State

georgedem975 · Aug 6, 2022 · 6931c52 · 6931c52
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diff --git a/State/README.md b/State/README.md
@@ -0,0 +1,13 @@
+### State
+---
+Состояние — поведенческий шаблон проектирования. Используется в тех случаях, когда во время выполнения программы объект должен менять своё поведение в зависимости от своего состояния. Классическая реализация предполагает создание базового абстрактного класса или интерфейса, содержащего все методы и по одному классу на каждое возможно состояние. Шаблон представляет собой частный случай рекомендации «заменяйте условные операторы полиморфизмом».
+
+![Patterns](https://github.com/georgedem975/georgedem975/blob/master/assets/relationships%20between%20classes.png)
+![State](https://github.com/georgedem975/georgedem975/blob/master/assets/state.jpg)
+
+---
+
+#### полезные ссылки:
++ [State](https://metanit.com/sharp/patterns/3.6.php) ✅
++ [State](https://www.rsdn.org/article/patterns/State.xml) ✅
++ [State](https://habr.com/ru/post/341134/) ✅
diff --git a/State/c#/State.cs b/State/c#/State.cs
@@ -0,0 +1,88 @@
+abstract class State
+{
+    protected TrafficLight _trafficLight;
+    public TrafficLight TrafficLight { set => _trafficLight = value; }
+    public abstract void NextState();
+    public abstract void PreviousState();
+}
+
+class TrafficLight
+{
+    private State _state;
+
+    public TrafficLight(State st) => SetState(st);
+
+    public void SetState(State st)
+    {
+        _state = st;
+        _state.TrafficLight = this;
+    }
+
+    public void NextState()
+    {
+        _state.NextState();
+    }
+
+    public void PreviousState()
+    {
+        _state.PreviousState();
+    }
+}
+
+class GreenState : State
+{
+    public override void NextState()
+    {
+        Console.WriteLine("from green to yellow");
+        _trafficLight.SetState(new YellowState());
+    }
+
+    public override void PreviousState()
+    {
+        Console.WriteLine("Green color");
+    }
+}
+
+class YellowState : State
+{
+    public override void NextState()
+    {
+        Console.WriteLine("from yellow to red");
+        _trafficLight.SetState(new RedState());
+    }
+
+    public override void PreviousState()
+    {
+        Console.WriteLine("from yellow to green");
+        _trafficLight.SetState(new GreenState());
+    }
+}
+
+class RedState : State
+{
+    public override void NextState()
+    {
+        Console.WriteLine("red color");
+    }
+
+    public override void PreviousState()
+    {
+        Console.WriteLine("from red to yellow");
+        _trafficLight.SetState(new YellowState());
+    }
+}
+
+class Program
+{
+    static void Main()
+    {
+        TrafficLight trafficLight = new TrafficLight(new GreenState());
+
+        trafficLight.NextState();
+        trafficLight.NextState();
+        trafficLight.NextState();
+        trafficLight.PreviousState();
+        trafficLight.PreviousState();
+        trafficLight.PreviousState();
+    }
+}
diff --git a/State/c++/State.cpp b/State/c++/State.cpp
@@ -0,0 +1,123 @@
+#include <iostream>
+
+class TrafficLight;
+
+class State
+{
+    protected:
+        TrafficLight* trafficLight;
+
+    public:
+        virtual ~State() {}
+        void SetTrafficLight(TrafficLight* tr);
+        virtual void nextState() = 0;
+        virtual void previousState() = 0;
+};
+
+class TrafficLight
+{
+    private:
+        State* state;
+
+    public:
+        TrafficLight(State* st) : state(nullptr)
+        {
+            SetState(st);
+        }
+        void SetState(State* st);
+        void nextState();
+        void previousState();
+};
+
+class GreenState : public State
+{
+    public:
+        void nextState() override;
+        void previousState() override;
+};
+
+class YellowState : public State
+{
+    public:
+        void nextState() override;
+        void previousState() override;
+};
+
+class RedState : public State
+{
+    public:
+        void nextState() override;
+        void previousState() override;
+};
+
+int main()
+{
+    TrafficLight* trafficLight = new TrafficLight(new GreenState());
+
+    trafficLight->nextState();
+    trafficLight->nextState();
+    trafficLight->nextState();
+    trafficLight->previousState();
+    trafficLight->previousState();
+    trafficLight->previousState();
+
+    delete trafficLight;
+
+    return 0;
+}
+
+void State::SetTrafficLight(TrafficLight *tr)
+{
+    trafficLight = tr;
+}
+
+void TrafficLight::SetState(State *st)
+{
+    if (state != nullptr) delete state;
+    state= st;
+    state->SetTrafficLight(this);
+}
+
+void TrafficLight::nextState()
+{
+    state->nextState();
+}
+
+void TrafficLight::previousState()
+{
+    state->previousState();
+}
+
+void GreenState::nextState()
+{
+    std::cout << "from green to yellow\n";
+    trafficLight->SetState(new YellowState());
+}
+
+void GreenState::previousState()
+{
+    std::cout << "green color\n";
+}
+
+void YellowState::nextState()
+{
+    std::cout << "from yellow to red\n";
+    trafficLight->SetState(new RedState());
+}
+
+void YellowState::previousState()
+{
+    std::cout << "from yellow to green\n";
+    trafficLight->SetState(new GreenState());
+}
+
+void RedState::nextState()
+{
+    std::cout << "red color\n";
+}
+
+void RedState::previousState()
+{
+    std::cout << "from red to yellow\n";
+    trafficLight->SetState(new YellowState());
+}
diff --git a/State/java/State.java b/State/java/State.java
@@ -0,0 +1,85 @@
+abstract class State{
+    protected TrafficLight trafficLight;
+
+    public void setTrafficLight(TrafficLight trafficLight){
+        this.trafficLight = trafficLight;
+    }
+
+    public abstract void nextState();
+
+    public abstract void previousState();
+}
+
+class TrafficLight{
+    private State state;
+
+    public TrafficLight(State st){
+        setState(st);
+    }
+
+    public void setState(State st){
+        state = st;
+        state.setTrafficLight(this);
+    }
+
+    public void nextState(){
+        state.nextState();
+    }
+
+    public void previousState(){
+        state.previousState();
+    }
+}
+
+class GreenState extends State{
+    @Override
+    public void nextState(){
+        System.out.println("from green to yellow");
+        trafficLight.setState(new YellowState());
+    }
+
+    @Override
+    public void previousState(){
+        System.out.println("green color");
+    }
+}
+
+class YellowState extends State{
+    @Override
+    public void nextState(){
+        System.out.println("from yellow to red");
+        trafficLight.setState(new RedState());
+    }
+
+    @Override
+    public void previousState(){
+        System.out.println("from yellow to green");
+        trafficLight.setState(new GreenState());
+    }
+}
+
+class RedState extends State{
+    @Override
+    public void nextState(){
+        System.out.println("red color");
+    }
+
+    @Override
+    public void previousState(){
+        System.out.println("from red to yellow");
+        trafficLight.setState(new YellowState());
+    }
+}
+
+public class Main {
+    public static void main(String[] args){
+        TrafficLight trafficLight = new TrafficLight(new GreenState());
+
+        trafficLight.nextState();
+        trafficLight.nextState();
+        trafficLight.nextState();
+        trafficLight.previousState();
+        trafficLight.previousState();
+        trafficLight.previousState();
+    }
+}
diff --git a/State/python/State.py b/State/python/State.py
@@ -0,0 +1,75 @@
+import abc
+
+
+class State(metaclass=abc.ABCMeta):
+
+    def __init__(self):
+        self._traffic_light: 'TrafficLight' = None
+
+    @abc.abstractmethod
+    def next_state(self):
+        pass
+
+    @abc.abstractmethod
+    def previous_state(self):
+        pass
+
+
+class TrafficLight:
+
+    def __init__(self, st: State):
+        self.__state = None
+        self.set_state(st)
+
+    def set_state(self, st: State):
+        self.__state = st
+        self.__state._traffic_light = self
+
+    def next_state(self):
+        self.__state.next_state()
+
+    def previous_state(self):
+        self.__state.previous_state()
+
+
+class GreenState(State):
+
+    def next_state(self):
+        print('from green to yellow')
+        self._traffic_light.set_state(YellowState())
+
+    def previous_state(self):
+        print('Green color')
+
+
+class YellowState(State):
+
+    def next_state(self):
+        print('from yellow to red')
+        self._traffic_light.set_state(RedState())
+
+    def previous_state(self):
+        print('from yellow to green')
+        self._traffic_light.set_state(GreenState())
+
+
+class RedState(State):
+
+    def next_state(self):
+        print('red color')
+
+    def previous_state(self):
+        print('from red to yellow')
+        self._traffic_light.set_state(YellowState())
+
+
+if __name__ == '__main__':
+
+    traffic_light = TrafficLight(GreenState())
+
+    traffic_light.next_state()
+    traffic_light.next_state()
+    traffic_light.next_state()
+    traffic_light.previous_state()
+    traffic_light.previous_state()
+    traffic_light.previous_state()