Using TCU Activity Manager APIs to set the TCU activity state

The below steps need to be followed by the applications that control the TCU-activity state, to change the TCU-activity state.

### 1. Implement a command response function ###

void commandResponse(ErrorCode error) {
    if (error == ErrorCode::SUCCESS) {
        std::cout << " Command executed successfully" << std::endl;
    } else {
        std::cout << " Command failed, errorCode: " << static_cast<int>(error) << std::endl;
    }
}

### 2. Implement ITcuActivityListener interface. ###

class MyTcuActivityStateListener : public ITcuActivityListener {
public:
    void onTcuActivityStateUpdate(TcuActivityState state) override;
};

### 3. Get the Power-Factory instance ###

auto &powerFactory = PowerFactory::getInstance();

### 4. Get TCU-activity manager instance ###

auto tcuActivityManager = powerFactory.getTcuActivityManager();

### 5. Wait for the TCU-activity management services to be initialized and ready ###

bool isReady = tcuActivityManager->isReady();
if(!isReady) {
    std::cout << "TCU-activity management service is not ready" << std::endl;
    std::cout << "Waiting uncondotionally for it to be ready " << std::endl;
    std::future<bool> f = tcuActivityManager->onReady();
    isReady = f.get();
}

### 6. Exit the application, if SDK is unable to initialize TCU-activity management service ###

if(isReady) {
    std::cout << " *** TCU-activity management service is Ready *** " << std::endl;
} else {
    std::cout << " *** ERROR - Unable to initialize TCU-activity management service" << std::endl;
    return 1;
}

### 7. Instantiate MyTcuActivityStateListener ###

auto myTcuStateListener = std::make_shared<MyTcuActivityStateListener>();

### 8. Register for updates on TCU-activity state and its management service status ###

tcuActivityManager->registerListener(myTcuStateListener);

### 9. Set the TCU-activity state ###

tcuActivityManager->setActivityState(state,&commandResponse);

10. Command response callback function is invoked with error code indicating whether the request was SUCCESS or FAILURE

### 11. This API on the listener is invoked to notify that the TCU-activity state is changing to the desired state ###

void MyTcuActivityStateListener::onTcuActivityStateUpdate(TcuActivityState state) {
    std::cout << std::endl << "********* TCU-activity state update *********" << std::endl;
    // Avoid long blocking calls when handling notifications
}

12. On SUSPEND/SHUTDOWN notification, save any required information and send one(despite multiple listeners) acknowledgement

tcuActivityManager->sendActivityStateAck(TcuActivityStateAck);