plugins/org.eclipse.emf.cdo.dawn.examples.acore.diagram/src/org/eclipse/emf/cdo/dawn/examples/acore/diagram/providers/AcoreEditPartProvider.java

/*
 * Copyright (c) 2010, 2012, 2015 Eike Stepper (Berlin, Germany) and others.
 * 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
 *
 * Contributors:
 *     Martin Fluegge - initial API and implementation
 *
 */
package org.eclipse.emf.cdo.dawn.examples.acore.diagram.providers;

import org.eclipse.emf.cdo.dawn.examples.acore.diagram.edit.parts.ACoreRootEditPart;
import org.eclipse.emf.cdo.dawn.examples.acore.diagram.edit.parts.AcoreEditPartFactory;
import org.eclipse.emf.cdo.dawn.examples.acore.diagram.part.AcoreVisualIDRegistry;

import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPartFactory;
import org.eclipse.gmf.runtime.common.core.service.IOperation;
import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
import org.eclipse.gmf.runtime.diagram.ui.services.editpart.AbstractEditPartProvider;
import org.eclipse.gmf.runtime.diagram.ui.services.editpart.CreateGraphicEditPartOperation;
import org.eclipse.gmf.runtime.diagram.ui.services.editpart.IEditPartOperation;
import org.eclipse.gmf.runtime.notation.View;

import java.lang.ref.WeakReference;

/**
 * @generated
 */
public class AcoreEditPartProvider extends AbstractEditPartProvider
{

  /**
   * @generated
   */
  private EditPartFactory factory;

  /**
   * @generated
   */
  private boolean allowCaching;

  /**
   * @generated
   */
  private WeakReference cachedPart;

  /**
   * @generated
   */
  private WeakReference cachedView;

  /**
   * @generated
   */
  public AcoreEditPartProvider()
  {
    setFactory(new AcoreEditPartFactory());
    setAllowCaching(true);
  }

  /**
   * @generated
   */
  public final EditPartFactory getFactory()
  {
    return factory;
  }

  /**
   * @generated
   */
  protected void setFactory(EditPartFactory factory)
  {
    this.factory = factory;
  }

  /**
   * @generated
   */
  public final boolean isAllowCaching()
  {
    return allowCaching;
  }

  /**
   * @generated
   */
  protected synchronized void setAllowCaching(boolean allowCaching)
  {
    this.allowCaching = allowCaching;
    if (!allowCaching)
    {
      cachedPart = null;
      cachedView = null;
    }
  }

  /**
   * @generated
   */
  protected IGraphicalEditPart createEditPart(View view)
  {
    EditPart part = factory.createEditPart(null, view);
    if (part instanceof IGraphicalEditPart)
    {
      return (IGraphicalEditPart)part;
    }
    return null;
  }

  /**
   * @generated
   */
  protected IGraphicalEditPart getCachedPart(View view)
  {
    if (cachedView != null && cachedView.get() == view)
    {
      return (IGraphicalEditPart)cachedPart.get();
    }
    return null;
  }

  /**
   * @generated
   */
  @Override
  public synchronized IGraphicalEditPart createGraphicEditPart(View view)
  {
    if (isAllowCaching())
    {
      IGraphicalEditPart part = getCachedPart(view);
      cachedPart = null;
      cachedView = null;
      if (part != null)
      {
        return part;
      }
    }
    return createEditPart(view);
  }

  /**
   * @generated
   */
  @Override
  public synchronized boolean provides(IOperation operation)
  {
    if (operation instanceof CreateGraphicEditPartOperation)
    {
      View view = ((IEditPartOperation)operation).getView();
      if (!ACoreRootEditPart.MODEL_ID.equals(AcoreVisualIDRegistry.getModelID(view)))
      {
        return false;
      }
      if (isAllowCaching() && getCachedPart(view) != null)
      {
        return true;
      }
      IGraphicalEditPart part = createEditPart(view);
      if (part != null)
      {
        if (isAllowCaching())
        {
          cachedPart = new WeakReference(part);
          cachedView = new WeakReference(view);
        }
        return true;
      }
    }
    return false;
  }
}