org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/newsourcepage/AddFolderToBuildpathAction.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2016 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.wizards.buildpaths.newsourcepage;

 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;

 import org.eclipse.swt.widgets.Shell;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.OperationCanceledException;
 import org.eclipse.core.runtime.SubProgressMonitor;

 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IWorkspaceRoot;

 import org.eclipse.jface.dialogs.IDialogConstants;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.operation.IRunnableContext;
 import org.eclipse.jface.operation.IRunnableWithProgress;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.StructuredSelection;

 import org.eclipse.ui.IWorkbenchSite;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.part.ISetSelectionTarget;

 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IPackageFragment;
 import org.eclipse.jdt.core.JavaCore;

 import org.eclipse.jdt.internal.core.manipulation.util.BasicElementLabels;
 import org.eclipse.jdt.internal.corext.buildpath.BuildpathDelta;
 import org.eclipse.jdt.internal.corext.buildpath.ClasspathModifier;
 import org.eclipse.jdt.internal.corext.util.Messages;

 import org.eclipse.jdt.ui.JavaElementLabels;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.JavaPluginImages;
 import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
 import org.eclipse.jdt.internal.ui.wizards.NewWizardMessages;
 import org.eclipse.jdt.internal.ui.wizards.buildpaths.BuildPathBasePage;
 import org.eclipse.jdt.internal.ui.wizards.buildpaths.BuildPathsBlock;
 import org.eclipse.jdt.internal.ui.wizards.buildpaths.CPListElement;
 import org.eclipse.jdt.internal.ui.wizards.buildpaths.newsourcepage.ClasspathModifierQueries.OutputFolderQuery;

 //SelectedElements iff enabled: IJavaProject || IPackageFrament || IFolder
 public class AddFolderToBuildpathAction extends BuildpathModifierAction {

 	private final IRunnableContext fContext;

 	public AddFolderToBuildpathAction(IWorkbenchSite site) {
 		this(site, null, PlatformUI.getWorkbench().getProgressService());
 	}

 	public AddFolderToBuildpathAction(IRunnableContext context, ISetSelectionTarget selectionTarget) {
 		this(null, selectionTarget, context);
 	}

 	private AddFolderToBuildpathAction(IWorkbenchSite site, ISetSelectionTarget selectionTarget, IRunnableContext context) {
 		super(site, selectionTarget, BuildpathModifierAction.ADD_SEL_SF_TO_BP);

 		fContext= context;

 		setText(NewWizardMessages.NewSourceContainerWorkbookPage_ToolBar_AddSelSFToCP_label);
 		setImageDescriptor(JavaPluginImages.DESC_ELCL_ADD_AS_SOURCE_FOLDER);
 		setToolTipText(NewWizardMessages.NewSourceContainerWorkbookPage_ToolBar_AddSelSFToCP_tooltip);
 	}

 	@Override
 	public String getDetailedDescription() {
 		if (!isEnabled())
 			return null;

 		if (getSelectedElements().size() != 1)
 			return NewWizardMessages.PackageExplorerActionGroup_FormText_Default_toBuildpath;

 		Object obj= getSelectedElements().get(0);
 		String elementLabel= JavaElementLabels.getTextLabel(obj, JavaElementLabels.ALL_DEFAULT);
 		if (obj instanceof IJavaProject) {
 			return Messages.format(NewWizardMessages.PackageExplorerActionGroup_FormText_ProjectToBuildpath, elementLabel);
 		} else if (obj instanceof IPackageFragment) {
 			return Messages.format(NewWizardMessages.PackageExplorerActionGroup_FormText_PackageToBuildpath, elementLabel);
 		} else if (obj instanceof IResource) {
 			return Messages.format(NewWizardMessages.PackageExplorerActionGroup_FormText_FolderToBuildpath, elementLabel);
 		}

 		return null;
 	}

 	@Override
 	public void run() {

 		try {
 			final IJavaProject project;
 			Object object= getSelectedElements().get(0);
 			if (object instanceof IJavaProject) {
 				project= (IJavaProject)object;
 			} else if (object instanceof IPackageFragment) {
 				project= ((IPackageFragment)object).getJavaProject();
 			} else {
 				IFolder folder= (IFolder)object;
 				project= JavaCore.create(folder.getProject());
 				if (project == null)
 					return;
 			}

 			final Shell shell= getShell();

 			final boolean removeProjectFromClasspath;
 			IPath outputLocation= project.getOutputLocation();
 			final IPath defaultOutputLocation= outputLocation.makeRelative();
 			final IPath newDefaultOutputLocation;
 			final boolean removeOldClassFiles;
 			IPath projPath= project.getProject().getFullPath();
 			if (((getSelectedElements().size() != 1) || !(getSelectedElements().get(0) instanceof IJavaProject)) && //if only the project should be added, then the query does not need to be executed
 					(outputLocation.equals(projPath) || defaultOutputLocation.segmentCount() == 1)) {


 				final OutputFolderQuery outputFolderQuery= ClasspathModifierQueries.getDefaultFolderQuery(shell, defaultOutputLocation);
 				if (outputFolderQuery.doQuery(true, ClasspathModifier.getValidator(getSelectedElements(), project), project)) {
 					newDefaultOutputLocation= outputFolderQuery.getOutputLocation();
 					removeProjectFromClasspath= outputFolderQuery.removeProjectFromClasspath();

 					if (BuildPathsBlock.hasClassfiles(project.getProject()) && outputLocation.equals(projPath)) {
 						String title= NewWizardMessages.BuildPathsBlock_RemoveBinariesDialog_title;
 						String message= Messages.format(NewWizardMessages.BuildPathsBlock_RemoveBinariesDialog_description, BasicElementLabels.getPathLabel(projPath, false));
 						MessageDialog dialog= new MessageDialog(shell, title, null, message, MessageDialog.QUESTION, new String[] { IDialogConstants.YES_LABEL, IDialogConstants.NO_LABEL, IDialogConstants.CANCEL_LABEL }, 0);
 						int answer= dialog.open();
 						switch (answer) {
 						case 0:
 							removeOldClassFiles= true;
 							break;
 						case 1:
 							removeOldClassFiles= false;
 							break;
 						default:
 							return;
 						}
 					} else {
 						removeOldClassFiles= false;
 					}
 				} else {
 					return;
 				}
 			} else {
 				removeProjectFromClasspath= false;
 				removeOldClassFiles= false;
 				newDefaultOutputLocation= defaultOutputLocation;
 			}

 			try {
 				final IRunnableWithProgress runnable= monitor -> {
 					try {
 						List<IJavaElement> result= addToClasspath(getSelectedElements(), project, newDefaultOutputLocation.makeAbsolute(), removeProjectFromClasspath, removeOldClassFiles, monitor);
 						selectAndReveal(new StructuredSelection(result));
 					} catch (CoreException e) {
 						throw new InvocationTargetException(e);
 					}
 				};
 				fContext.run(false, false, runnable);
 			} catch (final InvocationTargetException e) {
 				if (e.getCause() instanceof CoreException) {
 					showExceptionDialog((CoreException)e.getCause(), NewWizardMessages.AddSourceFolderToBuildpathAction_ErrorTitle);
 				} else {
 					JavaPlugin.log(e);
 				}
 			} catch (final InterruptedException e) {
 			}
 		} catch (CoreException e) {
 			showExceptionDialog(e, NewWizardMessages.AddSourceFolderToBuildpathAction_ErrorTitle);
 		}
 	}

 	private List<IJavaElement> addToClasspath(List<?> elements, IJavaProject project, IPath outputLocation, boolean removeProjectFromClasspath, boolean removeOldClassFiles, IProgressMonitor monitor) throws OperationCanceledException, CoreException {
 		if (!project.getProject().hasNature(JavaCore.NATURE_ID)) {
 			StatusInfo rootStatus= new StatusInfo();
 			rootStatus.setError(NewWizardMessages.ClasspathModifier_Error_NoNatures);
 			throw new CoreException(rootStatus);
 		}

 		try {
 			monitor.beginTask(NewWizardMessages.ClasspathModifier_Monitor_AddToBuildpath, elements.size() + 4);
 			IWorkspaceRoot workspaceRoot= JavaPlugin.getWorkspace().getRoot();

 			if (removeOldClassFiles) {
 				IResource res= workspaceRoot.findMember(project.getOutputLocation());
 				if (res instanceof IContainer && BuildPathsBlock.hasClassfiles(res)) {
 					BuildPathsBlock.removeOldClassfiles(res);
 				}
 			}

 			BuildpathDelta delta= new BuildpathDelta(getToolTipText());

 			if (!project.getOutputLocation().equals(outputLocation)) {
 				project.setOutputLocation(outputLocation, new SubProgressMonitor(monitor, 1));
 				delta.setDefaultOutputLocation(outputLocation);
 			} else {
 				monitor.worked(1);
 			}

 			List<CPListElement> existingEntries= ClasspathModifier.getExistingEntries(project);
 			if (removeProjectFromClasspath) {
 				ClasspathModifier.removeFromClasspath(project, existingEntries, new SubProgressMonitor(monitor, 1));
 			} else {
 				monitor.worked(1);
 			}

 			List<CPListElement> newEntries= new ArrayList<>();
 			for (Object element : elements) {
 				CPListElement entry;
 				if (element instanceof IResource)
 					entry= ClasspathModifier.addToClasspath((IResource) element, existingEntries, newEntries, project, new SubProgressMonitor(monitor, 1));
 				else
 					entry= ClasspathModifier.addToClasspath((IJavaElement) element, existingEntries, newEntries, project, new SubProgressMonitor(monitor, 1));
 				newEntries.add(entry);
 			}

 			Set<CPListElement> modifiedSourceEntries= new HashSet<>();
 			BuildPathBasePage.fixNestingConflicts(newEntries.toArray(new CPListElement[newEntries.size()]), existingEntries.toArray(new CPListElement[existingEntries.size()]), modifiedSourceEntries);

 			ClasspathModifier.setNewEntry(existingEntries, newEntries, project, new SubProgressMonitor(monitor, 1));

 			ClasspathModifier.commitClassPath(existingEntries, project, new SubProgressMonitor(monitor, 1));

 			delta.setNewEntries(existingEntries.toArray(new CPListElement[existingEntries.size()]));
 			informListeners(delta);

 			List<IJavaElement> result= new ArrayList<>();
 			for (CPListElement newEntrie : newEntries) {
 				IClasspathEntry entry= newEntrie.getClasspathEntry();
 				IJavaElement root;
 				if (entry.getPath().equals(project.getPath()))
 					root= project;
 				else
 					root= project.findPackageFragmentRoot(entry.getPath());
 				if (root != null) {
 					result.add(root);
 				}
 			}

 			return result;
 		} finally {
 			monitor.done();
 		}
 	}

 	@Override
 	protected boolean canHandle(IStructuredSelection elements) {
 		if (elements.size() == 0)
 			return false;
 		try {
 			for (Object element : elements) {
 				if (element instanceof IJavaProject) {
 					if (ClasspathModifier.isSourceFolder((IJavaProject)element))
 						return false;
 				} else if (element instanceof IPackageFragment) {
 					IPackageFragment fragment= (IPackageFragment)element;
 					if (ClasspathModifier.isDefaultFragment(fragment))
 						return false;

 					if (ClasspathModifier.isInExternalOrArchive(fragment))
 						return false;
 					IResource res;
 					if ((res= fragment.getResource()) != null && res.isVirtual())
 						return false;
 				} else if (element instanceof IFolder) {
 					IProject project= ((IFolder)element).getProject();
 					IJavaProject javaProject= JavaCore.create(project);
 					if (javaProject == null || !javaProject.exists() || ((IFolder)element).isVirtual())
 						return false;
 				} else {
 					return false;
 				}
 			}
 			return true;
 		} catch (CoreException e) {
 		}
 		return false;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2016 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.ui.wizards.buildpaths.newsourcepage;

	import java.lang.reflect.InvocationTargetException;
	import java.util.ArrayList;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Set;

	import org.eclipse.swt.widgets.Shell;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.OperationCanceledException;
	import org.eclipse.core.runtime.SubProgressMonitor;

	import org.eclipse.core.resources.IContainer;
	import org.eclipse.core.resources.IFolder;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.resources.IWorkspaceRoot;

	import org.eclipse.jface.dialogs.IDialogConstants;
	import org.eclipse.jface.dialogs.MessageDialog;
	import org.eclipse.jface.operation.IRunnableContext;
	import org.eclipse.jface.operation.IRunnableWithProgress;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.StructuredSelection;

	import org.eclipse.ui.IWorkbenchSite;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.part.ISetSelectionTarget;

	import org.eclipse.jdt.core.IClasspathEntry;
	import org.eclipse.jdt.core.IJavaElement;
	import org.eclipse.jdt.core.IJavaProject;
	import org.eclipse.jdt.core.IPackageFragment;
	import org.eclipse.jdt.core.JavaCore;

	import org.eclipse.jdt.internal.core.manipulation.util.BasicElementLabels;
	import org.eclipse.jdt.internal.corext.buildpath.BuildpathDelta;
	import org.eclipse.jdt.internal.corext.buildpath.ClasspathModifier;
	import org.eclipse.jdt.internal.corext.util.Messages;

	import org.eclipse.jdt.ui.JavaElementLabels;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.JavaPluginImages;
	import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
	import org.eclipse.jdt.internal.ui.wizards.NewWizardMessages;
	import org.eclipse.jdt.internal.ui.wizards.buildpaths.BuildPathBasePage;
	import org.eclipse.jdt.internal.ui.wizards.buildpaths.BuildPathsBlock;
	import org.eclipse.jdt.internal.ui.wizards.buildpaths.CPListElement;
	import org.eclipse.jdt.internal.ui.wizards.buildpaths.newsourcepage.ClasspathModifierQueries.OutputFolderQuery;

	//SelectedElements iff enabled: IJavaProject \|\| IPackageFrament \|\| IFolder
	public class AddFolderToBuildpathAction extends BuildpathModifierAction {

	private final IRunnableContext fContext;

	public AddFolderToBuildpathAction(IWorkbenchSite site) {
	this(site, null, PlatformUI.getWorkbench().getProgressService());
	}

	public AddFolderToBuildpathAction(IRunnableContext context, ISetSelectionTarget selectionTarget) {
	this(null, selectionTarget, context);
	}

	private AddFolderToBuildpathAction(IWorkbenchSite site, ISetSelectionTarget selectionTarget, IRunnableContext context) {
	super(site, selectionTarget, BuildpathModifierAction.ADD_SEL_SF_TO_BP);

	fContext= context;

	setText(NewWizardMessages.NewSourceContainerWorkbookPage_ToolBar_AddSelSFToCP_label);
	setImageDescriptor(JavaPluginImages.DESC_ELCL_ADD_AS_SOURCE_FOLDER);
	setToolTipText(NewWizardMessages.NewSourceContainerWorkbookPage_ToolBar_AddSelSFToCP_tooltip);
	}

	@Override
	public String getDetailedDescription() {
	if (!isEnabled())
	return null;

	if (getSelectedElements().size() != 1)
	return NewWizardMessages.PackageExplorerActionGroup_FormText_Default_toBuildpath;

	Object obj= getSelectedElements().get(0);
	String elementLabel= JavaElementLabels.getTextLabel(obj, JavaElementLabels.ALL_DEFAULT);
	if (obj instanceof IJavaProject) {
	return Messages.format(NewWizardMessages.PackageExplorerActionGroup_FormText_ProjectToBuildpath, elementLabel);
	} else if (obj instanceof IPackageFragment) {
	return Messages.format(NewWizardMessages.PackageExplorerActionGroup_FormText_PackageToBuildpath, elementLabel);
	} else if (obj instanceof IResource) {
	return Messages.format(NewWizardMessages.PackageExplorerActionGroup_FormText_FolderToBuildpath, elementLabel);
	}

	return null;
	}

	@Override
	public void run() {

	try {
	final IJavaProject project;
	Object object= getSelectedElements().get(0);
	if (object instanceof IJavaProject) {
	project= (IJavaProject)object;
	} else if (object instanceof IPackageFragment) {
	project= ((IPackageFragment)object).getJavaProject();
	} else {
	IFolder folder= (IFolder)object;
	project= JavaCore.create(folder.getProject());
	if (project == null)
	return;
	}

	final Shell shell= getShell();

	final boolean removeProjectFromClasspath;
	IPath outputLocation= project.getOutputLocation();
	final IPath defaultOutputLocation= outputLocation.makeRelative();
	final IPath newDefaultOutputLocation;
	final boolean removeOldClassFiles;
	IPath projPath= project.getProject().getFullPath();
	if (((getSelectedElements().size() != 1) \|\| !(getSelectedElements().get(0) instanceof IJavaProject)) && //if only the project should be added, then the query does not need to be executed
	(outputLocation.equals(projPath) \|\| defaultOutputLocation.segmentCount() == 1)) {


	final OutputFolderQuery outputFolderQuery= ClasspathModifierQueries.getDefaultFolderQuery(shell, defaultOutputLocation);
	if (outputFolderQuery.doQuery(true, ClasspathModifier.getValidator(getSelectedElements(), project), project)) {
	newDefaultOutputLocation= outputFolderQuery.getOutputLocation();
	removeProjectFromClasspath= outputFolderQuery.removeProjectFromClasspath();

	if (BuildPathsBlock.hasClassfiles(project.getProject()) && outputLocation.equals(projPath)) {
	String title= NewWizardMessages.BuildPathsBlock_RemoveBinariesDialog_title;
	String message= Messages.format(NewWizardMessages.BuildPathsBlock_RemoveBinariesDialog_description, BasicElementLabels.getPathLabel(projPath, false));
	MessageDialog dialog= new MessageDialog(shell, title, null, message, MessageDialog.QUESTION, new String[] { IDialogConstants.YES_LABEL, IDialogConstants.NO_LABEL, IDialogConstants.CANCEL_LABEL }, 0);
	int answer= dialog.open();
	switch (answer) {
	case 0:
	removeOldClassFiles= true;
	break;
	case 1:
	removeOldClassFiles= false;
	break;
	default:
	return;
	}
	} else {
	removeOldClassFiles= false;
	}
	} else {
	return;
	}
	} else {
	removeProjectFromClasspath= false;
	removeOldClassFiles= false;
	newDefaultOutputLocation= defaultOutputLocation;
	}

	try {
	final IRunnableWithProgress runnable= monitor -> {
	try {
	List<IJavaElement> result= addToClasspath(getSelectedElements(), project, newDefaultOutputLocation.makeAbsolute(), removeProjectFromClasspath, removeOldClassFiles, monitor);
	selectAndReveal(new StructuredSelection(result));
	} catch (CoreException e) {
	throw new InvocationTargetException(e);
	}
	};
	fContext.run(false, false, runnable);
	} catch (final InvocationTargetException e) {
	if (e.getCause() instanceof CoreException) {
	showExceptionDialog((CoreException)e.getCause(), NewWizardMessages.AddSourceFolderToBuildpathAction_ErrorTitle);
	} else {
	JavaPlugin.log(e);
	}
	} catch (final InterruptedException e) {
	}
	} catch (CoreException e) {
	showExceptionDialog(e, NewWizardMessages.AddSourceFolderToBuildpathAction_ErrorTitle);
	}
	}

	private List<IJavaElement> addToClasspath(List<?> elements, IJavaProject project, IPath outputLocation, boolean removeProjectFromClasspath, boolean removeOldClassFiles, IProgressMonitor monitor) throws OperationCanceledException, CoreException {
	if (!project.getProject().hasNature(JavaCore.NATURE_ID)) {
	StatusInfo rootStatus= new StatusInfo();
	rootStatus.setError(NewWizardMessages.ClasspathModifier_Error_NoNatures);
	throw new CoreException(rootStatus);
	}

	try {
	monitor.beginTask(NewWizardMessages.ClasspathModifier_Monitor_AddToBuildpath, elements.size() + 4);
	IWorkspaceRoot workspaceRoot= JavaPlugin.getWorkspace().getRoot();

	if (removeOldClassFiles) {
	IResource res= workspaceRoot.findMember(project.getOutputLocation());
	if (res instanceof IContainer && BuildPathsBlock.hasClassfiles(res)) {
	BuildPathsBlock.removeOldClassfiles(res);
	}
	}

	BuildpathDelta delta= new BuildpathDelta(getToolTipText());

	if (!project.getOutputLocation().equals(outputLocation)) {
	project.setOutputLocation(outputLocation, new SubProgressMonitor(monitor, 1));
	delta.setDefaultOutputLocation(outputLocation);
	} else {
	monitor.worked(1);
	}

	List<CPListElement> existingEntries= ClasspathModifier.getExistingEntries(project);
	if (removeProjectFromClasspath) {
	ClasspathModifier.removeFromClasspath(project, existingEntries, new SubProgressMonitor(monitor, 1));
	} else {
	monitor.worked(1);
	}

	List<CPListElement> newEntries= new ArrayList<>();
	for (Object element : elements) {
	CPListElement entry;
	if (element instanceof IResource)
	entry= ClasspathModifier.addToClasspath((IResource) element, existingEntries, newEntries, project, new SubProgressMonitor(monitor, 1));
	else
	entry= ClasspathModifier.addToClasspath((IJavaElement) element, existingEntries, newEntries, project, new SubProgressMonitor(monitor, 1));
	newEntries.add(entry);
	}

	Set<CPListElement> modifiedSourceEntries= new HashSet<>();
	BuildPathBasePage.fixNestingConflicts(newEntries.toArray(new CPListElement[newEntries.size()]), existingEntries.toArray(new CPListElement[existingEntries.size()]), modifiedSourceEntries);

	ClasspathModifier.setNewEntry(existingEntries, newEntries, project, new SubProgressMonitor(monitor, 1));

	ClasspathModifier.commitClassPath(existingEntries, project, new SubProgressMonitor(monitor, 1));

	delta.setNewEntries(existingEntries.toArray(new CPListElement[existingEntries.size()]));
	informListeners(delta);

	List<IJavaElement> result= new ArrayList<>();
	for (CPListElement newEntrie : newEntries) {
	IClasspathEntry entry= newEntrie.getClasspathEntry();
	IJavaElement root;
	if (entry.getPath().equals(project.getPath()))
	root= project;
	else
	root= project.findPackageFragmentRoot(entry.getPath());
	if (root != null) {
	result.add(root);
	}
	}

	return result;
	} finally {
	monitor.done();
	}
	}

	@Override
	protected boolean canHandle(IStructuredSelection elements) {
	if (elements.size() == 0)
	return false;
	try {
	for (Object element : elements) {
	if (element instanceof IJavaProject) {
	if (ClasspathModifier.isSourceFolder((IJavaProject)element))
	return false;
	} else if (element instanceof IPackageFragment) {
	IPackageFragment fragment= (IPackageFragment)element;
	if (ClasspathModifier.isDefaultFragment(fragment))
	return false;

	if (ClasspathModifier.isInExternalOrArchive(fragment))
	return false;
	IResource res;
	if ((res= fragment.getResource()) != null && res.isVirtual())
	return false;
	} else if (element instanceof IFolder) {
	IProject project= ((IFolder)element).getProject();
	IJavaProject javaProject= JavaCore.create(project);
	if (javaProject == null \|\| !javaProject.exists() \|\| ((IFolder)element).isVirtual())
	return false;
	} else {
	return false;
	}
	}
	return true;
	} catch (CoreException e) {
	}
	return false;
	}
	}