/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2005, 2011 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *    Patch 203186 from Bug 357411 contributed by Hernan Gonzalez
 *
 * </copyright>
 *
 *******************************************************************************/
package org.eclipse.graphiti.ui.internal.util;

import java.lang.reflect.Method;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.graphiti.internal.util.T;
import org.eclipse.swt.dnd.Transfer;

/**
 * In this class, we combine all reflection code introduced to make Graphiti run
 * in a lean RCP setup, that is, for instance without org.eclipse.ui.ide
 * installed. An alternative would be to use extension points which seems to be
 * rather heavy-weight.
 */
public class ReflectionUtil {

	private static final String CLASSNAME_RESOURCE_TRANSFER = "org.eclipse.ui.part.ResourceTransfer"; //$NON-NLS-1$
	private static final String METHODNAME_RESOURCE_TRANSFER = "getInstance"; //$NON-NLS-1$

	/**
	 * Typical scenario: input instance of IFileEditorInput 
	 * We don't want to depend on that interface, as it resides in org.eclipse.ui.ide. 
	 * We need to support an RCP scenario without having this plug-in installed.
	 */
	public static IFile getFile(Object input) {
		IFile file = null;
		if (input instanceof IAdaptable) {
			file = (IFile) ((IAdaptable) input).getAdapter(IFile.class);
		}
		return file;
	}

	/**
	 * ResourceTransfer resides in org.eclipse.ui.ide. We need to support an RCP
	 * scenario without having this plug-in installed. Therefore ashamed we use
	 * dynamic class-loading and reflection.
	 */
	public static Transfer getResourceTransfer() {
		Transfer resourceTransfer = null;
		try {
			Class<?> forName = Class.forName(CLASSNAME_RESOURCE_TRANSFER);
			Method method = forName.getMethod(METHODNAME_RESOURCE_TRANSFER);
			Object obj = method.invoke(forName);
			if (obj != null && obj instanceof Transfer)
				resourceTransfer = (Transfer) obj;
		} catch (Exception e) {
			T.racer().debug(e.getMessage());
		}
		return resourceTransfer;
	}
}