chromeos/dbus/bluetooth_gatt_descriptor_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_DESCRIPTOR_CLIENT_H_
   6 #define CHROMEOS_DBUS_BLUETOOTH_GATT_DESCRIPTOR_CLIENT_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/callback.h"
  13 #include "chromeos/chromeos_export.h"
  14 #include "chromeos/dbus/dbus_client.h"
  15 #include "dbus/object_path.h"
  16 #include "dbus/property.h"
  17
  18 namespace chromeos {
  19
  20 // BluetoothGattDescriptorClient is used to communicate with remote GATT
  21 // characteristic descriptor objects exposed by the Bluetooth daemon.
  22 class CHROMEOS_EXPORT BluetoothGattDescriptorClient : public DBusClient {
  23  public:
  24   // Structure of properties associated with GATT descriptors.
  25   struct Properties : public dbus::PropertySet {
  26     // The 128-bit characteristic descriptor UUID. [read-only]
  27     dbus::Property<std::string> uuid;
  28
  29     // Object path of the GATT characteristic the descriptor belongs to.
  30     // [read-only]
  31     dbus::Property<dbus::ObjectPath> characteristic;
  32
  33     // The cached value of the descriptor. This property gets updated only after
  34     // a successful read request. [read-only]
  35     dbus::Property<std::vector<uint8_t>> value;
  36
  37     Properties(dbus::ObjectProxy* object_proxy,
  38                const std::string& interface_name,
  39                const PropertyChangedCallback& callback);
  40     ~Properties() override;
  41   };
  42
  43   // Interface for observing changes from a remote GATT characteristic
  44   // descriptor.
  45   class Observer {
  46    public:
  47     virtual ~Observer() {}
  48
  49     // Called when the GATT descriptor with object path |object_path| is added
  50     // to the system.
  51     virtual void GattDescriptorAdded(const dbus::ObjectPath& object_path) {}
  52
  53     // Called when the GATT descriptor with object path |object_path| is removed
  54     // from the system.
  55     virtual void GattDescriptorRemoved(const dbus::ObjectPath& object_path) {}
  56
  57     // Called when the GATT descriptor with object path |object_path| has a
  58     // change in the value of the property named |property_name|.
  59     virtual void GattDescriptorPropertyChanged(
  60         const dbus::ObjectPath& object_path,
  61         const std::string& property_name) {}
  62   };
  63
  64   // Callbacks used to report the result of asynchronous methods.
  65   typedef base::Callback<void(const std::string& error_name,
  66                               const std::string& error_message)> ErrorCallback;
  67   typedef base::Callback<void(const std::vector<uint8>& value)> ValueCallback;
  68
  69   ~BluetoothGattDescriptorClient() override;
  70
  71   // Adds and removes observers for events on all remote GATT descriptors. Check
  72   // the |object_path| parameter of observer methods to determine which GATT
  73   // descriptor is issuing the event.
  74   virtual void AddObserver(Observer* observer) = 0;
  75   virtual void RemoveObserver(Observer* observer) = 0;
  76
  77   // Returns the list of GATT descriptor object paths known to the system.
  78   virtual std::vector<dbus::ObjectPath> GetDescriptors() = 0;
  79
  80   // Obtain the properties for the GATT descriptor with object path
  81   // |object_path|. Values should be copied if needed.
  82   virtual Properties* GetProperties(const dbus::ObjectPath& object_path) = 0;
  83
  84   // Issues a request to read the value of GATT descriptor with object path
  85   // |object_path| and returns the value in |callback| on success. On error,
  86   // invokes |error_callback|.
  87   virtual void ReadValue(const dbus::ObjectPath& object_path,
  88                          const ValueCallback& callback,
  89                          const ErrorCallback& error_callback) = 0;
  90
  91   // Issues a request to write the value of GATT descriptor with object path
  92   // |object_path| with value |value|. Invokes |callback| on success and
  93   // |error_callback| on failure.
  94   virtual void WriteValue(const dbus::ObjectPath& object_path,
  95                           const std::vector<uint8>& value,
  96                           const base::Closure& callback,
  97                           const ErrorCallback& error_callback) = 0;
  98
  99   // Creates the instance.
 100   static BluetoothGattDescriptorClient* Create();
 101
 102   // Constants used to indicate exceptional error conditions.
 103   static const char kNoResponseError[];
 104   static const char kUnknownDescriptorError[];
 105
 106  protected:
 107   BluetoothGattDescriptorClient();
 108
 109  private:
 110   DISALLOW_COPY_AND_ASSIGN(BluetoothGattDescriptorClient);
 111 };
 112
 113 }  // namespace chromeos
 114
 115 #endif  // CHROMEOS_DBUS_BLUETOOTH_GATT_DESCRIPTOR_CLIENT_H_