org.eclipse.wb.gef.core.tools.ToolUtilities.java Source code

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Here is the source code for org.eclipse.wb.gef.core.tools.ToolUtilities.java

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/*******************************************************************************
 * Copyright (c) 2011 Google, Inc.
 * 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:
 *    Google, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.wb.gef.core.tools;

import com.google.common.collect.Lists;

import org.eclipse.wb.gef.core.EditPart;
import org.eclipse.wb.gef.core.IEditPartViewer;

import java.util.Collections;
import java.util.List;

/**
 * Utilities for {@link Tool}'s.
 * 
 * @author lobas_av
 * @coverage gef.core
 */
public class ToolUtilities {
    /**
     * Returns a list containing the top level selected {@link EditPart}'s based on the viewer's
     * selection. If selection parents of edit parts is differed returns empty list.
     */
    public static List<EditPart> getSelectionWithoutDependants(IEditPartViewer viewer) {
        List<EditPart> operationSet = Lists.newArrayList();
        // add selected EditPart's only if their parent is not added yet
        {
            List<EditPart> selectedParts = viewer.getSelectedEditParts();
            for (EditPart part : selectedParts) {
                if (!isAncestorContainedIn(selectedParts, part)) {
                    operationSet.add(part);
                }
            }
        }
        // check that all EditPart's have same parent
        {
            EditPart commonParent = null;
            for (EditPart editPart : operationSet) {
                if (commonParent == null) {
                    commonParent = editPart.getParent();
                } else if (editPart.getParent() != commonParent) {
                    return Collections.emptyList();
                }
            }
        }
        // OK, we have valid set
        return operationSet;
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Internal
    //
    ////////////////////////////////////////////////////////////////////////////
    /**
     * @return <code>true</code> if <code>containers</code> contains parent of given {@link EditPart}.
     */
    private static boolean isAncestorContainedIn(List<EditPart> container, EditPart part) {
        EditPart parent = part.getParent();
        while (parent != null) {
            if (container.contains(parent)) {
                return true;
            }
            parent = parent.getParent();
        }
        return false;
    }
}