sdrtrunk/src/main/java/io/github/dsheirer/channel/state/State.java

/*******************************************************************************
 *     SDR Trunk 
 *     Copyright (C) 2014-2016 Dennis Sheirer
 *
 *     This program is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program.  If not, see <http://www.gnu.org/licenses/>
 ******************************************************************************/
package io.github.dsheirer.channel.state;

import java.util.EnumSet;

/**
 * Details the set of states for a channel and the allowable transition states
 */
public enum State
{
    IDLE("IDLE")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state != TEARDOWN && state != RESET && state != OVERFLOW;
            }
        },
    CALL("CALL")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state == CONTROL || state == DATA || state == ENCRYPTED || state == FADE || state == TEARDOWN;
            }
        },
    DATA("DATA")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state == CALL || state == CONTROL || state == ENCRYPTED || state == FADE || state == TEARDOWN;
            }
        },
    ENCRYPTED("ENCRYPTED")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state == FADE || state == TEARDOWN;
            }
        },
    CONTROL("CONTROL")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state == IDLE || state == FADE;
            }
        },
    FADE("FADE")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state != FADE && state != RESET && state != OVERFLOW;
            }
        },
    OVERFLOW("OVERFLOW")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return false;
            }
        },
    RESET("RESET")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state == IDLE;
            }
        },
    TEARDOWN("TEARDOWN")
        {
            @Override
            public boolean canChangeTo(State state)
            {
                return state == RESET;
            }
        };

    private String mDisplayValue;

    public static final EnumSet<State> CALL_STATES = EnumSet.of(CALL, CONTROL, DATA, ENCRYPTED);
    public static final EnumSet<State> IDLE_STATES = EnumSet.of(IDLE, FADE);

    private State(String displayValue)
    {
        mDisplayValue = displayValue;
    }

    public abstract boolean canChangeTo(State state);

    /**
     * Indicates that this state is an active (ie decoding) state and is one of the states
     * enumerated in the CALL_STATES enumeration set.
     *
     * @return true if this state is an active state
     */
    public boolean isActiveState()
    {
        return CALL_STATES.contains(this);
    }

    public String getDisplayValue()
    {
        return mDisplayValue;
    }
}