package brn.gui.linktable.diagram.providers;

import java.lang.ref.WeakReference;

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 brn.gui.linktable.diagram.edit.parts.ModelEditPartFactory;
import brn.gui.linktable.diagram.edit.parts.GraphEditPart;

import brn.gui.linktable.diagram.part.ModelVisualIDRegistry;

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

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

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

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

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

  /**
   * @generated
   */
  public ModelEditPartProvider() {
    setFactory(new ModelEditPartFactory());
    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
   */
  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
   */
  public synchronized boolean provides(IOperation operation) {
    if (operation instanceof CreateGraphicEditPartOperation) {
      View view = ((IEditPartOperation) operation).getView();
      if (!GraphEditPart.MODEL_ID
          .equals(ModelVisualIDRegistry.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;
  }
}