org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/wizards/NewContainerWizardPage.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2006 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.jdt.ui.wizards;

 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Path;

 import org.eclipse.swt.widgets.Composite;

 import org.eclipse.jface.text.ITextSelection;
 import org.eclipse.jface.viewers.ILabelProvider;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.jface.viewers.ViewerFilter;
 import org.eclipse.jface.window.Window;

 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IWorkbenchPart;
 import org.eclipse.ui.dialogs.ElementTreeSelectionDialog;
 import org.eclipse.ui.views.contentoutline.ContentOutline;

 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaModel;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IPackageFragmentRoot;
 import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.core.JavaModelException;

 import org.eclipse.jdt.ui.JavaElementLabelProvider;
 import org.eclipse.jdt.ui.JavaElementSorter;
 import org.eclipse.jdt.ui.StandardJavaElementContentProvider;

 import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
 import org.eclipse.jdt.internal.corext.util.Messages;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
 import org.eclipse.jdt.internal.ui.viewsupport.IViewPartInputProvider;
 import org.eclipse.jdt.internal.ui.wizards.NewWizardMessages;
 import org.eclipse.jdt.internal.ui.wizards.TypedElementSelectionValidator;
 import org.eclipse.jdt.internal.ui.wizards.TypedViewerFilter;
 import org.eclipse.jdt.internal.ui.wizards.dialogfields.DialogField;
 import org.eclipse.jdt.internal.ui.wizards.dialogfields.IDialogFieldListener;
 import org.eclipse.jdt.internal.ui.wizards.dialogfields.IStringButtonAdapter;
 import org.eclipse.jdt.internal.ui.wizards.dialogfields.LayoutUtil;
 import org.eclipse.jdt.internal.ui.wizards.dialogfields.StringButtonDialogField;

 /**
  * Wizard page that acts as a base class for wizard pages that create new Java elements.
  * The class provides a input field for source folders (called container in this class) and
  * API to validate the enter source folder name.
  *
  * <p>
  * Clients may subclass.
  * </p>
  *
  * @since 2.0
  */
 public abstract class NewContainerWizardPage extends NewElementWizardPage {

 	/** Id of the container field */
 	protected static final String CONTAINER= "NewContainerWizardPage.container"; //$NON-NLS-1$

 	/** The status of the last validation. */
 	protected IStatus fContainerStatus;

 	private StringButtonDialogField fContainerDialogField;

 	/*
 	 * package fragment root corresponding to the input type (can be null)
 	 */
 	private IPackageFragmentRoot fCurrRoot;

 	private IWorkspaceRoot fWorkspaceRoot;

 	/**
 	 * Create a new <code>NewContainerWizardPage</code>
 	 *
 	 * @param name the wizard page's name
 	 */
 	public NewContainerWizardPage(String name) {
 		super(name);
 		fWorkspaceRoot= ResourcesPlugin.getWorkspace().getRoot();
 		ContainerFieldAdapter adapter= new ContainerFieldAdapter();

 		fContainerDialogField= new StringButtonDialogField(adapter);
 		fContainerDialogField.setDialogFieldListener(adapter);
 		fContainerDialogField.setLabelText(getContainerLabel());
 		fContainerDialogField.setButtonLabel(NewWizardMessages.NewContainerWizardPage_container_button);

 		fContainerStatus= new StatusInfo();
 		fCurrRoot= null;
 	}

 	/**
 	 * Returns the label that is used for the container input field.
 	 *
 	 * @return the label that is used for the container input field.
 	 * @since 3.2
 	 */
 	protected String getContainerLabel() {
 		return NewWizardMessages.NewContainerWizardPage_container_label;
 	}

 	/**
 	 * Initializes the source folder field with a valid package fragment root.
 	 * The package fragment root is computed from the given Java element.
 	 *
 	 * @param elem the Java element used to compute the initial package
 	 *    fragment root used as the source folder
 	 */
 	protected void initContainerPage(IJavaElement elem) {
 		IPackageFragmentRoot initRoot= null;
 		if (elem != null) {
 			initRoot= JavaModelUtil.getPackageFragmentRoot(elem);
 			try {
 				if (initRoot == null || initRoot.getKind() != IPackageFragmentRoot.K_SOURCE) {
 					IJavaProject jproject= elem.getJavaProject();
 					if (jproject != null) {
 							initRoot= null;
 							if (jproject.exists()) {
 								IPackageFragmentRoot[] roots= jproject.getPackageFragmentRoots();
 								for (int i= 0; i < roots.length; i++) {
 									if (roots[i].getKind() == IPackageFragmentRoot.K_SOURCE) {
 										initRoot= roots[i];
 										break;
 									}
 								}
 							}
 						if (initRoot == null) {
 							initRoot= jproject.getPackageFragmentRoot(jproject.getResource());
 						}
 					}
 				}
 			} catch (JavaModelException e) {
 				JavaPlugin.log(e);
 			}
 		}
 		setPackageFragmentRoot(initRoot, true);
 	}

 	/**
 	 * Utility method to inspect a selection to find a Java element.
 	 *
 	 * @param selection the selection to be inspected
 	 * @return a Java element to be used as the initial selection, or <code>null</code>,
 	 * if no Java element exists in the given selection
 	 */
 	protected IJavaElement getInitialJavaElement(IStructuredSelection selection) {
 		IJavaElement jelem= null;
 		if (selection != null && !selection.isEmpty()) {
 			Object selectedElement= selection.getFirstElement();
 			if (selectedElement instanceof IAdaptable) {
 				IAdaptable adaptable= (IAdaptable) selectedElement;

 				jelem= (IJavaElement) adaptable.getAdapter(IJavaElement.class);
 				if (jelem == null) {
 					IResource resource= (IResource) adaptable.getAdapter(IResource.class);
 					if (resource != null && resource.getType() != IResource.ROOT) {
 						while (jelem == null && resource.getType() != IResource.PROJECT) {
 							resource= resource.getParent();
 							jelem= (IJavaElement) resource.getAdapter(IJavaElement.class);
 						}
 						if (jelem == null) {
 							jelem= JavaCore.create(resource); // java project
 						}
 					}
 				}
 			}
 		}
 		if (jelem == null) {
 			IWorkbenchPart part= JavaPlugin.getActivePage().getActivePart();
 			if (part instanceof ContentOutline) {
 				part= JavaPlugin.getActivePage().getActiveEditor();
 			}

 			if (part instanceof IViewPartInputProvider) {
 				Object elem= ((IViewPartInputProvider)part).getViewPartInput();
 				if (elem instanceof IJavaElement) {
 					jelem= (IJavaElement) elem;
 				}
 			}
 		}

 		if (jelem == null || jelem.getElementType() == IJavaElement.JAVA_MODEL) {
 			try {
 				IJavaProject[] projects= JavaCore.create(getWorkspaceRoot()).getJavaProjects();
 				if (projects.length == 1) {
 					jelem= projects[0];
 				}
 			} catch (JavaModelException e) {
 				JavaPlugin.log(e);
 			}
 		}
 		return jelem;
 	}

 	/**
 	 * Returns the text selection of the current editor. <code>null</code> is returned
 	 * when the current editor does not have focus or does not return a text selection.
 	 * @return Returns the text selection of the current editor or <code>null</code>.
      *
      * @since 3.0
 	 */
 	protected ITextSelection getCurrentTextSelection() {
 		IWorkbenchPart part= JavaPlugin.getActivePage().getActivePart();
 		if (part instanceof IEditorPart) {
 			ISelectionProvider selectionProvider= part.getSite().getSelectionProvider();
 			if (selectionProvider != null) {
 				ISelection selection= selectionProvider.getSelection();
 				if (selection instanceof ITextSelection) {
 					return (ITextSelection) selection;
 				}
 			}
 		}
 		return null;
 	}


 	/**
 	 * Returns the recommended maximum width for text fields (in pixels). This
 	 * method requires that createContent has been called before this method is
 	 * call. Subclasses may override to change the maximum width for text
 	 * fields.
 	 *
 	 * @return the recommended maximum width for text fields.
 	 */
 	protected int getMaxFieldWidth() {
 		return convertWidthInCharsToPixels(40);
 	}


 	/**
 	 * Creates the necessary controls (label, text field and browse button) to edit
 	 * the source folder location. The method expects that the parent composite
 	 * uses a <code>GridLayout</code> as its layout manager and that the
 	 * grid layout has at least 3 columns.
 	 *
 	 * @param parent the parent composite
 	 * @param nColumns the number of columns to span. This number must be
 	 *  greater or equal three
 	 */
 	protected void createContainerControls(Composite parent, int nColumns) {
 		fContainerDialogField.doFillIntoGrid(parent, nColumns);
 		LayoutUtil.setWidthHint(fContainerDialogField.getTextControl(null), getMaxFieldWidth());
 	}

 	/**
 	 * Sets the focus to the source folder's text field.
 	 */
 	protected void setFocusOnContainer() {
 		fContainerDialogField.setFocus();
 	}

 	// -------- ContainerFieldAdapter --------

 	private class ContainerFieldAdapter implements IStringButtonAdapter, IDialogFieldListener {

 		// -------- IStringButtonAdapter
 		public void changeControlPressed(DialogField field) {
 			containerChangeControlPressed(field);
 		}

 		// -------- IDialogFieldListener
 		public void dialogFieldChanged(DialogField field) {
 			containerDialogFieldChanged(field);
 		}
 	}

 	private void containerChangeControlPressed(DialogField field) {
 		// take the current jproject as init element of the dialog
 		IPackageFragmentRoot root= chooseContainer();
 		if (root != null) {
 			setPackageFragmentRoot(root, true);
 		}
 	}

 	private void containerDialogFieldChanged(DialogField field) {
 		if (field == fContainerDialogField) {
 			fContainerStatus= containerChanged();
 		}
 		// tell all others
 		handleFieldChanged(CONTAINER);
 	}

 	// ----------- validation ----------

 	/**
 	 * This method is a hook which gets called after the source folder's
 	 * text input field has changed. This default implementation updates
 	 * the model and returns an error status. The underlying model
 	 * is only valid if the returned status is OK.
 	 *
 	 * @return the model's error status
 	 */
 	protected IStatus containerChanged() {
 		StatusInfo status= new StatusInfo();

 		fCurrRoot= null;
 		String str= getPackageFragmentRootText();
 		if (str.length() == 0) {
 			status.setError(NewWizardMessages.NewContainerWizardPage_error_EnterContainerName);
 			return status;
 		}
 		IPath path= new Path(str);
 		IResource res= fWorkspaceRoot.findMember(path);
 		if (res != null) {
 			int resType= res.getType();
 			if (resType == IResource.PROJECT || resType == IResource.FOLDER) {
 				IProject proj= res.getProject();
 				if (!proj.isOpen()) {
 					status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_ProjectClosed, proj.getFullPath().toString()));
 					return status;
 				}
 				IJavaProject jproject= JavaCore.create(proj);
 				fCurrRoot= jproject.getPackageFragmentRoot(res);
 				if (res.exists()) {
 					try {
 						if (!proj.hasNature(JavaCore.NATURE_ID)) {
 							if (resType == IResource.PROJECT) {
 								status.setError(NewWizardMessages.NewContainerWizardPage_warning_NotAJavaProject);
 							} else {
 								status.setWarning(NewWizardMessages.NewContainerWizardPage_warning_NotInAJavaProject);
 							}
 							return status;
 						}
 						if (fCurrRoot.isArchive()) {
 							status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_ContainerIsBinary, str));
 							return status;
 						}
 						if (fCurrRoot.getKind() == IPackageFragmentRoot.K_BINARY) {
 							status.setWarning(Messages.format(NewWizardMessages.NewContainerWizardPage_warning_inside_classfolder, str));
 						} else if (!jproject.isOnClasspath(fCurrRoot)) {
 							status.setWarning(Messages.format(NewWizardMessages.NewContainerWizardPage_warning_NotOnClassPath, str));
 						}
 					} catch (CoreException e) {
 						status.setWarning(NewWizardMessages.NewContainerWizardPage_warning_NotAJavaProject);
 					}
 				}
 				return status;
 			} else {
 				status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_NotAFolder, str));
 				return status;
 			}
 		} else {
 			status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_ContainerDoesNotExist, str));
 			return status;
 		}
 	}

 	// -------- update message ----------------

 	/**
 	 * Hook method that gets called when a field on this page has changed. For this page the
 	 * method gets called when the source folder field changes.
 	 * <p>
 	 * Every sub type is responsible to call this method when a field on its page has changed.
 	 * Subtypes override (extend) the method to add verification when a own field has a
 	 * dependency to an other field. For example the class name input must be verified
 	 * again when the package field changes (check for duplicated class names).
 	 *
 	 * @param fieldName The name of the field that has changed (field id). For the
 	 * source folder the field id is <code>CONTAINER</code>
 	 */
 	protected void handleFieldChanged(String fieldName) {
 	}


 	// ---- get ----------------

 	/**
 	 * Returns the workspace root.
 	 *
 	 * @return the workspace root
 	 */
 	protected IWorkspaceRoot getWorkspaceRoot() {
 		return fWorkspaceRoot;
 	}

 	/**
 	 * Returns the <code>IPackageFragmentRoot</code> that corresponds to the current
 	 * value of the source folder field.
 	 *
 	 * @return the IPackageFragmentRoot or <code>null</code> if the current source
 	 * folder value is not a valid package fragment root
 	 *
 	 */
 	public IPackageFragmentRoot getPackageFragmentRoot() {
 		return fCurrRoot;
 	}

 	/**
 	 * Returns the current text of source folder text field.
 	 *
 	 * @return the text of the source folder text field
 	 */
 	public String getPackageFragmentRootText() {
 		return fContainerDialogField.getText();
 	}


 	/**
 	 * Sets the current source folder (model and text field) to the given package
 	 * fragment root.

 	 * @param root The new root.
 	 * @param canBeModified if <code>false</code> the source folder field can
 	 * not be changed by the user. If <code>true</code> the field is editable
 	 */
 	public void setPackageFragmentRoot(IPackageFragmentRoot root, boolean canBeModified) {
 		fCurrRoot= root;
 		String str= (root == null) ? "" : root.getPath().makeRelative().toString(); //$NON-NLS-1$
 		fContainerDialogField.setText(str);
 		fContainerDialogField.setEnabled(canBeModified);
 	}

 	// ------------- choose source container dialog

 	/**
 	 * Opens a selection dialog that allows to select a source container.
 	 *
 	 * @return returns the selected package fragment root  or <code>null</code> if the dialog has been canceled.
 	 * The caller typically sets the result to the container input field.
 	 * <p>
 	 * Clients can override this method if they want to offer a different dialog.
 	 * </p>
 	 *
 	 * @since 3.2
 	 */
 	protected IPackageFragmentRoot chooseContainer() {
 		IJavaElement initElement= getPackageFragmentRoot();
 		Class[] acceptedClasses= new Class[] { IPackageFragmentRoot.class, IJavaProject.class };
 		TypedElementSelectionValidator validator= new TypedElementSelectionValidator(acceptedClasses, false) {
 			public boolean isSelectedValid(Object element) {
 				try {
 					if (element instanceof IJavaProject) {
 						IJavaProject jproject= (IJavaProject)element;
 						IPath path= jproject.getProject().getFullPath();
 						return (jproject.findPackageFragmentRoot(path) != null);
 					} else if (element instanceof IPackageFragmentRoot) {
 						return (((IPackageFragmentRoot)element).getKind() == IPackageFragmentRoot.K_SOURCE);
 					}
 					return true;
 				} catch (JavaModelException e) {
 					JavaPlugin.log(e.getStatus()); // just log, no UI in validation
 				}
 				return false;
 			}
 		};

 		acceptedClasses= new Class[] { IJavaModel.class, IPackageFragmentRoot.class, IJavaProject.class };
 		ViewerFilter filter= new TypedViewerFilter(acceptedClasses) {
 			public boolean select(Viewer viewer, Object parent, Object element) {
 				if (element instanceof IPackageFragmentRoot) {
 					try {
 						return (((IPackageFragmentRoot)element).getKind() == IPackageFragmentRoot.K_SOURCE);
 					} catch (JavaModelException e) {
 						JavaPlugin.log(e.getStatus()); // just log, no UI in validation
 						return false;
 					}
 				}
 				return super.select(viewer, parent, element);
 			}
 		};

 		StandardJavaElementContentProvider provider= new StandardJavaElementContentProvider();
 		ILabelProvider labelProvider= new JavaElementLabelProvider(JavaElementLabelProvider.SHOW_DEFAULT);
 		ElementTreeSelectionDialog dialog= new ElementTreeSelectionDialog(getShell(), labelProvider, provider);
 		dialog.setValidator(validator);
 		dialog.setSorter(new JavaElementSorter());
 		dialog.setTitle(NewWizardMessages.NewContainerWizardPage_ChooseSourceContainerDialog_title);
 		dialog.setMessage(NewWizardMessages.NewContainerWizardPage_ChooseSourceContainerDialog_description);
 		dialog.addFilter(filter);
 		dialog.setInput(JavaCore.create(fWorkspaceRoot));
 		dialog.setInitialSelection(initElement);
 		dialog.setHelpAvailable(false);

 		if (dialog.open() == Window.OK) {
 			Object element= dialog.getFirstResult();
 			if (element instanceof IJavaProject) {
 				IJavaProject jproject= (IJavaProject)element;
 				return jproject.getPackageFragmentRoot(jproject.getProject());
 			} else if (element instanceof IPackageFragmentRoot) {
 				return (IPackageFragmentRoot)element;
 			}
 			return null;
 		}
 		return null;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2006 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.jdt.ui.wizards;

	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.resources.IWorkspaceRoot;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Path;

	import org.eclipse.swt.widgets.Composite;

	import org.eclipse.jface.text.ITextSelection;
	import org.eclipse.jface.viewers.ILabelProvider;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionProvider;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.Viewer;
	import org.eclipse.jface.viewers.ViewerFilter;
	import org.eclipse.jface.window.Window;

	import org.eclipse.ui.IEditorPart;
	import org.eclipse.ui.IWorkbenchPart;
	import org.eclipse.ui.dialogs.ElementTreeSelectionDialog;
	import org.eclipse.ui.views.contentoutline.ContentOutline;

	import org.eclipse.jdt.core.IJavaElement;
	import org.eclipse.jdt.core.IJavaModel;
	import org.eclipse.jdt.core.IJavaProject;
	import org.eclipse.jdt.core.IPackageFragmentRoot;
	import org.eclipse.jdt.core.JavaCore;
	import org.eclipse.jdt.core.JavaModelException;

	import org.eclipse.jdt.ui.JavaElementLabelProvider;
	import org.eclipse.jdt.ui.JavaElementSorter;
	import org.eclipse.jdt.ui.StandardJavaElementContentProvider;

	import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
	import org.eclipse.jdt.internal.corext.util.Messages;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
	import org.eclipse.jdt.internal.ui.viewsupport.IViewPartInputProvider;
	import org.eclipse.jdt.internal.ui.wizards.NewWizardMessages;
	import org.eclipse.jdt.internal.ui.wizards.TypedElementSelectionValidator;
	import org.eclipse.jdt.internal.ui.wizards.TypedViewerFilter;
	import org.eclipse.jdt.internal.ui.wizards.dialogfields.DialogField;
	import org.eclipse.jdt.internal.ui.wizards.dialogfields.IDialogFieldListener;
	import org.eclipse.jdt.internal.ui.wizards.dialogfields.IStringButtonAdapter;
	import org.eclipse.jdt.internal.ui.wizards.dialogfields.LayoutUtil;
	import org.eclipse.jdt.internal.ui.wizards.dialogfields.StringButtonDialogField;

	/**
	* Wizard page that acts as a base class for wizard pages that create new Java elements.
	* The class provides a input field for source folders (called container in this class) and
	* API to validate the enter source folder name.
	*
	* <p>
	* Clients may subclass.
	* </p>
	*
	* @since 2.0
	*/
	public abstract class NewContainerWizardPage extends NewElementWizardPage {

	/** Id of the container field */
	protected static final String CONTAINER= "NewContainerWizardPage.container"; //$NON-NLS-1$

	/** The status of the last validation. */
	protected IStatus fContainerStatus;

	private StringButtonDialogField fContainerDialogField;

	/*
	* package fragment root corresponding to the input type (can be null)
	*/
	private IPackageFragmentRoot fCurrRoot;

	private IWorkspaceRoot fWorkspaceRoot;

	/**
	* Create a new <code>NewContainerWizardPage</code>
	*
	* @param name the wizard page's name
	*/
	public NewContainerWizardPage(String name) {
	super(name);
	fWorkspaceRoot= ResourcesPlugin.getWorkspace().getRoot();
	ContainerFieldAdapter adapter= new ContainerFieldAdapter();

	fContainerDialogField= new StringButtonDialogField(adapter);
	fContainerDialogField.setDialogFieldListener(adapter);
	fContainerDialogField.setLabelText(getContainerLabel());
	fContainerDialogField.setButtonLabel(NewWizardMessages.NewContainerWizardPage_container_button);

	fContainerStatus= new StatusInfo();
	fCurrRoot= null;
	}

	/**
	* Returns the label that is used for the container input field.
	*
	* @return the label that is used for the container input field.
	* @since 3.2
	*/
	protected String getContainerLabel() {
	return NewWizardMessages.NewContainerWizardPage_container_label;
	}

	/**
	* Initializes the source folder field with a valid package fragment root.
	* The package fragment root is computed from the given Java element.
	*
	* @param elem the Java element used to compute the initial package
	* fragment root used as the source folder
	*/
	protected void initContainerPage(IJavaElement elem) {
	IPackageFragmentRoot initRoot= null;
	if (elem != null) {
	initRoot= JavaModelUtil.getPackageFragmentRoot(elem);
	try {
	if (initRoot == null \|\| initRoot.getKind() != IPackageFragmentRoot.K_SOURCE) {
	IJavaProject jproject= elem.getJavaProject();
	if (jproject != null) {
	initRoot= null;
	if (jproject.exists()) {
	IPackageFragmentRoot[] roots= jproject.getPackageFragmentRoots();
	for (int i= 0; i < roots.length; i++) {
	if (roots[i].getKind() == IPackageFragmentRoot.K_SOURCE) {
	initRoot= roots[i];
	break;
	}
	}
	}
	if (initRoot == null) {
	initRoot= jproject.getPackageFragmentRoot(jproject.getResource());
	}
	}
	}
	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}
	}
	setPackageFragmentRoot(initRoot, true);
	}

	/**
	* Utility method to inspect a selection to find a Java element.
	*
	* @param selection the selection to be inspected
	* @return a Java element to be used as the initial selection, or <code>null</code>,
	* if no Java element exists in the given selection
	*/
	protected IJavaElement getInitialJavaElement(IStructuredSelection selection) {
	IJavaElement jelem= null;
	if (selection != null && !selection.isEmpty()) {
	Object selectedElement= selection.getFirstElement();
	if (selectedElement instanceof IAdaptable) {
	IAdaptable adaptable= (IAdaptable) selectedElement;

	jelem= (IJavaElement) adaptable.getAdapter(IJavaElement.class);
	if (jelem == null) {
	IResource resource= (IResource) adaptable.getAdapter(IResource.class);
	if (resource != null && resource.getType() != IResource.ROOT) {
	while (jelem == null && resource.getType() != IResource.PROJECT) {
	resource= resource.getParent();
	jelem= (IJavaElement) resource.getAdapter(IJavaElement.class);
	}
	if (jelem == null) {
	jelem= JavaCore.create(resource); // java project
	}
	}
	}
	}
	}
	if (jelem == null) {
	IWorkbenchPart part= JavaPlugin.getActivePage().getActivePart();
	if (part instanceof ContentOutline) {
	part= JavaPlugin.getActivePage().getActiveEditor();
	}

	if (part instanceof IViewPartInputProvider) {
	Object elem= ((IViewPartInputProvider)part).getViewPartInput();
	if (elem instanceof IJavaElement) {
	jelem= (IJavaElement) elem;
	}
	}
	}

	if (jelem == null \|\| jelem.getElementType() == IJavaElement.JAVA_MODEL) {
	try {
	IJavaProject[] projects= JavaCore.create(getWorkspaceRoot()).getJavaProjects();
	if (projects.length == 1) {
	jelem= projects[0];
	}
	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}
	}
	return jelem;
	}

	/**
	* Returns the text selection of the current editor. <code>null</code> is returned
	* when the current editor does not have focus or does not return a text selection.
	* @return Returns the text selection of the current editor or <code>null</code>.
	*
	* @since 3.0
	*/
	protected ITextSelection getCurrentTextSelection() {
	IWorkbenchPart part= JavaPlugin.getActivePage().getActivePart();
	if (part instanceof IEditorPart) {
	ISelectionProvider selectionProvider= part.getSite().getSelectionProvider();
	if (selectionProvider != null) {
	ISelection selection= selectionProvider.getSelection();
	if (selection instanceof ITextSelection) {
	return (ITextSelection) selection;
	}
	}
	}
	return null;
	}


	/**
	* Returns the recommended maximum width for text fields (in pixels). This
	* method requires that createContent has been called before this method is
	* call. Subclasses may override to change the maximum width for text
	* fields.
	*
	* @return the recommended maximum width for text fields.
	*/
	protected int getMaxFieldWidth() {
	return convertWidthInCharsToPixels(40);
	}


	/**
	* Creates the necessary controls (label, text field and browse button) to edit
	* the source folder location. The method expects that the parent composite
	* uses a <code>GridLayout</code> as its layout manager and that the
	* grid layout has at least 3 columns.
	*
	* @param parent the parent composite
	* @param nColumns the number of columns to span. This number must be
	* greater or equal three
	*/
	protected void createContainerControls(Composite parent, int nColumns) {
	fContainerDialogField.doFillIntoGrid(parent, nColumns);
	LayoutUtil.setWidthHint(fContainerDialogField.getTextControl(null), getMaxFieldWidth());
	}

	/**
	* Sets the focus to the source folder's text field.
	*/
	protected void setFocusOnContainer() {
	fContainerDialogField.setFocus();
	}

	// -------- ContainerFieldAdapter --------

	private class ContainerFieldAdapter implements IStringButtonAdapter, IDialogFieldListener {

	// -------- IStringButtonAdapter
	public void changeControlPressed(DialogField field) {
	containerChangeControlPressed(field);
	}

	// -------- IDialogFieldListener
	public void dialogFieldChanged(DialogField field) {
	containerDialogFieldChanged(field);
	}
	}

	private void containerChangeControlPressed(DialogField field) {
	// take the current jproject as init element of the dialog
	IPackageFragmentRoot root= chooseContainer();
	if (root != null) {
	setPackageFragmentRoot(root, true);
	}
	}

	private void containerDialogFieldChanged(DialogField field) {
	if (field == fContainerDialogField) {
	fContainerStatus= containerChanged();
	}
	// tell all others
	handleFieldChanged(CONTAINER);
	}

	// ----------- validation ----------

	/**
	* This method is a hook which gets called after the source folder's
	* text input field has changed. This default implementation updates
	* the model and returns an error status. The underlying model
	* is only valid if the returned status is OK.
	*
	* @return the model's error status
	*/
	protected IStatus containerChanged() {
	StatusInfo status= new StatusInfo();

	fCurrRoot= null;
	String str= getPackageFragmentRootText();
	if (str.length() == 0) {
	status.setError(NewWizardMessages.NewContainerWizardPage_error_EnterContainerName);
	return status;
	}
	IPath path= new Path(str);
	IResource res= fWorkspaceRoot.findMember(path);
	if (res != null) {
	int resType= res.getType();
	if (resType == IResource.PROJECT \|\| resType == IResource.FOLDER) {
	IProject proj= res.getProject();
	if (!proj.isOpen()) {
	status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_ProjectClosed, proj.getFullPath().toString()));
	return status;
	}
	IJavaProject jproject= JavaCore.create(proj);
	fCurrRoot= jproject.getPackageFragmentRoot(res);
	if (res.exists()) {
	try {
	if (!proj.hasNature(JavaCore.NATURE_ID)) {
	if (resType == IResource.PROJECT) {
	status.setError(NewWizardMessages.NewContainerWizardPage_warning_NotAJavaProject);
	} else {
	status.setWarning(NewWizardMessages.NewContainerWizardPage_warning_NotInAJavaProject);
	}
	return status;
	}
	if (fCurrRoot.isArchive()) {
	status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_ContainerIsBinary, str));
	return status;
	}
	if (fCurrRoot.getKind() == IPackageFragmentRoot.K_BINARY) {
	status.setWarning(Messages.format(NewWizardMessages.NewContainerWizardPage_warning_inside_classfolder, str));
	} else if (!jproject.isOnClasspath(fCurrRoot)) {
	status.setWarning(Messages.format(NewWizardMessages.NewContainerWizardPage_warning_NotOnClassPath, str));
	}
	} catch (CoreException e) {
	status.setWarning(NewWizardMessages.NewContainerWizardPage_warning_NotAJavaProject);
	}
	}
	return status;
	} else {
	status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_NotAFolder, str));
	return status;
	}
	} else {
	status.setError(Messages.format(NewWizardMessages.NewContainerWizardPage_error_ContainerDoesNotExist, str));
	return status;
	}
	}

	// -------- update message ----------------

	/**
	* Hook method that gets called when a field on this page has changed. For this page the
	* method gets called when the source folder field changes.
	* <p>
	* Every sub type is responsible to call this method when a field on its page has changed.
	* Subtypes override (extend) the method to add verification when a own field has a
	* dependency to an other field. For example the class name input must be verified
	* again when the package field changes (check for duplicated class names).
	*
	* @param fieldName The name of the field that has changed (field id). For the
	* source folder the field id is <code>CONTAINER</code>
	*/
	protected void handleFieldChanged(String fieldName) {
	}


	// ---- get ----------------

	/**
	* Returns the workspace root.
	*
	* @return the workspace root
	*/
	protected IWorkspaceRoot getWorkspaceRoot() {
	return fWorkspaceRoot;
	}

	/**
	* Returns the <code>IPackageFragmentRoot</code> that corresponds to the current
	* value of the source folder field.
	*
	* @return the IPackageFragmentRoot or <code>null</code> if the current source
	* folder value is not a valid package fragment root
	*
	*/
	public IPackageFragmentRoot getPackageFragmentRoot() {
	return fCurrRoot;
	}

	/**
	* Returns the current text of source folder text field.
	*
	* @return the text of the source folder text field
	*/
	public String getPackageFragmentRootText() {
	return fContainerDialogField.getText();
	}


	/**
	* Sets the current source folder (model and text field) to the given package
	* fragment root.

	* @param root The new root.
	* @param canBeModified if <code>false</code> the source folder field can
	* not be changed by the user. If <code>true</code> the field is editable
	*/
	public void setPackageFragmentRoot(IPackageFragmentRoot root, boolean canBeModified) {
	fCurrRoot= root;
	String str= (root == null) ? "" : root.getPath().makeRelative().toString(); //$NON-NLS-1$
	fContainerDialogField.setText(str);
	fContainerDialogField.setEnabled(canBeModified);
	}

	// ------------- choose source container dialog

	/**
	* Opens a selection dialog that allows to select a source container.
	*
	* @return returns the selected package fragment root or <code>null</code> if the dialog has been canceled.
	* The caller typically sets the result to the container input field.
	* <p>
	* Clients can override this method if they want to offer a different dialog.
	* </p>
	*
	* @since 3.2
	*/
	protected IPackageFragmentRoot chooseContainer() {
	IJavaElement initElement= getPackageFragmentRoot();
	Class[] acceptedClasses= new Class[] { IPackageFragmentRoot.class, IJavaProject.class };
	TypedElementSelectionValidator validator= new TypedElementSelectionValidator(acceptedClasses, false) {
	public boolean isSelectedValid(Object element) {
	try {
	if (element instanceof IJavaProject) {
	IJavaProject jproject= (IJavaProject)element;
	IPath path= jproject.getProject().getFullPath();
	return (jproject.findPackageFragmentRoot(path) != null);
	} else if (element instanceof IPackageFragmentRoot) {
	return (((IPackageFragmentRoot)element).getKind() == IPackageFragmentRoot.K_SOURCE);
	}
	return true;
	} catch (JavaModelException e) {
	JavaPlugin.log(e.getStatus()); // just log, no UI in validation
	}
	return false;
	}
	};

	acceptedClasses= new Class[] { IJavaModel.class, IPackageFragmentRoot.class, IJavaProject.class };
	ViewerFilter filter= new TypedViewerFilter(acceptedClasses) {
	public boolean select(Viewer viewer, Object parent, Object element) {
	if (element instanceof IPackageFragmentRoot) {
	try {
	return (((IPackageFragmentRoot)element).getKind() == IPackageFragmentRoot.K_SOURCE);
	} catch (JavaModelException e) {
	JavaPlugin.log(e.getStatus()); // just log, no UI in validation
	return false;
	}
	}
	return super.select(viewer, parent, element);
	}
	};

	StandardJavaElementContentProvider provider= new StandardJavaElementContentProvider();
	ILabelProvider labelProvider= new JavaElementLabelProvider(JavaElementLabelProvider.SHOW_DEFAULT);
	ElementTreeSelectionDialog dialog= new ElementTreeSelectionDialog(getShell(), labelProvider, provider);
	dialog.setValidator(validator);
	dialog.setSorter(new JavaElementSorter());
	dialog.setTitle(NewWizardMessages.NewContainerWizardPage_ChooseSourceContainerDialog_title);
	dialog.setMessage(NewWizardMessages.NewContainerWizardPage_ChooseSourceContainerDialog_description);
	dialog.addFilter(filter);
	dialog.setInput(JavaCore.create(fWorkspaceRoot));
	dialog.setInitialSelection(initElement);
	dialog.setHelpAvailable(false);

	if (dialog.open() == Window.OK) {
	Object element= dialog.getFirstResult();
	if (element instanceof IJavaProject) {
	IJavaProject jproject= (IJavaProject)element;
	return jproject.getPackageFragmentRoot(jproject.getProject());
	} else if (element instanceof IPackageFragmentRoot) {
	return (IPackageFragmentRoot)element;
	}
	return null;
	}
	return null;
	}

	}