nu.bibi.breadcrumb.files.FileViewerComparator.java Source code

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Here is the source code for nu.bibi.breadcrumb.files.FileViewerComparator.java

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/*******************************************************************************
 * Copyright (c) 2008 Laurent Muller.
 * 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:
 *     Laurent Muller - initial API and implementation
 *******************************************************************************/
package nu.bibi.breadcrumb.files;

import java.io.File;

import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;

/**
 * File Viewer Comparator. This comparator uses the following categories:
 * <ul>
 * <li><code>0 - Computer</code></li>
 * <li><code>1 - Drive (File.getParent() ==  null)</code></li>
 * <li><code>2 - Directory (File.isDirectory())</code></li>
 * <li><code>3 - File</code></li>
 * <li><code>4 - Other objects</code></li>
 * </ul>
 * If the two categories are equals; this comparator uses the file absolute path
 * property (<code>File.getAbsolutePath()</code> to compare values; ignoring
 * case differences.
 * 
 * @author Laurent Muller
 * @version 1.0
 */
public class FileViewerComparator extends ViewerComparator {

    /**
     * The default file viewer comparator instance.
     */
    public final static FileViewerComparator DEFAULT = new FileViewerComparator();

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jface.viewers.ViewerComparator#category(java.lang.Object)
     */
    @Override
    public int category(final Object element) {
        if (element instanceof Computer) {
            // computer
            return 0;
        }
        if (element instanceof File) {
            final File file = (File) element;
            if (file.getParent() == null) {
                // drive
                return 1;
            }
            if (file.isDirectory()) {
                // directory
                return 2;
            }
            // file
            return 3;
        }

        // other
        return 4;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.eclipse.jface.viewers.ViewerComparator#compare(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
     */
    @Override
    public int compare(final Viewer viewer, final Object e1, final Object e2) {
        // compare categories
        final int cat1 = category(e1);
        final int cat2 = category(e2);
        if (cat1 != cat2) {
            return cat1 - cat2;
        }

        // compare files
        if (e1 instanceof File && e2 instanceof File) {
            final File file1 = (File) e1;
            final File file2 = (File) e2;
            if (file1 == file2) {
                return 0;
            }
            if (file1 == null) {
                return -1;
            }
            if (file2 == null) {
                return 1;
            }
            return file1.compareTo(file2);
            //         .getAbsolutePath().compareToIgnoreCase(file2.getAbsolutePath());
        }

        // default
        return super.compare(viewer, e1, e2);
    }
}