plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/features/impl/DefaultRemoveFeature.java

/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2005, 2014 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *    Benjamin Schmeling - mwenz - Bug 367483 - Support composite connections
 *    mgorning - Bug 376572 - Generic context buttons name changeable via getName() method
 *    mwenz - Bug 380400 - Remove final from DefaultRemoveFeature.remove
 *    mwenz - Bug 453553 - Provide an abort possibility for delete and remove features in case 'pre' methods fail
 *
 * </copyright>
 *
 *******************************************************************************/
package org.eclipse.graphiti.features.impl;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.ecore.util.EcoreUtil;
import org.eclipse.graphiti.features.IFeatureProvider;
import org.eclipse.graphiti.features.IRemoveFeature;
import org.eclipse.graphiti.features.context.IContext;
import org.eclipse.graphiti.features.context.IRemoveContext;
import org.eclipse.graphiti.features.context.impl.RemoveContext;
import org.eclipse.graphiti.internal.Messages;
import org.eclipse.graphiti.internal.services.GraphitiInternal;
import org.eclipse.graphiti.mm.pictograms.AdvancedAnchor;
import org.eclipse.graphiti.mm.pictograms.Anchor;
import org.eclipse.graphiti.mm.pictograms.CompositeConnection;
import org.eclipse.graphiti.mm.pictograms.Connection;
import org.eclipse.graphiti.mm.pictograms.ConnectionDecorator;
import org.eclipse.graphiti.mm.pictograms.ContainerShape;
import org.eclipse.graphiti.mm.pictograms.Diagram;
import org.eclipse.graphiti.mm.pictograms.PictogramElement;
import org.eclipse.graphiti.mm.pictograms.Shape;
import org.eclipse.graphiti.services.Graphiti;

/**
 * The Class DefaultRemoveFeature.
 */
public class DefaultRemoveFeature extends AbstractFeature implements IRemoveFeature {

	private static final String NAME = Messages.DefaultRemoveFeature_0_xfld;
	private static final String DESC = Messages.ContextEntryHelper_3_xfld;

	/**
	 * Creates a new {@link DefaultRemoveFeature}.
	 * 
	 * @param fp
	 *            the feature provider
	 */
	public DefaultRemoveFeature(IFeatureProvider fp) {
		super(fp);
	}

	public boolean canRemove(IRemoveContext context) {
		return !(context.getPictogramElement() instanceof Diagram);
	}

	public void remove(IRemoveContext context) {
		if (!getUserDecision()) {
			return;
		}
		preRemove(context);
		if (isRemoveAbort()) {
			throw new OperationCanceledException();
		}

		PictogramElement pe = context.getPictogramElement();

		if (pe instanceof Shape) {
			Shape shape = (Shape) pe;
			removeAllConnections(shape);
		} else if (pe instanceof AdvancedAnchor) {
			removeAllConnections((AdvancedAnchor) pe);
		} else if (pe instanceof CompositeConnection) {
			removeCompositeConnections((CompositeConnection) pe);
		}

		Graphiti.getPeService().deletePictogramElement(pe);

		postRemove(context);
	}

	private void removeCompositeConnections(CompositeConnection composite) {
		List<Connection> children = new ArrayList<Connection>(composite.getChildren());
		for (Connection childConnection : children) {
			RemoveContext context = new RemoveContext(childConnection);
			remove(context);
		}
	}

	public void preRemove(IRemoveContext context) {
	}

	/**
	 * @since 0.12
	 */
	@Override
	public boolean isRemoveAbort() {
		return false;
	}

	/**
	 * Removes the all connections.
	 * 
	 * @param shape
	 *            the shape
	 */
	protected void removeAllConnections(Shape shape) {
		if (shape instanceof ContainerShape) {
			EList<Shape> children = ((ContainerShape) shape).getChildren();
			for (Shape childShape : children) {
				removeAllConnections(childShape);
			}
		}
		List<Anchor> anchors = shape.getAnchors();
		for (Anchor anchor : anchors) {
			removeAllConnections(anchor);
		}
	}

	/**
	 * @since 0.9
	 */
	protected void removeAllConnections(Anchor anchor) {
		IFeatureProvider featureProvider = getFeatureProvider();
		List<Connection> allConnections = Graphiti.getPeService().getAllConnections(anchor);
		for (Connection connection : allConnections) {
			if (GraphitiInternal.getEmfService().isObjectAlive(connection)) {
				IRemoveContext rc = new RemoveContext(connection);
				IRemoveFeature removeFeature = featureProvider.getRemoveFeature(rc);
				if (removeFeature != null) {
					ConnectionDecorator decorators[] = connection.getConnectionDecorators().toArray(
							new ConnectionDecorator[0]);
					for (ConnectionDecorator decorator : decorators) {
						if (decorator != null && GraphitiInternal.getEmfService().isObjectAlive(decorator)) {
							EcoreUtil.delete(decorator, true);
						}
					}
					removeFeature.remove(rc);
				}
			}
		}
	}

	public void postRemove(IRemoveContext context) {
	}

	public boolean canExecute(IContext context) {
		boolean ret = false;
		if (context instanceof IRemoveContext) {
			ret = canRemove((IRemoveContext) context);
		}
		return ret;
	}

	public void execute(IContext context) {
		if (context instanceof IRemoveContext) {
			remove((IRemoveContext) context);
		}
	}

	@Override
	public String getName() {
		return NAME;
	}

	@Override
	public String getDescription() {
		return DESC;
	}
}