org.eclipse.osbp.preferences.ui.page/src/org/eclipse/osbp/preferences/ui/data/ProductProjectScope.java

/**
 *                                                                            
 * Copyright (c) 2011, 2016 - Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 *                                                                            
 * 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:   
 * Christophe Loetz (Loetz GmbH&Co.KG) - initial implementation 
 */
package org.eclipse.osbp.preferences.ui.data;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import org.eclipse.core.internal.resources.ProjectPreferences;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.osgi.service.prefs.BackingStoreException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.eclipse.osbp.preferences.ProductConfigurationPrefs;

public final class ProductProjectScope implements IScopeContext {

	private static final Logger LOGGER = LoggerFactory.getLogger(ProductProjectScope.class);
	
	/**
	 * String constant (value of <code>"project"</code>) used for the 
	 * scope name for this preference scope.
	 */
	public static final String SCOPE = "project"; //$NON-NLS-1$
	
	private IProject context;

	/**
	 * Create and return a new project scope for the given project. The given
	 * project must not be <code>null</code>.
	 * 
	 * @param context the project
	 * @exception IllegalArgumentException if the project is <code>null</code>
	 */
	public ProductProjectScope(IProject context) {
		super();
		if (context == null)
			throw new IllegalArgumentException();
		this.context = context;
	}

	/*
	 * @see org.eclipse.core.runtime.preferences.IScopeContext#getLocation()
	 */
	public IPath getLocation() {
		IProject project = ((IResource) context).getProject();
		IResource resource = ProductConfigurationPrefs.getPrefsFile(project);
		if	(resource == null) {
			IPath location = project.getLocation();
			return location == null ? null : location.append(ProductConfigurationPrefs.PREFERENCES_FULL_PATH);
		}
		else {
			return resource.getLocation();
		}
	}

	/*
	 * @see org.eclipse.core.runtime.IScopeContext#getNode(java.lang.String)
	 */
	public IEclipsePreferences getNode(String qualifier) {
		IEclipsePreferences preference = null;
		if (qualifier == null)
			throw new IllegalArgumentException();
		preference = (IEclipsePreferences) Platform.getPreferencesService().getRootNode().node(SCOPE).node(context.getName()).node(qualifier);
		IFile prefsFile = null;
		if	(context instanceof IProject) {
			IResource resource = ProductConfigurationPrefs.getPrefsFile((IProject)context);
			if	(resource instanceof IFile) {
				prefsFile = (IFile) resource;
			}
		}
		if	(prefsFile == null) {
			prefsFile = context.getFile(new Path(ProductConfigurationPrefs.PREFERENCES_FULL_PATH));
		}
		if	(prefsFile instanceof IFile) {
		    try {
			    Class<?> preferenceClass = preference.getClass();
			    Method getLoadLevel = preferenceClass.getDeclaredMethod("getLoadLevel");
			    getLoadLevel.setAccessible(true);
		    	ProjectPreferences loadLevelInstance = (ProjectPreferences) getLoadLevel.invoke(preference);
			    Class<?>loadLevelClass = loadLevelInstance.getClass();
			    Field fileField = loadLevelClass.getDeclaredField("file");
			    fileField.setAccessible(true);
			    IFile activeFile = (IFile) fileField.get(loadLevelInstance);
			    if	((activeFile == null) || !activeFile.getFullPath().toOSString().equals(prefsFile.getFullPath().toOSString())) {
			    	fileField.set(loadLevelInstance, prefsFile);
			    	preference.sync();
			    	LOGGER.info("set preference file to: "+prefsFile.getFullPath().toOSString());
			    }
			}
		    catch (NoSuchFieldException | IllegalArgumentException | IllegalAccessException | BackingStoreException | NoSuchMethodException | SecurityException | InvocationTargetException x) {
		    	LOGGER.error("exception while trying to check and set preference file", x);
			}
		}
		return preference;
	}

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

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

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