1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROMEOS_DBUS_BLUETOOTH_GATT_CHARACTERISTIC_CLIENT_H_ 6 #define CHROMEOS_DBUS_BLUETOOTH_GATT_CHARACTERISTIC_CLIENT_H_ 7 8 #include <string> 9 10 #include "base/basictypes.h" 11 #include "base/callback.h" 12 #include "chromeos/chromeos_export.h" 13 #include "chromeos/dbus/dbus_client.h" 14 #include "dbus/object_path.h" 15 #include "dbus/property.h" 16 17 namespace chromeos { 18 19 // BluetoothGattCharacteristicClient is used to communicate with remote GATT 20 // characteristic objects exposed by the Bluetooth daemon. 21 class CHROMEOS_EXPORT BluetoothGattCharacteristicClient : public DBusClient { 22 public: 23 // Structure of properties associated with GATT characteristics. 24 struct Properties : public dbus::PropertySet { 25 // The 128-bit characteristic UUID. [read-only] 26 dbus::Property<std::string> uuid; 27 28 // Object path of the GATT service the characteristic belongs to. 29 // [read-only] 30 dbus::Property<dbus::ObjectPath> service; 31 32 // Whether or not this characteristic is currently sending ValueUpdated 33 // signals. [read-only] 34 dbus::Property<bool> notifying; 35 36 // List of flags representing the GATT "Characteristic Properties bit field" 37 // and properties read from the GATT "Characteristic Extended Properties" 38 // descriptor bit field. [read-only, optional] 39 dbus::Property<std::vector<std::string> > flags; 40 41 // Array of object paths representing the descriptors of this 42 // characteristic. [read-only] 43 dbus::Property<std::vector<dbus::ObjectPath> > descriptors; 44 45 Properties(dbus::ObjectProxy* object_proxy, 46 const std::string& interface_name, 47 const PropertyChangedCallback& callback); 48 virtual ~Properties(); 49 }; 50 51 // Interface for observing changes from a remote GATT characteristic. 52 class Observer { 53 public: ~Observer()54 virtual ~Observer() {} 55 56 // Called when the GATT characteristic with object path |object_path| is 57 // added to the system. GattCharacteristicAdded(const dbus::ObjectPath & object_path)58 virtual void GattCharacteristicAdded(const dbus::ObjectPath& object_path) {} 59 60 // Called when the GATT characteristic with object path |object_path| is 61 // removed from the system. GattCharacteristicRemoved(const dbus::ObjectPath & object_path)62 virtual void GattCharacteristicRemoved( 63 const dbus::ObjectPath& object_path) {} 64 65 // Called when the GATT characteristic with object path |object_path| has a 66 // change in the value of the property named |property_name|. GattCharacteristicPropertyChanged(const dbus::ObjectPath & object_path,const std::string & property_name)67 virtual void GattCharacteristicPropertyChanged( 68 const dbus::ObjectPath& object_path, 69 const std::string& property_name) {} 70 71 // Called when a "ValueUpdated" signal is received from the remote GATT 72 // characteristic with object path |object_path| with characteristic value 73 // |value|. GattCharacteristicValueUpdated(const dbus::ObjectPath & object_path,const std::vector<uint8> & value)74 virtual void GattCharacteristicValueUpdated( 75 const dbus::ObjectPath& object_path, 76 const std::vector<uint8>& value) {} 77 }; 78 79 // Callbacks used to report the result of asynchronous methods. 80 typedef base::Callback<void(const std::string& error_name, 81 const std::string& error_message)> ErrorCallback; 82 typedef base::Callback<void(const std::vector<uint8>& value)> ValueCallback; 83 84 virtual ~BluetoothGattCharacteristicClient(); 85 86 // Adds and removes observers for events on all remote GATT characteristics. 87 // Check the |object_path| parameter of observer methods to determine which 88 // GATT characteristic is issuing the event. 89 virtual void AddObserver(Observer* observer) = 0; 90 virtual void RemoveObserver(Observer* observer) = 0; 91 92 // Returns the list of GATT characteristic object paths known to the system. 93 virtual std::vector<dbus::ObjectPath> GetCharacteristics() = 0; 94 95 // Obtain the properties for the GATT characteristic with object path 96 // |object_path|. Values should be copied if needed. 97 virtual Properties* GetProperties(const dbus::ObjectPath& object_path) = 0; 98 99 // Issues a request to read the value of GATT characteristic with object path 100 // |object_path| and returns the value in |callback| on success. On error, 101 // invokes |error_callback|. 102 virtual void ReadValue(const dbus::ObjectPath& object_path, 103 const ValueCallback& callback, 104 const ErrorCallback& error_callback) = 0; 105 106 // Issues a request to write the value of GATT characteristic with object path 107 // |object_path| with value |value|. Invokes |callback| on success and 108 // |error_callback| on failure. 109 virtual void WriteValue(const dbus::ObjectPath& object_path, 110 const std::vector<uint8>& value, 111 const base::Closure& callback, 112 const ErrorCallback& error_callback) = 0; 113 114 // Starts a notification session from this characteristic with object path 115 // |object_path| if it supports value notifications or indications. Invokes 116 // |callback| on success and |error_callback| on failure. 117 virtual void StartNotify(const dbus::ObjectPath& object_path, 118 const base::Closure& callback, 119 const ErrorCallback& error_callback) = 0; 120 121 // Cancels any previous StartNotify transaction for characteristic with 122 // object path |object_path|. Invokes |callback| on success and 123 // |error_callback| on failure. 124 virtual void StopNotify(const dbus::ObjectPath& object_path, 125 const base::Closure& callback, 126 const ErrorCallback& error_callback) = 0; 127 128 // Creates the instance. 129 static BluetoothGattCharacteristicClient* Create(); 130 131 // Constants used to indicate exceptional error conditions. 132 static const char kNoResponseError[]; 133 static const char kUnknownCharacteristicError[]; 134 135 protected: 136 BluetoothGattCharacteristicClient(); 137 138 private: 139 DISALLOW_COPY_AND_ASSIGN(BluetoothGattCharacteristicClient); 140 }; 141 142 } // namespace chromeos 143 144 #endif // CHROMEOS_DBUS_BLUETOOTH_GATT_CHARACTERISTIC_CLIENT_H_ 145