/*******************************************************************************
 * 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 
 * funded by European Union project number: FP6-IST-034327 
 * http://www.geclipse.eu/
 *  
 * Contributors:
 *     RUR (http://acet.rdg.ac.uk/)
 *     - Ashish Thandavan - initial API and implementation
 ******************************************************************************/
package eu.geclipse.workflow.ui.part;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.util.FeatureMap;
import org.eclipse.emf.edit.provider.IWrapperItemProvider;
import org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider;
import org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;

import eu.geclipse.workflow.ui.internal.WorkflowDiagramEditorPlugin;

/**
 * Wizard page that allows to select element from model.
 * 
 * @generated
 */
public class ModelElementSelectionPage extends WizardPage {

  /**
   * @generated
   */
  protected EObject selectedModelElement;
  /**
   * @generated
   */
  private TreeViewer modelVewer;

  /**
   * @generated
   */
  public ModelElementSelectionPage( String pageName ) {
    super( pageName );
  }

  /**
   * @generated
   */
  public EObject getModelElement() {
    return selectedModelElement;
  }

  /**
   * @generated
   */
  public void setModelElement( EObject modelElement ) {
    selectedModelElement = modelElement;
    if( modelVewer != null ) {
      if( selectedModelElement != null ) {
        modelVewer.setInput( selectedModelElement.eResource() );
        modelVewer.setSelection( new StructuredSelection( selectedModelElement ) );
      } else {
        modelVewer.setInput( null );
      }
      setPageComplete( validatePage() );
    }
  }

  /**
   * @generated
   */
  public void createControl( Composite parent ) {
    initializeDialogUnits( parent );
    Composite plate = new Composite( parent, SWT.NONE );
    plate.setLayoutData( new GridData( GridData.FILL_BOTH ) );
    GridLayout layout = new GridLayout();
    layout.marginWidth = 0;
    plate.setLayout( layout );
    setControl( plate );
    Label label = new Label( plate, SWT.NONE );
    label.setText( getSelectionTitle() );
    label.setLayoutData( new GridData( GridData.HORIZONTAL_ALIGN_BEGINNING ) );
    modelVewer = new TreeViewer( plate, SWT.SINGLE
                                        | SWT.H_SCROLL
                                        | SWT.V_SCROLL
                                        | SWT.BORDER );
    GridData layoutData = new GridData( GridData.FILL_BOTH );
    layoutData.heightHint = 300;
    layoutData.widthHint = 300;
    modelVewer.getTree().setLayoutData( layoutData );
    modelVewer.setContentProvider( new AdapterFactoryContentProvider( WorkflowDiagramEditorPlugin.getInstance()
      .getItemProvidersAdapterFactory() ) );
    modelVewer.setLabelProvider( new AdapterFactoryLabelProvider( WorkflowDiagramEditorPlugin.getInstance()
      .getItemProvidersAdapterFactory() ) );
    if( selectedModelElement != null ) {
      modelVewer.setInput( selectedModelElement.eResource() );
      modelVewer.setSelection( new StructuredSelection( selectedModelElement ) );
    }
    modelVewer.addSelectionChangedListener( new ISelectionChangedListener() {

      public void selectionChanged( SelectionChangedEvent event ) {
        ModelElementSelectionPage.this.updateSelection( ( IStructuredSelection )event.getSelection() );
      }
    } );
    setPageComplete( validatePage() );
  }

  /**
   * Override to provide custom model element description.
   * 
   * @generated
   */
  protected String getSelectionTitle() {
    return "Select model element:"; //$NON-NLS-1$
  }

  /**
   * @generated
   */
  protected void updateSelection( IStructuredSelection selection ) {
    selectedModelElement = null;
    if( selection.size() == 1 ) {
      Object selectedElement = selection.getFirstElement();
      if( selectedElement instanceof IWrapperItemProvider ) {
        selectedElement = ( ( IWrapperItemProvider )selectedElement ).getValue();
      }
      if( selectedElement instanceof FeatureMap.Entry ) {
        selectedElement = ( ( FeatureMap.Entry )selectedElement ).getValue();
      }
      if( selectedElement instanceof EObject ) {
        selectedModelElement = ( EObject )selectedElement;
      }
    }
    setPageComplete( validatePage() );
  }

  /**
   * Override to provide specific validation of the selected model element.
   * 
   * @generated
   */
  protected boolean validatePage() {
    return true;
  }
}