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comparison dwtx/jface/internal/text/revisions/ChangeRegion.d @ 129:eb30df5ca28b

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Added JFace Text sources
author Frank Benoit <benoit@tionex.de>
date Sat, 23 Aug 2008 19:10:48 +0200
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children c4fb132a086c
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128:8df1d4193877 129:eb30df5ca28b
1 /*******************************************************************************
2 * Copyright (c) 2000, 2006 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13 module dwtx.jface.internal.text.revisions.ChangeRegion;
14
15 import dwt.dwthelper.utils;
16
17 import java.util.LinkedList;
18 import java.util.List;
19 import java.util.ListIterator;
20
21 import dwtx.core.runtime.Assert;
22 import dwtx.jface.text.revisions.Revision;
23 import dwtx.jface.text.source.ILineRange;
24 import dwtx.jface.text.source.LineRange;
25
26 /**
27 * A change region describes a contiguous range of lines that was changed in the same revision of a
28 * document. Once it is adjusted to diff information, the originally contiguous range may be split
29 * into several ranges or even be empty.
30 *
31 * @since 3.2
32 */
33 public final class ChangeRegion {
34 private final Revision fRevision;
35 private final ILineRange fLines;
36 private final List fAdjusted= new LinkedList();
37
38 /**
39 * Creates a new change region for the given revision and line range.
40 *
41 * @param revision the revision of the new region
42 * @param lines the line range of the new region
43 * @throws IndexOutOfBoundsException if the line range is not well-formed
44 */
45 public ChangeRegion(Revision revision, ILineRange lines) throws IndexOutOfBoundsException {
46 Assert.isLegal(revision !is null);
47 Assert.isLegal(lines !is null);
48 fLines= Range.copy(lines);
49 fRevision=revision;
50 clearDiff();
51 }
52
53 /**
54 * Returns the revision that this region belongs to.
55 *
56 * @return the revision that this region belongs to
57 */
58 public Revision getRevision() {
59 return fRevision;
60 }
61
62 /**
63 * Returns the original (before applying diff information) line range of this change region.
64 *
65 * @return the original (before applying diff information) line range of this change region
66 */
67 public ILineRange getOriginalRange() {
68 return fLines;
69 }
70
71 /**
72 * Returns the list of {@link ILineRange}s of this change region for which the revision
73 * information is still valid.
74 *
75 * @return the list of adjusted line ranges
76 */
77 public List getAdjustedRanges() {
78 return fAdjusted;
79 }
80
81 /**
82 * Returns the line coverage of the adjusted ranges, an empty range if the coverage is empty.
83 *
84 * @return the line coverage of the adjusted ranges
85 */
86 public ILineRange getAdjustedCoverage() {
87 if (fAdjusted.isEmpty())
88 return new LineRange(fLines.getStartLine(), 0);
89
90 Range first= (Range) fAdjusted.get(0);
91 Range last= (Range) fAdjusted.get(fAdjusted.size() - 1);
92
93 return Range.createAbsolute(first.start(), last.end());
94 }
95
96 /**
97 * Clears any adjusted ranges, restoring the original range.
98 */
99 public void clearDiff() {
100 fAdjusted.clear();
101 fAdjusted.add(Range.copy(fLines));
102 }
103
104 /**
105 * Adjusts this change region to a diff hunk. This will change the adjusted ranges.
106 *
107 * @param hunk the diff hunk to adjust to
108 */
109 public void adjustTo(Hunk hunk) {
110 for (ListIterator it= fAdjusted.listIterator(); it.hasNext();) {
111 Range range= (Range) it.next();
112
113 // do we need a split?
114 int unchanged= getUnchanged(hunk, range.start());
115 if (unchanged > 0) {
116 if (unchanged >= range.length())
117 continue;
118 range= range.split(unchanged);
119 it.add(range);
120 it.previous(); it.next(); // needed so we can remove below
121 }
122
123 int line= range.start();
124 Assert.isTrue(hunk.line <= line);
125
126 // by how much do we shrink?
127 int overlap= getOverlap(hunk, line);
128 if (overlap >= range.length()) {
129 it.remove();
130 continue;
131 }
132
133 // by how much do we move?
134 range.moveBy(hunk.delta + overlap);
135 range.resizeBy(-overlap);
136 }
137
138 }
139
140 private int getUnchanged(Hunk hunk, int line) {
141 return Math.max(0, hunk.line - line);
142 }
143
144 /*
145 * Returns the number of lines after line that the hunk reports as changed.
146 */
147 private int getOverlap(Hunk hunk, int line) {
148
149 int deltaLine= hunk.line + hunk.changed;
150 if (hunk.delta >= 0) {
151 if (deltaLine <= line)
152 return 0;
153 return deltaLine - line;
154 }
155
156 // hunk.delta < 0
157 int hunkEnd= deltaLine - hunk.delta;
158 int cutCount= hunkEnd - line;
159 return Math.max(0, cutCount);
160 }
161
162 /*
163 * @see java.lang.Object#toString()
164 */
165 public String toString() {
166 return "ChangeRegion [" + fRevision.toString() + ", [" + fLines.getStartLine() + "+" + fLines.getNumberOfLines() + ")]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
167 }
168 }