add examples for the ObjectManager API

CMakeLists.txt

@@ -164,6 +164,17 @@ if(BUILD_CODE_GEN)
     add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/tools")
 endif()
 
+#----------------------------------
+# EXAMPLES
+#----------------------------------
+
+option(BUILD_EXAMPLES "Build example programs (default OFF)" OFF)
+
+if(BUILD_EXAMPLES)
+    message(STATUS "Building with examples")
+    add_subdirectory(examples)
+endif()
+
 #----------------------------------
 # DOCUMENTATION
 #----------------------------------

README.md

@@ -70,6 +70,10 @@ $ sudo cmake --build . --target install
 
   This is a global CMake flag, promoted in sdbus-c++ project to a CMake option. Use this to control whether sdbus-c++ is built as either a shared or static library. Default value: `ON`.
 
+* `BUILD_EXAMPLES` [boolean]
+
+  Build example programs which are located in the _example_ directory. Examples are not installed. Default value: `OFF`
+
 Dependencies
 ------------
 

docs/using-sdbus-c++.md

@@ -1252,7 +1252,7 @@ For example, for our `Concatenator` example above in this tutorial, we may want
 
 Note that signals of afore-mentioned standard D-Bus interfaces are not emitted by the library automatically. It's clients who are supposed to emit them.
 
-Working examples of using standard D-Bus interfaces can be found in [sdbus-c++ integration tests](/tests/integrationtests/DBusStandardInterfacesTests.cpp).
+Working examples of using standard D-Bus interfaces can be found in [sdbus-c++ integration tests](/tests/integrationtests/DBusStandardInterfacesTests.cpp) or the [examples](/examples) directory.
 
 Conclusion
 ----------

examples/CMakeLists.txt

@@ -0,0 +1,6 @@
+
+add_executable(obj-manager-server org.freedesktop.DBus.ObjectManager/obj-manager-server.cpp)
+target_link_libraries(obj-manager-server sdbus-c++)
+
+add_executable(obj-manager-client org.freedesktop.DBus.ObjectManager/obj-manager-client.cpp)
+target_link_libraries(obj-manager-client sdbus-c++)

examples/org.freedesktop.DBus.ObjectManager/examplemanager-planet1-client-glue.h

@@ -0,0 +1,50 @@
+
+/*
+ * This file was automatically generated by sdbus-c++-xml2cpp; DO NOT EDIT!
+ */
+
+#ifndef __sdbuscpp__examplemanager_planet1_client_glue_h__proxy__H__
+#define __sdbuscpp__examplemanager_planet1_client_glue_h__proxy__H__
+
+#include <sdbus-c++/sdbus-c++.h>
+#include <string>
+#include <tuple>
+
+namespace org {
+namespace sdbuscpp {
+namespace ExampleManager {
+
+class Planet1_proxy
+{
+public:
+    static constexpr const char* INTERFACE_NAME = "org.sdbuscpp.ExampleManager.Planet1";
+
+protected:
+    Planet1_proxy(sdbus::IProxy& proxy)
+        : proxy_(proxy)
+    {
+    }
+
+    ~Planet1_proxy() = default;
+
+public:
+    uint64_t GetPopulation()
+    {
+        uint64_t result;
+        proxy_.callMethod("GetPopulation").onInterface(INTERFACE_NAME).storeResultsTo(result);
+        return result;
+    }
+
+public:
+    std::string Name()
+    {
+        return proxy_.getProperty("Name").onInterface(INTERFACE_NAME);
+    }
+
+private:
+    sdbus::IProxy& proxy_;
+};
+
+}}} // namespaces
+
+#endif

examples/org.freedesktop.DBus.ObjectManager/examplemanager-planet1-server-glue.h

@@ -0,0 +1,44 @@
+
+/*
+ * This file was automatically generated by sdbus-c++-xml2cpp; DO NOT EDIT!
+ */
+
+#ifndef __sdbuscpp__examplemanager_planet1_server_glue_h__adaptor__H__
+#define __sdbuscpp__examplemanager_planet1_server_glue_h__adaptor__H__
+
+#include <sdbus-c++/sdbus-c++.h>
+#include <string>
+#include <tuple>
+
+namespace org {
+namespace sdbuscpp {
+namespace ExampleManager {
+
+class Planet1_adaptor
+{
+public:
+    static constexpr const char* INTERFACE_NAME = "org.sdbuscpp.ExampleManager.Planet1";
+
+protected:
+    Planet1_adaptor(sdbus::IObject& object)
+        : object_(object)
+    {
+        object_.registerMethod("GetPopulation").onInterface(INTERFACE_NAME).withOutputParamNames("population").implementedAs([this](){ return this->GetPopulation(); });
+        object_.registerProperty("Name").onInterface(INTERFACE_NAME).withGetter([this](){ return this->Name(); });
+    }
+
+    ~Planet1_adaptor() = default;
+
+private:
+    virtual uint64_t GetPopulation() = 0;
+
+private:
+    virtual std::string Name() = 0;
+
+private:
+    sdbus::IObject& object_;
+};
+
+}}} // namespaces
+
+#endif

examples/org.freedesktop.DBus.ObjectManager/obj-manager-client.cpp

@@ -0,0 +1,110 @@
+/**
+ * Example of a D-Bus client which implements org.freedesktop.DBus.ObjectManager
+ *
+ * The example uses the generated stub API layer to listen to interfaces added to new objects under
+ * "org.sdbuscpp.examplemanager". If added, we access "org.sdbuscpp.ExampleManager.Planet1" to print
+ * info like this:
+ * /org/sdbuscpp/examplemanager/Planet1/Earth added:	org.sdbuscpp.ExampleManager.Planet1
+ * Earth has a population of 7874965825.
+ *
+ */
+
+#include "examplemanager-planet1-client-glue.h"
+#include <sdbus-c++/sdbus-c++.h>
+#include <iostream>
+#include <thread>
+
+class PlanetProxy : public sdbus::ProxyInterfaces< org::sdbuscpp::ExampleManager::Planet1_proxy >
+{
+public:
+    PlanetProxy(sdbus::IConnection& connection, std::string destination, std::string path)
+    : ProxyInterfaces(connection, std::move(destination), std::move(path))
+    {
+        registerProxy();
+    }
+
+    ~PlanetProxy()
+    {
+        unregisterProxy();
+    }
+};
+
+class ManagerProxy : public sdbus::ProxyInterfaces< sdbus::ObjectManager_proxy >
+{
+public:
+    ManagerProxy(sdbus::IConnection& connection, const std::string& destination, std::string path)
+    : ProxyInterfaces(connection, destination, std::move(path))
+    , m_connection(connection)
+    , m_destination(destination)
+    {
+        registerProxy();
+    }
+
+    ~ManagerProxy()
+    {
+        unregisterProxy();
+    }
+
+    void handleExistingObjects()
+    {
+        std::map<sdbus::ObjectPath, std::map<std::string, std::map<std::string, sdbus::Variant>>> objectsInterfacesAndProperties;
+        objectsInterfacesAndProperties = GetManagedObjects();
+        for (const auto& [object, interfacesAndProperties] : objectsInterfacesAndProperties) {
+            onInterfacesAdded(object, interfacesAndProperties);
+        }
+    }
+
+private:
+    void onInterfacesAdded( const sdbus::ObjectPath& objectPath
+            , const std::map<std::string, std::map<std::string, sdbus::Variant>>& interfacesAndProperties) override
+    {
+        std::cout << objectPath << " added:\t";
+        for (const auto& [interface, _] : interfacesAndProperties) {
+            std::cout << interface << " ";
+        }
+        std::cout << std::endl;
+
+        // Parse and print some more info
+        auto planetInterface = interfacesAndProperties.find(org::sdbuscpp::ExampleManager::Planet1_proxy::INTERFACE_NAME);
+        if (planetInterface == interfacesAndProperties.end()) {
+            return;
+        }
+        const auto& properties = planetInterface->second;
+        // get a property which was passed as part of the signal.
+        const auto& name = properties.at("Name").get<std::string>();
+        // or create a proxy instance to the newly added object.
+        PlanetProxy planet(m_connection, m_destination, objectPath);
+        std::cout << name << " has a population of " << planet.GetPopulation() << ".\n" << std::endl;
+    }
+
+    void onInterfacesRemoved( const sdbus::ObjectPath& objectPath
+            , const std::vector<std::string>& interfaces) override
+    {
+        std::cout << objectPath << " removed:\t";
+        for (const auto& interface : interfaces) {
+            std::cout << interface << " ";
+        }
+        std::cout << std::endl;
+    }
+
+    sdbus::IConnection& m_connection;
+    std::string m_destination;
+};
+
+int main()
+{
+    auto connection = sdbus::createSessionBusConnection();
+
+    auto managerProxy = std::make_unique<ManagerProxy>(*connection, "org.sdbuscpp.examplemanager", "/org/sdbuscpp/examplemanager");
+    try {
+        managerProxy->handleExistingObjects();
+    }
+    catch (const sdbus::Error& e) {
+        if (e.getName() == "org.freedesktop.DBus.Error.ServiceUnknown") {
+            std::cout << "Waiting for server to start ..." << std::endl;
+        }
+    }
+
+    connection->enterEventLoop();
+    return 0;
+}

examples/org.freedesktop.DBus.ObjectManager/obj-manager-server.cpp

@@ -0,0 +1,108 @@
+/**
+ * Example of a D-Bus server which implements org.freedesktop.DBus.ObjectManager
+ *
+ * The example uses the generated stub API layer to register an object manager under "org.sdbuscpp.examplemanager"
+ * and add objects underneath which implement "org.sdbuscpp.ExampleManager.Planet1".
+ *
+ * We add and remove objects after a few seconds and print info like this:
+ * Creating PlanetAdaptor in 5 4 3 2 1
+ * Creating PlanetAdaptor in 5 4 3 2 1
+ * Creating PlanetAdaptor in 5 4 3 2 1
+ * Removing PlanetAdaptor in 5 4 3 2 1
+ * Removing PlanetAdaptor in 5 4 3 2 1
+ */
+
+#include "examplemanager-planet1-server-glue.h"
+#include <sdbus-c++/sdbus-c++.h>
+#include <iostream>
+#include <memory>
+#include <thread>
+#include <chrono>
+
+class ManagerAdaptor : public sdbus::AdaptorInterfaces< sdbus::ObjectManager_adaptor >
+{
+public:
+    ManagerAdaptor(sdbus::IConnection& connection, std::string path)
+    : AdaptorInterfaces(connection, std::move(path))
+    {
+        registerAdaptor();
+    }
+
+    ~ManagerAdaptor()
+    {
+        unregisterAdaptor();
+    }
+};
+
+class PlanetAdaptor : public sdbus::AdaptorInterfaces< org::sdbuscpp::ExampleManager::Planet1_adaptor,
+                                                sdbus::ManagedObject_adaptor,
+                                                sdbus::Properties_adaptor >
+{
+public:
+    PlanetAdaptor(sdbus::IConnection& connection, std::string path, std::string name, uint64_t poulation)
+    : AdaptorInterfaces(connection, std::move(path))
+    , m_name(std::move(name))
+    , m_population(poulation)
+    {
+        registerAdaptor();
+        emitInterfacesAddedSignal({org::sdbuscpp::ExampleManager::Planet1_adaptor::INTERFACE_NAME});
+    }
+
+    ~PlanetAdaptor()
+    {
+        emitInterfacesRemovedSignal({org::sdbuscpp::ExampleManager::Planet1_adaptor::INTERFACE_NAME});
+        unregisterAdaptor();
+    }
+
+    uint64_t GetPopulation() override
+    {
+        return m_population;
+    }
+
+    std::string Name() override
+    {
+        return m_name;
+    }
+
+private:
+    std::string m_name;
+    uint64_t m_population;
+};
+
+void printCountDown(const std::string& message, int seconds)
+{
+    std::cout << message << std::flush;
+    for (int i = seconds; i > 0; i--) {
+        std::this_thread::sleep_for(std::chrono::seconds(1));
+        std::cout << i << " " << std::flush;
+    }
+    std::cout << std::endl;
+}
+
+int main()
+{
+    auto connection = sdbus::createSessionBusConnection();
+    connection->requestName("org.sdbuscpp.examplemanager");
+    connection->enterEventLoopAsync();
+
+    auto manager = std::make_unique<ManagerAdaptor>(*connection, "/org/sdbuscpp/examplemanager");
+    while (true)
+    {
+        printCountDown("Creating PlanetAdaptor in ", 5);
+        auto earth = std::make_unique<PlanetAdaptor>(*connection, "/org/sdbuscpp/examplemanager/Planet1/Earth", "Earth", 7'874'965'825);
+        printCountDown("Creating PlanetAdaptor in ", 5);
+        auto trantor = std::make_unique<PlanetAdaptor>(*connection, "/org/sdbuscpp/examplemanager/Planet1/Trantor", "Trantor", 40'000'000'000);
+        printCountDown("Creating PlanetAdaptor in ", 5);
+        auto laconia = std::make_unique<PlanetAdaptor>(*connection, "/org/sdbuscpp/examplemanager/Planet1/Laconia", "Laconia", 231'721);
+        printCountDown("Removing PlanetAdaptor in ", 5);
+        earth.reset();
+        printCountDown("Removing PlanetAdaptor in ", 5);
+        trantor.reset();
+        printCountDown("Removing PlanetAdaptor in ", 5);
+        laconia.reset();
+    }
+
+    connection->releaseName("org.sdbuscpp.examplemanager");
+    connection->leaveEventLoop();
+    return 0;
+}

examples/org.freedesktop.DBus.ObjectManager/org.sdbuscpp.ExampleManager.Planet1.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE node PUBLIC "-//freedesktop//DTD D-BUS Object Introspection 1.0//EN" "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd">
+<node>
+    <interface name="org.sdbuscpp.ExampleManager.Planet1">
+
+        <!--
+          @brief get the population of this planet
+          @param [out] population of the planet
+        -->
+        <method name="GetPopulation">
+            <arg name="population" type="t" direction="out" />
+        </method>
+
+        <!--
+          @brief This planet's name
+        -->
+        <property name="Name" type="s" access="read"/>
+
+    </interface>
+</node>