/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2004 Sun
 * Microsystems, Inc. All Rights Reserved.
 */

package org.openide.loaders;

import java.awt.datatransfer.*;
import java.beans.*;
import java.io.*;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
import javax.swing.Action;

import org.openide.ErrorManager;
import org.openide.filesystems.*;
import org.openide.filesystems.FileSystem.HtmlStatus;
import org.openide.util.datatransfer.*;
import org.openide.util.HelpCtx;
import org.openide.util.RequestProcessor;
import org.openide.util.NbBundle;
import org.openide.util.actions.SystemAction;
import org.openide.nodes.*;
import org.openide.util.Mutex;

/** Standard node representing a data object.
*
* @author Jaroslav Tulach
*/
public class DataNode extends AbstractNode {

    /** generated Serialized Version UID */
    static final long serialVersionUID = -7882925922830244768L;

    /** DataObject of this node. */
    private DataObject obj;

    /** property change listener */
    private PropL propL;

    /** should file extensions be displayed? */
    private static boolean showFileExtensions = true;

    /** Create a data node for a given data object.
    * The provided children object will be used to hold all child nodes.
    * The name is always set to the base name of the primary file;
    * the display name may instead be set to the base name with extension.
    * @param obj object to work with
    * @param ch children container for the node
    * @see #getShowFileExtensions
    */
    public DataNode (DataObject obj, Children ch) {
        super (ch);
        this.obj = obj;

        propL = new PropL ();

        obj.addPropertyChangeListener (org.openide.util.WeakListeners.propertyChange (propL, obj));

        super.setName (obj.getName ());
        updateDisplayName ();
    }

    private void updateDisplayName () {
        FileObject prim = obj.getPrimaryFile ();
        String newDisplayName;
        
        if (prim.isRoot()) {
            // Special case - getName{,Ext} will just return "".
            // Used to be handled by org.netbeans.core.RootFolderNode
            // but might as well do it here.
            // XXX replace with #37549
            File f = FileUtil.toFile(prim);
            if (f == null) {
                // Check for a JAR root explicitly.
                FileObject archiveFile = FileUtil.getArchiveFile(prim);
                if (archiveFile != null) {
                    f = FileUtil.toFile(archiveFile);
                }
            }
            if (f != null) {
                // E.g. /tmp/foo or /tmp/foo.jar
                newDisplayName = f.getAbsolutePath();
            } else {
                try {
                    // E.g. http://webdavhost.nowhere.net/mystuff/
                    newDisplayName = prim.getURL().toExternalForm();
                } catch (FileStateInvalidException e) {
                    // Should not happen in practice.
                    newDisplayName = "???"; // NOI18N
                }
            }
        } else if (showFileExtensions || obj instanceof DataFolder || obj instanceof DefaultDataObject) {
            newDisplayName = prim.getNameExt();
        } else {
            newDisplayName = prim.getName ();
        }

        if (displayFormat != null)
            setDisplayName (displayFormat.format (new Object[] { newDisplayName }));
        else
            setDisplayName (newDisplayName);
    }

    /** Get the represented data object.
     * @return the data object
    */
    public DataObject getDataObject() {
        return obj;
    }

    /** Changes the name of the node and may also rename the data object.
    * If the object is renamed and file extensions are to be shown,
    * the display name is also updated accordingly.
    *
    * @param name new name for the object
    * @param rename rename the data object?
    * @exception IllegalArgumentException if the rename failed
    */
    public void setName (String name, boolean rename) {
        try {
            if (rename) {
                obj.rename (name);
            }

            super.setName (name);
            if (rename) updateDisplayName ();
        } catch (IOException ex) {
            String msg = null;
            if ((ex.getLocalizedMessage() == null) || 
                (ex.getLocalizedMessage().equals(ex.getMessage()))) {
                msg = NbBundle.getMessage (DataNode.class, "MSG_renameError", getName (), name); // NOI18N
            } else {
                msg = ex.getLocalizedMessage();
            }
            
            RuntimeException e = new IllegalArgumentException();
            ErrorManager.getDefault().copyAnnotation (e, ex);
            ErrorManager.getDefault().annotate (e, ErrorManager.USER, null, msg, null, null);
            throw e;
        }
    }

    /* Rename the data object.
    * @param name new name for the object
    * @exception IllegalArgumentException if the rename failed
    */
    public void setName (String name) {
        setName (name, true);
    }


    /** Get the display name for the node.
     * A filesystem may {@link org.openide.filesystems.FileSystem#getStatus specially alter} this.
     * Subclassers overriding this method should consider the recommendations
     * in {@link DataObject#createNodeDelegate}.
     * @return the desired name
    */
    public String getDisplayName () {
        String s = super.getDisplayName ();

        try {
            s = obj.getPrimaryFile ().getFileSystem ().getStatus ().annotateName (s, new LazyFilesSet());
        } catch (FileStateInvalidException e) {
            // no fs, do nothing
        }

        return s;
    }

     
     /** Get a display name formatted using the limited HTML subset supported
      * by HtmlRenderer.  If the underlying 
      * FileSystem.Status is an instance of HmlStatus,
      * this method will return non-null if status information is added.
      *
      * @return a string containing compliant HTML markup or null
      * @see org.openide.awt.HtmlRenderer
      * @see org.openide.nodes.Node#getHtmlDisplayName
      * @since 4.13 
      */
     public String getHtmlDisplayName() {
         try {
             FileSystem.Status stat = 
                 obj.getPrimaryFile().getFileSystem().getStatus();
             if (stat instanceof HtmlStatus) {
                 HtmlStatus hstat = (HtmlStatus) stat;
                 
                 String result = hstat.annotateNameHtml (
                     super.getDisplayName(), new LazyFilesSet());
                 
                 //Make sure the super string was really modified
                 if (!super.getDisplayName().equals(result)) {
                     return result;
                 }
             }
         } catch (FileStateInvalidException e) {
             //do nothing and fall through
         }
         return super.getHtmlDisplayName();
     }    

    /** Get the displayed icon for this node.
     * A filesystem may {@link org.openide.filesystems.FileSystem#getStatus specially alter} this.
     * Subclassers overriding this method should consider the recommendations
     * in {@link DataObject#createNodeDelegate}.
     * @param type the icon type from {@link java.beans.BeanInfo}
     * @return the desired icon
    */
    public java.awt.Image getIcon (int type) {
        java.awt.Image img = super.getIcon (type);

        try {
            img = obj.getPrimaryFile ().getFileSystem ().getStatus ().annotateIcon (img, type, new LazyFilesSet());
        } catch (FileStateInvalidException e) {
            // no fs, do nothing
        }

        return img;
    }

    /** Get the displayed icon for this node.
    * A filesystem may {@link org.openide.filesystems.FileSystem#getStatus specially alter} this.
     * Subclassers overriding this method should consider the recommendations
     * in {@link DataObject#createNodeDelegate}.
    * @param type the icon type from {@link java.beans.BeanInfo}
    * @return the desired icon
    */
    public java.awt.Image getOpenedIcon (int type) {
        java.awt.Image img = super.getOpenedIcon(type);

        try {
            img = obj.getPrimaryFile ().getFileSystem ().getStatus ().annotateIcon (img, type, new LazyFilesSet());
        } catch (FileStateInvalidException e) {
            // no fs, do nothing
        }

        return img;
    }
    
    public HelpCtx getHelpCtx () {
        return obj.getHelpCtx ();
    }

    /** Indicate whether the node may be renamed.
    * @return tests {@link DataObject#isRenameAllowed}
    */
    public boolean canRename () {
        return obj.isRenameAllowed ();
    }

    /** Indicate whether the node may be destroyed.
     * @return tests {@link DataObject#isDeleteAllowed}
     */
    public boolean canDestroy () {
        return obj.isDeleteAllowed ();
    }

    /* Destroyes the node
    */
    public void destroy () throws IOException {
        if (obj.isDeleteAllowed ()) {
            obj.delete ();
        }
        super.destroy ();
    }

    /* Returns true if this object allows copying.
    * @returns true if this object allows copying.
    */
    public boolean canCopy () {
        return obj.isCopyAllowed ();
    }

    /* Returns true if this object allows cutting.
    * @returns true if this object allows cutting.
    */
    public boolean canCut () {
        return obj.isMoveAllowed ();
    }

    /** This method returns null to signal that actions
    * provide by DataLoader.getActions should be returned from 
    * method getActions. If overriden to provide some actions,
    * then these actions will be preferred to the loader's ones.
    *
    * @return null
    */
    protected SystemAction[] createActions () {
        return null;
    }

    /** Get actions for this data object.
    * @see DataLoader#getActions
    * @return array of actions or null
    */
    public SystemAction[] getActions () {
        if (systemActions == null) {
            systemActions = createActions ();
        }

        if (systemActions != null) {
            return systemActions;
        }

        return obj.getLoader ().getActions ();
    }

    /** Get default action. In the current implementation the 
    *null is returned in case the underlying data 
    * object is a template. The templates should not have any default 
    * action.
    * @return no action if the underlying data object is a template. 
    *    Otherwise the abstract node's default action is returned, if null then
    *    the first action returned from getActions (false) method is used.
    */
    public Action getPreferredAction () {
        if (obj.isTemplate ()) {
            return null;
        } else {
            Action action = super.getPreferredAction ();
            if (action != null) {
                return action;
            }
            Action[] arr = getActions(false);
            if (arr != null && arr.length > 0) {
                return arr[0];
            }
            return null;
        }
    }

    /** Get a cookie.
     * First of all {@link DataObject#getCookie} is
    * called. If it produces non-null result, that is returned.
    * Otherwise the superclass is tried.
     * Subclassers overriding this method should consider the recommendations
     * in {@link DataObject#createNodeDelegate}.
    *
    * @return the cookie or null
    */
    public Node.Cookie getCookie (Class cl) {
        Node.Cookie c = obj.getCookie (cl);
        if (c != null) {
            return c;
        } else {
            return super.getCookie (cl);
        }
    }

    /* Initializes sheet of properties. Allow subclasses to
    * overwrite it.
    * @return the default sheet to use
    */
    protected Sheet createSheet () {
        Sheet s = Sheet.createDefault ();
        Sheet.Set ss = s.get (Sheet.PROPERTIES);

        Node.Property p;

        p = createNameProperty (obj);
        ss.put (p);

        FileObject fo = getDataObject().getPrimaryFile();
        if (couldBeTemplate(fo) && !fo.isReadOnly()) {
            try {            
                p = new PropertySupport.Reflection(obj, Boolean.TYPE, "isTemplate", "setTemplate"); // NOI18N
                p.setName(DataObject.PROP_TEMPLATE);
                p.setDisplayName(DataObject.getString("PROP_template"));
                p.setShortDescription(DataObject.getString("HINT_template"));
                ss.put(p);
            } catch (Exception ex) {
                throw new InternalError();
            }
        }

        if (fo.isData()) {
            ss.put(new AllFilesProperty());
            ss.put(new SizeProperty());
            ss.put(new LastModifiedProperty());
        }

        return s;
    }
    
    private static boolean couldBeTemplate(FileObject fo) {
        FileSystem fs;
        try {
            fs = fo.getFileSystem();
        } catch (FileStateInvalidException e) {
            return false;
        }
        return fs.isDefault() && fo.getPath().startsWith("Templates/"); // NOI18N
    }
    
    /**
     * A property with a list of all contained files.
     * Sorted to first show primary file, then all secondary files alphabetically.
     * Shows absolute file path or the closest equivalent.
     */
    private final class AllFilesProperty extends PropertySupport.ReadOnly {
        
        public AllFilesProperty() {
            super(DataObject.PROP_FILES, String[].class,
                  DataObject.getString("PROP_files"), DataObject.getString("HINT_files"));
        }
        
        public Object getValue() {
            Set files = obj.files();
            String[] toret = new String[files.size()];
            int i = 0; for (Iterator it = files.iterator(); it.hasNext(); i++) {
                toret[i] = name((FileObject)it.next());
            }
            final String pfilename = name(obj.getPrimaryFile());
            Arrays.sort(toret, new Comparator() {
                public int compare(Object o1, Object o2) {
                    String fname1 = (String) o1;
                    String fname2 = (String) o2;
                    if (fname1.equals(pfilename))
                        return -1;
                    else if (fname2.equals(pfilename))
                        return 1;
                    else
                        return fname1.compareTo(fname2);
                }
            });
            return toret;
        }
        
        private String name(FileObject fo) {
            return FileUtil.getFileDisplayName(fo);
        }
        
    }
    
    private final class SizeProperty extends PropertySupport.ReadOnly {
        
        public SizeProperty() {
            super("size", Long.TYPE, DataObject.getString("PROP_size"), DataObject.getString("HINT_size"));
        }
        
        public Object getValue() {
            return new Long(getDataObject().getPrimaryFile().getSize());
        }
        
    }
    
    private final class LastModifiedProperty extends PropertySupport.ReadOnly {
        
        public LastModifiedProperty() {
            super("lastModified", Date.class, DataObject.getString("PROP_lastModified"), DataObject.getString("HINT_lastModified"));
        }
        
        public Object getValue() {
            return getDataObject().getPrimaryFile().lastModified();
        }
        
    }
    
    /** Copy this node to the clipboard.
    *
    * @return {@link org.openide.util.datatransfer.ExTransferable.Single} with one copy flavor
    * @throws IOException if it could not copy
    * @see NodeTransfer
    */
    public Transferable clipboardCopy () throws IOException {
        ExTransferable t = ExTransferable.create (super.clipboardCopy ());
        t.put (LoaderTransfer.transferable (
            getDataObject (), 
            LoaderTransfer.CLIPBOARD_COPY)
        );
        return t;
    }

    /** Cut this node to the clipboard.
    *
    * @return {@link org.openide.util.datatransfer.ExTransferable.Single} with one cut flavor
    * @throws IOException if it could not cut
    * @see NodeTransfer
    */
    public Transferable clipboardCut () throws IOException {
        ExTransferable t = ExTransferable.create (super.clipboardCut ());
        t.put (LoaderTransfer.transferable (
            getDataObject (), 
            LoaderTransfer.CLIPBOARD_CUT)
        );
        return t;
    }
    
    /** Creates a name property for given data object.
    */
    static Node.Property createNameProperty (final DataObject obj) {
        Node.Property p = new PropertySupport.ReadWrite (
                              DataObject.PROP_NAME,
                              String.class,
                              DataObject.getString("PROP_name"),
                              DataObject.getString("HINT_name")
                          ) {
                              public Object getValue () {
                                  return obj.getName();
                              }

                              public void setValue (Object val) throws IllegalAccessException,
                                  IllegalArgumentException, InvocationTargetException {
                                  if (!canWrite())
                                      throw new IllegalAccessException();
                                  if (!(val instanceof String))
                                      throw new IllegalArgumentException();

                                  try {
                                      obj.rename ((String)val);
                                  } catch (IOException ex) {
                                      String msg = null;
                                      if ((ex.getLocalizedMessage() == null) || 
                                          (ex.getLocalizedMessage().equals(ex.getMessage()))) {
                                          msg = NbBundle.getMessage (DataNode.class, "MSG_renameError", obj.getName(), val); // NOI18N
                                      } else {
                                          msg = ex.getLocalizedMessage();
                                      }
                                      ErrorManager.getDefault().annotate (ex, ErrorManager.USER, null, msg, null, null);
                                      throw new InvocationTargetException(ex);
                                  }
                              }

                              public boolean canWrite () {
                                  return obj.isRenameAllowed();
                              }

                              // #33296 - suppress custom editor
                              public Object getValue(String key) {
                                  if ("suppressCustomEditor".equals (key)) { //NOI18N
                                      return Boolean.TRUE;
                                  } else {
                                      return super.getValue (key);
                                  }
                              }

                          };

        return p;
    }

    /** Support for firing property change.
    * @param ev event describing the change
    */
    void fireChange(final PropertyChangeEvent ev) {
        Mutex.EVENT.writeAccess(new Runnable() {
            public void run() {

                if (DataFolder.PROP_CHILDREN.equals(ev.getPropertyName())) {
                    // the node is not interested in children changes
                    return;
                }

                if (DataObject.PROP_PRIMARY_FILE.equals(ev.getPropertyName())) {
                    // the node is not interested in children changes
                    propL.updateStatusListener();
                    setName(obj.getName(), false);
                    return;
                }

                if (DataObject.PROP_NAME.equals(ev.getPropertyName())) {
                    DataNode.super.setName(obj.getName());
                    updateDisplayName();
                    return;
                }
                if (DataObject.PROP_COOKIE.equals(ev.getPropertyName())) {
                    fireCookieChange();
                    //return;
                } 
        
                // if the DataOjbect is not valid the node should be
                // removed
                if (DataObject.PROP_VALID.equals(ev.getPropertyName())) {
                    Object newVal = ev.getNewValue();
                    if ((newVal instanceof Boolean) && (!((Boolean) newVal).booleanValue())) {
                        fireNodeDestroyed();
                    }
                    return;
                } 
                
                 /*See #31413*/
                List transmitProperties = Arrays.asList(new String[] {
                    DataObject.PROP_NAME, DataObject.PROP_FILES, DataObject.PROP_TEMPLATE});
                if (transmitProperties.contains(ev.getPropertyName())) {
                    firePropertyChange(ev.getPropertyName(), ev.getOldValue(), ev.getNewValue());   
                }                
            }
        });
    }

    /** Handle for location of given data object.
    * @return handle that remembers the data object.
    */
    public Handle getHandle () {
        return new ObjectHandle(obj, obj.isValid() ? (this != obj.getNodeDelegate()) : /* to be safe */ true);
    }

    /** Access method to fire icon change.
    */
    final void fireChangeAccess (boolean icon, boolean name) {
        if (name) {
            fireDisplayNameChange (null, null);
        }
        if (icon) {
            fireIconChange ();
        }
    }

    /** Determine whether file extensions should be shown by default.
    * By default, no.
    * @return true if so
    */
    public static boolean getShowFileExtensions () {
        return showFileExtensions;
    }

    /** Set whether file extensions should be shown by default.
    * @param s true if so
    */
    public static void setShowFileExtensions (boolean s) {
        boolean refresh = ( showFileExtensions != s );
        showFileExtensions = s;
        
        if ( refresh ) {
            // refresh current nodes display name
            RequestProcessor.postRequest(new Runnable () {
                public void run () { 
                    Iterator it = DataObjectPool.getPOOL().getActiveDataObjects();
                    while ( it.hasNext() ) {
                        DataObject obj = ((DataObjectPool.Item)it.next()).getDataObjectOrNull();
                        if ( obj != null && obj.getNodeDelegate() instanceof DataNode ) {
                            ((DataNode)obj.getNodeDelegate()).updateDisplayName();            
                        }
                    }        
                }
            }, 300, Thread.MIN_PRIORITY);                    
        }        
        
    }
    
    /** Request processor task to update a bunch of names/icons.
     * Potentially faster to do many nodes at once; see #16478.
     */
    private static RequestProcessor.Task refreshNamesIconsTask = null;
    /** nodes which should be refreshed */
    private static Set refreshNameNodes = null; // Set
    private static Set refreshIconNodes = null; // Set
    /** whether the task is current scheduled and will still look in above sets */
    private static boolean refreshNamesIconsRunning = false;
    private static final Object refreshNameIconLock = "DataNode.refreshNameIconLock"; // NOI18N
    
    /** Property listener on data object that delegates all changes of
    * properties to this node.
    */
    private class PropL extends Object
        implements PropertyChangeListener, FileStatusListener, Runnable {
        /** weak version of this listener */
        private FileStatusListener weakL;
        /** previous filesystem we were attached to */
        private FileSystem previous;

        public PropL () {
            updateStatusListener ();
        }

        public void propertyChange (PropertyChangeEvent ev) {
            fireChange (ev);
        }

        /** Updates listening on a status of filesystem.
        */
        private void updateStatusListener () {
            if (previous != null) {
                previous.removeFileStatusListener (weakL);
            }
            try {
                previous = obj.getPrimaryFile ().getFileSystem ();

                if (weakL == null) {
                    weakL = org.openide.filesystems.FileUtil.weakFileStatusListener (this, null);
                }

                previous.addFileStatusListener (weakL);
            } catch (FileStateInvalidException ex) {
                previous = null;
            }
        }

        /** Notifies listener about change in annotataion of a few files.
        * @param ev event describing the change
        */
        public void annotationChanged (FileStatusEvent ev) {
            // #16541: listen for changes in both primary and secondary files
            boolean thisChanged = false;
            Iterator it = obj.files().iterator();
            while (it.hasNext()) {
                FileObject fo = (FileObject)it.next();
                if (ev.hasChanged(fo)) {
                    thisChanged = true;
                    break;
                }
            }
            if (thisChanged) {
                // #12368: fire display name & icon changes asynch
                synchronized (refreshNameIconLock) {
                    boolean post = false;
                    if (ev.isNameChange()) {
                        if (refreshNameNodes == null) {
                            refreshNameNodes = new HashSet();
                        }
                        post |= refreshNameNodes.add(DataNode.this);
                    }
                    if (ev.isIconChange()) {
                        if (refreshIconNodes == null) {
                            refreshIconNodes = new HashSet();
                        }
                        post |= refreshIconNodes.add(DataNode.this);
                    }
                    if (post && !refreshNamesIconsRunning) {
                        refreshNamesIconsRunning = true;
                        if (refreshNamesIconsTask == null) {
                            refreshNamesIconsTask = RequestProcessor.postRequest(this);
                        } else {
                            // Should be OK even if it is running right now.
                            // (Cf. RequestProcessorTest.testScheduleWhileRunning.)
                            refreshNamesIconsTask.schedule(0);
                        }
                    }
                }
            }
        }
        
        /** Refreshes names and icons for a whole batch of data nodes at once.
         */
        public void run() {
            DataNode[] _refreshNameNodes, _refreshIconNodes;
            synchronized (refreshNameIconLock) {
                if (refreshNameNodes != null) {
                    _refreshNameNodes = (DataNode[])refreshNameNodes.toArray(new DataNode[refreshNameNodes.size()]);
                    refreshNameNodes.clear();
                } else {
                    _refreshNameNodes = new DataNode[0];
                }
                if (refreshIconNodes != null) {
                    _refreshIconNodes = (DataNode[])refreshIconNodes.toArray(new DataNode[refreshIconNodes.size()]);
                    refreshIconNodes.clear();
                } else {
                    _refreshIconNodes = new DataNode[0];
                }
                refreshNamesIconsRunning = false;
            }
            for (int i = 0; i < _refreshNameNodes.length; i++) {
                _refreshNameNodes[i].fireChangeAccess(false, true);
            }
            for (int i = 0; i < _refreshIconNodes.length; i++) {
                _refreshIconNodes[i].fireChangeAccess(true, false);
            }
        }
        
    }

    /** Handle for data object nodes */
    private static class ObjectHandle extends Object implements Handle {
        private FileObject obj;
        private boolean clone;

        static final long serialVersionUID =6616060729084681518L;


        public ObjectHandle (DataObject obj, boolean clone) {
            this.obj = obj.getPrimaryFile ();
            this.clone = clone;
        }

        public Node getNode () throws IOException {
            if (obj == null) {
                // Serialization problem? Seems to occur frequently with connection support:
                // java.lang.IllegalArgumentException: Called DataObject.find on null
                //         at org.openide.loaders.DataObject.find(DataObject.java:435)
                //         at org.openide.loaders.DataNode$ObjectHandle.getNode(DataNode.java:757)
                //         at org.netbeans.modules.java.JavaDataObject$PersistentConnectionHandle.getNode(JavaDataObject.java:977)
                //         at org.openide.loaders.ConnectionSupport$Pair.getNode(ConnectionSupport.java:357)
                //         at org.openide.loaders.ConnectionSupport.register(ConnectionSupport.java:94)
                //         at org.netbeans.modules.java.codesync.SourceConnectionSupport.registerDependency(SourceConnectionSupport.java:475)
                //         at org.netbeans.modules.java.codesync.SourceConnectionSupport.addDependency(SourceConnectionSupport.java:554)
                //         at org.netbeans.modules.java.codesync.ClassDependencyImpl.supertypesAdded(ClassDependencyImpl.java:241)
                //         at org.netbeans.modules.java.codesync.ClassDependencyImpl.refreshClass(ClassDependencyImpl.java:121)
                //         at org.netbeans.modules.java.codesync.SourceConnectionSupport.refreshLinks(SourceConnectionSupport.java:357)
                //         at org.netbeans.modules.java.codesync.SourceConnectionSupport.access$000(SourceConnectionSupport.java:44)
                //         at org.netbeans.modules.java.codesync.SourceConnectionSupport$2.run(SourceConnectionSupport.java:223)
                throw new IOException("File could not be restored"); // NOI18N
            }
            Node n = DataObject.find (obj).getNodeDelegate ();
            return clone ? n.cloneNode () : n;
        }
    }
    
    /** Wrapping class for obj.files(). Used in getIcon() and getDisplayName()
        to have something lazy to pass to annotateIcon() and annotateName()
        instead of calling obj.files() immediately. */
    private class LazyFilesSet implements Set {
        
        private Set obj_files;
        
        synchronized private void lazyInitialization () {
           obj_files = obj.files();
        }
        
        public boolean add(Object o) {
            lazyInitialization();
            return obj_files.add(o);
        }
        
        public boolean addAll(Collection c) {
            lazyInitialization();
            return obj_files.addAll(c);
        }
        
        public void clear() {
            lazyInitialization();
            obj_files.clear();
        }
        
        public boolean contains(Object o) {
            lazyInitialization();
            return obj_files.contains(o);
        }
        
        public boolean containsAll(Collection c) {
            lazyInitialization();
            return obj_files.containsAll(c);
        }
        
        public boolean isEmpty() {
            lazyInitialization();
            return obj_files.isEmpty();
        }
        
        public Iterator iterator() {
            lazyInitialization();
            return obj_files.iterator();
        }
        
        public boolean remove(Object o) {
            lazyInitialization();
            return obj_files.remove(o);
        }
        
        public boolean removeAll(Collection c) {
            lazyInitialization();
            return obj_files.removeAll(c);
        }
        
        public boolean retainAll(Collection c) {
            lazyInitialization();
            return obj_files.retainAll(c);
        }
        
        public int size() {
            lazyInitialization();
            return obj_files.size();
        }
        
        public Object[] toArray() {
            lazyInitialization();
            return obj_files.toArray();
        }
        
        public Object[] toArray(Object[] a) {
            lazyInitialization();
            return obj_files.toArray(a);
        }
        
    }    
    
}