AccessorAdapter.java

/*******************************************************************************
 * Copyright (c) 2012, 2013 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.compare.ide.ui.internal.contentmergeviewer.accessor;

import java.io.ByteArrayInputStream;
import java.io.InputStream;

import org.eclipse.compare.IStreamContentAccessor;
import org.eclipse.compare.ITypedElement;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.emf.compare.ide.ui.internal.contentmergeviewer.util.OSGIVersionUtil;
import org.eclipse.swt.graphics.Image;
import org.osgi.framework.Bundle;
import org.osgi.framework.Version;

/**
 * @author <a href="mailto:mikael.barbero@obeo.fr">Mikael Barbero</a>
 */
public final class AccessorAdapter implements ITypedElement, IStreamContentAccessor {

	/**
	 * Fix for #293926 has been release in org.eclipse.compare 3.5.201.R37x_v20110817-0800
	 */
	private static final Version BUG_293926_VERSION = Version.parseVersion("3.5.201"); //$NON-NLS-1$

	private final Object target;

	private AccessorAdapter(Object target) {
		this.target = target;
	}

	/**
	 * 
	 */
	public Object getTarget() {
		return target;
	}

	public static AccessorAdapter adapt(Object target) {
		return new AccessorAdapter(target);
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.compare.IStreamContentAccessor#getContents()
	 */
	public InputStream getContents() throws CoreException {
		if (target instanceof org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.IStreamContentAccessor) {
			return ((org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.IStreamContentAccessor)target)
					.getContents();
		}
		/*
		 * #293926 : Whatever we return has no importance as long as it is not "null", this is only to make
		 * CompareUIPlugin#guessType happy. However, it is only happy if what we return resembles a text. Note
		 * that this bug has been fixed in 3.7.1, we're keeping this around for the compatibility with 3.5 and
		 * 3.6.
		 */
		Bundle compareBundle = Platform.getBundle("org.eclipse.compare"); //$NON-NLS-1$
		Version compareBundleVersion = compareBundle.getVersion();
		if (OSGIVersionUtil.compare(compareBundleVersion, BUG_293926_VERSION) < 0) {
			// workaround for before before indigo SR1 - 3.7.1
			return new ByteArrayInputStream(new byte[] {' ' });
		} else {
			return null;
		}
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.compare.ITypedElement#getName()
	 */
	public String getName() {
		if (target instanceof org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.ITypedElement) {
			return ((org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.ITypedElement)target)
					.getName();
		}
		return null;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.compare.ITypedElement#getImage()
	 */
	public Image getImage() {
		if (target instanceof org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.ITypedElement) {
			return ((org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.ITypedElement)target)
					.getImage();
		}
		return null;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @see org.eclipse.compare.ITypedElement#getType()
	 */
	public String getType() {
		if (target instanceof org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.ITypedElement) {
			return ((org.eclipse.emf.compare.rcp.ui.contentmergeviewer.accessor.legacy.ITypedElement)target)
					.getType();
		}
		return null;
	}

}