chromeos/dbus/bluetooth_gatt_characteristic_client.h

   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:
  54     virtual ~Observer() {}
  55
  56     // Called when the GATT characteristic with object path |object_path| is
  57     // added to the system.
  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.
  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|.
  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|.
  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_