chromeos/dbus/bluetooth_media_transport_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_MEDIA_TRANSPORT_CLIENT_H_
   6 #define CHROMEOS_DBUS_BLUETOOTH_MEDIA_TRANSPORT_CLIENT_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback.h"
  12 #include "chromeos/chromeos_export.h"
  13 #include "chromeos/dbus/dbus_client.h"
  14 #include "dbus/file_descriptor.h"
  15 #include "dbus/object_path.h"
  16 #include "dbus/property.h"
  17
  18 namespace chromeos {
  19
  20 class CHROMEOS_EXPORT BluetoothMediaTransportClient : public DBusClient {
  21  public:
  22   struct Properties : public dbus::PropertySet {
  23     // The path to the device object which the transport is connected to.
  24     // Read-only.
  25     dbus::Property<dbus::ObjectPath> device;
  26
  27     // UUID of the profile which the transport is for. Read-only.
  28     dbus::Property<std::string> uuid;
  29
  30     // Assigned codec value supported by the media transport. Read-only.
  31     dbus::Property<uint8_t> codec;
  32
  33     // The configuration used by the media transport. Read-only.
  34     dbus::Property<std::vector<uint8_t>> configuration;
  35
  36     // The state of the transport. Read-only.
  37     // The values can be one of the following:
  38     // "idle": not streaming
  39     // "pending": streaming but not acquired
  40     // "active": streaming and acquired
  41     dbus::Property<std::string> state;
  42
  43     // The unit of transport delay is in 1/10 of millisecond. This property is
  44     // only writeable when the transport was aquired by the sender. Optional.
  45     dbus::Property<uint16_t> delay;
  46
  47     // The volume level of the transport. This property is only writable when
  48     // the transport was aquired by the sender. Optional.
  49     dbus::Property<uint16_t> volume;
  50
  51     Properties(dbus::ObjectProxy* object_proxy,
  52                const std::string& interface_name,
  53                const PropertyChangedCallback& callback);
  54     ~Properties() override;
  55   };
  56
  57   class Observer {
  58    public:
  59     virtual ~Observer() {}
  60
  61     // Called when the Media Transport with object path |object_path| is added
  62     // to the system.
  63     virtual void MediaTransportAdded(const dbus::ObjectPath& object_path) {}
  64
  65     // Called when the Media Transport with object path |object_path| is removed
  66     // from the system.
  67     virtual void MediaTransportRemoved(const dbus::ObjectPath& object_path) {}
  68
  69     // Called when the Media Transport with object path |object_path| has
  70     // a change in the value of the property with name |property_name|.
  71     virtual void MediaTransportPropertyChanged(
  72         const dbus::ObjectPath& object_path,
  73         const std::string& property_name) {}
  74   };
  75
  76   // TODO(mcchou): Move all static constants to service_constants.h.
  77   // Constants used for the names of Media Transport's properties.
  78   static const char kDeviceProperty[];
  79   static const char kUUIDProperty[];
  80   static const char kCodecProperty[];
  81   static const char kConfigurationProperty[];
  82   static const char kStateProperty[];
  83   static const char kDelayProperty[];
  84   static const char kVolumeProperty[];
  85
  86   // All possible states of a valid media transport object.
  87   static const char kStateIdle[];
  88   static const char kStatePending[];
  89   static const char kStateActive[];
  90
  91   ~BluetoothMediaTransportClient() override;
  92
  93   // The ErrorCallback is used by media transport API methods to indicate
  94   // failure. It receives two arguments: the name of the error in |error_name|
  95   // and an optional message in |error_message|.
  96   typedef base::Callback<void(const std::string& error_name,
  97                               const std::string& error_message)> ErrorCallback;
  98
  99   // The AcquireCallback is used by |Acquire| method of media tansport API tp
 100   // indicate the success of the method.
 101   typedef base::Callback<void(dbus::FileDescriptor* fd,
 102                               const uint16_t read_mtu,
 103                               const uint16_t write_mtu)> AcquireCallback;
 104
 105   // Adds and removes observers for events on all remote Media Transports. Check
 106   // the |object_path| parameter of observer methods to determine which Media
 107   // Transport is issuing the event.
 108   virtual void AddObserver(Observer* observer) = 0;
 109   virtual void RemoveObserver(Observer* observer) = 0;
 110
 111   virtual Properties* GetProperties(const dbus::ObjectPath& object_path) = 0;
 112
 113   // Acquires transport file descriptor and the MTU for read and write.
 114   virtual void Acquire(const dbus::ObjectPath& object_path,
 115                        const AcquireCallback& callback,
 116                        const ErrorCallback& error_callback) = 0;
 117
 118   // Acquires transport file descriptor only if the transport is in "pending"
 119   // state at the time the message is received by BlueZ. Otherwise no request
 120   // will be sent to the remote device and the function will just fail with
 121   // org.bluez.Error.NotAvailable.
 122   virtual void TryAcquire(const dbus::ObjectPath& object_path,
 123                           const AcquireCallback& callback,
 124                           const ErrorCallback& error_callback) = 0;
 125
 126   // Releases the file descriptor of the transport.
 127   virtual void Release(const dbus::ObjectPath& object_path,
 128                        const base::Closure& callback,
 129                        const ErrorCallback& error_callback) = 0;
 130
 131   static BluetoothMediaTransportClient* Create();
 132
 133  protected:
 134   BluetoothMediaTransportClient();
 135
 136  private:
 137   DISALLOW_COPY_AND_ASSIGN(BluetoothMediaTransportClient);
 138 };
 139
 140 }  // namespace chromeos
 141
 142 #endif  // CHROMEOS_DBUS_BLUETOOTH_MEDIA_TRANSPORT_CLIENT_H_