org.eclipse.xtext.ui.preferences.EclipsePreferencesProvider.java Source code

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Here is the source code for org.eclipse.xtext.ui.preferences.EclipsePreferencesProvider.java

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/*******************************************************************************
 * Copyright (c) 2012 itemis AG (http://www.itemis.eu) 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
 *******************************************************************************/
package org.eclipse.xtext.ui.preferences;

import java.util.Map;

import org.apache.log4j.Logger;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.xtext.preferences.IPreferenceValues;
import org.eclipse.xtext.preferences.IPreferenceValuesProvider;
import org.eclipse.xtext.preferences.PreferenceKey;
import org.eclipse.xtext.ui.editor.preferences.IPreferenceStoreAccess;

import com.google.common.collect.Maps;
import com.google.inject.Inject;

/**
 * @author Sven Efftinge - Initial contribution and API
 */
public class EclipsePreferencesProvider implements IPreferenceValuesProvider {

    private final static Logger log = Logger.getLogger(EclipsePreferencesProvider.class);
    @Inject
    IPreferenceStoreAccess access;

    @Override
    public IPreferenceValues getPreferenceValues(Resource context) {
        final IProject project = getProject(context);
        final IPreferenceStore store = project != null ? access.getContextPreferenceStore(project)
                : access.getPreferenceStore();

        final Map<String, String> preferenceCache = Maps.newHashMap();

        return new IPreferenceValues() {
            @Override
            public String getPreference(PreferenceKey key) {
                try {
                    String id = key.getId();
                    String string = preferenceCache.get(id);
                    if (string == null) {
                        string = store.getString(id);
                        preferenceCache.put(id, string);
                    }
                    return org.eclipse.jface.preference.IPreferenceStore.STRING_DEFAULT_DEFAULT.equals(string)
                            ? key.getDefaultValue()
                            : string;
                } catch (Exception e) {
                    log.error("Error getting preference for key '" + key.getId() + "'.", e);
                    return key.getDefaultValue();
                }
            }
        };
    }

    private IProject getProject(Resource resource) {
        URI uri = resource.getURI();
        if (uri.isPlatformResource()) {
            final IProject project = getWorkspaceRoot().getProject(uri.segment(1));
            if (project.isAccessible())
                return project;
        }
        return null;
    }

    private IWorkspaceRoot getWorkspaceRoot() {
        return ResourcesPlugin.getWorkspace().getRoot();
    }

}