org.eclipse.emf.ecp.navigator.TreeLabelProvider.java Source code

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Here is the source code for org.eclipse.emf.ecp.navigator.TreeLabelProvider.java

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/*******************************************************************************
 * Copyright (c) 2008-2011 Chair for Applied Software Engineering,
 * Technische Universitaet Muenchen.
 * 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:
 ******************************************************************************/
package org.eclipse.emf.ecp.navigator;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.Platform;
import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
import org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider;
import org.eclipse.jface.viewers.DecoratingLabelProvider;
import org.eclipse.jface.viewers.IBaseLabelProvider;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.ui.PlatformUI;

/**
 * Composed Label provider with all registered label providers.
 * 
 * @author helming
 * @author emueller
 */
public class TreeLabelProvider {

    private ILabelProvider defaultLabelProvider;
    private IBaseLabelProvider replacedLabelProvider;
    private ComposedAdapterFactory adapterFactory;

    /**
     * Default constructor.
     */
    public TreeLabelProvider() {
        adapterFactory = new ComposedAdapterFactory(ComposedAdapterFactory.Descriptor.Registry.INSTANCE);
        defaultLabelProvider = new DecoratingLabelProvider(new AdapterFactoryLabelProvider(adapterFactory),
                PlatformUI.getWorkbench().getDecoratorManager().getLabelDecorator());
        replaceLabelProvider();
    }

    private void replaceLabelProvider() {

        IConfigurationElement[] confs = Platform.getExtensionRegistry()
                .getConfigurationElementsFor("org.eclipse.emf.ecp.navigator.replaceLabelProvider");

        if (confs.length > 1) {
            Exception exception = new IllegalStateException("Two or more ReplaceLabel Providers registered");
            Activator.getDefault().logException(exception.getMessage(), exception);
        } else if (confs.length == 1) {
            IConfigurationElement element = confs[0];

            try {
                replacedLabelProvider = (IBaseLabelProvider) element.createExecutableExtension("class");
            } catch (CoreException e) {
                Activator.getDefault().logException(e.getMessage(), e);
            }
        }
    }

    /**
     * Returns the {@link ILabelProvider}.  If the default label provider has been replaced, that one 
     * will be returned.  If more than one label providers have been registered to replace the default
     * label provider the first one will be returned.
     * @return the label provider to be used by the {@link TreeView}
     */
    public IBaseLabelProvider getLabelProvider() {
        if (replacedLabelProvider != null) {
            return replacedLabelProvider;
        }

        return defaultLabelProvider;
    }

    /**
     * */
    public void dispose() {
        if (adapterFactory != null) {
            adapterFactory.dispose();
        }

    }
}