org.eclipse.osee.framework.ui.swt.TreeViewerUtility.java Source code

Introduction

Here is the source code for org.eclipse.osee.framework.ui.swt.TreeViewerUtility.java

Source

/*******************************************************************************
 * Copyright (c) 2004, 2007 Boeing.
 * 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:
 *     Boeing - initial API and implementation
 *******************************************************************************/
package org.eclipse.osee.framework.ui.swt;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.TreeViewer;

/**
 * Provides utility methods for the TreeViewer
 * 
 * @author Jeff C. Phillips
 * @author Robert A. Fisher
 */
public class TreeViewerUtility {
    private static final Object dummy = new Object();

    /**
     * Retrieve a listing of all the selected items in preorder sequence.
     * 
     * @param treeViewer The tree to be traversed
     */
    public static <A extends Object> void getPreorderSelection(TreeViewer treeViewer, List<A> selectedTreeItems) {
        Map<A, Object> expansionHash = new HashMap<A, Object>();
        Map<A, Object> selectionHash = new HashMap<A, Object>();
        populateSelectionHash(treeViewer, selectionHash);
        populateExpansionHash(treeViewer, expansionHash);
        traverseTree(((ITreeContentProvider) treeViewer.getContentProvider()).getChildren(treeViewer.getInput()),
                (ITreeContentProvider) treeViewer.getContentProvider(), selectedTreeItems, selectionHash,
                expansionHash);
    }

    @SuppressWarnings("unchecked")
    private static <A extends Object> void populateExpansionHash(TreeViewer tree, Map<A, Object> selectionHash) {

        for (Object obj : tree.getExpandedElements()) {
            selectionHash.put((A) obj, dummy);
        }
    }

    @SuppressWarnings("unchecked")
    private static <A extends Object> void populateSelectionHash(TreeViewer tree, Map<A, Object> selectionHash) {
        Iterator<?> iterator = ((IStructuredSelection) tree.getSelection()).iterator();

        while (iterator.hasNext()) {
            selectionHash.put((A) iterator.next(), dummy);
        }
    }

    @SuppressWarnings("unchecked")
    private static <A extends Object> void traverseTree(Object[] items, ITreeContentProvider contentProvider,
            List<A> selectedTreeItems, Map<A, Object> selectionHash, Map<A, Object> expandedHash) {
        for (Object item : items) {
            if (selectionHash.containsKey(item)) {
                selectedTreeItems.add((A) item);
            }
            if (expandedHash.containsKey(item)) {
                traverseTree(contentProvider.getChildren(item), contentProvider, selectedTreeItems, selectionHash,
                        expandedHash);
            }
        }
    }
}