org.eclipse.pde.internal.ui.compare.PluginStructureViewerCreator.java Source code

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Here is the source code for org.eclipse.pde.internal.ui.compare.PluginStructureViewerCreator.java

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/*******************************************************************************
 * Copyright (c) 2007, 2009 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.pde.internal.ui.compare;

import org.eclipse.compare.*;
import org.eclipse.compare.structuremergeviewer.*;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.swt.widgets.Composite;

public class PluginStructureViewerCreator implements IViewerCreator {

    public PluginStructureViewerCreator() {
        // Nothing to do
    }

    public Viewer createViewer(Composite parent, CompareConfiguration config) {
        StructureDiffViewer viewer = new StructureDiffViewer(parent, config);
        viewer.setStructureCreator(new PluginStructureCreator());
        viewer.setComparator(new ViewerComparator() {
            public int compare(Viewer viewer, Object e1, Object e2) {
                if (e1 instanceof DiffNode) {
                    if (e2 instanceof DiffNode) {
                        ITypedElement e1Element = ((DiffNode) e1).getAncestor();
                        ITypedElement e2Element = ((DiffNode) e2).getAncestor();
                        if (!(e1Element instanceof DocumentRangeNode))
                            e1Element = ((DiffNode) e1).getLeft();
                        if (!(e2Element instanceof DocumentRangeNode))
                            e2Element = ((DiffNode) e2).getLeft();
                        if (e1Element instanceof DocumentRangeNode && e2Element instanceof DocumentRangeNode) {
                            float e1off = getRelativeOffset(((DocumentRangeNode) e1Element));
                            float e2off = getRelativeOffset(((DocumentRangeNode) e2Element));
                            return e1off - e2off < 0 ? -1 : 1;
                        }
                        return 0;
                    }
                    return -1;
                }
                return 1;
            }

            // we may be comparing the ancestor to the left (local) document
            // since the lengths may be different, base the comparison on the relative position in the doc
            private float getRelativeOffset(DocumentRangeNode node) {
                float absoluteOffset = node.getRange().getOffset();
                float documentLength = node.getDocument().getLength();
                return absoluteOffset / documentLength;
            }
        });
        return viewer;
    }

}