Source Code for Demo Signal Listener Plugin

Location

./src/examples/src/adtf/system_services/signal_listening/signal_listener/

Build Environment

To see how to set up the build environment have a look at ADTF CMake Environment

this implementation shows:

• how to implement a System Service
• how to access signals in the Signal Registry Service

Header

 
#ifndef _DEMO_SDL_APP_SERVICE_HEADER_
#define _DEMO_SDL_APP_SERVICE_HEADER_
 
#define CID_DEMO_ADTF_SIGNAL_LISTENER "demo_signal_listener.service.adtf.cid"
 
class cSignalDumper;
 
class cDemoSignalListener : public cADTFService, public ISignalListening::ISignalsListener
{
    public:
        ADTF_CLASS_ID_NAME(cDemoSignalListener, CID_DEMO_ADTF_SIGNAL_LISTENER, "Demo Signal Listener");
 
        ADTF_CLASS_DEPENDENCIES(REQUIRE_INTERFACE(adtf::services::ISignalListening));
 
        cDemoSignalListener();
 
    public: // overrides cService
 
        virtual tResult ServiceInit() override;
        virtual tResult ServiceShutdown() override;
 
    public:
        virtual void SignalAdded(const ISignalRegistry::tSignalAttributes& sSignalAttributes) override;
        virtual void SignalRemoved(const ISignalRegistry::tSignalAttributes& sSignalAttributes) override;
 
    private:
        object_ptr<ISignalListening> m_pSignalListening;
        std::unordered_map<ISignalRegistry::tSignalID, std::unique_ptr<cSignalDumper>> m_oDumper;
};
 
#endif // _DEMO_SERVICE_HEADER_

Implementation

 
#include "stdafx.h"
#include "demo_signal_listener_service.h"
#include <cinttypes>
 
ADTF_PLUGIN("Demo Signal Listener",
            cDemoSignalListener);
 
class cSignalDumper: public ISignalListening::ISignalListener
{
    public:
        cSignalDumper(const char* strSignalName):
            m_strSignalName(strSignalName)
        {
        }
 
    public:
        virtual void SignalUpdated(ISignalRegistry::tSignalID /* nSignalID */, const ISignalRegistry::tSignalValueNs& sValue) override
        {
            LOG_INFO("%s @ %" PRIi64 ": %f", m_strSignalName.GetPtr(), sValue.nTimeStamp.nCount, sValue.f64Value);
        }
 
    private:
        cString m_strSignalName;
};
 
 
cDemoSignalListener::cDemoSignalListener()
{
    SetDefaultRunlevel(tADTFRunLevel::RL_Session);
 
    // sets a short description for the component
    SetDescription("Use this System Service to print signal updates (e.g. send by 'Demo Signal Provider', see Filters.");
 
    // set help link to jump to documentation from ADTF Configuration Editor
    SetHelpLink("$(ADTF_DIR)/doc/adtf_html/page_demo_signal_listener.html");
}
 
tResult cDemoSignalListener::ServiceInit()
{
    RETURN_IF_FAILED(_runtime->GetObject(m_pSignalListening));
    RETURN_IF_FAILED(m_pSignalListening->RegisterSignalsListener(*this));
 
    RETURN_NOERROR;
}
 
tResult cDemoSignalListener::ServiceShutdown()
{
    for (auto& oDumper: m_oDumper)
    {
        m_pSignalListening->CancelSignalUpdates(oDumper.first, *oDumper.second.get());
    }
 
    RETURN_IF_FAILED(m_pSignalListening->UnregisterSignalsListener(*this));
    m_pSignalListening.Reset();
 
    RETURN_NOERROR;
}
 
void cDemoSignalListener::SignalAdded(const ISignalRegistry::tSignalAttributes& sSignalAttributes)
{
    std::unique_ptr<cSignalDumper> pDumper(new cSignalDumper(sSignalAttributes.strName));
    if (IS_OK(m_pSignalListening->RequestSignalUpdates(sSignalAttributes.nSignalID, *pDumper.get())))
    {
        m_oDumper.emplace(sSignalAttributes.nSignalID, std::move(pDumper));
    }
}
 
void cDemoSignalListener::SignalRemoved(const ISignalRegistry::tSignalAttributes& sSignalAttributes)
{
    m_oDumper.erase(sSignalAttributes.nSignalID);
}