/*******************************************************************************
* Copyright (c) 2006, 2012 Oracle 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:
* Oracle Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.bpel.ui.dnd;
import java.util.List;
import org.eclipse.bpel.ui.BPELEditor;
import org.eclipse.bpel.ui.util.TransferBuffer;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPartViewer;
import org.eclipse.gef.Request;
import org.eclipse.gef.dnd.AbstractTransferDropTargetListener;
import org.eclipse.gef.requests.CreateRequest;
import org.eclipse.gef.requests.CreationFactory;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.TextTransfer;
/**
*
* A drop handler that is used to transfer text representations of BPEL into the graphical
* editor.
*
* @author Michal Chmielewski (michal.chmielewski@oracle.com)
* @date Aug 20, 2007
*
*/
public class BPELTextTransferDropTargetListener extends AbstractTransferDropTargetListener {
@SuppressWarnings("nls")
/** The reader which we use as a conversion */
org.eclipse.bpel.model.resource.BPELReader fReader = null;
/** The create request that we generate from the content of the clipboard. */
Request fTargetRequest = null;
/** The target resource */
protected Resource fTargetResource;
protected BPELEditor fEditor;
/** The from source factory */
class FromSourceFactory implements CreationFactory {
EObject fNewObject = null;
FromSourceFactory ( EObject newObject) {
this.fNewObject = newObject;
}
/**
* @see org.eclipse.gef.requests.CreationFactory#getNewObject()
*/
@Override
public Object getNewObject() {
return this.fNewObject;
}
/**
* @see org.eclipse.gef.requests.CreationFactory#getObjectType()
*/
@Override
public Object getObjectType() {
EObject eObj = (EObject) getNewObject();
if (eObj != null) {
return eObj.eClass();
}
return null;
}
}
@Override
protected void unload() {
super.unload();
this.fTargetRequest = null;
}
/**
* Constructs a listener on the specified viewer.
* @param viewer the EditPartViewer
* @param editor
*/
public BPELTextTransferDropTargetListener (EditPartViewer viewer, BPELEditor editor ) {
super(viewer, TextTransfer.getInstance() );
this.fReader = new org.eclipse.bpel.model.resource.BPELReader();
this.fEditor = editor;
}
/**
* We create the target request once from the content of the clipboard.
* We attempt to parse the clipboard and then push the result in the creation
* factory so that the usual editor mechanics apply.
*
* @see org.eclipse.gef.dnd.AbstractTransferDropTargetListener#createTargetRequest()
*/
@SuppressWarnings("nls")
@Override
protected Request createTargetRequest() {
CreateRequest request = new CreateRequest();
String data = (String) TextTransfer.getInstance().nativeToJava(getCurrentEvent().currentDataType);
try {
List<EObject> list = this.fReader.fromXML(TransferBuffer.adjustXMLSource(data), "Drag-Session", this.fEditor.getResource() ); //$NON-NLS-1$
if (list.size() > 0) {
request.setFactory(new FromSourceFactory(list.get(0)) );
return request;
}
} catch (Throwable t) {
t.printStackTrace();
}
// Mickael Istria:
// In case nothing to DND or error occurred
// Command cannot be executed because not CreationFactory was provided. Then dropListener.isEnabled will return false.
// Vincent Zurczak:
// Yes, but, in fact, the command may not be created (illegal argument exception because the factory is null)
// Fixed below by surrounding the isEnabled by a try/catch
setEnablementDeterminedByCommand( true );
return request;
}
/*
* (non-Javadoc)
* @see org.eclipse.gef.dnd.AbstractTransferDropTargetListener
* #isEnabled(org.eclipse.swt.dnd.DropTargetEvent)
*/
@Override
public boolean isEnabled( DropTargetEvent event ) {
boolean result = false;
try {
result = super.isEnabled( event );
} catch( Exception e ) {
// nothing
}
return result;
}
/**
* A helper method that casts the target Request to a CreateRequest.
* @return CreateRequest
*/
protected final CreateRequest getCreateRequest() {
return (CreateRequest) getTargetRequest();
}
/**
*
* @see AbstractTransferDropTargetListener#handleDragOperationChanged()
*/
@Override
protected void handleDragOperationChanged() {
if (getCreateRequest().getNewObject() == null ) {
getCurrentEvent().detail = DND.DROP_NONE;
} else {
getCurrentEvent().detail = DND.DROP_COPY;
}
super.handleDragOperationChanged();
}
/**
* The purpose of a template is to be copied. Therefore, the Drop operation is set to
* <code>DND.DROP_COPY</code> by default.
* @see org.eclipse.gef.dnd.AbstractTransferDropTargetListener#handleDragOver()
*/
@Override
protected void handleDragOver() {
if ( getCreateRequest().getNewObject() == null ) {
getCurrentEvent().detail = DND.DROP_NONE;
getCurrentEvent().detail = DND.FEEDBACK_NONE;
} else {
getCurrentEvent().detail = DND.DROP_COPY;
getCurrentEvent().feedback = DND.FEEDBACK_SCROLL | DND.FEEDBACK_EXPAND;
}
super.handleDragOver();
}
/**
* Overridden to select the created object.
* @see org.eclipse.gef.dnd.AbstractTransferDropTargetListener#handleDrop()
*/
@Override
protected void handleDrop() {
CreateRequest cr = getCreateRequest();
super.handleDrop();
selectAddedObject( cr );
}
private void selectAddedObject ( CreateRequest cr ) {
Object model = cr.getNewObject();
if (model == null) {
return ;
}
EditPartViewer viewer = getViewer();
viewer.getControl().forceFocus();
Object editpart = viewer.getEditPartRegistry().get(model);
if (editpart instanceof EditPart) {
//Force a layout first.
getViewer().flush();
viewer.select((EditPart)editpart);
}
}
/**
*
*/
@Override
protected Request getTargetRequest() {
if (this.fTargetRequest == null) {
this.fTargetRequest = createTargetRequest();
}
return this.fTargetRequest;
}
/**
* Assumes that the target request is a {@link CreateRequest}.
*/
@Override
protected void updateTargetRequest() {
CreateRequest request = getCreateRequest();
request.setLocation(getDropLocation());
}
}