/******************************************************************************* * Copyright (c) 2000, 2004 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.internal.image;import org.eclipse.swt.*;final class JPEGScanHeader extends JPEGVariableSizeSegment {	public int[][] componentParameters;public JPEGScanHeader(byte[] reference) {	super(reference);}public JPEGScanHeader(LEDataInputStream byteStream) {	super(byteStream);	initializeComponentParameters();}public int getApproxBitPositionHigh() {	return (reference[(2 * getNumberOfImageComponents()) + 7] & 0xFF) / 16;}public int getApproxBitPositionLow() {	return (reference[(2 * getNumberOfImageComponents()) + 7] & 0xFF) % 16;}public int getEndOfSpectralSelection() {	return (reference[(2 * getNumberOfImageComponents()) + 6] & 0xFF);}public int getNumberOfImageComponents() {	return (reference[4] & 0xFF);}public int getStartOfSpectralSelection() {	return (reference[(2 * getNumberOfImageComponents()) + 5] & 0xFF);}/* Used when decoding. */void initializeComponentParameters() {	int compCount = getNumberOfImageComponents();	componentParameters = new int[0][];	for (int i = 0; i < compCount; i++) {		int ofs = 5 + i * 2;		int cid = reference[ofs] & 0xFF;		int dc = (reference[ofs + 1] & 0xFF) / 16;		int ac = (reference[ofs + 1] & 0xFF) % 16;		if (componentParameters.length <= cid) {			int[][] newParams = new int[cid + 1][];			System.arraycopy(componentParameters, 0, newParams, 0, componentParameters.length);			componentParameters = newParams;		}		componentParameters[cid] = new int[] { dc, ac };	}}/* Used when encoding. */public void initializeContents() {	int compCount = getNumberOfImageComponents();	int[][] compSpecParams = componentParameters;	if (compCount == 0 || compCount != compSpecParams.length) {		SWT.error(SWT.ERROR_INVALID_IMAGE);	}	for (int i = 0; i < compCount; i++) {		int ofs = i * 2 + 5;		int[] compParams = compSpecParams[i];		reference[ofs] = (byte)(i + 1);		reference[ofs + 1] = (byte)(compParams[0] * 16 + compParams[1]);	}}public void setEndOfSpectralSelection(int anInteger) {	reference[(2 * getNumberOfImageComponents()) + 6] = (byte)anInteger;}public void setNumberOfImageComponents(int anInteger) {	reference[4] = (byte)(anInteger & 0xFF);}public void setStartOfSpectralSelection(int anInteger) {	reference[(2 * getNumberOfImageComponents()) + 5] = (byte)anInteger;}public int signature() {	return JPEGFileFormat.SOS;}public boolean verifyProgressiveScan() {	int start = getStartOfSpectralSelection();	int end = getEndOfSpectralSelection();	int low = getApproxBitPositionLow();	int high = getApproxBitPositionHigh();	int count = getNumberOfImageComponents();	if ((start == 0 && end == 00) || (start <= end && end <= 63)) {		if (low <= 13 && high <= 13 && (high == 0 || high == low + 1)) {			return start == 0 || (start > 0 && count == 1);		}	}	return false;}public boolean isACProgressiveScan() {	return getStartOfSpectralSelection() != 0 && getEndOfSpectralSelection() != 0;}public boolean isDCProgressiveScan() {	return getStartOfSpectralSelection() == 0 && getEndOfSpectralSelection() == 0;}public boolean isFirstScan() {	return getApproxBitPositionHigh() == 0;}}