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sdbus-cpp/include/sdbus-c++/IObject.h
2024-04-24 20:20:29 +02:00

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/**
* (C) 2016 - 2021 KISTLER INSTRUMENTE AG, Winterthur, Switzerland
* (C) 2016 - 2024 Stanislav Angelovic <stanislav.angelovic@protonmail.com>
*
* @file IObject.h
*
* Created on: Nov 8, 2016
* Project: sdbus-c++
* Description: High-level D-Bus IPC C++ library based on sd-bus
*
* This file is part of sdbus-c++.
*
* sdbus-c++ is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 2.1 of the License, or
* (at your option) any later version.
*
* sdbus-c++ is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with sdbus-c++. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef SDBUS_CXX_IOBJECT_H_
#define SDBUS_CXX_IOBJECT_H_
#include <sdbus-c++/VTableItems.h>
#include <sdbus-c++/ConvenienceApiClasses.h>
#include <sdbus-c++/TypeTraits.h>
#include <sdbus-c++/Flags.h>
#include <functional>
#include <string>
#include <memory>
#include <vector>
// Forward declarations
namespace sdbus {
class Signal;
class IConnection;
}
namespace sdbus {
/********************************************//**
* @class IObject
*
* IObject class represents a D-Bus object instance identified by a specific object path.
* D-Bus object provides its interfaces, methods, signals and properties on a bus
* identified by a specific bus name.
*
* All IObject member methods throw @c sdbus::Error in case of D-Bus or sdbus-c++ error.
* The IObject class has been designed as thread-aware. However, the operation of
* creating and sending asynchronous method replies, as well as creating and emitting
* signals, is thread-safe by design.
*
***********************************************/
class IObject
{
public:
virtual ~IObject() = default;
/*!
* @brief Adds a declaration of methods, properties and signals of the object at a given interface
*
* @param[in] interfaceName Name of an interface the the vtable is registered for
* @param[in] items Individual instances of VTable item structures
*
* This method is used to declare attributes for the object under the given interface.
* Parameter `items' represents a vtable definition that may contain method declarations
* (using MethodVTableItem struct), property declarations (using PropertyVTableItem
* struct), signal declarations (using SignalVTableItem struct), or global interface
* flags (using InterfaceFlagsVTableItem struct).
*
* An interface can have any number of vtables attached to it.
*
* Consult manual pages for underlying `sd_bus_add_object_vtable` function for more information.
*
* The method can be called at any time during object's lifetime. For each vtable an internal
* match slot is created and its lifetime is tied to the lifetime of the Object instance.
*
* The function provides strong exception guarantee. The state of the object remains
* unmodified in face of an exception.
*
* @throws sdbus::Error in case of failure
*/
template < typename... VTableItems
, typename = std::enable_if_t<(is_one_of_variants_types<VTableItem, std::decay_t<VTableItems>> && ...)> >
void addVTable(std::string interfaceName, VTableItems&&... items);
/*!
* @brief Adds a declaration of methods, properties and signals of the object at a given interface
*
* @param[in] interfaceName Name of an interface the the vtable is registered for
* @param[in] vtable A list of individual descriptions in the form of VTable item instances
*
* This method is used to declare attributes for the object under the given interface.
* The `vtable' parameter may contain method declarations (using MethodVTableItem struct),
* property declarations (using PropertyVTableItem struct), signal declarations (using
* SignalVTableItem struct), or global interface flags (using InterfaceFlagsVTableItem struct).
*
* An interface can have any number of vtables attached to it.
*
* Consult manual pages for underlying `sd_bus_add_object_vtable` function for more information.
*
* The method can be called at any time during object's lifetime. For each vtable an internal
* match slot is created and its lifetime is tied to the lifetime of the Object instance.
*
* The function provides strong exception guarantee. The state of the object remains
* unmodified in face of an exception.
*
* @throws sdbus::Error in case of failure
*/
virtual void addVTable(std::string interfaceName, std::vector<VTableItem> vtable) = 0;
/*!
* @brief Adds a declaration of methods, properties and signals of the object at a given interface
*
* @param[in] interfaceName Name of an interface the the vtable is registered for
* @param[in] vtable A list of individual descriptions in the form of VTable item instances
*
* This method is used to declare attributes for the object under the given interface.
* The `vtable' parameter may contain method declarations (using MethodVTableItem struct),
* property declarations (using PropertyVTableItem struct), signal declarations (using
* SignalVTableItem struct), or global interface flags (using InterfaceFlagsVTableItem struct).
*
* An interface can have any number of vtables attached to it.
*
* Consult manual pages for underlying `sd_bus_add_object_vtable` function for more information.
*
* The method can be called at any time during object's lifetime. For each vtable an internal
* match slot is created and is returned to the caller. The returned slot should be destroyed
* when the vtable is not needed anymore. This allows for "dynamic" object API where vtables
* can be added or removed by the user at runtime.
*
* The function provides strong exception guarantee. The state of the object remains
* unmodified in face of an exception.
*
* @throws sdbus::Error in case of failure
*/
[[nodiscard]] virtual Slot addVTable(std::string interfaceName, std::vector<VTableItem> vtable, return_slot_t) = 0;
/*!
* @brief A little more convenient overload of addVTable() above
*
* This version allows method chaining for a little safer and more readable VTable registration.
*
* See addVTable() overloads above for detailed documentation.
*/
template < typename... VTableItems
, typename = std::enable_if_t<(is_one_of_variants_types<VTableItem, std::decay_t<VTableItems>> && ...)> >
[[nodiscard]] VTableAdder addVTable(VTableItems&&... items);
/*!
* @brief A little more convenient overload of addVTable() above
*
* This version allows method chaining for a little safer and more readable VTable registration.
*
* See addVTable() overloads above for detailed documentation.
*/
[[nodiscard]] VTableAdder addVTable(std::vector<VTableItem> vtable);
/*!
* @brief Unregisters object's API and removes object from the bus
*
* This method unregisters the object, its interfaces, methods, signals and properties
* from the bus. Unregistration is done automatically also in object's destructor. This
* method makes sense if, in the process of object removal, we need to make sure that
* callbacks are unregistered explicitly before the final destruction of the object instance.
*
* @throws sdbus::Error in case of failure
*/
virtual void unregister() = 0;
/*!
* @brief Creates a signal message
*
* @param[in] interfaceName Name of an interface that the signal belongs under
* @param[in] signalName Name of the signal
* @return A signal message
*
* Serialize signal arguments into the returned message and emit the signal by passing
* the message with serialized arguments to the @c emitSignal function.
* Alternatively, use higher-level API @c emitSignal(const std::string& signalName) defined below.
*
* @throws sdbus::Error in case of failure
*/
[[nodiscard]] virtual Signal createSignal(const std::string& interfaceName, const std::string& signalName) = 0;
/*!
* @brief Emits signal for this object path
*
* @param[in] message Signal message to be sent out
*
* Note: To avoid messing with messages, use higher-level API defined below.
*
* @throws sdbus::Error in case of failure
*/
virtual void emitSignal(const sdbus::Signal& message) = 0;
/*!
* @brief Emits PropertyChanged signal for specified properties under a given interface of this object path
*
* @param[in] interfaceName Name of an interface that properties belong to
* @param[in] propNames Names of properties that will be included in the PropertiesChanged signal
*
* @throws sdbus::Error in case of failure
*/
virtual void emitPropertiesChangedSignal(const std::string& interfaceName, const std::vector<std::string>& propNames) = 0;
/*!
* @brief Emits PropertyChanged signal for all properties on a given interface of this object path
*
* @param[in] interfaceName Name of an interface
*
* @throws sdbus::Error in case of failure
*/
virtual void emitPropertiesChangedSignal(const std::string& interfaceName) = 0;
/*!
* @brief Emits InterfacesAdded signal on this object path
*
* This emits an InterfacesAdded signal on this object path, by iterating all registered
* interfaces on the path. All properties are queried and included in the signal.
* This call is equivalent to emitInterfacesAddedSignal() with an explicit list of
* registered interfaces. However, unlike emitInterfacesAddedSignal(interfaces), this
* call can figure out the list of supported interfaces itself. Furthermore, it properly
* adds the builtin org.freedesktop.DBus.* interfaces.
*
* @throws sdbus::Error in case of failure
*/
virtual void emitInterfacesAddedSignal() = 0;
/*!
* @brief Emits InterfacesAdded signal on this object path
*
* This emits an InterfacesAdded signal on this object path with explicitly provided list
* of registered interfaces. Since v2.0, sdbus-c++ supports dynamically addable/removable
* object interfaces and their vtables, so this method now makes more sense.
*
* @throws sdbus::Error in case of failure
*/
virtual void emitInterfacesAddedSignal(const std::vector<std::string>& interfaces) = 0;
/*!
* @brief Emits InterfacesRemoved signal on this object path
*
* This is like sd_bus_emit_object_added(), but emits an InterfacesRemoved signal on this
* object path. This only includes any registered interfaces but skips the properties.
* This function shall be called (just) before destroying the object.
*
* @throws sdbus::Error in case of failure
*/
virtual void emitInterfacesRemovedSignal() = 0;
/*!
* @brief Emits InterfacesRemoved signal on this object path
*
* This emits an InterfacesRemoved signal on the given path with explicitly provided list
* of registered interfaces. Since v2.0, sdbus-c++ supports dynamically addable/removable
* object interfaces and their vtables, so this method now makes more sense.
*
* @throws sdbus::Error in case of failure
*/
virtual void emitInterfacesRemovedSignal(const std::vector<std::string>& interfaces) = 0;
/*!
* @brief Adds an ObjectManager interface at the path of this D-Bus object
*
* Creates an ObjectManager interface at the specified object path on
* the connection. This is a convenient way to interrogate a connection
* to see what objects it has.
*
* @throws sdbus::Error in case of failure
*/
virtual void addObjectManager() = 0;
/*!
* @brief Removes an ObjectManager interface from the path of this D-Bus object
*
* @throws sdbus::Error in case of failure
*/
virtual void removeObjectManager() = 0;
/*!
* @brief Tests whether ObjectManager interface is added at the path of this D-Bus object
* @return True if ObjectManager interface is there, false otherwise
*/
[[nodiscard]] virtual bool hasObjectManager() const = 0;
/*!
* @brief Provides D-Bus connection used by the object
*
* @return Reference to the D-Bus connection
*/
[[nodiscard]] virtual sdbus::IConnection& getConnection() const = 0;
/*!
* @brief Emits signal on D-Bus
*
* @param[in] signalName Name of the signal
* @return A helper object for convenient emission of signals
*
* This is a high-level, convenience way of emitting D-Bus signals that abstracts
* from the D-Bus message concept. Signal arguments are automatically serialized
* in a message and D-Bus signatures automatically deduced from the provided native arguments.
*
* Example of use:
* @code
* int arg1 = ...;
* double arg2 = ...;
* object_.emitSignal("fooSignal").onInterface("com.kistler.foo").withArguments(arg1, arg2);
* @endcode
*
* @throws sdbus::Error in case of failure
*/
[[nodiscard]] SignalEmitter emitSignal(const std::string& signalName);
/*!
* @brief Returns object path of the underlying DBus object
*/
[[nodiscard]] virtual const std::string& getObjectPath() const = 0;
/*!
* @brief Provides access to the currently processed D-Bus message
*
* This method provides access to the currently processed incoming D-Bus message.
* "Currently processed" means that the registered callback handler(s) for that message
* are being invoked. This method is meant to be called from within a callback handler
* (e.g. from a D-Bus signal handler, or async method reply handler, etc.). In such a case it is
* guaranteed to return a valid D-Bus message instance for which the handler is called.
* If called from other contexts/threads, it may return a valid or invalid message, depending
* on whether a message was processed or not at the time of the call.
*
* @return Currently processed D-Bus message
*/
[[nodiscard]] virtual Message getCurrentlyProcessedMessage() const = 0;
};
// Out-of-line member definitions
inline SignalEmitter IObject::emitSignal(const std::string& signalName)
{
return SignalEmitter(*this, signalName);
}
template <typename... VTableItems, typename>
void IObject::addVTable(std::string interfaceName, VTableItems&&... items)
{
addVTable(std::move(interfaceName), {std::forward<VTableItems>(items)...});
}
template <typename... VTableItems, typename>
VTableAdder IObject::addVTable(VTableItems&&... items)
{
return addVTable(std::vector<VTableItem>{std::forward<VTableItems>(items)...});
}
inline VTableAdder IObject::addVTable(std::vector<VTableItem> vtable)
{
return VTableAdder(*this, std::move(vtable));
}
/*!
* @brief Creates instance representing a D-Bus object
*
* @param[in] connection D-Bus connection to be used by the object
* @param[in] objectPath Path of the D-Bus object
* @return Pointer to the object representation instance
*
* The provided connection will be used by the object to export methods,
* issue signals and provide properties.
*
* Creating a D-Bus object instance is (thread-)safe even upon the connection
* which is already running its I/O event loop.
*
* Code example:
* @code
* auto proxy = sdbus::createObject(connection, "/com/kistler/foo");
* @endcode
*/
[[nodiscard]] std::unique_ptr<sdbus::IObject> createObject(sdbus::IConnection& connection, std::string objectPath);
}
#include <sdbus-c++/VTableItems.inl>
#include <sdbus-c++/ConvenienceApiClasses.inl>
#endif /* SDBUS_CXX_IOBJECT_H_ */