/* FeatureViewer.java
 *
 * created: Thu Nov 19 1998
 *
 * This file is part of Artemis
 * 
 * Copyright (C) 1998,1999,2000  Genome Research Limited
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header: /cvsroot/pathsoft/artemis/uk/ac/sanger/artemis/components/FeatureViewer.java,v 1.1 2004/06/09 09:46:46 tjc Exp $
 */

package uk.ac.sanger.artemis.components;

import uk.ac.sanger.artemis.*;

import java.io.*;
import java.awt.event.*;

/**
 *  A viewer for Feature objects.
 *
 *  @author Kim Rutherford
 *  @version $Id: FeatureViewer.java,v 1.1 2004/06/09 09:46:46 tjc Exp $
 *
 **/

public class FeatureViewer
    implements EntryChangeListener, FeatureChangeListener {
  /**
   *  Create a new FeatureViewer object from the given Feature.
   **/
  public FeatureViewer (Feature view_feature) {
    this.view_feature = view_feature;
    this.entry = view_feature.getEntry ();
    
    file_viewer = new FileViewer ("Artemis Feature View: " +
                                  view_feature.getIDString ());
    readFeature (view_feature);

    view_feature.getEntry ().addEntryChangeListener (this);
    view_feature.addFeatureChangeListener (this);

    file_viewer.addWindowListener (new WindowAdapter () {
      public void windowClosed (WindowEvent event) {
        stopListening ();
      }
    });
  }

  /**
   *  Remove this object as a feature and entry change listener.
   **/
  public void stopListening () {
    getEntry ().removeEntryChangeListener (this);
    getFeature ().removeFeatureChangeListener (this);
  }
  
  /**
   *  Implementation of the EntryChangeListener interface.  We listen to
   *  EntryChange events so we can delete this component if the feature gets
   *  deleted.
   **/
  public void entryChanged (EntryChangeEvent event) {
    switch (event.getType ()) {
    case EntryChangeEvent.FEATURE_DELETED:
      if (event.getFeature () == view_feature) {
        stopListening ();
        file_viewer.dispose ();
      }
      break;
    default:
      // do nothing;
      break;
    }
  }

  /**
   *  Implementation of the FeatureChangeListener interface.  We need to
   *  listen to feature change events from the Features in this object so that
   *  we can keep the display up to date.
   *  @param event The change event.
   **/
  public void featureChanged (FeatureChangeEvent event) {
    // re-read the information from the feature
    readFeature (view_feature);
  }

  /**
   *  Read the given Feature into this FeatureViewer object.
   **/
  public void readFeature (Feature feature) {
    try {
      file_viewer.clear ();
      file_viewer.appendFile (view_feature.toReader ());
    } catch (uk.ac.sanger.artemis.io.ReadFormatException e) {
      throw new Error ("internal error - unexpected exception: " +
                       e.getMessage () +
                       (e.getLineNumber () > 1 ?
                        " at line " + e.getLineNumber () :
                        ""));
    } catch (IOException e) {
      throw new Error ("internal error - unexpected exception: " +
                       e.getMessage ());
    }
  }

  /**
   *  Return the Feature we are viewing.
   **/
  public Feature getFeature () {
    return view_feature;
  }
  
  /**
   *  Return the Entry that contains the Feature this object is displaying.
   **/
  private Entry getEntry () {
    return entry;
  }

  /**
   *  The Feature this object is displaying.
   **/
  private Feature view_feature;

  /**
   *  The Entry that contains the Feature this object is displaying.
   **/
  private Entry entry;

  /**
   *  The FileViewer object that is displaying the feature.
   **/
  private FileViewer file_viewer;
}


