statemachine.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/util/stateMachine/StateMachine.java,v $
// $RCSfile: StateMachine.java,v $
// $Revision: 1.2.2.3 $
// $Date: 2005/08/10 22:45:14 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.layer.util.stateMachine;

import java.util.Enumeration;
import java.util.Vector;

/**
 * The StateMachine lets you organize event handling, if the order of
 * the events are important to you. You can use the setState commands
 * with the state you want, if you are holding on a copy of it.
 * Otherwise, the state machine assumes you know the index of the
 * state you want.
 */
public class StateMachine {
    /** The states to track. */
    protected Vector states = new Vector();
    /** The current state that will receive the next event. */
    protected State currentState;
    /** The state to go to whan all is bad. */
    protected State resetState;

    public StateMachine() {}

    /**
     * Define the state machine using the array of states. Order is
     * maintained.
     * 
     * @param s array of states.
     */
    public StateMachine(State[] s) {
        for (int i = 0; i < s.length; i++)
            states.addElement(s[i]);
    }

    /** Sets the current state to the reset state. */
    public void reset() {
        currentState = resetState;
    }

    /**
     * Set the states to the new array.
     * 
     * @param s array of states.
     */
    public void setStates(State[] s) {
        states.clear();
        addStates(s);
    }

    /**
     * Set the states to the vector of States.
     * 
     * @param s
     */
    public void setStates(Vector s) {
        states = s;
    }

    /**
     * Get the Vector of States.
     * 
     * @return Vector
     */
    public Vector getStates() {
        return states;
    }

    /**
     * Append States to the state Vector.
     * 
     * @param s an Array of States.
     */
    public void addStates(State[] s) {
        for (int i = 0; i < s.length; i++)
            states.addElement(s[i]);
    }

    /**
     * Set the current state to the given state. If the state is not
     * in the state machine, then the state is added to the end to the
     * state vector.
     * 
     * @param state the state to set to the current one.
     */
    public void setState(State state) {
        if (!states.contains(state))
            states.addElement(state);
        currentState = state;
    }

    /**
     * Set the current state to the state residing in the vector at
     * the given index. If the index is larger than the number of
     * states in the machine, the statemachine is reset.
     * 
     * @param stateIndex the index of the current state.
     */
    public void setState(int stateIndex) {
        try {
            currentState = (State) states.elementAt(stateIndex);
        } catch (ArrayIndexOutOfBoundsException e) {
            reset();
            System.err.println("StateMachine: out of bounds exception caught!");
        }
    }

    /**
     * Set the state at an index to new State Object. If the index
     * isn't currently being used, the StateMachine is reset.
     * 
     * @param stateIndex
     * @param state
     */
    public void setStateAt(int stateIndex, State state) {
        try {
            states.setElementAt(state, stateIndex);
        } catch (ArrayIndexOutOfBoundsException e) {
            System.err.println("StateMachine: out of bounds exception caught when trying to replace State that didn't exist.");
        }
    }

    /** Return the current State. */
    public State getState() {
        return currentState;
    }

    /**
     * Return the state at the given index. If the index is larger
     * that the number of states, null is returned.
     */
    public State getState(int stateIndex) {
        try {
            return (State) states.elementAt(stateIndex);
        } catch (ArrayIndexOutOfBoundsException e) {
            System.err.println("StateMachine: out of bounds exception caught!");
            return null;
        }
    }

    /**
     * Set the state to be gone to if the state machine is reset. If
     * the state does not exist in the state machine already, it will
     * be added to the end of the state vector.
     */
    public void setResetState(State state) {
        if (!states.contains(state))
            states.addElement(state);
        resetState = state;
    }

    /**
     * Set the reset state to be used by the state machine. If a bad
     * integer value is given, the first state in the state vector is
     * made the reset state.
     */
    public void setResetState(int stateIndex) {
        try {
            resetState = (State) states.elementAt(stateIndex);
        } catch (ArrayIndexOutOfBoundsException e) {
            System.err.println("StateMachine: out of bounds exception caught!");
            if (states.size() > 1)
                resetState = (State) states.elementAt(0);
        }
    }

    /** Return the reset state. */
    public State getResetState() {
        return resetState;
    }

    /** Set the MapMouseListenerResponse for all the states. */
    public void setMapMouseListenerResponses(boolean value) {
        Enumeration sItems = states.elements();
        while (sItems.hasMoreElements()) {
            State state = (State) sItems.nextElement();
            state.setMapMouseListenerResponse(value);
        }
    }
}