prefStore = new ScopedPreferenceStore(new UserScope(symbolicBundleName), "someUserData");

package at.arctis.license.client.preferences;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.osgi.service.prefs.Preferences;

public class UserScope implements IScopeContext {

	/**
	 * String constant (value of <code>"user"</code>) used for the 
	 * scope name for this preference scope.
	 */
	public static final String SCOPE = "user"; //$NON-NLS-1$

	/**
	 * the root context.
	 */
	String context = "";

	protected UserPreferences licUserPreferences = null;
	
	/**
	 * Create and return a new user scope with the given context.
	 * 
	 * @param context the context
	 */
	public UserScope(String context) {
		this.context = context;
		licUserPreferences = 
			(UserPreferences) new UserPreferences().node(UserScope.SCOPE).node(context);
	}
	public UserScope() {
		this("");
	}

	/*
	 * @see org.eclipse.core.runtime.IScopeContext#getNode(java.lang.String)
	 */
	public IEclipsePreferences getNode(String qualifier) {
		if (qualifier == null)
			throw new IllegalArgumentException();
		final Preferences qualifierNode = licUserPreferences.node(qualifier);
		return (IEclipsePreferences) qualifierNode;
	}

	/**
	 * @see org.eclipse.core.runtime.preferences.IScopeContext#getLocation()
	 */
	public IPath getLocation() {
		return UserPreferences.getStaticLocation();
	}

	/**
	 * @see org.eclipse.core.runtime.preferences.IScopeContext#getName()
	 */
	public String getName() {
		return SCOPE;
	}

	/**
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (!super.equals(obj))
			return false;
		if (!(obj instanceof UserScope))
			return false;
		UserScope other = (UserScope) obj;
		return context.equals(other.context);
	}

	/**
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		return super.hashCode() + context.hashCode();
	}

}

/*******************************************************************************
 * 
 * Copyright (c) 2004, 2008 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
 *     arctis Softwaretechnologie - Derived from class org.eclipse.core.internal.resources.ProjectPreferences
 */
package at.arctis.license.client.preferences;

import java.io.File;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.StringTokenizer;

import org.eclipse.core.internal.preferences.EclipsePreferences;
import org.eclipse.core.runtime.ILog;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.osgi.service.datalocation.Location;

public class UserPreferences extends EclipsePreferences {

	// cached values
	private String qualifier;
	private IEclipsePreferences loadLevel;
	int segmentCount;
	// cache which nodes have been loaded from disk
	private static Set<String> loadedNodes = Collections.synchronizedSet(new HashSet<String>());
	private static boolean initialized = false;
	private static IPath baseLocation;
	private IPath location;

	static {
		ILog logger = Platform.getLog(Platform.getBundle(AbstractLicensePreferencePage.PLUGIN_ID));
		
		
		Location something = Platform.getUserLocation();
		System.err.println(something.getURL());
		
		String userHome = System.getProperty("user.home");

		if (userHome == null) {
			logger
					.log(new Status(Status.WARNING, AbstractLicensePreferencePage.PLUGIN_ID,
							"Cannot determine user home"));
		} else {
			File homeDir = new File(userHome);
			final File eclipsePrefDir = new File(homeDir, ".eclipse");
			if ((!eclipsePrefDir.exists() && !homeDir.canWrite()) || !eclipsePrefDir.canWrite()) {
				logger.log(new Status(Status.WARNING, AbstractLicensePreferencePage.PLUGIN_ID,
						"Cannot write to user home at " + homeDir.getAbsolutePath()));
			} else {
				baseLocation = new Path(eclipsePrefDir.getAbsolutePath());
			}
		}
	}

	/**
	 * Default constructor. Should only be called by #createExecutableExtension.
	 */
	public UserPreferences() {
		this(null, null);
	}

	private UserPreferences(EclipsePreferences parent, String name) {
		super(parent, name);

		initializeChildren();

//		// cache the segment count
		String path = absolutePath();
		StringTokenizer tokenizer = new StringTokenizer(path, String.valueOf(IPath.SEPARATOR));
		segmentCount = tokenizer.countTokens();
		if (segmentCount < 2)
			return;

		// cache the qualifier
		qualifier = getSegment(path, 1);

		// cache the location
		if (qualifier == null)
			return;
		if (baseLocation != null)
			location = computeLocation(baseLocation, qualifier);
	}

	@Override
	public IPath getLocation() {
		return location;
	}

	public static IPath getStaticLocation() {
		return baseLocation;
	}

	@Override
	protected boolean isAlreadyLoaded(IEclipsePreferences node) {
		return loadedNodes.contains(node.name());
	}

	@Override
	protected void loaded() {
		loadedNodes.add(name());
	}

	/*
	 * Return the node at which these preferences are loaded/saved.
	 */
	@Override
	protected IEclipsePreferences getLoadLevel() {
		if (loadLevel == null) {
			if (qualifier == null)
				return null;
			// Make it relative to this node rather than navigating to it from
			// the root.
			// Walk backwards up the tree starting at this node.
			// This is important to avoid a chicken/egg thing on startup.
			IEclipsePreferences node = this;
			for (int i = 2; i < segmentCount; i++)
				node = (EclipsePreferences) node.parent();
			loadLevel = node;
		}
		return loadLevel;
	}

	protected void initializeChildren() {
		if (initialized || parent == null)
			return;
		try {
			synchronized (this) {
				if (baseLocation == null)
					return;
				String[] names = computeChildren(baseLocation);
				for (int i = 0; i < names.length; i++)
					addChild(names[i], null);
			}
		} finally {
			initialized = true;
		}
	}
	@Override
	protected EclipsePreferences internalCreate(EclipsePreferences nodeParent, String nodeName, Object context) {
		return new UserPreferences(nodeParent, nodeName);
	}
}