org.vclipse.bapi.actions.ContributionReader.java Source code

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Here is the source code for org.vclipse.bapi.actions.ContributionReader.java

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/*******************************************************************************
 * Copyright (c) 2010 - 2013 webXcerpt Software GmbH.
 * 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:
 *        webXcerpt Software GmbH - initial creator
 *       www.webxcerpt.com
 ******************************************************************************/
package org.vclipse.bapi.actions;

import java.lang.reflect.Method;
import java.util.Collection;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multimaps;

public class ContributionReader {

    public static final String VCLIPSE_SAP_COMMANDS_PREFIX = "org.vclipse.sap.commands";

    public static final String HANDLER_EP_ID = "org.eclipse.ui.handlers";

    private static final String COMMAND_ATTRIBUTE = "commandId";
    private static final String CLASS_ATTRIBUTE = "class";
    private static final String ATTRIBUTE_HANDLER = "handler";

    private final Multimap<String, IBAPIActionRunner<?>> type2Action;

    public ContributionReader() {
        type2Action = HashMultimap.create();
    }

    protected void read() {
        IExtensionRegistry registry = Platform.getExtensionRegistry();
        IExtensionPoint point = registry.getExtensionPoint(HANDLER_EP_ID);
        for (IExtension extension : point.getExtensions()) {
            for (IConfigurationElement element : extension.getConfigurationElements()) {
                String elementName = element.getName();
                if (ATTRIBUTE_HANDLER.equals(elementName)) {
                    String attribute = element.getAttribute(COMMAND_ATTRIBUTE);
                    if (attribute.startsWith(VCLIPSE_SAP_COMMANDS_PREFIX)) {
                        try {
                            Object object = element.createExecutableExtension(CLASS_ATTRIBUTE);
                            if (object instanceof IBAPIActionRunner<?>) {
                                IBAPIActionRunner<?> handler = (IBAPIActionRunner<?>) object;
                                for (Method method : handler.getClass().getMethods()) {
                                    if (method.getName().equals("run")) {
                                        Class<?>[] parameterTypes = method.getParameterTypes();
                                        if (parameterTypes.length > 0) {
                                            type2Action.put(parameterTypes[0].getCanonicalName(), handler);
                                        }
                                    }
                                    break;
                                }
                                type2Action.put(handler.getClass().getName(), handler);
                            }
                        } catch (CoreException exception) {
                            BAPIActionPlugin.log(IStatus.ERROR, exception.getMessage());
                        }
                    }
                }
            }
        }
    }

    public Collection<IBAPIActionRunner<?>> getHandler(String type) {
        if (type2Action.isEmpty()) {
            read();
        }
        return type2Action.get(type);
    }

    public Multimap<String, IBAPIActionRunner<?>> getExtensions() {
        if (type2Action.isEmpty()) {
            read();
        }
        return Multimaps.unmodifiableMultimap(type2Action);
    }
}