javauis/mmapi_qt/baseline/javasrc/com/nokia/microedition/media/tone/BlockEndEvent.java
/*
* Copyright (c) 2002 Nokia Corporation and/or its subsidiary(-ies).
* All rights reserved.
* This component and the accompanying materials are made available
* under the terms of "Eclipse Public License v1.0"
* which accompanies this distribution, and is available
* at the URL "http://www.eclipse.org/legal/epl-v10.html".
*
* Initial Contributors:
* Nokia Corporation - initial contribution.
*
* Contributors:
*
* Description: Event processor class for tone sequence BLOCK_END events
*
*/
package com.nokia.microedition.media.tone;
import javax.microedition.media.control.ToneControl;
/**
* Event processor class for tone sequence BLOCK_END events
*/
public class BlockEndEvent extends Event
{
BlockEndEvent(byte[] aSequence, MidiSequence aMidiSequence)
{
super(aSequence, aMidiSequence);
}
public int advance(int aPosition)
throws MidiSequenceException, IllegalArgumentException
{
int retVal = doValidate(aPosition);
if (retVal == 0)
{
return 0;
}
// if stack is already empty, we cannot revert back. Thus
// this BLOCK_END must be invalid
if (iReturnPositionStack.empty())
{
throw new IllegalArgumentException("Illegal BLOCK_END");
}
// If valid, go back to last position before entering block
int lastPos = ((Integer)iReturnPositionStack.pop()).intValue();
retVal = lastPos - aPosition;
return retVal;
}
/**
* Child class defined functionality for validate
* @return new position offset related to aPosition in tone sequence
* array. Must be positive.
*/
protected int doValidate(int aPosition)
throws IllegalArgumentException
{
int type = iSequence[ aPosition ];
int data = iSequence[ aPosition + 1 ];
int retVal = 0;
if (type == ToneControl.BLOCK_END)
{
leaveBlock(data); // fails if block number is incorrect
retVal = EVENT_SIZE;
}
return retVal;
}
/**
* Child class defined functionality for checkEventAtNextPosition
* @param aPosition position in tone sequence array where to check
*/
protected void checkEventAtNextPosition(int aPosition)
throws IllegalArgumentException
{
// After this event there can be:
// Tone, BlockStart, PlayBlock, Volume, Repeat
int type = 0;
try
{
type = iSequence[ aPosition ];
}
catch (ArrayIndexOutOfBoundsException aioobe)
{
throw new IllegalArgumentException(
"Validation failed, invalid position found in sequence");
}
if (type >= ToneControl.SILENCE ||
type == ToneControl.BLOCK_START ||
type == ToneControl.PLAY_BLOCK ||
type == ToneControl.SET_VOLUME ||
type == ToneControl.REPEAT)
{
return;
}
throw new IllegalArgumentException(
"Illegal event found; sequence is corrupted");
}
} // end of class