#include #include using namespace std; class state { public: virtual void goToGym() = 0; virtual void startToGoToOffice() = 0; virtual void startToGoToHome() = 0; virtual void listenMusic() = 0; virtual void attendMeeting() = 0; virtual void goToMeetingRoom() = 0; }; class atHome : public state { public: void goToGym() { cout << "Going to gym and came back home\n"; } void startToGoToOffice() { cout << "Going to office\n";} void startToGoToHome() { throw invalid_argument("Already at home. Cannot go to home\n"); } void listenMusic() { cout << "Listening to music\n"; } void attendMeeting() { throw invalid_argument("Already at home. Cannot attend meeting\n"); } void goToMeetingRoom() { throw invalid_argument("Already at home. Cannot go to meeting room\n"); } }; class atOffice : public state { public: void goToGym() { throw invalid_argument("Already at office. Cannot go to gym\n"); } void startToGoToOffice() { throw invalid_argument("Already at office. Cannot go to office\n"); } void startToGoToHome() { cout << "Going to home\n"; } void listenMusic() { throw invalid_argument("Already at office. Cannot listen lound music\n"); } void attendMeeting() { cout << "Going to attend a meeting\n"; } void goToMeetingRoom() { cout << "Going to a meeting room\n"; } }; class Employee { public: Employee() : m_pState(make_shared()) {} shared_ptr getState() { return m_pState; } void setState(shared_ptr pNewState) { m_pState = pNewState; } void goToGym() { try { m_pState->goToGym(); } catch (exception& ex) { cout << " Exception:-->" << ex.what(); } } void startToGoToOffice() { try { m_pState->startToGoToOffice(); setState(make_shared()); } catch (exception& ex) { cout << " Exception:-->" << ex.what(); } } void startToGoToHome() { try { m_pState->startToGoToHome(); setState(make_shared());} catch (exception& ex) { cout << " Exception:-->" << ex.what(); } } void attendMeeting() { try { m_pState->attendMeeting(); } catch (exception& ex) { cout << " Exception:-->" << ex.what(); } } void goToMeetingRoom() { try { m_pState->goToMeetingRoom(); } catch (exception& ex) { cout << " Exception:-->" << ex.what(); } } void listenMusic() { try { m_pState->listenMusic(); } catch (exception& ex) { cout << " Exception:-->" << ex.what(); } } private: shared_ptr m_pState; }; int main() { shared_ptr pEmployee = make_shared(); pEmployee->goToMeetingRoom(); pEmployee->attendMeeting(); pEmployee->goToGym(); pEmployee->listenMusic(); pEmployee->startToGoToHome(); pEmployee->startToGoToOffice(); pEmployee->goToMeetingRoom(); pEmployee->attendMeeting(); pEmployee->goToGym(); pEmployee->listenMusic(); pEmployee->startToGoToOffice(); pEmployee->startToGoToHome(); return 0; }

State Design Pattern