org.eclipse.gmf.runtime.common.ui.services.dnd/src/org/eclipse/gmf/runtime/common/ui/services/dnd/drop/AbstractDropTargetListener.java - gmf-runtime/org.eclipse.gmf-runtime - Git at Google

 /******************************************************************************
  * Copyright (c) 2002, 2010 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:
  *    IBM Corporation - initial API and implementation
  ****************************************************************************/

 package org.eclipse.gmf.runtime.common.ui.services.dnd.drop;

 import java.lang.ref.WeakReference;
 import java.lang.reflect.InvocationTargetException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Vector;

 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.commands.operations.IOperationHistory;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.jface.dialogs.ProgressMonitorDialog;
 import org.eclipse.jface.operation.IRunnableWithProgress;
 import org.eclipse.swt.custom.BusyIndicator;
 import org.eclipse.swt.dnd.DND;
 import org.eclipse.swt.dnd.DropTargetEvent;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IWorkbenchPartSite;

 import org.eclipse.gmf.runtime.common.core.command.ICommand;
 import org.eclipse.gmf.runtime.common.core.util.EnumeratedType;
 import org.eclipse.gmf.runtime.common.core.util.Log;
 import org.eclipse.gmf.runtime.common.core.util.Trace;
 import org.eclipse.gmf.runtime.common.ui.services.dnd.core.ITransferAgent;
 import org.eclipse.gmf.runtime.common.ui.services.dnd.internal.CommonUIServicesDNDDebugOptions;
 import org.eclipse.gmf.runtime.common.ui.services.dnd.internal.CommonUIServicesDNDPlugin;
 import org.eclipse.gmf.runtime.common.ui.services.dnd.internal.CommonUIServicesDNDStatusCodes;

 /**
  * Abstract parent of all the drop target listeners
  *
  * @author Vishy Ramaswamy
  */
 public abstract class AbstractDropTargetListener
 	implements IDropTargetListener {

 	/**
 	 * Attribute for the drop target context.
 	 */
 	private WeakReference<IDropTargetContext> context = null;

 	/**
 	 * Attribute for the current transfer agent.
 	 */
 	private ITransferAgent currentAgent = null;

 	/**
 	 * Attribute for the current event.
 	 */
 	private IDropTargetEvent currentEvent = null;

 	/**
 	 * Attribute for the supporting transfer ids.
 	 */
 	private final List transferIds = new Vector();

 	/**
 	 * Enumerated type for work indicator type
 	 */
 	public static class WorkIndicatorType
 		extends EnumeratedType {

 		private static final long serialVersionUID = 1L;

 		private static int nextOrdinal = 0;

 		/** None work indicator type. */
 		public static final WorkIndicatorType NONE = new WorkIndicatorType(
 			"None"); //$NON-NLS-1$

 		/** Busy work indicator type. */
 		public static final WorkIndicatorType BUSY = new WorkIndicatorType(
 			"Busy"); //$NON-NLS-1$

 		/** Progress monitor indicator type. */
 		public static final WorkIndicatorType PROGRESS_MONITOR = new WorkIndicatorType(
 			"Progress Monitor"); //$NON-NLS-1$

 		/** Cancelable progress monitor indicator type. */
 		public static final WorkIndicatorType CANCELABLE_PROGRESS_MONITOR = new WorkIndicatorType(
 			"Cancelable Progress Monitor"); //$NON-NLS-1$

 		/**
 		 * The list of values for this enumerated type.
 		 */
 		private static final WorkIndicatorType[] VALUES = {NONE, BUSY,
 			PROGRESS_MONITOR, CANCELABLE_PROGRESS_MONITOR};

 		/**
 		 * Constructor for WorkIndicatorType.
 		 *
 		 * @param name
 		 *            The name for the WorkIndicatorType
 		 * @param ordinal
 		 *            The ordinal for theWorkIndicatorType
 		 */
 		protected WorkIndicatorType(String name, int ordinal) {
 			super(name, ordinal);
 		}

 		/**
 		 * Constructor for WorkIndicatorType.
 		 *
 		 * @param name
 		 *            The name for the WorkIndicatorType
 		 */
 		private WorkIndicatorType(String name) {
 			this(name, nextOrdinal++);
 		}

 		/**
 		 * Retrieves the list of constants for this enumerated type.
 		 *
 		 * @return The list of constants for this enumerated type.
 		 */
 		protected List getValues() {
 			return Collections.unmodifiableList(Arrays.asList(VALUES));
 		}
 	}

 	/**
 	 * Constructor for AbstractDropTargetListener.
 	 *
 	 * @param transferIdArray
 	 *            The transfer agent ids
 	 */
 	public AbstractDropTargetListener(String[] transferIdArray) {
 		super();

 		assert null!=transferIdArray : "transferIdArray cannot be null"; //$NON-NLS-1$
 		assert transferIdArray.length > 0 : "transferIdArray cannot be empty"; //$NON-NLS-1$

 		this.transferIds.addAll(Arrays.asList(transferIdArray));
 	}

 	/**
 	 * Default Constructor for AbstractDropTargetListener.
 	 *
 	 */
 	public AbstractDropTargetListener() {
 		super();
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#getSupportingTransferIds()
 	 */
 	public final String[] getSupportingTransferIds() {
 		return (String[]) transferIds.toArray(new String[transferIds.size()]);
 	}

 	/**
 	 * Add transfer id to the list of transferIds.
 	 *
 	 * @param transferId
 	 *            String id to add
 	 */
 	public final void addSupportingTransferId(String transferId) {
 		assert null != transferId : "transferId cannot be null"; //$NON-NLS-1$

 		if (!transferIds.contains(transferId)) {
 			transferIds.add(transferId);
 		}
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.swt.dnd.DropTargetListener#dragEnter(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public void dragEnter(DropTargetEvent event) {
 		/* method not implemented */
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.swt.dnd.DropTargetListener#dragLeave(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public void dragLeave(DropTargetEvent event) {
 		/* method not implemented */
 		currentAgent = null;
 		currentEvent = null;
 		context = null;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.swt.dnd.DropTargetListener#dragOperationChanged(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public void dragOperationChanged(DropTargetEvent event) {
 		/* method not implemented */
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.swt.dnd.DropTargetListener#dragOver(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public void dragOver(DropTargetEvent event) {
 		/* method not implemented */
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.swt.dnd.DropTargetListener#drop(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public final void drop(DropTargetEvent event) {
 		/* Check the target and data */
 		// Fix for RATLC00528158 - Linux: Cannot DnD Tables or Database from
 		// Data Definition View to Class Diagram
 		// Removed check "event.data == null"
 		if (getContext().getCurrentTarget() == null) {
 			event.detail = DND.DROP_NONE;
 			return;
 		}

 		/* Get the command */
 		final ICommand command = getExecutableContext(event);

 		/* Get the command manager */
 		final IOperationHistory manager = (IOperationHistory) getContext()
 			.getActivePart().getAdapter(IOperationHistory.class);

 		/* Check the manager and command */
 		if (manager == null || command == null) {
 			event.detail = DND.DROP_NONE;
 			return;
 		}

 		WorkIndicatorType type = getWorkIndicatorType();

 		if (type == WorkIndicatorType.PROGRESS_MONITOR) {
 			runCommandInProgressMonitorDialog(command, false);

 		} else if (type == WorkIndicatorType.CANCELABLE_PROGRESS_MONITOR) {
 			runCommandInProgressMonitorDialog(command, true);

 		} else if (type == WorkIndicatorType.BUSY) {
             /* display hour glass cursor */
             BusyIndicator.showWhile(null, new Runnable() {

                 public void run() {
                     try {
                         manager.execute(command, new NullProgressMonitor(),
                             null);
                     } catch (ExecutionException e) {
                         Trace
                             .catching(
                                 CommonUIServicesDNDPlugin.getDefault(),
                                 CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
                                 getClass(), "drop", e); //$NON-NLS-1$
                         Log.error(CommonUIServicesDNDPlugin.getDefault(),
                             CommonUIServicesDNDStatusCodes.SERVICE_FAILURE,
                             "drop", e); //$NON-NLS-1$
                     }

                 }
             });
         } else {
             try {
                 manager.execute(command, new NullProgressMonitor(), null);
             } catch (ExecutionException e) {
                 Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
                     CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
                     getClass(), "drop", e); //$NON-NLS-1$
                 Log.error(CommonUIServicesDNDPlugin.getDefault(),
                     CommonUIServicesDNDStatusCodes.SERVICE_FAILURE, "drop", e); //$NON-NLS-1$
             }
         }

 		/* Set the event detail */
 		event.detail = (command.getCommandResult().getStatus().isOK()) ? event.detail
 			: DND.DROP_NONE;

 		currentAgent = null;
 		currentEvent = null;
 		context = null;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.swt.dnd.DropTargetListener#dropAccept(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public void dropAccept(DropTargetEvent event) {
 		/* method not implemented */
 	}

 	/**
 	 * Returns the context.
 	 *
 	 * @return IDropTargetContext
 	 */
 	protected final IDropTargetContext getContext() {
 		if(context==null) return null;
 		return context.get();
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#getExecutableContext(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public ICommand getExecutableContext(DropTargetEvent event) {
 		return null;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#setFeedback(org.eclipse.swt.dnd.DropTargetEvent)
 	 */
 	public void setFeedback(DropTargetEvent event) {
 		event.feedback |= DND.FEEDBACK_EXPAND | DND.FEEDBACK_SCROLL;
 		switch (getContext().getRelativeLocation()) {
 			case IDropTargetContext.LOCATION_BEFORE:
 				event.feedback |= DND.FEEDBACK_INSERT_BEFORE;
 				break;
 			case IDropTargetContext.LOCATION_AFTER:
 				event.feedback |= DND.FEEDBACK_INSERT_AFTER;
 				break;
 			case IDropTargetContext.LOCATION_ON:
 			default:
 				event.feedback |= DND.FEEDBACK_SELECT;
 				break;
 		}
 	}

 	/**
 	 * Returns whether the listener can support handling drop operations on the
 	 * current target context and the current event.
 	 *
 	 * @return true or false
 	 */
 	public abstract boolean canSupport();

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#canSupport(org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetContext,
 	 *      org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetEvent,
 	 *      org.eclipse.gmf.runtime.common.ui.services.dnd.core.ITransferAgent)
 	 */
 	public final boolean canSupport(IDropTargetContext cntxt,
 			IDropTargetEvent currEvent, ITransferAgent currAgent) {
 		/* Set the context */
 		this.context = new WeakReference<IDropTargetContext>(cntxt);
 		/* Set the event */
 		this.currentEvent = currEvent;
 		/* Set the agent */
 		this.currentAgent = currAgent;

 		return canSupport();
 	}

 	/**
 	 * Returns the current event.
 	 *
 	 * @return IDropTargetEvent
 	 */
 	protected final IDropTargetEvent getCurrentEvent() {
 		return currentEvent;
 	}

 	/**
 	 * Returns the current transfer agent.
 	 *
 	 * @return ITransferAgent
 	 */
 	protected final ITransferAgent getCurrentAgent() {
 		return currentAgent;
 	}

 	/**
 	 * Returns the current shell.
 	 *
 	 * @return Shell
 	 */
 	protected final Shell getShell() {
 		IWorkbenchPartSite site = getContext().getActivePart().getSite();

 		return site != null ? site.getShell()
 			: null;
 	}

 	/**
 	 * Gets type of work indicator (progress monitor, hourglass, or none).
 	 *
 	 * @return type of work indicator
 	 */
 	protected WorkIndicatorType getWorkIndicatorType() {
 		return WorkIndicatorType.BUSY;
 	}

 	/**
 	 * Runs <code>command</code> in the context of a progress monitor dialog.
 	 * The command runs in the same thread as the dialog. The cancel button on
 	 * the dialog is enabled if <code>cancelable</code> is <code>true</code>.
 	 *
 	 * @param command
 	 *            the command to run
 	 * @param cancelable
 	 *            <code>true</code> if the progress monitor should have an
 	 *            enabled cancel button, <code>false</code> otherwise.
 	 *
 	 * @exception RuntimeException
 	 *                if any exception or error occurs while running the action
 	 */
 	private void runCommandInProgressMonitorDialog(final ICommand command,
 			boolean cancelable) {

 		/* Get the operation history */
 		final IOperationHistory manager = (IOperationHistory) getContext()
 			.getActivePart().getAdapter(IOperationHistory.class);

 		IRunnableWithProgress runnable = new IRunnableWithProgress() {

 			public void run(IProgressMonitor monitor) {
                 try {
                     manager.execute(command, monitor, null);

                 } catch (ExecutionException e) {
                     Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
                         CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
                         getClass(), "drop", e); //$NON-NLS-1$
                     Log.error(CommonUIServicesDNDPlugin.getDefault(),
                         CommonUIServicesDNDStatusCodes.SERVICE_FAILURE, "drop", e); //$NON-NLS-1$

                     RuntimeException re = new RuntimeException(e);

                     Trace.throwing(CommonUIServicesDNDPlugin.getDefault(),
                         CommonUIServicesDNDDebugOptions.EXCEPTIONS_THROWING,
                         getClass(), "runCommandInProgressMonitorDialog", re); //$NON-NLS-1$
                     throw re;
                 }

 			}
 		};
 		runInProgressMonitorDialog(runnable, cancelable);
 	}

 	/**
 	 * Runs <code>runnable</code> in a progress monitor dialog. The runnable
 	 * runs in the same thread as the dialog. The cancel button on the dialog is
 	 * enabled if <code>cancelable</code> is <code>true</code>.
 	 *
 	 * @param runnable
 	 *            the runnable to run in the context of the progress dialog
 	 * @param cancelable
 	 *            <code>true</code> if the progress monitor should have an
 	 *            enabled cancel button, <code>false</code> otherwise.
 	 *
 	 * @exception RuntimeException
 	 *                if any exception or error occurs while running the
 	 *                runnable
 	 */
 	private void runInProgressMonitorDialog(IRunnableWithProgress runnable,
 			boolean cancelable) {

 		try {
 			if (System.getProperty("RUN_PROGRESS_IN_UI_HACK") != null) { //$NON-NLS-1$
 				new ProgressMonitorDialog(null).run(false, cancelable, runnable);
 			} else {
 				new ProgressMonitorDialog(null).run(true, cancelable, runnable);
 			}

 		} catch (InvocationTargetException ite) {
 			Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
 				CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
 				getClass(), "runInProgressMonitorDialog", ite); //$NON-NLS-1$
 			Log.error(CommonUIServicesDNDPlugin.getDefault(),
 				CommonUIServicesDNDStatusCodes.SERVICE_FAILURE,
 				"runInProgressMonitorDialog", ite); //$NON-NLS-1$

 			RuntimeException cre = new RuntimeException(ite
 				.getTargetException());

 			Trace.throwing(CommonUIServicesDNDPlugin.getDefault(),
 				CommonUIServicesDNDDebugOptions.EXCEPTIONS_THROWING,
 				getClass(), "runInProgressMonitorDialog", cre); //$NON-NLS-1$
 			throw cre;

 		} catch (InterruptedException ie) {
 			Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
 				CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
 				getClass(), "runInProgressMonitorDialog", ie); //$NON-NLS-1$
 		}
 	}

 }
	/******************************************************************************
	* Copyright (c) 2002, 2010 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:
	* IBM Corporation - initial API and implementation
	****************************************************************************/

	package org.eclipse.gmf.runtime.common.ui.services.dnd.drop;

	import java.lang.ref.WeakReference;
	import java.lang.reflect.InvocationTargetException;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.List;
	import java.util.Vector;

	import org.eclipse.core.commands.ExecutionException;
	import org.eclipse.core.commands.operations.IOperationHistory;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.jface.dialogs.ProgressMonitorDialog;
	import org.eclipse.jface.operation.IRunnableWithProgress;
	import org.eclipse.swt.custom.BusyIndicator;
	import org.eclipse.swt.dnd.DND;
	import org.eclipse.swt.dnd.DropTargetEvent;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.ui.IWorkbenchPartSite;

	import org.eclipse.gmf.runtime.common.core.command.ICommand;
	import org.eclipse.gmf.runtime.common.core.util.EnumeratedType;
	import org.eclipse.gmf.runtime.common.core.util.Log;
	import org.eclipse.gmf.runtime.common.core.util.Trace;
	import org.eclipse.gmf.runtime.common.ui.services.dnd.core.ITransferAgent;
	import org.eclipse.gmf.runtime.common.ui.services.dnd.internal.CommonUIServicesDNDDebugOptions;
	import org.eclipse.gmf.runtime.common.ui.services.dnd.internal.CommonUIServicesDNDPlugin;
	import org.eclipse.gmf.runtime.common.ui.services.dnd.internal.CommonUIServicesDNDStatusCodes;

	/**
	* Abstract parent of all the drop target listeners
	*
	* @author Vishy Ramaswamy
	*/
	public abstract class AbstractDropTargetListener
	implements IDropTargetListener {

	/**
	* Attribute for the drop target context.
	*/
	private WeakReference<IDropTargetContext> context = null;

	/**
	* Attribute for the current transfer agent.
	*/
	private ITransferAgent currentAgent = null;

	/**
	* Attribute for the current event.
	*/
	private IDropTargetEvent currentEvent = null;

	/**
	* Attribute for the supporting transfer ids.
	*/
	private final List transferIds = new Vector();

	/**
	* Enumerated type for work indicator type
	*/
	public static class WorkIndicatorType
	extends EnumeratedType {

	private static final long serialVersionUID = 1L;

	private static int nextOrdinal = 0;

	/** None work indicator type. */
	public static final WorkIndicatorType NONE = new WorkIndicatorType(
	"None"); //$NON-NLS-1$

	/** Busy work indicator type. */
	public static final WorkIndicatorType BUSY = new WorkIndicatorType(
	"Busy"); //$NON-NLS-1$

	/** Progress monitor indicator type. */
	public static final WorkIndicatorType PROGRESS_MONITOR = new WorkIndicatorType(
	"Progress Monitor"); //$NON-NLS-1$

	/** Cancelable progress monitor indicator type. */
	public static final WorkIndicatorType CANCELABLE_PROGRESS_MONITOR = new WorkIndicatorType(
	"Cancelable Progress Monitor"); //$NON-NLS-1$

	/**
	* The list of values for this enumerated type.
	*/
	private static final WorkIndicatorType[] VALUES = {NONE, BUSY,
	PROGRESS_MONITOR, CANCELABLE_PROGRESS_MONITOR};

	/**
	* Constructor for WorkIndicatorType.
	*
	* @param name
	* The name for the WorkIndicatorType
	* @param ordinal
	* The ordinal for theWorkIndicatorType
	*/
	protected WorkIndicatorType(String name, int ordinal) {
	super(name, ordinal);
	}

	/**
	* Constructor for WorkIndicatorType.
	*
	* @param name
	* The name for the WorkIndicatorType
	*/
	private WorkIndicatorType(String name) {
	this(name, nextOrdinal++);
	}

	/**
	* Retrieves the list of constants for this enumerated type.
	*
	* @return The list of constants for this enumerated type.
	*/
	protected List getValues() {
	return Collections.unmodifiableList(Arrays.asList(VALUES));
	}
	}

	/**
	* Constructor for AbstractDropTargetListener.
	*
	* @param transferIdArray
	* The transfer agent ids
	*/
	public AbstractDropTargetListener(String[] transferIdArray) {
	super();

	assert null!=transferIdArray : "transferIdArray cannot be null"; //$NON-NLS-1$
	assert transferIdArray.length > 0 : "transferIdArray cannot be empty"; //$NON-NLS-1$

	this.transferIds.addAll(Arrays.asList(transferIdArray));
	}

	/**
	* Default Constructor for AbstractDropTargetListener.
	*
	*/
	public AbstractDropTargetListener() {
	super();
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#getSupportingTransferIds()
	*/
	public final String[] getSupportingTransferIds() {
	return (String[]) transferIds.toArray(new String[transferIds.size()]);
	}

	/**
	* Add transfer id to the list of transferIds.
	*
	* @param transferId
	* String id to add
	*/
	public final void addSupportingTransferId(String transferId) {
	assert null != transferId : "transferId cannot be null"; //$NON-NLS-1$

	if (!transferIds.contains(transferId)) {
	transferIds.add(transferId);
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.swt.dnd.DropTargetListener#dragEnter(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public void dragEnter(DropTargetEvent event) {
	/* method not implemented */
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.swt.dnd.DropTargetListener#dragLeave(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public void dragLeave(DropTargetEvent event) {
	/* method not implemented */
	currentAgent = null;
	currentEvent = null;
	context = null;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.swt.dnd.DropTargetListener#dragOperationChanged(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public void dragOperationChanged(DropTargetEvent event) {
	/* method not implemented */
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.swt.dnd.DropTargetListener#dragOver(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public void dragOver(DropTargetEvent event) {
	/* method not implemented */
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.swt.dnd.DropTargetListener#drop(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public final void drop(DropTargetEvent event) {
	/* Check the target and data */
	// Fix for RATLC00528158 - Linux: Cannot DnD Tables or Database from
	// Data Definition View to Class Diagram
	// Removed check "event.data == null"
	if (getContext().getCurrentTarget() == null) {
	event.detail = DND.DROP_NONE;
	return;
	}

	/* Get the command */
	final ICommand command = getExecutableContext(event);

	/* Get the command manager */
	final IOperationHistory manager = (IOperationHistory) getContext()
	.getActivePart().getAdapter(IOperationHistory.class);

	/* Check the manager and command */
	if (manager == null \|\| command == null) {
	event.detail = DND.DROP_NONE;
	return;
	}

	WorkIndicatorType type = getWorkIndicatorType();

	if (type == WorkIndicatorType.PROGRESS_MONITOR) {
	runCommandInProgressMonitorDialog(command, false);

	} else if (type == WorkIndicatorType.CANCELABLE_PROGRESS_MONITOR) {
	runCommandInProgressMonitorDialog(command, true);

	} else if (type == WorkIndicatorType.BUSY) {
	/* display hour glass cursor */
	BusyIndicator.showWhile(null, new Runnable() {

	public void run() {
	try {
	manager.execute(command, new NullProgressMonitor(),
	null);
	} catch (ExecutionException e) {
	Trace
	.catching(
	CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
	getClass(), "drop", e); //$NON-NLS-1$
	Log.error(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDStatusCodes.SERVICE_FAILURE,
	"drop", e); //$NON-NLS-1$
	}

	}
	});
	} else {
	try {
	manager.execute(command, new NullProgressMonitor(), null);
	} catch (ExecutionException e) {
	Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
	getClass(), "drop", e); //$NON-NLS-1$
	Log.error(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDStatusCodes.SERVICE_FAILURE, "drop", e); //$NON-NLS-1$
	}
	}

	/* Set the event detail */
	event.detail = (command.getCommandResult().getStatus().isOK()) ? event.detail
	: DND.DROP_NONE;

	currentAgent = null;
	currentEvent = null;
	context = null;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.swt.dnd.DropTargetListener#dropAccept(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public void dropAccept(DropTargetEvent event) {
	/* method not implemented */
	}

	/**
	* Returns the context.
	*
	* @return IDropTargetContext
	*/
	protected final IDropTargetContext getContext() {
	if(context==null) return null;
	return context.get();
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#getExecutableContext(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public ICommand getExecutableContext(DropTargetEvent event) {
	return null;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#setFeedback(org.eclipse.swt.dnd.DropTargetEvent)
	*/
	public void setFeedback(DropTargetEvent event) {
	event.feedback \|= DND.FEEDBACK_EXPAND \| DND.FEEDBACK_SCROLL;
	switch (getContext().getRelativeLocation()) {
	case IDropTargetContext.LOCATION_BEFORE:
	event.feedback \|= DND.FEEDBACK_INSERT_BEFORE;
	break;
	case IDropTargetContext.LOCATION_AFTER:
	event.feedback \|= DND.FEEDBACK_INSERT_AFTER;
	break;
	case IDropTargetContext.LOCATION_ON:
	default:
	event.feedback \|= DND.FEEDBACK_SELECT;
	break;
	}
	}

	/**
	* Returns whether the listener can support handling drop operations on the
	* current target context and the current event.
	*
	* @return true or false
	*/
	public abstract boolean canSupport();

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetListener#canSupport(org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetContext,
	* org.eclipse.gmf.runtime.common.ui.services.dnd.drop.IDropTargetEvent,
	* org.eclipse.gmf.runtime.common.ui.services.dnd.core.ITransferAgent)
	*/
	public final boolean canSupport(IDropTargetContext cntxt,
	IDropTargetEvent currEvent, ITransferAgent currAgent) {
	/* Set the context */
	this.context = new WeakReference<IDropTargetContext>(cntxt);
	/* Set the event */
	this.currentEvent = currEvent;
	/* Set the agent */
	this.currentAgent = currAgent;

	return canSupport();
	}

	/**
	* Returns the current event.
	*
	* @return IDropTargetEvent
	*/
	protected final IDropTargetEvent getCurrentEvent() {
	return currentEvent;
	}

	/**
	* Returns the current transfer agent.
	*
	* @return ITransferAgent
	*/
	protected final ITransferAgent getCurrentAgent() {
	return currentAgent;
	}

	/**
	* Returns the current shell.
	*
	* @return Shell
	*/
	protected final Shell getShell() {
	IWorkbenchPartSite site = getContext().getActivePart().getSite();

	return site != null ? site.getShell()
	: null;
	}

	/**
	* Gets type of work indicator (progress monitor, hourglass, or none).
	*
	* @return type of work indicator
	*/
	protected WorkIndicatorType getWorkIndicatorType() {
	return WorkIndicatorType.BUSY;
	}

	/**
	* Runs <code>command</code> in the context of a progress monitor dialog.
	* The command runs in the same thread as the dialog. The cancel button on
	* the dialog is enabled if <code>cancelable</code> is <code>true</code>.
	*
	* @param command
	* the command to run
	* @param cancelable
	* <code>true</code> if the progress monitor should have an
	* enabled cancel button, <code>false</code> otherwise.
	*
	* @exception RuntimeException
	* if any exception or error occurs while running the action
	*/
	private void runCommandInProgressMonitorDialog(final ICommand command,
	boolean cancelable) {

	/* Get the operation history */
	final IOperationHistory manager = (IOperationHistory) getContext()
	.getActivePart().getAdapter(IOperationHistory.class);

	IRunnableWithProgress runnable = new IRunnableWithProgress() {

	public void run(IProgressMonitor monitor) {
	try {
	manager.execute(command, monitor, null);

	} catch (ExecutionException e) {
	Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
	getClass(), "drop", e); //$NON-NLS-1$
	Log.error(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDStatusCodes.SERVICE_FAILURE, "drop", e); //$NON-NLS-1$

	RuntimeException re = new RuntimeException(e);

	Trace.throwing(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_THROWING,
	getClass(), "runCommandInProgressMonitorDialog", re); //$NON-NLS-1$
	throw re;
	}

	}
	};
	runInProgressMonitorDialog(runnable, cancelable);
	}

	/**
	* Runs <code>runnable</code> in a progress monitor dialog. The runnable
	* runs in the same thread as the dialog. The cancel button on the dialog is
	* enabled if <code>cancelable</code> is <code>true</code>.
	*
	* @param runnable
	* the runnable to run in the context of the progress dialog
	* @param cancelable
	* <code>true</code> if the progress monitor should have an
	* enabled cancel button, <code>false</code> otherwise.
	*
	* @exception RuntimeException
	* if any exception or error occurs while running the
	* runnable
	*/
	private void runInProgressMonitorDialog(IRunnableWithProgress runnable,
	boolean cancelable) {

	try {
	if (System.getProperty("RUN_PROGRESS_IN_UI_HACK") != null) { //$NON-NLS-1$
	new ProgressMonitorDialog(null).run(false, cancelable, runnable);
	} else {
	new ProgressMonitorDialog(null).run(true, cancelable, runnable);
	}

	} catch (InvocationTargetException ite) {
	Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
	getClass(), "runInProgressMonitorDialog", ite); //$NON-NLS-1$
	Log.error(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDStatusCodes.SERVICE_FAILURE,
	"runInProgressMonitorDialog", ite); //$NON-NLS-1$

	RuntimeException cre = new RuntimeException(ite
	.getTargetException());

	Trace.throwing(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_THROWING,
	getClass(), "runInProgressMonitorDialog", cre); //$NON-NLS-1$
	throw cre;

	} catch (InterruptedException ie) {
	Trace.catching(CommonUIServicesDNDPlugin.getDefault(),
	CommonUIServicesDNDDebugOptions.EXCEPTIONS_CATCHING,
	getClass(), "runInProgressMonitorDialog", ie); //$NON-NLS-1$
	}
	}

	}