content: /*******************************************************************************
   * Copyright (c) 2006, 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.navigator;
  
  import java.lang.reflect.InvocationTargetException;
  import java.util.List;
  
  import org.eclipse.core.resources.IContainer;
  import org.eclipse.core.resources.IResource;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.core.runtime.Status;
  import org.eclipse.jface.viewers.ISelection;
  import org.eclipse.jface.viewers.IStructuredSelection;
  import org.eclipse.swt.dnd.DND;
  import org.eclipse.swt.dnd.DropTargetEvent;
  import org.eclipse.swt.dnd.FileTransfer;
  import org.eclipse.swt.dnd.TransferData;
  import org.eclipse.ui.actions.CopyFilesAndFoldersOperation;
  import org.eclipse.ui.navigator.CommonDropAdapter;
  import org.eclipse.ui.navigator.CommonDropAdapterAssistant;
  import org.eclipse.ui.views.navigator.LocalSelectionTransfer;
  import org.eclipse.wst.jsdt.core.IJavaScriptElement;
  import org.eclipse.wst.jsdt.core.JavaScriptModelException;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.reorg.JavaCopyProcessor;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.reorg.JavaMoveProcessor;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.reorg.ReorgPolicyFactory;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.reorg.ReorgUtils;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.reorg.IReorgPolicy.ICopyPolicy;
  import org.eclipse.wst.jsdt.internal.corext.refactoring.reorg.IReorgPolicy.IMovePolicy;
  import org.eclipse.wst.jsdt.internal.ui.packageview.PackagesMessages;
  import org.eclipse.wst.jsdt.internal.ui.refactoring.RefactoringMessages;
  import org.eclipse.wst.jsdt.internal.ui.refactoring.reorg.ReorgCopyStarter;
  import org.eclipse.wst.jsdt.internal.ui.refactoring.reorg.ReorgMoveStarter;
  import org.eclipse.wst.jsdt.internal.ui.util.ExceptionHandler;
  
  public class JavaDropAdapterAssistant extends CommonDropAdapterAssistant {
  
  	private List fElements;
  	private JavaMoveProcessor fMoveProcessor;
  	private int fCanMoveElements;
  	private JavaCopyProcessor fCopyProcessor;
  	private int fCanCopyElements; 
  
  	public IStatus handleDrop(CommonDropAdapter dropAdapter, DropTargetEvent dropTargetEvent, Object target) { 
  		if (LocalSelectionTransfer.getInstance().isSupportedType(dropAdapter.getCurrentTransfer())) {
  			try {
  
  				switch (dropAdapter.getCurrentOperation()) {
  					case DND.DROP_MOVE :
  						handleDropMove(target);
  						break;
  					case DND.DROP_COPY :
  						handleDropCopy(target);
  						break;
  				}
  			} catch (JavaScriptModelException e) {
  				ExceptionHandler.handle(e, PackagesMessages.SelectionTransferDropAdapter_error_title, PackagesMessages.SelectionTransferDropAdapter_error_message); 
  			} catch (InvocationTargetException e) {
  				ExceptionHandler.handle(e, RefactoringMessages.OpenRefactoringWizardAction_refactoring, RefactoringMessages.OpenRefactoringWizardAction_exception); 
  			} catch (InterruptedException e) {
  				//ok
  			} finally {
  				// The drag source listener must not perform any operation
  				// since this drop adapter did the remove of the source even
  				// if we moved something.
  				//event.detail= DND.DROP_NONE;
  			}
  			clear();
  			return Status.OK_STATUS;
  		} else if (FileTransfer.getInstance().isSupportedType(dropAdapter.getCurrentTransfer())) {
  			try {
  
  				final Object data = FileTransfer.getInstance().nativeToJava(dropAdapter.getCurrentTransfer());
  				if (!(data instanceof String[]))
  					return Status.CANCEL_STATUS;
  
  				final IContainer targetContainer = getActualTarget(target);
  				if (targetContainer == null)
  					return Status.CANCEL_STATUS;
  
  
  				getShell().forceActive();
  				new CopyFilesAndFoldersOperation(getShell()).copyFiles((String[]) data, targetContainer);
  			} catch (JavaScriptModelException e) {
  				String title = PackagesMessages.DropAdapter_errorTitle; 
  				String message = PackagesMessages.DropAdapter_errorMessage; 
  				ExceptionHandler.handle(e, getShell(), title, message);
  			}
  			return Status.OK_STATUS;
  		}
  		return Status.CANCEL_STATUS;
  	}
  
  	public IStatus validateDrop(Object target, int operation, TransferData transferType) { 
  		IStatus result = Status.OK_STATUS;
  		if (LocalSelectionTransfer.getInstance().isSupportedType(transferType)) {
  			initializeSelection();
  			try {
  				switch (operation) {
  					case DND.DROP_DEFAULT :
  						if (handleValidateDefault(target) != DND.DROP_NONE) {
  							result = Status.OK_STATUS;
  						} else {
  							result = Status.CANCEL_STATUS;
  						}
  						break;
  					case DND.DROP_COPY :
  						if (handleValidateCopy(target) != DND.DROP_NONE) {
  							result = Status.OK_STATUS;
  						} else {
  							result = Status.CANCEL_STATUS;
  						}
  						break;
  					case DND.DROP_MOVE :
  						if (handleValidateMove(target) != DND.DROP_NONE) {
  							result = Status.OK_STATUS;
  						} else {
  							result = Status.CANCEL_STATUS;
  						} 
  						break;
  				}
  			} catch (JavaScriptModelException e) {
  				ExceptionHandler.handle(e, PackagesMessages.SelectionTransferDropAdapter_error_title, PackagesMessages.SelectionTransferDropAdapter_error_message); 
  				//event.detail= DND.DROP_NONE;
  				result = Status.CANCEL_STATUS;
  			}
  		}
  		return result;
  	} 
  	
  	public boolean isSupportedType(TransferData transferType) {
  		return super.isSupportedType(transferType) || FileTransfer.getInstance().isSupportedType(transferType);
  	}
  	
  	private IContainer getActualTarget(Object dropTarget) throws JavaScriptModelException {
  		if (dropTarget instanceof IContainer)
  			return (IContainer) dropTarget;
  		else if (dropTarget instanceof IJavaScriptElement)
  			return getActualTarget(((IJavaScriptElement) dropTarget).getCorrespondingResource());
  		return null;
  	}
  
  	protected void initializeSelection() {
  		if (fElements != null)
  			return;
  		ISelection s = LocalSelectionTransfer.getInstance().getSelection();
  		if (!(s instanceof IStructuredSelection))
  			return;
  		fElements = ((IStructuredSelection) s).toList();
  	}
  
  	private void handleDropMove(final Object target) throws JavaScriptModelException, InvocationTargetException, InterruptedException {
  		IJavaScriptElement[] javaElements = ReorgUtils.getJavaElements(fElements);
  		IResource[] resources = ReorgUtils.getResources(fElements);
  		ReorgMoveStarter starter = null;
  		if (target instanceof IResource)
  			starter = ReorgMoveStarter.create(javaElements, resources, (IResource) target);
  		else if (target instanceof IJavaScriptElement)
  			starter = ReorgMoveStarter.create(javaElements, resources, (IJavaScriptElement) target);
  		if (starter != null)
  			starter.run(getShell());
  	}
   
  	private void handleDropCopy(final Object target) throws JavaScriptModelException, InvocationTargetException, InterruptedException {
  		IJavaScriptElement[] javaElements = ReorgUtils.getJavaElements(fElements);
  		IResource[] resources = ReorgUtils.getResources(fElements);
  		ReorgCopyStarter starter = null;
  		if (target instanceof IResource)
  			starter = ReorgCopyStarter.create(javaElements, resources, (IResource) target);
  		else if (target instanceof IJavaScriptElement)
  			starter = ReorgCopyStarter.create(javaElements, resources, (IJavaScriptElement) target);
  		if (starter != null)
  			starter.run(getShell());
  	}
   
  	private int handleValidateCopy(Object target) throws JavaScriptModelException {
  
  		final ICopyPolicy policy= ReorgPolicyFactory.createCopyPolicy(ReorgUtils.getResources(fElements), ReorgUtils.getJavaElements(fElements));
  		fCopyProcessor= policy.canEnable() ? new JavaCopyProcessor(policy) : null;
  		
  		if (!canCopyElements())
  			return DND.DROP_NONE;	
  
  		if (target instanceof IResource && fCopyProcessor != null && fCopyProcessor.setDestination((IResource)target).isOK())
  			return DND.DROP_COPY;
  		else if (target instanceof IJavaScriptElement && fCopyProcessor != null && fCopyProcessor.setDestination((IJavaScriptElement)target).isOK())
  			return DND.DROP_COPY;
  		else
  			return DND.DROP_NONE;					
  	}
   
  	private int handleValidateDefault(Object target) throws JavaScriptModelException {
  		if (target == null)
  			return DND.DROP_NONE;
  
  		return handleValidateMove(target);
  	}
  
  	private int handleValidateMove(Object target) throws JavaScriptModelException {
  		if (target == null)
  			return DND.DROP_NONE;
  		
  		IMovePolicy policy= ReorgPolicyFactory.createMovePolicy(ReorgUtils.getResources(fElements), ReorgUtils.getJavaElements(fElements));
  		fMoveProcessor= (policy.canEnable()) ? new JavaMoveProcessor(policy) : null;
  
  		if (!canMoveElements())
  			return DND.DROP_NONE;	
  
  		if (target instanceof IResource && fMoveProcessor != null && fMoveProcessor.setDestination((IResource)target).isOK())
  			return DND.DROP_MOVE;
  		else if (target instanceof IJavaScriptElement && fMoveProcessor != null && fMoveProcessor.setDestination((IJavaScriptElement)target).isOK())
  			return DND.DROP_MOVE;
  		else
  			return DND.DROP_NONE;	
  	}
  
  
  	private boolean canMoveElements() {
  		if (fCanMoveElements == 0) {
  			fCanMoveElements = 2;
  			if (fMoveProcessor == null)
  				fCanMoveElements = 1;
  		}
  		return fCanMoveElements == 2;
  	}
  
  
  	private boolean canCopyElements() {
  		if (fCanCopyElements == 0) {
  			fCanCopyElements = 2;
  			if (fCopyProcessor == null)
  				fCanCopyElements = 1;
  		}
  		return fCanCopyElements == 2;
  	}
  
  	private void clear() {
  		fElements = null;
  		fMoveProcessor = null;
  		fCanMoveElements = 0;
  		fCopyProcessor = null;
  		fCanCopyElements = 0;
  	}
  }
  