Adds Item provider preference page.

[EMFCompare2.git] / plugins / org.eclipse.emf.compare.rcp / src / org / eclipse / emf / compare / rcp / internal / adapterfactory / RankedAdapterFactoryDescriptorImpl.java

/*******************************************************************************
 * Copyright (c) 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.rcp.internal.adapterfactory;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.emf.common.notify.AdapterFactory;
import org.eclipse.emf.compare.internal.adapterfactory.RankedAdapterFactoryDescriptor;
import org.eclipse.emf.compare.rcp.extension.PluginClassDescriptor;

/**
 * Default implementation of {@link RankedAdapterFactoryDescriptor}.
 * 
 * @author <a href="mailto:axel.richard@obeo.fr">Axel Richard</a>
 */
public class RankedAdapterFactoryDescriptorImpl extends PluginClassDescriptor<AdapterFactory> implements RankedAdapterFactoryDescriptor {

        /** Optional attribute in extension point. */
        private static final String ATT_OPTIONAL = "optional"; //$NON-NLS-1$

        /** Label attribute in extension point. */
        private static final String ATT_LABEL = "label"; //$NON-NLS-1$

        /** Description attribute in extension point. */
        private static final String ATT_DESCRIPTION = "description"; //$NON-NLS-1$

        /** The wrapped adapter factory. */
        private AdapterFactory factory;

        /** Ranking of this adapter factory. */
        private final int ranking;

        /** Holds the id of this descriptor. */
        private final String id;

        /**
         * Creates a descriptor corresponding to the information of the given <em>element</em>.
         * 
         * @param element
         *            Configuration element from which to create this descriptor.
         * @param ranking
         *            The ranking of the adapter factory.
         */
        public RankedAdapterFactoryDescriptorImpl(IConfigurationElement element, int ranking) {
                super(element, AdapterFactoryDescriptorRegistryListener.ATT_CLASS);
                this.ranking = ranking;
                this.id = element.getAttribute(AdapterFactoryDescriptorRegistryListener.ATT_CLASS);
        }

        /**
         * {@inheritDoc}
         * 
         * @see org.eclipse.emf.compare.internal.adapterfactory.RankedAdapterFactoryDescriptor#createAdapterFactory()
         */
        public AdapterFactory createAdapterFactory() {
                if (factory == null) {
                        factory = this.createInstance();
                }
                return factory;
        }

        /**
         * {@inheritDoc}
         * 
         * @see org.eclipse.emf.compare.internal.adapterfactory.RankedAdapterFactoryDescriptor#getRanking()
         */
        public int getRanking() {
                return ranking;
        }

        /**
         * {@inheritDoc}
         * 
         * @see RankedAdapterFactoryDescriptor#getId()
         */
        public String getId() {
                return id;
        }

        /**
         * {@inheritDoc}
         * 
         * @see {org.eclipse.emf.compare.internal.adapterfactory.RankedAdapterFactoryDescriptor#getLabel()}
         */
        public String getLabel() {
                String label = element.getAttribute(ATT_LABEL);
                if (label == null) {
                        label = element.getAttribute(AdapterFactoryDescriptorRegistryListener.ATT_CLASS);
                }
                return label;
        }

        /**
         * {@inheritDoc}
         * 
         * @see {@link org.eclipse.emf.compare.internal.adapterfactory.RankedAdapterFactoryDescriptor#getDescription()}
         */
        public String getDescription() {
                return element.getAttribute(ATT_DESCRIPTION);
        }

        /**
         * {@inheritDoc}
         * 
         * @see {@link org.eclipse.emf.compare.internal.adapterfactory.RankedAdapterFactoryDescriptor#isOptional()}
         */
        public boolean isOptional() {
                return Boolean.parseBoolean(element.getAttribute(ATT_OPTIONAL));
        }

}