/*****************************************************************************
 * Copyright (c) 2006, 2007 g-Eclipse Consortium 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Initial development of the original code was made for the
 * g-Eclipse project founded by European Union
 * project number: FP6-IST-034327  http://www.geclipse.eu/
 *
 * Contributors:
 *    Mathias Stuempert - initial API and implementation
 *****************************************************************************/

package eu.geclipse.ui.views;

import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeColumn;

import eu.geclipse.core.model.IGridContainer;
import eu.geclipse.core.model.IGridElement;
import eu.geclipse.ui.comparators.TreeColumnComparator;
import eu.geclipse.ui.listeners.TreeColumnListener;

public abstract class TreeControlViewPart extends GridModelViewPart {
  
  @Override
  public void refreshViewer( final IGridElement element ) {
    if ( ( element != null ) && ( element instanceof IGridContainer ) ) {
      final IGridContainer container = ( IGridContainer ) element;
      if ( container.isLazy() && container.isDirty() ) {
        Control control = this.viewer.getControl();
        if ( ! control.isDisposed() ) {
          Display display = control.getDisplay();
          display.syncExec( new Runnable() {
            public void run() {
              TreeViewer tViewer = ( TreeViewer ) getViewer();
              tViewer.setChildCount( container, container.getChildCount() );
            }
          } );
        }
      }
    }
    super.refreshViewer( element );
  }

  /* (non-Javadoc)
   * @see eu.geclipse.ui.views.GridModelViewPart#createViewer(org.eclipse.swt.widgets.Composite)
   */
  @Override
  protected StructuredViewer createViewer( final Composite parent ) {
    TreeViewer tViewer = new TreeViewer( parent, SWT.VIRTUAL | SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL );
    Tree tree = tViewer.getTree();
    boolean hasColumns = createTreeColumns( tree );
    if ( hasColumns ) {
      tree.setHeaderVisible( true );

      // Add listener for column sorting
      TreeColumnListener columnListener = new TreeColumnListener( tViewer );
      for ( TreeColumn column : tree.getColumns() ) {
        column.addSelectionListener( columnListener );
      }
      
      // Initially sort by the first column, ascending
      TreeColumn firstColumn = tree.getColumn( 0 );
      tree.setSortColumn( firstColumn );
      tree.setSortDirection( SWT.UP );
      // Set also the first column as fallback sorting column
      tViewer.setComparator( new TreeColumnComparator( firstColumn ) );
    }
    
    return tViewer;
  }
  
  protected boolean createTreeColumns( @SuppressWarnings("unused")
                                       final Tree tree ) {
    return false;
  }
  
}