/*
 *                 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.netbeans.modules.url;

import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.ImageIcon;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JSeparator;

import org.openide.awt.Actions;
import org.openide.awt.JMenuPlus;
import org.openide.loaders.DataFolder;
import org.openide.loaders.DataObject;
import org.openide.loaders.InstanceDataObject;
import org.openide.filesystems.FileObject;
import org.openide.filesystems.Repository;
import org.openide.util.actions.Presenter;
import org.openide.util.actions.SystemAction;
import org.openide.util.NbBundle;
import org.openide.util.HelpCtx;
import org.openide.util.WeakListeners;
import org.openide.util.Utilities;


/** Only purpose of this dummy action is to present Places/Bookmarks folder in menu.
 *
 * @author Ian Formanek, Peter Zavadsky
 * @author  Marian Petras
 * @see org.openide.Places#bookmarks
 */
public class BookmarksAction extends SystemAction implements Presenter.Menu {

    /** Icon. */
    private static ImageIcon icon;
    
    /** Generated serial veriosn UID. */
    static final long serialVersionUID =2183102479251760123L;
    

    /** */
    public String getName() {
        return NbBundle.getMessage(BookmarksAction.class,
                                   "ACT_Bookmarks");                    //NOI18N
    }

    /** */
    public HelpCtx getHelpCtx() {
        return new HelpCtx(BookmarksAction.class);
    }

    /** */
    protected String iconResource() {
        return "org/netbeans/modules/url/bookmarks.gif"; // NOI18N
    }

    /** */
    public JMenuItem getMenuPresenter() {
        JMenuItem menu = null;
        FileObject bookmarksFolder = Repository.getDefault()
                                     .getDefaultFileSystem()
                                     .findResource("Bookmarks");        //NOI18N
        if (bookmarksFolder != null && bookmarksFolder.isFolder()) {
            String menuLabel = NbBundle.getMessage(BookmarksAction.class,
                                                   "Bookmarks");        //NOI18N
            menu = new LazyMenu(
                    DataFolder.findFolder(bookmarksFolder),
                    menuLabel);
        }
        return menu;
    }

    /** Dummy implementation of superclass abstract method. */
    public void actionPerformed(ActionEvent evt) {}


    /**
     * Menu item which will create its items lazilly when the popup be first asked.
     * Performance savings.
     */
    private static class LazyMenu extends JMenuPlus {

        /** Bookmarks node on which menu to create. */
        private DataFolder folder;
        
        /** Indicates whether menu items were uptodate. */
        private boolean uptodate = false;
        
        /** Listener on changes in folder (children/order). */
        private PropertyChangeListener propertyListener;
        

        /** Constructor. */
        public LazyMenu(DataFolder folder, String name) {
            this.folder = folder;
            Actions.setMenuText(this, name, true);
            
            if (icon == null) {
                icon = new ImageIcon(Utilities.loadImage(
                        "org/netbeans/modules/url/bookmarks.gif"));     //NOI18N
            }
            setIcon(icon);

            this.folder.addPropertyChangeListener(WeakListeners.propertyChange(propertyListener = new PropertyChangeListener() {
                public void propertyChange(PropertyChangeEvent evt) {
                    String propName = evt.getPropertyName();
                    if (propName != null) {
                        if (propName.equals(DataFolder.PROP_CHILDREN)
                                || propName.equals(DataFolder.PROP_ORDER)) {
                            uptodate = false;                    
                        } else if (propName.equals(DataFolder.PROP_NAME)) {
                            Actions.setMenuText(LazyMenu.this,
                                                LazyMenu.this.folder.getName(),
                                                true);
                        }
                    }
                }
            }, this.folder));
        }

        /** Gets popup menu. Adds lazy menu items creation. */
        public JPopupMenu getPopupMenu() {
            if (!uptodate) {
                createMenuItems();
            }
            return super.getPopupMenu();
        }
  
        /** Creates items when actually needed. */
        private void createMenuItems() {
            uptodate = true;
            removeAll();

            DataObject[] childrenDataObjects = folder.getChildren();
            
            for (int i = 0; i < childrenDataObjects.length; i++) {
                DataObject childDO = childrenDataObjects[i];
                if (childDO instanceof URLDataObject) {
                    URLDataObject urlDataObject = (URLDataObject) childDO;
                    add(new URLPresenter(urlDataObject).getMenuPresenter());
                } else if (childDO instanceof InstanceDataObject) {
                    InstanceDataObject instanceDO = (InstanceDataObject)
                                                    childDO;
                    if (instanceDO.instanceOf(JSeparator.class)) {
                        addSeparator();
                    }
                } else if (childDO instanceof DataFolder) {
                    DataFolder dataFolder = (DataFolder) childDO;
                    add(new LazyMenu(dataFolder, 
                                     dataFolder.getNodeDelegate().getName())
                    );
                }
            }
            
            if (getItemCount() == 0) {
                String itemName = NbBundle.getMessage(
                        BookmarksAction.class,
                        "LBL_EmptyMenuItem");                           //NOI18N
                JMenuItem emptyMenuItem = new JMenuItem(itemName); 
                emptyMenuItem.setEnabled(false);
                
                add(emptyMenuItem);
            }
        }
        
    } // End of class LazyMenu.

}