org.eclipse.emf.compare.ide.ui.internal.util.JFaceUtil.java Source code

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Here is the source code for org.eclipse.emf.compare.ide.ui.internal.util.JFaceUtil.java

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/*******************************************************************************
 * Copyright (c) 2013 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.ide.ui.internal.util;

import static com.google.common.collect.Sets.newHashSet;

import com.google.common.base.Predicate;

import java.util.Set;

import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.ViewerFilter;
import org.eclipse.swt.widgets.TreeItem;

/**
 * @author <a href="mailto:mikael.barbero@obeo.fr">Mikael Barbero</a>
 */
public class JFaceUtil {

    /**
     * All element filter tests must go through this method.
     * 
     * @param viewer
     *            the viewer
     * @param object
     *            the object to filter
     * @param parent
     *            the parent
     * @return true if the element is filtered
     */
    public static boolean isFiltered(StructuredViewer viewer, Object object, Object parent) {
        for (ViewerFilter filter : viewer.getFilters()) {
            if (!filter.select(viewer, parent, object)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Return the set of visible elements from the given viewer filtered by the given predicate.
     * 
     * @param treeViewer
     * @param predicate
     * @return
     */
    public static Set<?> visibleElements(TreeViewer treeViewer, Predicate<? super Object> predicate) {
        Set<Object> acc = newHashSet();
        appendNonFilteredChildren(treeViewer, treeViewer.getTree().getItems(), null, predicate, acc);
        return acc;
    }

    /**
     * @param cp
     * @param children
     * @param diffs
     * @return
     */
    private static void appendNonFilteredChildren(TreeViewer treeViewer, TreeItem[] elements, Object parent,
            Predicate<? super Object> predicate, Set<Object> acc) {
        for (TreeItem element : elements) {
            if (!isFiltered(treeViewer, element.getData(), parent) && predicate.apply(element.getData())) {
                acc.add(element.getData());
            }
            TreeItem[] children = element.getItems();
            appendNonFilteredChildren(treeViewer, children, element, predicate, acc);
        }
    }
}