plugins/org.eclipse.actf.visualization.engines.blind.html/src/org/eclipse/actf/visualization/engines/blind/html/ui/elementViewer/ElementInfoProviderExtension.java

/*******************************************************************************
 * 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:
 *    Kentarou FUKUDA - initial API and implementation
 *******************************************************************************/

package org.eclipse.actf.visualization.engines.blind.html.ui.elementViewer;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.actf.util.ui.IElementViewerInfoProvider;
import org.eclipse.actf.visualization.engines.blind.html.HtmlVizPlugin;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.Platform;



public class ElementInfoProviderExtension {

    private static final String PROVIDER = "provider";

    private static final String ATTR_CLASS = "class";

    private static ElementInfoProviderExtension[] extensions;

    private static IElementViewerInfoProvider[] providers = null;

    public static IElementViewerInfoProvider[] getProviders() {
        if (providers != null){
            return providers;
        }

        ElementInfoProviderExtension[] tmpExtensions = getExtensions();
        ArrayList<IElementViewerInfoProvider> tmpList = new ArrayList<IElementViewerInfoProvider>();
        if (tmpExtensions != null) {
            for (int i = 0; i < tmpExtensions.length; i++) {
                IElementViewerInfoProvider tmpProvider = tmpExtensions[i].getElementViewerInfoProvider();
                if (tmpProvider != null){
                    tmpList.add(tmpProvider);
                }
            }
        }
        providers = new IElementViewerInfoProvider[tmpList.size()];
        tmpList.toArray(providers);
        return providers;
    }

    private static ElementInfoProviderExtension[] getExtensions() {
        if (extensions != null)
            return extensions;

        IExtension[] tmpExtensions = Platform.getExtensionRegistry().getExtensionPoint(HtmlVizPlugin.PLUGIN_ID,
                "elementInfoProvider").getExtensions();
        
        if(Platform.inDevelopmentMode() || Platform.inDebugMode()){
            System.out.println("ElementInfo extensions:"+tmpExtensions.length);
        }
        List<ElementInfoProviderExtension> l = new ArrayList<ElementInfoProviderExtension>();
        for (int i = 0; i < tmpExtensions.length; i++) {
            IConfigurationElement[] configElements = tmpExtensions[i].getConfigurationElements();
            for (int j = 0; j < configElements.length; j++) {
                ElementInfoProviderExtension ex = parseExtension(configElements[j]);
                if (ex != null){
                    l.add(ex);
                }
            }
        }
        extensions = l.toArray(new ElementInfoProviderExtension[l.size()]);
        return extensions;
    }

    private static ElementInfoProviderExtension parseExtension(IConfigurationElement configElement) {
        if (!configElement.getName().equals(PROVIDER)){
            return null;
        }
        try {
            return new ElementInfoProviderExtension(configElement);
        } catch (Exception e) {
        }
        return null;
    }

    private IElementViewerInfoProvider provider = null;

    private ElementInfoProviderExtension(IConfigurationElement configElement) {
        try {
            this.provider = (IElementViewerInfoProvider) configElement.createExecutableExtension(ATTR_CLASS);            
        } catch (Exception e) {
        }
    }

    private IElementViewerInfoProvider getElementViewerInfoProvider() {
        return this.provider;
    }

}