/**
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.internal.util;
import android.os.Message;
/**
* {@hide}
*
* The interface for implementing states in a {@link StateMachine}
*/
public interface IState {
/**
* Returned by processMessage to indicate the the message was processed.
*/
static final boolean HANDLED = true;
/**
* Returned by processMessage to indicate the the message was NOT processed.
*/
static final boolean NOT_HANDLED = false;
/**
* Called when a state is entered.
*/
void enter();
/**
* Called when a state is exited.
*/
void exit();
/**
* Called when a message is to be processed by the
* state machine.
*
* This routine is never reentered thus no synchronization
* is needed as only one processMessage method will ever be
* executing within a state machine at any given time. This
* does mean that processing by this routine must be completed
* as expeditiously as possible as no subsequent messages will
* be processed until this routine returns.
*
* @param msg to process
* @return HANDLED if processing has completed and NOT_HANDLED
* if the message wasn't processed.
*/
boolean processMessage(Message msg);
/**
* Name of State for debugging purposes.
*
* @return name of state.
*/
String getName();
}