/*******************************************************************************
* Copyright (c) 2006, 2008 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.jface.internal.text.revisions;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.jface.text.source.ILineDiffInfo;
import org.eclipse.jface.text.source.ILineDiffer;
/**
* Computes the diff hunks from an {@link ILineDiffer}.
*
* @since 3.3
*/
public final class HunkComputer {
/**
* Converts the line-based information of {@link ILineDiffer} into {@link Hunk}s, grouping
* contiguous blocks of lines that are changed (added, deleted).
*
* @param differ the line differ to query
* @param lines the number of lines to query
* @return the corresponding {@link Hunk} information
*/
public static Hunk[] computeHunks(ILineDiffer differ, int lines) {
List<Hunk> hunks= new ArrayList<>(lines);
int added= 0;
int changed= 0;
ILineDiffInfo info= null;
for (int line= 0; line < lines; line++) {
info= differ.getLineInfo(line);
if (info == null)
continue;
int changeType= info.getChangeType();
switch (changeType) {
case ILineDiffInfo.ADDED:
added++;
continue;
case ILineDiffInfo.CHANGED:
changed++;
continue;
case ILineDiffInfo.UNCHANGED:
added -= info.getRemovedLinesAbove();
if (added != 0 || changed != 0) {
hunks.add(new Hunk(line - changed - Math.max(0, added), added, changed));
added= 0;
changed= 0;
}
}
}
// last hunk
if (info != null) {
added -= info.getRemovedLinesBelow();
if (added != 0 || changed != 0) {
hunks.add(new Hunk(lines - changed, added, changed));
added= 0;
changed= 0;
}
}
return hunks.toArray(new Hunk[hunks.size()]);
}
private HunkComputer() {
}
}