/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
module dwt.internal.image;


import dwt.DWT;

class PngIendChunk : PngChunk {

PngIendChunk() {
    super(0);
    setType(TYPE_IEND);
    setCRC(computeCRC());
}

PngIendChunk(byte[] reference){
    super(reference);
}

int getChunkType() {
    return CHUNK_IEND;
}

/**
 * Answer whether the chunk is a valid IEND chunk.
 */
void validate(PngFileReadState readState, PngIhdrChunk headerChunk) {
    // An IEND chunk is invalid if no IHDR has been read.
    // Or if a palette is required and has not been read.
    // Or if no IDAT chunk has been read.
    if (!readState.readIHDR
        || (headerChunk.getMustHavePalette() && !readState.readPLTE)
        || !readState.readIDAT
        || readState.readIEND) 
    {
        DWT.error(DWT.ERROR_INVALID_IMAGE);
    } else {
        readState.readIEND = true;
    }
    
    super.validate(readState, headerChunk);
    
    // IEND chunks are not allowed to have any data.
    if (getLength() > 0) DWT.error(DWT.ERROR_INVALID_IMAGE);
}

}