content: /*******************************************************************************
   * Copyright (c) 2000, 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:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.ui.dnd;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.eclipse.core.resources.IResource;
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.core.runtime.IAdaptable;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.core.runtime.MultiStatus;
  import org.eclipse.jface.dialogs.ErrorDialog;
  import org.eclipse.jface.util.TransferDragSourceListener;
  import org.eclipse.jface.viewers.ISelection;
  import org.eclipse.jface.viewers.ISelectionProvider;
  import org.eclipse.jface.viewers.IStructuredSelection;
  import org.eclipse.swt.dnd.DND;
  import org.eclipse.swt.dnd.DragSourceAdapter;
  import org.eclipse.swt.dnd.DragSourceEvent;
  import org.eclipse.swt.dnd.Transfer;
  import org.eclipse.swt.widgets.Shell;
  import org.eclipse.ui.part.ResourceTransfer;
  import org.eclipse.wst.jsdt.core.IJavaScriptElement;
  import org.eclipse.wst.jsdt.internal.ui.IJavaStatusConstants;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  import org.eclipse.wst.jsdt.internal.ui.JavaUIMessages;
  import org.eclipse.wst.jsdt.internal.ui.util.SWTUtil;
  
  /**
   * A drag adapter that transfers the current selection as </code>
   * IResource</code>. Only those elements in the selection are part 
   * of the transfer which can be converted into an <code>IResource
   * </code>.
   */
  public class ResourceTransferDragAdapter extends DragSourceAdapter implements TransferDragSourceListener {
  
  	private ISelectionProvider fProvider;
  
  	private static final List EMPTY_LIST= new ArrayList(0);
  
  	/**
  	 * Creates a new ResourceTransferDragAdapter for the given selection
  	 * provider.
  	 * 
  	 * @param provider the selection provider to access the viewer's selection
  	 */
  	public ResourceTransferDragAdapter(ISelectionProvider provider) {
  		fProvider= provider;
  		Assert.isNotNull(fProvider);
  	}
  	
  	public Transfer getTransfer() {
  		return ResourceTransfer.getInstance();
  	}
  	
  	public void dragStart(DragSourceEvent event) {
  		event.doit= convertSelection().size() > 0;
  	}
  	
  	public void dragSetData(DragSourceEvent event) {
  		List resources= convertSelection();
  		event.data= resources.toArray(new IResource[resources.size()]);
  	}
  	
  	public void dragFinished(DragSourceEvent event) {
  		if (!event.doit)
  			return;
  
  		if (event.detail == DND.DROP_MOVE) {
  			handleFinishedDropMove(event);
  		}	
  	}
  	
  	private List convertSelection() {
  		ISelection s= fProvider.getSelection();
  		if (!(s instanceof IStructuredSelection))
  			return EMPTY_LIST;
  		IStructuredSelection selection= (IStructuredSelection)s;
  		List result= new ArrayList(selection.size());
  		for (Iterator iter= selection.iterator(); iter.hasNext();) {
  			Object element= iter.next();
  			IResource resource= null;
  			if (element instanceof IJavaScriptElement) {
  				// don't use IAdaptable as for members only the top level type adapts
  				resource= ((IJavaScriptElement) element).getResource();
  			} else if (element instanceof IAdaptable) {
  				resource= (IResource) ((IAdaptable) element).getAdapter(IResource.class);
  			}
  			if (resource != null)
  				result.add(resource);
  		}
  		return result;
  	}
  	
  	private void handleFinishedDropMove(DragSourceEvent event) {
  		MultiStatus status= new MultiStatus(
  			JavaScriptPlugin.getPluginId(), 
  			IJavaStatusConstants.INTERNAL_ERROR, 
  			JavaUIMessages.ResourceTransferDragAdapter_cannot_delete_resource,  
  			null);
  		List resources= convertSelection();
  		for (Iterator iter= resources.iterator(); iter.hasNext();) {
  			IResource resource= (IResource) iter.next();
  			try {
  				resource.delete(true, null);
  			} catch (CoreException e) {
  				status.add(e.getStatus());
  			}
  		}
  		if (status.getChildren().length > 0) {
  			Shell parent= SWTUtil.getShell(event.widget);
  			ErrorDialog error= new ErrorDialog(parent, 
  				JavaUIMessages.ResourceTransferDragAdapter_moving_resource,  
  				JavaUIMessages.ResourceTransferDragAdapter_cannot_delete_files,  
  				status, IStatus.ERROR);
  			error.open();
  		}
  	}
  }
  
  