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The osx x86_64 swt jar as available in the Eclipse 4.6 (Neon) release for OSX. It is suitable for use with jface and other dependencies available from maven central in the org.eclipse.scout.sdk.deps group. The sources is copied from swt-4.6-cocoa-macosx-x86_64.zip from http://download.eclipse.org/eclipse/downloads/drops4/R-4.6-201606061100/ and javadoc is generated from sources.

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/*******************************************************************************
 * Copyright (c) 2000, 2011 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
 *******************************************************************************/
package org.eclipse.swt.internal.image;


import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;

public class PngTrnsChunk extends PngChunk {
	static final int TRANSPARENCY_TYPE_PIXEL = 0;
	static final int TRANSPARENCY_TYPE_ALPHAS = 1;
	static final int RGB_DATA_LENGTH = 6;

PngTrnsChunk(RGB rgb) {
	super(RGB_DATA_LENGTH);
	setType(TYPE_tRNS);
	setInt16(DATA_OFFSET, rgb.red);
	setInt16(DATA_OFFSET + 2, rgb.green);
	setInt16(DATA_OFFSET + 4, rgb.blue);
	setCRC(computeCRC());
}

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

@Override
int getChunkType() {
	return CHUNK_tRNS;
}

void validateLength(PngIhdrChunk header, PngPlteChunk paletteChunk) {
	boolean valid;
	switch (header.getColorType()) {
		case PngIhdrChunk.COLOR_TYPE_RGB:
			// Three 2-byte values (RGB)
			valid = getLength() == 6;
			break;
		case PngIhdrChunk.COLOR_TYPE_PALETTE:
			// Three 2-byte values (RGB)
			valid = getLength() <= paletteChunk.getLength();
			break;
		case PngIhdrChunk.COLOR_TYPE_GRAYSCALE:
			// One 2-byte value
			valid = getLength() == 2;
			break;
		// Cannot use both Alpha and tRNS
		case PngIhdrChunk.COLOR_TYPE_RGB_WITH_ALPHA:
		case PngIhdrChunk.COLOR_TYPE_GRAYSCALE_WITH_ALPHA:
		default:
			valid = false;
	}
	if (!valid) {
		SWT.error(SWT.ERROR_INVALID_IMAGE);
	}
}

/**
 * Answer whether the chunk is a valid tRNS chunk.
 */
void validate(PngFileReadState readState, PngIhdrChunk headerChunk, PngPlteChunk paletteChunk) {
	if (!readState.readIHDR
		|| (headerChunk.getMustHavePalette() && !readState.readPLTE)
		|| readState.readIDAT
		|| readState.readIEND)
	{
		SWT.error(SWT.ERROR_INVALID_IMAGE);
	} else {
		readState.readTRNS = true;
	}

	validateLength(headerChunk, paletteChunk);

	super.validate(readState, headerChunk);
}


int getTransparencyType(PngIhdrChunk header) {
	if (header.getColorType() == PngIhdrChunk.COLOR_TYPE_PALETTE) {
		return TRANSPARENCY_TYPE_ALPHAS;
	}
	return TRANSPARENCY_TYPE_PIXEL;
}

/**
 * Answer the transparent pixel RGB value.
 * This is not valid for palette color types.
 * This is not valid for alpha color types.
 * This will convert a grayscale value into
 * a palette index.
 * It will compress a 6 byte RGB into a 3 byte
 * RGB.
 */
int getSwtTransparentPixel(PngIhdrChunk header) {
	switch (header.getColorType()) {
		case PngIhdrChunk.COLOR_TYPE_GRAYSCALE:
			int gray = ((reference[DATA_OFFSET] & 0xFF) << 8)
				+ (reference[DATA_OFFSET + 1] & 0xFF);
			if (header.getBitDepth() > 8) {
				return PNGFileFormat.compress16BitDepthTo8BitDepth(gray);
			}
			return gray & 0xFF;
		case PngIhdrChunk.COLOR_TYPE_RGB:
			int red = ((reference[DATA_OFFSET] & 0xFF) << 8)
				| (reference[DATA_OFFSET + 1] & 0xFF);
			int green = ((reference[DATA_OFFSET + 2] & 0xFF) << 8)
				| (reference[DATA_OFFSET + 3] & 0xFF);
			int blue = ((reference[DATA_OFFSET + 4] & 0xFF) << 8)
				| (reference[DATA_OFFSET + 5] & 0xFF);
			if (header.getBitDepth() > 8) {
				red = PNGFileFormat.compress16BitDepthTo8BitDepth(red);
				green = PNGFileFormat.compress16BitDepthTo8BitDepth(green);
				blue = PNGFileFormat.compress16BitDepthTo8BitDepth(blue);
			}
			return (red << 16) | (green << 8) | blue;
		default:
			SWT.error(SWT.ERROR_INVALID_IMAGE);
			return -1;
	}
}

/**
 * Answer an array of Alpha values that correspond to the
 * colors in the palette.
 * This is only valid for the COLOR_TYPE_PALETTE color type.
 */
byte[] getAlphaValues(PngIhdrChunk header, PngPlteChunk paletteChunk) {
	if (header.getColorType() != PngIhdrChunk.COLOR_TYPE_PALETTE) {
		SWT.error(SWT.ERROR_INVALID_IMAGE);
	}
	byte[] alphas = new byte[paletteChunk.getPaletteSize()];
	int dataLength = getLength();
	int i = 0;
	for (i = 0; i < dataLength; i++) {
		alphas[i] = reference[DATA_OFFSET + i];
	}
	/**
	 * Any palette entries which do not have a corresponding
	 * alpha value in the tRNS chunk are spec'd to have an
	 * alpha of 255.
	 */
	for (int j = i; j < alphas.length; j++) {
		alphas[j] = (byte) 255;
	}
	return alphas;
}
}