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| 1 // Copyright (c) 2013 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 DBUS_OBJECT_MANAGER_H_ |
| 6 #define DBUS_OBJECT_MANAGER_H_ |
| 7 |
| 8 #include <map> |
| 9 |
| 10 #include "base/memory/ref_counted.h" |
| 11 #include "base/memory/weak_ptr.h" |
| 12 #include "dbus/object_path.h" |
| 13 #include "dbus/property.h" |
| 14 |
| 15 // Newer D-Bus services implement the Object Manager interface to inform other |
| 16 // clients about the objects they export, the properties of those objects, and |
| 17 // notification of changes in the set of available objects: |
| 18 // http://dbus.freedesktop.org/doc/dbus-specification.html |
| 19 // #standard-interfaces-objectmanager |
| 20 // |
| 21 // This interface is very closely tied to the Properties interface, and uses |
| 22 // even more levels of nested dictionaries and variants. In addition to |
| 23 // simplifying implementation, since there tends to be a single object manager |
| 24 // per service, spanning the complete set of objects an interfaces available, |
| 25 // the classes implemented here make dealing with this interface simpler. |
| 26 // |
| 27 // Except where noted, use of this class replaces the need for the code |
| 28 // documented in dbus/property.h |
| 29 // |
| 30 // Client implementation classes should begin by deriving from the |
| 31 // dbus::ObjectManager::Interface class, and defining a Properties structure as |
| 32 // documented in dbus/property.h. |
| 33 // |
| 34 // Example: |
| 35 // class ExampleClient : public dbus::ObjectManager::Interface { |
| 36 // public: |
| 37 // struct Properties : public dbus::PropertySet { |
| 38 // dbus::Property<std::string> name; |
| 39 // dbus::Property<uint16> version; |
| 40 // dbus::Property<dbus::ObjectPath> parent; |
| 41 // dbus::Property<std::vector<std::string> > children; |
| 42 // |
| 43 // Properties(dbus::ObjectProxy* object_proxy, |
| 44 // const PropertyChangedCallback callback) |
| 45 // : dbus::PropertySet(object_proxy, kExampleInterface, callback) { |
| 46 // RegisterProperty("Name", &name); |
| 47 // RegisterProperty("Version", &version); |
| 48 // RegisterProperty("Parent", &parent); |
| 49 // RegisterProperty("Children", &children); |
| 50 // } |
| 51 // virtual ~Properties() {} |
| 52 // }; |
| 53 // |
| 54 // The link between the implementation class and the object manager is set up |
| 55 // in the constructor and removed in the destructor; the class should maintain |
| 56 // a pointer to its object manager for use in other methods and establish |
| 57 // itself as the implementation class for its interface. |
| 58 // |
| 59 // Example: |
| 60 // explicit ExampleClient::ExampleClient(dbus::Bus* bus) |
| 61 // : bus_(bus), |
| 62 // weak_ptr_factory_(this) { |
| 63 // object_manager_ = bus_->GetObjectManager(kServiceName, kManagerPath); |
| 64 // object_manager_->RegisterInterface(kInterface, this); |
| 65 // } |
| 66 // |
| 67 // virtual ExampleClient::~ExampleClient() { |
| 68 // object_manager_->UnregisterInterface(kInterface); |
| 69 // } |
| 70 // |
| 71 // The D-Bus thread manager takes care of issuing the necessary call to |
| 72 // GetManagedObjects() after the implementation classes have been set up. |
| 73 // |
| 74 // The object manager interface class has one abstract method that must be |
| 75 // implemented by the class to create Properties structures on demand. As well |
| 76 // as implementing this, you will want to implement a public GetProperties() |
| 77 // method. |
| 78 // |
| 79 // Example: |
| 80 // dbus::PropertySet* CreateProperties(dbus::ObjectProxy* object_proxy, |
| 81 // const std::string& interface_name) |
| 82 // OVERRIDE { |
| 83 // Properties* properties = new Properties( |
| 84 // object_proxy, interface_name, |
| 85 // base::Bind(&PropertyChanged, |
| 86 // weak_ptr_factory_.GetWeakPtr(), |
| 87 // object_path)); |
| 88 // return static_cast<dbus::PropertySet*>(properties); |
| 89 // } |
| 90 // |
| 91 // Properties* GetProperties(const dbus::ObjectPath& object_path) { |
| 92 // return static_cast<Properties*>( |
| 93 // object_manager_->GetProperties(object_path, kInterface)); |
| 94 // } |
| 95 // |
| 96 // Note that unlike classes that only use dbus/property.h there is no need |
| 97 // to connect signals or obtain the initial values of properties. The object |
| 98 // manager class handles that for you. |
| 99 // |
| 100 // PropertyChanged is a method of your own to notify your observers of a change |
| 101 // in your properties, either as a result of a signal from the Properties |
| 102 // interface or from the Object Manager interface. You may also wish to |
| 103 // implement the optional ObjectAdded and ObjectRemoved methods of the class |
| 104 // to likewise notify observers. |
| 105 // |
| 106 // When your class needs an object proxy for a given object path, it may |
| 107 // obtain it from the object manager. Unlike the equivalent method on the bus |
| 108 // this will return NULL if the object is not known. |
| 109 // |
| 110 // object_proxy = object_manager_->GetObjectProxy(object_path); |
| 111 // if (object_proxy) { |
| 112 // ... |
| 113 // } |
| 114 // |
| 115 // There is no need for code using your implementation class to be aware of the |
| 116 // use of object manager behind the scenes, the rules for updating properties |
| 117 // documented in dbus/property.h still apply. |
| 118 |
| 119 namespace dbus { |
| 120 |
| 121 const char kObjectManagerInterface[] = "org.freedesktop.DBus.ObjectManager"; |
| 122 const char kObjectManagerGetManagedObjects[] = "GetManagedObjects"; |
| 123 const char kObjectManagerInterfacesAdded[] = "InterfacesAdded"; |
| 124 const char kObjectManagerInterfacesRemoved[] = "InterfacesRemoved"; |
| 125 |
| 126 class Bus; |
| 127 class MessageReader; |
| 128 class ObjectProxy; |
| 129 class Response; |
| 130 class Signal; |
| 131 |
| 132 // ObjectManager implements both the D-Bus client components of the D-Bus |
| 133 // Object Manager interface, as internal methods, and a public API for |
| 134 // client classes to utilize. |
| 135 class CHROME_DBUS_EXPORT ObjectManager |
| 136 : public base::RefCountedThreadSafe<ObjectManager> { |
| 137 public: |
| 138 // ObjectManager::Interface must be implemented by any class wishing to have |
| 139 // its remote objects managed by an ObjectManager. |
| 140 class Interface { |
| 141 public: |
| 142 virtual ~Interface() {} |
| 143 |
| 144 // Called by ObjectManager to create a Properties structure for the remote |
| 145 // D-Bus object identified by |object_path| and accessibile through |
| 146 // |object_proxy|. The D-Bus interface name |interface_name| is that passed |
| 147 // to RegisterInterface() by the implementation class. |
| 148 // |
| 149 // The implementation class should create and return an instance of its own |
| 150 // subclass of dbus::PropertySet; ObjectManager will then connect signals |
| 151 // and update the properties from its own internal message reader. |
| 152 virtual PropertySet* CreateProperties( |
| 153 ObjectProxy *object_proxy, |
| 154 const dbus::ObjectPath& object_path, |
| 155 const std::string& interface_name) = 0; |
| 156 |
| 157 // Called by ObjectManager to inform the implementation class that an |
| 158 // object has been added with the path |object_path|. The D-Bus interface |
| 159 // name |interface_name| is that passed to RegisterInterface() by the |
| 160 // implementation class. |
| 161 // |
| 162 // If a new object implements multiple interfaces, this method will be |
| 163 // called on each interface implementation with differing values of |
| 164 // |interface_name| as appropriate. An implementation class will only |
| 165 // receive multiple calls if it has registered for multiple interfaces. |
| 166 virtual void ObjectAdded(const ObjectPath& object_path, |
| 167 const std::string& interface_name) { } |
| 168 |
| 169 // Called by ObjectManager to inform the implementation class than an |
| 170 // object with the path |object_path| has been removed. Ths D-Bus interface |
| 171 // name |interface_name| is that passed to RegisterInterface() by the |
| 172 // implementation class. Multiple interfaces are handled as with |
| 173 // ObjectAdded(). |
| 174 // |
| 175 // This method will be called before the Properties structure and the |
| 176 // ObjectProxy object for the given interface are cleaned up, it is safe |
| 177 // to retrieve them during removal to vary processing. |
| 178 virtual void ObjectRemoved(const ObjectPath& object_path, |
| 179 const std::string& interface_name) { } |
| 180 }; |
| 181 |
| 182 // Client code should use Bus::GetObjectManager() instead of this constructor. |
| 183 ObjectManager(Bus* bus, |
| 184 const std::string& service_name, |
| 185 const ObjectPath& object_path); |
| 186 |
| 187 // Register a client implementation class |interface| for the given D-Bus |
| 188 // interface named in |interface_name|. That object's CreateProperties() |
| 189 // method will be used to create instances of dbus::PropertySet* when |
| 190 // required. |
| 191 void RegisterInterface(const std::string& interface_name, |
| 192 Interface* interface); |
| 193 |
| 194 // Unregister the implementation class for the D-Bus interface named in |
| 195 // |interface_name|, objects and properties of this interface will be |
| 196 // ignored. |
| 197 void UnregisterInterface(const std::string& interface_name); |
| 198 |
| 199 // Returns a list of object paths, in an undefined order, of objects known |
| 200 // to this manager. |
| 201 std::vector<ObjectPath> GetObjects(); |
| 202 |
| 203 // Returns the list of object paths, in an undefined order, of objects |
| 204 // implementing the interface named in |interface_name| known to this manager. |
| 205 std::vector<ObjectPath> GetObjectsWithInterface( |
| 206 const std::string& interface_name); |
| 207 |
| 208 // Returns a ObjectProxy pointer for the given |object_path|. Unlike |
| 209 // the equivalent method on Bus this will return NULL if the object |
| 210 // manager has not been informed of that object's existance. |
| 211 ObjectProxy* GetObjectProxy(const ObjectPath& object_path); |
| 212 |
| 213 // Returns a PropertySet* pointer for the given |object_path| and |
| 214 // |interface_name|, or NULL if the object manager has not been informed of |
| 215 // that object's existance or the interface's properties. The caller should |
| 216 // cast the returned pointer to the appropriate type, e.g.: |
| 217 // static_cast<Properties*>(GetProperties(object_path, my_interface)); |
| 218 PropertySet* GetProperties(const ObjectPath& object_path, |
| 219 const std::string& interface_name); |
| 220 |
| 221 // Instructs the object manager to refresh its list of managed objects; |
| 222 // automatically called by the D-Bus thread manager, there should never be |
| 223 // a need to call this manually. |
| 224 void GetManagedObjects(); |
| 225 |
| 226 protected: |
| 227 virtual ~ObjectManager(); |
| 228 |
| 229 private: |
| 230 friend class base::RefCountedThreadSafe<ObjectManager>; |
| 231 |
| 232 |
| 233 // Called by dbus:: in response to the GetManagedObjects() method call. |
| 234 void OnGetManagedObjects(Response* response); |
| 235 |
| 236 // Called by dbus:: when an InterfacesAdded signal is received and initially |
| 237 // connected. |
| 238 void InterfacesAddedReceived(Signal* signal); |
| 239 void InterfacesAddedConnected(const std::string& interface_name, |
| 240 const std::string& signal_name, |
| 241 bool success); |
| 242 |
| 243 // Called by dbus:: when an InterfacesRemoved signal is received and |
| 244 // initially connected. |
| 245 void InterfacesRemovedReceived(Signal* signal); |
| 246 void InterfacesRemovedConnected(const std::string& interface_name, |
| 247 const std::string& signal_name, |
| 248 bool success); |
| 249 |
| 250 // Updates the map entry for the object with path |object_path| using the |
| 251 // D-Bus message in |reader|, which should consist of an dictionary mapping |
| 252 // interface names to properties dictionaries as recieved by both the |
| 253 // GetManagedObjects() method return and the InterfacesAdded() signal. |
| 254 void UpdateObject(const ObjectPath& object_path, MessageReader* reader); |
| 255 |
| 256 // Updates the properties structure of the object with path |object_path| |
| 257 // for the interface named |interface_name| using the D-Bus message in |
| 258 // |reader| which should consist of the properties dictionary for that |
| 259 // interface. |
| 260 // |
| 261 // Called by UpdateObjects() for each interface in the dictionary; this |
| 262 // method takes care of both creating the entry in the ObjectMap and |
| 263 // ObjectProxy if required, as well as the PropertySet instance for that |
| 264 // interface if necessary. |
| 265 void AddInterface(const ObjectPath& object_path, |
| 266 const std::string& interface_name, |
| 267 MessageReader* reader); |
| 268 |
| 269 // Removes the properties structure of the object with path |object_path| |
| 270 // for the interfaces named |interface_name|. |
| 271 // |
| 272 // If no further interfaces remain, the entry in the ObjectMap is discarded. |
| 273 void RemoveInterface(const ObjectPath& object_path, |
| 274 const std::string& interface_name); |
| 275 |
| 276 Bus* bus_; |
| 277 std::string service_name_; |
| 278 ObjectPath object_path_; |
| 279 ObjectProxy* object_proxy_; |
| 280 |
| 281 // Maps the name of an interface to the implementation class used for |
| 282 // instantiating PropertySet structures for that interface's properties. |
| 283 typedef std::map<std::string, Interface*> InterfaceMap; |
| 284 InterfaceMap interface_map_; |
| 285 |
| 286 // Each managed object consists of a ObjectProxy used to make calls |
| 287 // against that object and a collection of D-Bus interface names and their |
| 288 // associated PropertySet structures. |
| 289 struct Object { |
| 290 Object(); |
| 291 ~Object(); |
| 292 |
| 293 ObjectProxy* object_proxy; |
| 294 |
| 295 // Maps the name of an interface to the specific PropertySet structure |
| 296 // of that interface's properties. |
| 297 typedef std::map<const std::string, PropertySet*> PropertiesMap; |
| 298 PropertiesMap properties_map; |
| 299 }; |
| 300 |
| 301 // Maps the object path of an object to the Object structure. |
| 302 typedef std::map<const ObjectPath, Object*> ObjectMap; |
| 303 ObjectMap object_map_; |
| 304 |
| 305 // Weak pointer factory for generating 'this' pointers that might live longer |
| 306 // than we do. |
| 307 // Note: This should remain the last member so it'll be destroyed and |
| 308 // invalidate its weak pointers before any other members are destroyed. |
| 309 base::WeakPtrFactory<ObjectManager> weak_ptr_factory_; |
| 310 |
| 311 DISALLOW_COPY_AND_ASSIGN(ObjectManager); |
| 312 }; |
| 313 |
| 314 } // namespace dbus |
| 315 |
| 316 #endif // DBUS_OBJECT_MANAGER_H_ |
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