Manage selected filters in ContentMergeViewer parts.

[EMFCompare2.git] / plugins / org.eclipse.emf.compare.rcp.ui / src / org / eclipse / emf / compare / rcp / ui / internal / mergeviewer / item / IMergeViewerItem.java

/*******************************************************************************
 * Copyright (c) 2012 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.compare.rcp.ui.internal.mergeviewer.item;

import com.google.common.base.Predicate;

import java.util.Collection;

import org.eclipse.emf.common.notify.Adapter;
import org.eclipse.emf.compare.Diff;
import org.eclipse.emf.compare.rcp.ui.internal.mergeviewer.IMergeViewer.MergeViewerSide;
import org.eclipse.emf.compare.rcp.ui.internal.structuremergeviewer.filters.IDifferenceFilter;

/**
 * @author <a href="mailto:mikael.barbero@obeo.fr">Mikael Barbero</a>
 */
public interface IMergeViewerItem extends Adapter {

        Diff getDiff();

        Object getLeft();

        Object getRight();

        Object getAncestor();

        Object getSideValue(MergeViewerSide side);

        MergeViewerSide getSide();

        boolean isInsertionPoint();

        /**
         * Returns the parent of this element. If the object is the root of a hierarchy <code>null</code> is
         * returned.
         * 
         * @return the parent of this element, or <code>null</code> if the element has no parent
         */
        Container getParent();

        public static final Predicate<IMergeViewerItem> IS_INSERTION_POINT = new Predicate<IMergeViewerItem>() {
                public boolean apply(IMergeViewerItem item) {
                        return item.isInsertionPoint();
                }
        };

        interface Container extends IMergeViewerItem {
                /**
                 * Returns whether this container has at least one child. In some cases this methods avoids having to
                 * call the potential more costly <code>getChildren</code> method.
                 * 
                 * @param selectedFilters
                 *            the active filters.
                 * @return <code>true</code> if this container has at least one child
                 */
                boolean hasChildren(Collection<IDifferenceFilter> selectedFilters);

                /**
                 * Returns the children of this container. If this container has no children an empty array is
                 * returned (not <code>null</code>).
                 * 
                 * @param selectedFilters
                 *            the active filters.
                 * @return the children of this container as an array
                 */
                IMergeViewerItem[] getChildren(Collection<IDifferenceFilter> selectedFilters);
        }
}