/*

 *                 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 1997-2005 Sun

 * Microsystems, Inc. All Rights Reserved.

 */

import java.util.Collection;

import javax.swing.JComponent;

import javax.swing.JLabel;

import org.netbeans.spi.navigator.NavigatorPanel;

import org.openide.util.Lookup;

import org.openide.util.LookupEvent;

import org.openide.util.LookupListener;

/**

 * Basic dummy implementation of NavigatorPanel interface.

 */

public class BasicNavPanelImpl implements NavigatorPanel {

    /** holds UI of this panel */

    private JComponent panelUI;

    /** template for finding data in given context.

     * Object used as example, replace with your own data source, for example JavaDataObject etc */

    private static final Lookup.Template MY_DATA = new Lookup.Template(Object.class);

    /** current context to work on */

    private Lookup.Result curContext;

    /** listener to context changes */

    private LookupListener contextL;

    /** public no arg constructor needed for system to instantiate provider well */

    public BasicNavPanelImpl() {

    }

    public String getDisplayHint() {

        return "Basic dummy implementation of NavigatorPanel interface";

    }

    public String getDisplayName() {

        return "Dummy View";

    }

    public JComponent getComponent() {

        if (panelUI == null) {

            panelUI = new JLabel("Dummy label");

            // You can override requestFocusInWindow() on the component if desired.

        }

        return panelUI;

    }

    public void panelActivated(Lookup context) {

        // lookup context and listen to result to get notified about context changes

        curContext = context.lookup(MY_DATA);

        curContext.addLookupListener(getContextListener());

        // get actual data and recompute content

        Collection data = curContext.allInstances();

        setNewContent(data);

    }

    public void panelDeactivated() {

        curContext.removeLookupListener(getContextListener());

        curContext = null;

    }

    public Lookup getLookup () {

        // go with default activated Node strategy

        return null;

    }

    /************* non - public part ************/

    private void setNewContent (Collection newData) {

        // put your code here that grabs information you need from given

        // collection of data, recompute UI of your panel and show it.

        // Note - be sure to compute the content OUTSIDE event dispatch thread,

        // just final repainting of UI should be done in event dispatch thread.

        // Please use RequestProcessor and Swing.invokeLater to achieve this.

    }

    /** Accessor for listener to context */

    private LookupListener getContextListener () {

        if (contextL == null) {

            contextL = new ContextListener();

        }

        return contextL;

    }

    /** Listens to changes of context and triggers proper action */

    private class ContextListener implements LookupListener {

        public void resultChanged(LookupEvent ev) {

            Collection data = ((Lookup.Result)ev.getSource()).allInstances();

            setNewContent(data);

        }

    } // end of ContextListener

}