// Project: Patterns2
// Module: Elevator
// Source code file: StateManager.java
// Illustrates the State Pattern with two states.

public class StateManager {
    private State _firstFloorState;
    private State _secondFloorState;

    // Elevator is initialized to 1st floor.
    State _floor;

    // StateManager object contains all state objects
    // and an instance variable to keep track of
    // current state.
    public StateManager( ) {
        _firstFloorState = new FirstFloorState(this);
        _secondFloorState = new SecondFloorState(this);
        _floor = _firstFloorState;
    }

    // Pressing first floor button notifies FirstFloor
    // state object that this button has been pressed.
    public void pressFirstFloorButton( ) {
        _floor.pressFirstFloorButton( );
    }

    // Pressing second floor button notifies SecondFloor
    // state object that this button has been pressed.
    public void pressSecondFloorButton( ) {
        _floor.pressSecondFloorButton( );
    }

    // Change state object to FirstFloorState.
    public void setFirstFloor( ) {
        _floor = _firstFloorState;
    }

    // Change state object to SecondFloorState.
    public void setSecondFloor( ) {
        _floor = _secondFloorState;
    }
}