1 /*
2 * Copyright 2011-2012 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package de.smartics.util.source;
17
18 import java.io.Serializable;
19
20 /**
21 * Provides information about a source code location.
22 *
23 * @todo Serial: check validity of lines and columns when read from stream.
24 */
25 public class SourceCodeLocation implements Serializable
26 {
27 // ********************************* Fields *********************************
28
29 // --- constants ------------------------------------------------------------
30
31 /**
32 * The class version identifier.
33 * <p>
34 * The value of this constant is {@value}.
35 * </p>
36 */
37 private static final long serialVersionUID = 1L;
38
39 /**
40 * Defines an unknown location. The fields must not be accessed.
41 */
42 public static final SourceCodeLocation UNKNOWN_LOCATION =
43 new SourceCodeLocation(Position.INVALID_POSITION,
44 Position.INVALID_POSITION)
45 {
46 private static final long serialVersionUID = 1L;
47
48 @Override
49 public String toString()
50 {
51 return "INVALID";
52 }
53 };
54
55 // --- members --------------------------------------------------------------
56
57 /**
58 * The start position of the source code location.
59 *
60 * @serial
61 */
62 private final Position start;
63
64 /**
65 * The end position of the source code location.
66 *
67 * @serial
68 */
69 private final Position end;
70
71 // ****************************** Initializer *******************************
72
73 // ****************************** Constructors ******************************
74
75 /**
76 * Default constructor.
77 *
78 * @param start the start position of the source code location.
79 * @param end the end position of the source code location.
80 * @throws IllegalArgumentException if <code>start</code> or <code>end</code>
81 * are <code>null</code> or <code>start</code> position is greater
82 * than the <code>end</code> position.
83 */
84 public SourceCodeLocation(final Position start, final Position end)
85 throws IllegalArgumentException
86 {
87 checkArguments(start, end);
88 this.start = start;
89 this.end = end;
90 }
91
92 // ****************************** Inner Classes *****************************
93
94 /**
95 * Defines a position in the source code.
96 *
97 * @todo Serial: check validity of lines and columns when read from stream.
98 */
99 public static class Position implements Serializable, Comparable<Position>
100 {
101 // ******************************** Fields ********************************
102
103 // --- constants ----------------------------------------------------------
104
105 /**
106 * The class version identifier.
107 * <p>
108 * The value of this constant is {@value}.
109 * </p>
110 */
111 private static final long serialVersionUID = 1L;
112
113 /**
114 * An invalid position.
115 */
116 private static final Position INVALID_POSITION = new Position() // NOPMD
117 {
118 private static final long serialVersionUID = 1L;
119
120 @Override
121 public String toString()
122 {
123 return "INVALID";
124 }
125 };
126
127 // --- members ------------------------------------------------------------
128 /**
129 * The line number of the position. The lines start by <code>1</code>.
130 *
131 * @serial
132 */
133 private final long line;
134
135 /**
136 * The column number of the position. The columns start by <code>1</code>.
137 *
138 * @serial
139 */
140 private final long column;
141
142 // ***************************** Initializer ******************************
143
144 // ***************************** Constructors *****************************
145
146 /**
147 * Invalid instance constructor.
148 */
149 private Position()
150 {
151 this.line = 0;
152 this.column = 0;
153 }
154
155 /**
156 * Default constructor.
157 *
158 * @param line the line number of the position.
159 * @param column the column number of the position.
160 * @throws IllegalArgumentException if <code>line</code> or
161 * <code>column</code> is smaller than <code>1</code>.
162 */
163 public Position(final long line, final long column)
164 throws IllegalArgumentException
165 {
166 checkArguments(line, column);
167 this.line = line;
168 this.column = column;
169 }
170
171 // ***************************** Inner Classes ****************************
172
173 // ******************************** Methods *******************************
174
175 // --- init ---------------------------------------------------------------
176
177 private static void checkArguments(final long line, final long column)
178 throws IllegalArgumentException
179 {
180 if (line < 1L)
181 {
182 throw new IllegalArgumentException(
183 "The line number is required to be within [1, MAX_LONG], but is: "
184 + line);
185 }
186 if (column < 1L)
187 {
188 throw new IllegalArgumentException(
189 "The column number is required to be within [1, MAX_LONG], but is: "
190 + column);
191 }
192 }
193
194 // --- get&set ------------------------------------------------------------
195
196 /**
197 * Returns the line number of the position. The lines start by
198 * <code>1</code>.
199 *
200 * @return the line number of the position.
201 */
202 public long getLine()
203 {
204 return line;
205 }
206
207 /**
208 * Returns the column number of the position. The columns start by
209 * <code>1</code>.
210 *
211 * @return the column number of the position.
212 */
213 public long getColumn()
214 {
215 return column;
216 }
217
218 // --- business -----------------------------------------------------------
219
220 // --- object basics ------------------------------------------------------
221
222 /**
223 * {@inheritDoc}
224 */
225 @Override
226 public int compareTo(final Position other)
227 {
228 if (line == other.line)
229 {
230 final long columnCompare = column - other.column;
231 if (columnCompare < 0)
232 {
233 return -1;
234 }
235 else if (columnCompare > 0)
236 {
237 return 1;
238 }
239 else
240 {
241 return 0;
242 }
243 }
244 else
245 {
246 final long lineCompare = line - other.line;
247 if (lineCompare < 0)
248 {
249 return -1;
250 }
251 else
252 {
253 return 1;
254 }
255 }
256 }
257
258 /**
259 * Returns the hash code of the object.
260 *
261 * @return the hash code.
262 */
263 @Override
264 public int hashCode()
265 {
266 int result = 17;
267 result = 37 * result + (int) (line ^ (line >>> 32));
268 result = 37 * result + (int) (column ^ (column >>> 32));
269 return result;
270 }
271
272 /**
273 * Returns <code>true</code> if the given object is semantically equal to
274 * the given object, <code>false</code> otherwise.
275 *
276 * @param object the instance to compare to.
277 * @return <code>true</code> if the given object is semantically equal to
278 * the given object, <code>false</code> otherwise.
279 */
280 @Override
281 public boolean equals(final Object object)
282 {
283 if (this == object)
284 {
285 return true;
286 }
287 else if (object == null || getClass() != object.getClass())
288 {
289 return false;
290 }
291
292 final SourceCodeLocation.Position other =
293 (SourceCodeLocation.Position) object;
294
295 return (line == other.line && column == other.column);
296 }
297
298 /**
299 * Delegates call to {@link java.lang.StringBuilder#toString()}.
300 *
301 * @return the result of the call to
302 * {@link java.lang.StringBuilder#toString()}.
303 * @see java.lang.StringBuilder#toString()
304 */
305 @Override
306 public String toString()
307 {
308 final StringBuilder buffer = new StringBuilder();
309 buffer.append(line).append(':').append(column);
310 return buffer.toString();
311 }
312 }
313
314 // ********************************* Methods ********************************
315
316 // --- init -----------------------------------------------------------------
317
318 private static void checkArguments(final Position start, final Position end)
319 throws IllegalArgumentException
320 {
321 if (start == null)
322 {
323 throw new IllegalArgumentException(
324 "The start position of the location is required.");
325 }
326 if (end == null)
327 {
328 throw new IllegalArgumentException(
329 "The end position of the location is required.");
330 }
331 if (start.compareTo(end) > 0)
332 {
333 throw new IllegalArgumentException(
334 "The start position '" + start
335 + " must not be after the end position " + end + "'.");
336 }
337 }
338
339 // --- get&set --------------------------------------------------------------
340
341 /**
342 * Returns the start position of the source code location.
343 *
344 * @return the start position of the source code location.
345 */
346 public Position getStart()
347 {
348 return start;
349 }
350
351 /**
352 * Returns the end position of the source code location.
353 *
354 * @return the end position of the source code location.
355 */
356 public Position getEnd()
357 {
358 return end;
359 }
360
361 // --- business -------------------------------------------------------------
362
363 /**
364 * Checks if the location is known.
365 *
366 * @return <code>true</code> if it is a known location with valid content,
367 * <code>false</code> if it is an unknown location identified by
368 * {@link #UNKNOWN_LOCATION}.
369 */
370 public boolean isKnown()
371 {
372 return this != UNKNOWN_LOCATION;
373 }
374
375 // --- object basics --------------------------------------------------------
376
377 /**
378 * Returns the string representation of the object.
379 *
380 * @return the string representation of the object.
381 */
382 @Override
383 public String toString()
384 {
385 final StringBuilder buffer = new StringBuilder();
386
387 buffer.append(start).append('-').append(end);
388
389 return buffer.toString();
390 }
391 }