| /* |
| * Copyright (C) 2008-2009, Johannes E. Schindelin <johannes.schindelin@gmx.de> and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.diff; |
| |
| /** |
| * A modified region detected between two versions of roughly the same content. |
| * <p> |
| * An edit covers the modified region only. It does not cover a common region. |
| * <p> |
| * Regions should be specified using 0 based notation, so add 1 to the start and |
| * end marks for line numbers in a file. |
| * <p> |
| * An edit where {@code beginA == endA && beginB < endB} is an insert edit, that |
| * is sequence B inserted the elements in region <code>[beginB, endB)</code> at |
| * <code>beginA</code>. |
| * <p> |
| * An edit where {@code beginA < endA && beginB == endB} is a delete edit, that |
| * is sequence B has removed the elements between <code>[beginA, endA)</code>. |
| * <p> |
| * An edit where {@code beginA < endA && beginB < endB} is a replace edit, that |
| * is sequence B has replaced the range of elements between |
| * <code>[beginA, endA)</code> with those found in <code>[beginB, endB)</code>. |
| */ |
| public class Edit { |
| /** Type of edit */ |
| public enum Type { |
| /** Sequence B has inserted the region. */ |
| INSERT, |
| |
| /** Sequence B has removed the region. */ |
| DELETE, |
| |
| /** Sequence B has replaced the region with different content. */ |
| REPLACE, |
| |
| /** Sequence A and B have zero length, describing nothing. */ |
| EMPTY; |
| } |
| |
| int beginA; |
| |
| int endA; |
| |
| int beginB; |
| |
| int endB; |
| |
| /** |
| * Create a new empty edit. |
| * |
| * @param as |
| * beginA: start and end of region in sequence A; 0 based. |
| * @param bs |
| * beginB: start and end of region in sequence B; 0 based. |
| */ |
| public Edit(int as, int bs) { |
| this(as, as, bs, bs); |
| } |
| |
| /** |
| * Create a new edit. |
| * |
| * @param as |
| * beginA: start of region in sequence A; 0 based. |
| * @param ae |
| * endA: end of region in sequence A; must be >= as. |
| * @param bs |
| * beginB: start of region in sequence B; 0 based. |
| * @param be |
| * endB: end of region in sequence B; must be > = bs. |
| */ |
| public Edit(int as, int ae, int bs, int be) { |
| beginA = as; |
| endA = ae; |
| |
| beginB = bs; |
| endB = be; |
| } |
| |
| /** |
| * Get type |
| * |
| * @return the type of this region |
| */ |
| public final Type getType() { |
| if (beginA < endA) { |
| if (beginB < endB) { |
| return Type.REPLACE; |
| } |
| return Type.DELETE; |
| |
| } |
| if (beginB < endB) { |
| return Type.INSERT; |
| } |
| // beginB == endB) |
| return Type.EMPTY; |
| } |
| |
| /** |
| * Whether edit is empty |
| * |
| * @return {@code true} if the edit is empty (lengths of both a and b is |
| * zero) |
| */ |
| public final boolean isEmpty() { |
| return beginA == endA && beginB == endB; |
| } |
| |
| /** |
| * Get start point in sequence A |
| * |
| * @return start point in sequence A |
| */ |
| public final int getBeginA() { |
| return beginA; |
| } |
| |
| /** |
| * Get end point in sequence A |
| * |
| * @return end point in sequence A |
| */ |
| public final int getEndA() { |
| return endA; |
| } |
| |
| /** |
| * Get start point in sequence B |
| * |
| * @return start point in sequence B |
| */ |
| public final int getBeginB() { |
| return beginB; |
| } |
| |
| /** |
| * Get end point in sequence B |
| * |
| * @return end point in sequence B |
| */ |
| public final int getEndB() { |
| return endB; |
| } |
| |
| /** |
| * Get length of the region in A |
| * |
| * @return length of the region in A |
| */ |
| public final int getLengthA() { |
| return endA - beginA; |
| } |
| |
| /** |
| * Get length of the region in B |
| * |
| * @return return length of the region in B |
| */ |
| public final int getLengthB() { |
| return endB - beginB; |
| } |
| |
| /** |
| * Move the edit region by the specified amount. |
| * |
| * @param amount |
| * the region is shifted by this amount, and can be positive or |
| * negative. |
| * @since 4.8 |
| */ |
| public final void shift(int amount) { |
| beginA += amount; |
| endA += amount; |
| beginB += amount; |
| endB += amount; |
| } |
| |
| /** |
| * Construct a new edit representing the region before cut. |
| * |
| * @param cut |
| * the cut point. The beginning A and B points are used as the |
| * end points of the returned edit. |
| * @return an edit representing the slice of {@code this} edit that occurs |
| * before {@code cut} starts. |
| */ |
| public final Edit before(Edit cut) { |
| return new Edit(beginA, cut.beginA, beginB, cut.beginB); |
| } |
| |
| /** |
| * Construct a new edit representing the region after cut. |
| * |
| * @param cut |
| * the cut point. The ending A and B points are used as the |
| * starting points of the returned edit. |
| * @return an edit representing the slice of {@code this} edit that occurs |
| * after {@code cut} ends. |
| */ |
| public final Edit after(Edit cut) { |
| return new Edit(cut.endA, endA, cut.endB, endB); |
| } |
| |
| /** |
| * Increase {@link #getEndA()} by 1. |
| */ |
| public void extendA() { |
| endA++; |
| } |
| |
| /** |
| * Increase {@link #getEndB()} by 1. |
| */ |
| public void extendB() { |
| endB++; |
| } |
| |
| /** |
| * Swap A and B, so the edit goes the other direction. |
| */ |
| public void swap() { |
| final int sBegin = beginA; |
| final int sEnd = endA; |
| |
| beginA = beginB; |
| endA = endB; |
| |
| beginB = sBegin; |
| endB = sEnd; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int hashCode() { |
| return beginA ^ endA; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean equals(Object o) { |
| if (o instanceof Edit) { |
| final Edit e = (Edit) o; |
| return this.beginA == e.beginA && this.endA == e.endA |
| && this.beginB == e.beginB && this.endB == e.endB; |
| } |
| return false; |
| } |
| |
| /** {@inheritDoc} */ |
| @SuppressWarnings("nls") |
| @Override |
| public String toString() { |
| final Type t = getType(); |
| return t + "(" + beginA + "-" + endA + "," + beginB + "-" + endB + ")"; |
| } |
| } |