org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageFragmentProvider.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2002 International Business Machines Corp. and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v0.5
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v05.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  ******************************************************************************/
 package org.eclipse.jdt.internal.ui.packageview;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;

 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;

 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.jface.viewers.ITreeContentProvider;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.jface.viewers.Viewer;

 import org.eclipse.jdt.core.ElementChangedEvent;
 import org.eclipse.jdt.core.IElementChangedListener;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaElementDelta;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IPackageFragment;
 import org.eclipse.jdt.core.IPackageFragmentRoot;
 import org.eclipse.jdt.core.JavaCore;
 import org.eclipse.jdt.core.JavaModelException;

 import org.eclipse.jdt.internal.compiler.env.ICompilationUnit;
 import org.eclipse.jdt.internal.ui.JavaPlugin;

 import org.eclipse.jdt.internal.ui.preferences.AppearancePreferencePage;

 /**
  * Content provider which provides package fragments for hierarchical
  * Package Explorer layout.
  *
  * @since 2.1
  */
 public class PackageFragmentProvider implements  IPropertyChangeListener, ITreeContentProvider, IElementChangedListener{

 	private TreeViewer fViewer;
 	private boolean fFoldPackages;

 	public PackageFragmentProvider() {
 		fFoldPackages= AppearancePreferencePage.arePackagesFoldedInHierarchicalLayout();
 		JavaPlugin.getDefault().getPreferenceStore().addPropertyChangeListener(this);
 	}

 	/*
 	 * @see org.eclipse.jface.viewers.ITreeContentProvider#getChildren(Object)
 	 */
 	public Object[] getChildren(Object parentElement) {
 		try {
 			if (parentElement instanceof IJavaElement) {
 				IJavaElement iJavaElement= (IJavaElement) parentElement;
 				int type= iJavaElement.getElementType();

 				switch (type) {
 					case IJavaElement.JAVA_PROJECT: {
 						IJavaProject project= (IJavaProject)iJavaElement;
 						IProject proj= project.getProject();

 						List children= new ArrayList();

 						IPackageFragmentRoot defaultroot= project.getPackageFragmentRoot(proj);
 						if(defaultroot.exists()){
 							IJavaElement[] els= defaultroot.getChildren();
 							children= getTopLevelChildrenByElementName(els);

 						}

 						return filter(children.toArray());
 					}

 					case IJavaElement.PACKAGE_FRAGMENT_ROOT :
 						{
 							IPackageFragmentRoot root = (IPackageFragmentRoot) parentElement;
 							if (root.exists()) {
 								IResource resource = root.getUnderlyingResource();
 								if (root.isArchive()) {
 									IJavaElement[] els = root.getChildren();
 									return filter(getTopLevelChildrenByElementName(els).toArray());

 								} else if (resource instanceof IFolder) {
 									IFolder folder = (IFolder) resource;
 									IResource[] reses = folder.members();

 									List children = getFolders(reses);
 									IPackageFragment defaultPackage= root.getPackageFragment(""); //$NON-NLS-1$
 									if(defaultPackage.exists())
 										children.add(defaultPackage);

 									return filter(children.toArray());
 								}
 							}
 							break;
 						}
 					case IJavaElement.PACKAGE_FRAGMENT :
 						{
 							IPackageFragment packageFragment = (IPackageFragment) parentElement;
 							if (!packageFragment.isDefaultPackage()) {
 								IResource resource = packageFragment.getUnderlyingResource();
 								if (resource != null && resource instanceof IFolder) {
 									IFolder folder = (IFolder) resource;
 									IResource[] reses = folder.members();
 									Object[] children = getFolders(reses).toArray();
 									return filter(children);
 									//if the resource is null, maybe member of an archive
 								} else {
 									IJavaElement parent = packageFragment.getParent();
 									if (parent instanceof IPackageFragmentRoot) {
 										IPackageFragmentRoot root = (IPackageFragmentRoot) parent;
 										Object[] children = findNextLevelChildrenByElementName(root, packageFragment);
 										return filter(children);
 									}
 								}
 							}
 							break;
 						}
 					default :
 						// do nothing
 				}
 			}
 		} catch (JavaModelException e) {
 			JavaPlugin.log(e);
 		} catch (CoreException e) {
 			JavaPlugin.log(e);
 		}
 		return new Object[0];
 	}

 	private Object[] filter(Object[] children) {
 		if (fFoldPackages) {
 			for (int i = 0; i < children.length; i++) {
 				if (children[i] instanceof IPackageFragment) {
 					IPackageFragment fragment = (IPackageFragment) children[i];
 					if(!fragment.isDefaultPackage())
 						children[i] = getBottomPackage(fragment);
 				}
 			}
 		}
 		return children;
 	}

 	private Object getBottomPackage(IPackageFragment iPackageFragment) {
 		try {
 			if(isEmpty(iPackageFragment))
 				return findChildrenToBeCompounded(iPackageFragment);
 		} catch (JavaModelException e) {
 			JavaPlugin.log(e);
 		}
 		return iPackageFragment;
 	}

 	private IPackageFragment findChildrenToBeCompounded(IPackageFragment fragment) throws JavaModelException {

 		Object[] children = getChildren(fragment);
 		if ((children.length == 1) && (children[0] instanceof IPackageFragment)) {
 			if (isEmpty((IPackageFragment) children[0]))
 				return findChildrenToBeCompounded((IPackageFragment) children[0]);
 			else return (IPackageFragment)children[0];
 		}
 		return fragment;
 	}

 	private boolean isEmpty(IPackageFragment fragment) throws JavaModelException {
 		return (!fragment.containsJavaResources()) && (fragment.getNonJavaResources().length==0);
 	}


 	private Object[] findNextLevelChildrenByElementName(IPackageFragmentRoot parent, IPackageFragment fragment) {
 		List list= new ArrayList();
 		try {

 			IJavaElement[] children= parent.getChildren();
 			String fragmentname= fragment.getElementName();
 			for (int i= 0; i < children.length; i++) {
 				IJavaElement element= children[i];
 				if (element instanceof IPackageFragment) {
 					IPackageFragment frag= (IPackageFragment) element;

 					String name= element.getElementName();
 					if (!"".equals(fragmentname) && name.startsWith(fragmentname) && !name.equals(fragmentname)) { //$NON-NLS-1$
 						String tail= name.substring(fragmentname.length() + 1);
 						if (!"".equals(tail) && (tail.indexOf(".") == -1)) {//$NON-NLS-1$ //$NON-NLS-2$
 							list.add(frag);
 						}
 					}
 				}
 			}

 		} catch (JavaModelException e) {
 			JavaPlugin.log(e);
 		}
 		return list.toArray();

 	}

 	private List getTopLevelChildrenByElementName(IJavaElement[] elements){
 		List topLevelElements= new ArrayList();
 		for (int i= 0; i < elements.length; i++) {
 			IJavaElement iJavaElement= elements[i];
 			//if the name of the PackageFragment is the top level package it will contain no "." separators
 			if((iJavaElement.getElementName().indexOf(".")==-1) && (iJavaElement instanceof IPackageFragment)){ //$NON-NLS-1$
 				topLevelElements.add(iJavaElement);
 			}
 		}
 		return topLevelElements;
 	}

 	private List getFolders(IResource[] resources) throws JavaModelException {
 		List list= new ArrayList();
 		for (int i= 0; i < resources.length; i++) {
 			IResource resource= resources[i];

 			if (resource instanceof IFolder) {
 				IFolder folder= (IFolder) resource;
 				IJavaElement element= JavaCore.create(folder);

 				if (element instanceof IPackageFragment) {
 					list.add(element);
 				}
 			}
 		}
 		return list;
 	}


 	/*
 	 * @see org.eclipse.jface.viewers.ITreeContentProvider#getParent(Object)
 	 */
 	public Object getParent(Object element) {

 		if (element instanceof IPackageFragment) {
 			IPackageFragment frag = (IPackageFragment) element;
 			//@Changed: a fix, before: if(frag.exists() && isEmpty(frag))

 			return filterParent(getActualParent(frag));
 		}
 		return null;
 	}

 	public Object getActualParent(IPackageFragment fragment) {
 		try {

 			if (fragment.exists()) {
 				IJavaElement parent = fragment.getParent();

 				if ((parent instanceof IPackageFragmentRoot) && parent.exists()) {
 					IPackageFragmentRoot root = (IPackageFragmentRoot) parent;
 					if (root.isArchive()) {
 						return findNextLevelChildrenByElementName(fragment, root);
 					} else {

 						IResource resource = fragment.getUnderlyingResource();
 						if ((resource != null) && (resource instanceof IFolder)) {
 							IFolder folder = (IFolder) resource;
 							IResource res = folder.getParent();

 							IJavaElement el = JavaCore.create(res);
 							return el;
 						}
 					}
 					return parent;
 				}
 			}

 		} catch (JavaModelException e) {
 			JavaPlugin.log(e);
 		}
 		return null;
 	}

 	private Object filterParent(Object parent) {
 		if (fFoldPackages && (parent!=null)) {
 			try {
 				if (parent instanceof IPackageFragment) {
 					IPackageFragment fragment = (IPackageFragment) parent;
 					if (isEmpty(fragment) && hasSingleChild(fragment)) {
 						return filterParent(getActualParent(fragment));
 					}
 				}
 			} catch (JavaModelException e) {
 				JavaPlugin.log(e);
 			}
 		}
 		return parent;
 	}

 	private boolean hasSingleChild(IPackageFragment fragment) {
 		return getChildren(fragment).length==1;
 	}


 	private Object findNextLevelChildrenByElementName(IJavaElement child, IJavaElement parent) {
 		String name= child.getElementName();

 		if(name.indexOf(".")==-1) //$NON-NLS-1$
 			return parent;

 		try {
 			String realParentName= child.getElementName().substring(0,name.lastIndexOf(".")); //$NON-NLS-1$
 			IJavaElement[] children= new IJavaElement[0];

 			if(parent instanceof IPackageFragmentRoot){
 				IPackageFragmentRoot root = (IPackageFragmentRoot) parent;
 				children= root.getChildren();
 			} else if (parent instanceof IJavaProject) {
 				IJavaProject project = (IJavaProject) parent;
 				children= project.getPackageFragments();
 			}

 			for (int i= 0; i < children.length; i++) {
 				IJavaElement element= children[i];
 				if(element.getElementName().equals(realParentName))
 					return element;
 			}
 		} catch (JavaModelException e) {
 			JavaPlugin.log(e);
 		}

 		return parent;
 	}


 	/*
 	 * @see org.eclipse.jface.viewers.ITreeContentProvider#hasChildren(Object)
 	 */
 	public boolean hasChildren(Object element) {

 		if (element instanceof IPackageFragment) {
 			IPackageFragment fragment= (IPackageFragment) element;
 			if(fragment.isDefaultPackage())
 				return false;
 		}
 		return getChildren(element).length > 0;
 	}

 	/*
 	 * @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(Object)
 	 */
 	public Object[] getElements(Object inputElement) {
 		return getChildren(inputElement);
 	}

 	/*
 	 * @see org.eclipse.jface.viewers.IContentProvider#dispose()
 	 */
 	public void dispose() {
 		JavaPlugin.getDefault().getPreferenceStore().removePropertyChangeListener(this);
 	}

 	/**
 	 * Called when the view is closed and opened.
 	 *
 	 * @see org.eclipse.jface.viewers.IContentProvider#inputChanged(Viewer, Object, Object)
 	 */
 	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
 		fViewer= (TreeViewer)viewer;
 	}

 	/*
 	 * @see org.eclipse.jdt.core.IElementChangedListener#elementChanged(org.eclipse.jdt.core.ElementChangedEvent)
 	 */
 	public void elementChanged(ElementChangedEvent event) {
 		processDelta(event.getDelta());
 	}

 	public void processDelta(IJavaElementDelta delta) {

 		int kind = delta.getKind();
 		final IJavaElement element = delta.getElement();

 		if (element instanceof IPackageFragment) {

 			if (kind == IJavaElementDelta.REMOVED) {

 				postRunnable(new Runnable() {
 					public void run() {
 						Control ctrl = fViewer.getControl();
 						if (ctrl != null && !ctrl.isDisposed()) {
 							ctrl.setRedraw(false);
 							if (!fFoldPackages)
 								 ((TreeViewer) fViewer).remove(element);
 							else
 								refreshGrandParent(element);
 							ctrl.setRedraw(true);
 						}
 					}
 				});
 				return;

 			} else if (kind == IJavaElementDelta.ADDED) {

 				final Object parent = getParent(element);
 				if (parent != null) {
 					postRunnable(new Runnable() {
 						public void run() {
 							Control ctrl = fViewer.getControl();
 							if (ctrl != null && !ctrl.isDisposed()) {
 								ctrl.setRedraw(false);
 								if (!fFoldPackages)
 									 ((TreeViewer) fViewer).add(parent, element);
 								else
 									refreshGrandParent(element);
 								ctrl.setRedraw(true);
 							}
 						}
 					});
 				}
 				return;

 			} else if (kind == IJavaElementDelta.CHANGED) {

 				postRunnable(new Runnable() {
 					public void run() {
 						Control ctrl = fViewer.getControl();
 						if (ctrl != null && !ctrl.isDisposed()) {
 							ctrl.setRedraw(false);
 							refreshGrandParent(element);
 							ctrl.setRedraw(true);
 						}
 					}
 				});
 				return;
 			}

 		}

 		IJavaElementDelta[] affectedChildren = delta.getAffectedChildren();
 		processAffectedChildren(affectedChildren);

 	}


 	// XXX: needs to be revisited - might be a performance issue
 	private void refreshGrandParent(final IJavaElement element) {
 		if (element instanceof IPackageFragment) {
 			Object gp= getGrandParent((IPackageFragment)element);
 			if (gp instanceof IJavaElement) {
 				IJavaElement el = (IJavaElement) gp;
 				if(el.exists())
 					fViewer.refresh(gp);
 			}
 		}
 	}

 	private Object getGrandParent(IPackageFragment element) {

 		Object parent= findNextLevelChildrenByElementName(element, element.getParent());
 		if (parent instanceof IPackageFragmentRoot) {
 			IPackageFragmentRoot root= (IPackageFragmentRoot) parent;
 			if(isRootProject(root))
 				return root.getJavaProject();
 			else return root;
 		}

 		Object grandParent= getParent(parent);
 		if(grandParent==null){
 			return parent;
 		}
 		return grandParent;
 	}

 	private boolean isRootProject(IPackageFragmentRoot root) {
 		return IPackageFragmentRoot.DEFAULT_PACKAGEROOT_PATH.equals(root.getElementName());
 	}

 	protected void processAffectedChildren(IJavaElementDelta[] affectedChildren) {
 		for (int i= 0; i < affectedChildren.length; i++) {
 			if (!(affectedChildren[i] instanceof ICompilationUnit)) {
 				processDelta(affectedChildren[i]);
 			}
 		}
 	}

 	private void postRunnable(final Runnable r) {
 		Control ctrl= fViewer.getControl();
 		if (ctrl != null && !ctrl.isDisposed()) {

 			Display currentDisplay= Display.getCurrent();
 			if (currentDisplay != null && currentDisplay.equals(ctrl.getDisplay()))
 				ctrl.getDisplay().syncExec(r);
 			else
 				ctrl.getDisplay().asyncExec(r);
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
 	 */
 	public void propertyChange(PropertyChangeEvent event) {
 		if(AppearancePreferencePage.arePackagesFoldedInHierarchicalLayout()!=fFoldPackages){
 			fFoldPackages= AppearancePreferencePage.arePackagesFoldedInHierarchicalLayout();
 			fViewer.getControl().setRedraw(false);
 			Object[] expandedObjects= fViewer.getExpandedElements();
 			fViewer.refresh();
 			fViewer.setExpandedElements(expandedObjects);
 			fViewer.getControl().setRedraw(true);
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2002 International Business Machines Corp. and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v0.5
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v05.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	******************************************************************************/
	package org.eclipse.jdt.internal.ui.packageview;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.core.resources.IFolder;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.runtime.CoreException;

	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;

	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.jface.viewers.ITreeContentProvider;
	import org.eclipse.jface.viewers.TreeViewer;
	import org.eclipse.jface.viewers.Viewer;

	import org.eclipse.jdt.core.ElementChangedEvent;
	import org.eclipse.jdt.core.IElementChangedListener;
	import org.eclipse.jdt.core.IJavaElement;
	import org.eclipse.jdt.core.IJavaElementDelta;
	import org.eclipse.jdt.core.IJavaProject;
	import org.eclipse.jdt.core.IPackageFragment;
	import org.eclipse.jdt.core.IPackageFragmentRoot;
	import org.eclipse.jdt.core.JavaCore;
	import org.eclipse.jdt.core.JavaModelException;

	import org.eclipse.jdt.internal.compiler.env.ICompilationUnit;
	import org.eclipse.jdt.internal.ui.JavaPlugin;

	import org.eclipse.jdt.internal.ui.preferences.AppearancePreferencePage;

	/**
	* Content provider which provides package fragments for hierarchical
	* Package Explorer layout.
	*
	* @since 2.1
	*/
	public class PackageFragmentProvider implements IPropertyChangeListener, ITreeContentProvider, IElementChangedListener{

	private TreeViewer fViewer;
	private boolean fFoldPackages;

	public PackageFragmentProvider() {
	fFoldPackages= AppearancePreferencePage.arePackagesFoldedInHierarchicalLayout();
	JavaPlugin.getDefault().getPreferenceStore().addPropertyChangeListener(this);
	}

	/*
	* @see org.eclipse.jface.viewers.ITreeContentProvider#getChildren(Object)
	*/
	public Object[] getChildren(Object parentElement) {
	try {
	if (parentElement instanceof IJavaElement) {
	IJavaElement iJavaElement= (IJavaElement) parentElement;
	int type= iJavaElement.getElementType();

	switch (type) {
	case IJavaElement.JAVA_PROJECT: {
	IJavaProject project= (IJavaProject)iJavaElement;
	IProject proj= project.getProject();

	List children= new ArrayList();

	IPackageFragmentRoot defaultroot= project.getPackageFragmentRoot(proj);
	if(defaultroot.exists()){
	IJavaElement[] els= defaultroot.getChildren();
	children= getTopLevelChildrenByElementName(els);

	}

	return filter(children.toArray());
	}

	case IJavaElement.PACKAGE_FRAGMENT_ROOT :
	{
	IPackageFragmentRoot root = (IPackageFragmentRoot) parentElement;
	if (root.exists()) {
	IResource resource = root.getUnderlyingResource();
	if (root.isArchive()) {
	IJavaElement[] els = root.getChildren();
	return filter(getTopLevelChildrenByElementName(els).toArray());

	} else if (resource instanceof IFolder) {
	IFolder folder = (IFolder) resource;
	IResource[] reses = folder.members();

	List children = getFolders(reses);
	IPackageFragment defaultPackage= root.getPackageFragment(""); //$NON-NLS-1$
	if(defaultPackage.exists())
	children.add(defaultPackage);

	return filter(children.toArray());
	}
	}
	break;
	}
	case IJavaElement.PACKAGE_FRAGMENT :
	{
	IPackageFragment packageFragment = (IPackageFragment) parentElement;
	if (!packageFragment.isDefaultPackage()) {
	IResource resource = packageFragment.getUnderlyingResource();
	if (resource != null && resource instanceof IFolder) {
	IFolder folder = (IFolder) resource;
	IResource[] reses = folder.members();
	Object[] children = getFolders(reses).toArray();
	return filter(children);
	//if the resource is null, maybe member of an archive
	} else {
	IJavaElement parent = packageFragment.getParent();
	if (parent instanceof IPackageFragmentRoot) {
	IPackageFragmentRoot root = (IPackageFragmentRoot) parent;
	Object[] children = findNextLevelChildrenByElementName(root, packageFragment);
	return filter(children);
	}
	}
	}
	break;
	}
	default :
	// do nothing
	}
	}
	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	} catch (CoreException e) {
	JavaPlugin.log(e);
	}
	return new Object[0];
	}

	private Object[] filter(Object[] children) {
	if (fFoldPackages) {
	for (int i = 0; i < children.length; i++) {
	if (children[i] instanceof IPackageFragment) {
	IPackageFragment fragment = (IPackageFragment) children[i];
	if(!fragment.isDefaultPackage())
	children[i] = getBottomPackage(fragment);
	}
	}
	}
	return children;
	}

	private Object getBottomPackage(IPackageFragment iPackageFragment) {
	try {
	if(isEmpty(iPackageFragment))
	return findChildrenToBeCompounded(iPackageFragment);
	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}
	return iPackageFragment;
	}

	private IPackageFragment findChildrenToBeCompounded(IPackageFragment fragment) throws JavaModelException {

	Object[] children = getChildren(fragment);
	if ((children.length == 1) && (children[0] instanceof IPackageFragment)) {
	if (isEmpty((IPackageFragment) children[0]))
	return findChildrenToBeCompounded((IPackageFragment) children[0]);
	else return (IPackageFragment)children[0];
	}
	return fragment;
	}

	private boolean isEmpty(IPackageFragment fragment) throws JavaModelException {
	return (!fragment.containsJavaResources()) && (fragment.getNonJavaResources().length==0);
	}


	private Object[] findNextLevelChildrenByElementName(IPackageFragmentRoot parent, IPackageFragment fragment) {
	List list= new ArrayList();
	try {

	IJavaElement[] children= parent.getChildren();
	String fragmentname= fragment.getElementName();
	for (int i= 0; i < children.length; i++) {
	IJavaElement element= children[i];
	if (element instanceof IPackageFragment) {
	IPackageFragment frag= (IPackageFragment) element;

	String name= element.getElementName();
	if (!"".equals(fragmentname) && name.startsWith(fragmentname) && !name.equals(fragmentname)) { //$NON-NLS-1$
	String tail= name.substring(fragmentname.length() + 1);
	if (!"".equals(tail) && (tail.indexOf(".") == -1)) {//$NON-NLS-1$ //$NON-NLS-2$
	list.add(frag);
	}
	}
	}
	}

	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}
	return list.toArray();

	}

	private List getTopLevelChildrenByElementName(IJavaElement[] elements){
	List topLevelElements= new ArrayList();
	for (int i= 0; i < elements.length; i++) {
	IJavaElement iJavaElement= elements[i];
	//if the name of the PackageFragment is the top level package it will contain no "." separators
	if((iJavaElement.getElementName().indexOf(".")==-1) && (iJavaElement instanceof IPackageFragment)){ //$NON-NLS-1$
	topLevelElements.add(iJavaElement);
	}
	}
	return topLevelElements;
	}

	private List getFolders(IResource[] resources) throws JavaModelException {
	List list= new ArrayList();
	for (int i= 0; i < resources.length; i++) {
	IResource resource= resources[i];

	if (resource instanceof IFolder) {
	IFolder folder= (IFolder) resource;
	IJavaElement element= JavaCore.create(folder);

	if (element instanceof IPackageFragment) {
	list.add(element);
	}
	}
	}
	return list;
	}


	/*
	* @see org.eclipse.jface.viewers.ITreeContentProvider#getParent(Object)
	*/
	public Object getParent(Object element) {

	if (element instanceof IPackageFragment) {
	IPackageFragment frag = (IPackageFragment) element;
	//@Changed: a fix, before: if(frag.exists() && isEmpty(frag))

	return filterParent(getActualParent(frag));
	}
	return null;
	}

	public Object getActualParent(IPackageFragment fragment) {
	try {

	if (fragment.exists()) {
	IJavaElement parent = fragment.getParent();

	if ((parent instanceof IPackageFragmentRoot) && parent.exists()) {
	IPackageFragmentRoot root = (IPackageFragmentRoot) parent;
	if (root.isArchive()) {
	return findNextLevelChildrenByElementName(fragment, root);
	} else {

	IResource resource = fragment.getUnderlyingResource();
	if ((resource != null) && (resource instanceof IFolder)) {
	IFolder folder = (IFolder) resource;
	IResource res = folder.getParent();

	IJavaElement el = JavaCore.create(res);
	return el;
	}
	}
	return parent;
	}
	}

	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}
	return null;
	}

	private Object filterParent(Object parent) {
	if (fFoldPackages && (parent!=null)) {
	try {
	if (parent instanceof IPackageFragment) {
	IPackageFragment fragment = (IPackageFragment) parent;
	if (isEmpty(fragment) && hasSingleChild(fragment)) {
	return filterParent(getActualParent(fragment));
	}
	}
	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}
	}
	return parent;
	}

	private boolean hasSingleChild(IPackageFragment fragment) {
	return getChildren(fragment).length==1;
	}


	private Object findNextLevelChildrenByElementName(IJavaElement child, IJavaElement parent) {
	String name= child.getElementName();

	if(name.indexOf(".")==-1) //$NON-NLS-1$
	return parent;

	try {
	String realParentName= child.getElementName().substring(0,name.lastIndexOf(".")); //$NON-NLS-1$
	IJavaElement[] children= new IJavaElement[0];

	if(parent instanceof IPackageFragmentRoot){
	IPackageFragmentRoot root = (IPackageFragmentRoot) parent;
	children= root.getChildren();
	} else if (parent instanceof IJavaProject) {
	IJavaProject project = (IJavaProject) parent;
	children= project.getPackageFragments();
	}

	for (int i= 0; i < children.length; i++) {
	IJavaElement element= children[i];
	if(element.getElementName().equals(realParentName))
	return element;
	}
	} catch (JavaModelException e) {
	JavaPlugin.log(e);
	}

	return parent;
	}


	/*
	* @see org.eclipse.jface.viewers.ITreeContentProvider#hasChildren(Object)
	*/
	public boolean hasChildren(Object element) {

	if (element instanceof IPackageFragment) {
	IPackageFragment fragment= (IPackageFragment) element;
	if(fragment.isDefaultPackage())
	return false;
	}
	return getChildren(element).length > 0;
	}

	/*
	* @see org.eclipse.jface.viewers.IStructuredContentProvider#getElements(Object)
	*/
	public Object[] getElements(Object inputElement) {
	return getChildren(inputElement);
	}

	/*
	* @see org.eclipse.jface.viewers.IContentProvider#dispose()
	*/
	public void dispose() {
	JavaPlugin.getDefault().getPreferenceStore().removePropertyChangeListener(this);
	}

	/**
	* Called when the view is closed and opened.
	*
	* @see org.eclipse.jface.viewers.IContentProvider#inputChanged(Viewer, Object, Object)
	*/
	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
	fViewer= (TreeViewer)viewer;
	}

	/*
	* @see org.eclipse.jdt.core.IElementChangedListener#elementChanged(org.eclipse.jdt.core.ElementChangedEvent)
	*/
	public void elementChanged(ElementChangedEvent event) {
	processDelta(event.getDelta());
	}

	public void processDelta(IJavaElementDelta delta) {

	int kind = delta.getKind();
	final IJavaElement element = delta.getElement();

	if (element instanceof IPackageFragment) {

	if (kind == IJavaElementDelta.REMOVED) {

	postRunnable(new Runnable() {
	public void run() {
	Control ctrl = fViewer.getControl();
	if (ctrl != null && !ctrl.isDisposed()) {
	ctrl.setRedraw(false);
	if (!fFoldPackages)
	((TreeViewer) fViewer).remove(element);
	else
	refreshGrandParent(element);
	ctrl.setRedraw(true);
	}
	}
	});
	return;

	} else if (kind == IJavaElementDelta.ADDED) {

	final Object parent = getParent(element);
	if (parent != null) {
	postRunnable(new Runnable() {
	public void run() {
	Control ctrl = fViewer.getControl();
	if (ctrl != null && !ctrl.isDisposed()) {
	ctrl.setRedraw(false);
	if (!fFoldPackages)
	((TreeViewer) fViewer).add(parent, element);
	else
	refreshGrandParent(element);
	ctrl.setRedraw(true);
	}
	}
	});
	}
	return;

	} else if (kind == IJavaElementDelta.CHANGED) {

	postRunnable(new Runnable() {
	public void run() {
	Control ctrl = fViewer.getControl();
	if (ctrl != null && !ctrl.isDisposed()) {
	ctrl.setRedraw(false);
	refreshGrandParent(element);
	ctrl.setRedraw(true);
	}
	}
	});
	return;
	}

	}

	IJavaElementDelta[] affectedChildren = delta.getAffectedChildren();
	processAffectedChildren(affectedChildren);

	}


	// XXX: needs to be revisited - might be a performance issue
	private void refreshGrandParent(final IJavaElement element) {
	if (element instanceof IPackageFragment) {
	Object gp= getGrandParent((IPackageFragment)element);
	if (gp instanceof IJavaElement) {
	IJavaElement el = (IJavaElement) gp;
	if(el.exists())
	fViewer.refresh(gp);
	}
	}
	}

	private Object getGrandParent(IPackageFragment element) {

	Object parent= findNextLevelChildrenByElementName(element, element.getParent());
	if (parent instanceof IPackageFragmentRoot) {
	IPackageFragmentRoot root= (IPackageFragmentRoot) parent;
	if(isRootProject(root))
	return root.getJavaProject();
	else return root;
	}

	Object grandParent= getParent(parent);
	if(grandParent==null){
	return parent;
	}
	return grandParent;
	}

	private boolean isRootProject(IPackageFragmentRoot root) {
	return IPackageFragmentRoot.DEFAULT_PACKAGEROOT_PATH.equals(root.getElementName());
	}

	protected void processAffectedChildren(IJavaElementDelta[] affectedChildren) {
	for (int i= 0; i < affectedChildren.length; i++) {
	if (!(affectedChildren[i] instanceof ICompilationUnit)) {
	processDelta(affectedChildren[i]);
	}
	}
	}

	private void postRunnable(final Runnable r) {
	Control ctrl= fViewer.getControl();
	if (ctrl != null && !ctrl.isDisposed()) {

	Display currentDisplay= Display.getCurrent();
	if (currentDisplay != null && currentDisplay.equals(ctrl.getDisplay()))
	ctrl.getDisplay().syncExec(r);
	else
	ctrl.getDisplay().asyncExec(r);
	}
	}

	/*
	* @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
	*/
	public void propertyChange(PropertyChangeEvent event) {
	if(AppearancePreferencePage.arePackagesFoldedInHierarchicalLayout()!=fFoldPackages){
	fFoldPackages= AppearancePreferencePage.arePackagesFoldedInHierarchicalLayout();
	fViewer.getControl().setRedraw(false);
	Object[] expandedObjects= fViewer.getExpandedElements();
	fViewer.refresh();
	fViewer.setExpandedElements(expandedObjects);
	fViewer.getControl().setRedraw(true);
	}
	}
	}