyScannerFactory; 96 97 // Constructor shouldn't be called directly as instances are meant to be 98 // obtained from the factory. 99 LowEnergyScanner(Adapter& adapter, const Uuid& uuid, int scanner_id); 100 101 // Calls and clears the pending callbacks. 102 void InvokeAndClearStartCallback(BLEStatus status); 103 void InvokeAndClearStopCallback(BLEStatus status); 104 105 // Raw pointer to the Bluetooth Adapter. 106 Adapter& adapter_; 107 108 // See getters above for documentation. 109 Uuid app_identifier_; 110 int scanner_id_; 111 112 // Protects device scan related members below. 113 std::mutex scan_fields_lock_; 114 115 // Current scan settings. 116 ScanSettings scan_settings_; 117 118 // If true, then this client have a BLE device scan in progress. 119 std::atomic_bool scan_started_; 120 121 // Raw handle to the Delegate, which must outlive this LowEnergyScanner 122 // instance. 123 std::mutex delegate_mutex_; 124 Delegate* delegate_; 125 }; 126 127 // LowEnergyScannerFactory is used to register and obtain a per-application 128 // LowEnergyScanner instance. Users should call RegisterInstance to obtain their 129 // own unique LowEnergyScanner instance that has been registered with the 130 // Bluetooth stack. 131 class LowEnergyScannerFactory 132 : private hal::BluetoothGattInterface::ScannerObserver, 133 public BluetoothInstanceFactory { 134 public: 135 // Don't construct/destruct directly except in tests. Instead, obtain a handle 136 // from an Adapter instance. 137 explicit LowEnergyScannerFactory(Adapter& adapter); 138 LowEnergyScannerFactory(const LowEnergyScannerFactory&) = delete; 139 LowEnergyScannerFactory& operator=(const LowEnergyScannerFactory&) = delete; 140 141 ~LowEnergyScannerFactory() override; 142 143 // BluetoothInstanceFactory override: 144 bool RegisterInstance(const Uuid& app_uuid, 145 const RegisterCallback& callback) override; 146 147 private: 148 friend class LowEnergyScanner; 149 150 // BluetoothGattInterface::ScannerObserver overrides: 151 void RegisterScannerCallback(const RegisterCallback& callback, 152 const Uuid& app_uuid, uint8_t scanner_id, 153 uint8_t status); 154 155 // Map of pending calls to register. 156 std::mutex pending_calls_lock_; 157 std::unordered_set<Uuid> pending_calls_; 158 159 // Raw pointer to the Adapter that owns this factory. 160 Adapter& adapter_; 161 }; 162 163 } // namespace bluetooth 164