001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * ---------------------------
028 * SlidingCategoryDataset.java
029 * ---------------------------
030 * (C) Copyright 2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 08-May-2008 : Version 1 (DG);
038 *
039 */
040
041 package org.jfree.data.category;
042
043 import java.util.Collections;
044 import java.util.List;
045
046 import org.jfree.data.UnknownKeyException;
047 import org.jfree.data.general.AbstractDataset;
048 import org.jfree.data.general.DatasetChangeEvent;
049 import org.jfree.util.PublicCloneable;
050
051 /**
052 * A {@link CategoryDataset} implementation that presents a subset of the
053 * categories in an underlying dataset. The index of the first "visible"
054 * category can be modified, which provides a means of "sliding" through
055 * the categories in the underlying dataset.
056 *
057 * @since 1.0.10
058 */
059 public class SlidingCategoryDataset extends AbstractDataset
060 implements CategoryDataset {
061
062 /** The underlying dataset. */
063 private CategoryDataset underlying;
064
065 /** The index of the first category to present. */
066 private int firstCategoryIndex;
067
068 /** The maximum number of categories to present. */
069 private int maximumCategoryCount;
070
071 /**
072 * Creates a new instance.
073 *
074 * @param underlying the underlying dataset (<code>null</code> not
075 * permitted).
076 * @param firstColumn the index of the first visible column from the
077 * underlying dataset.
078 * @param maxColumns the maximumColumnCount.
079 */
080 public SlidingCategoryDataset(CategoryDataset underlying, int firstColumn,
081 int maxColumns) {
082 this.underlying = underlying;
083 this.firstCategoryIndex = firstColumn;
084 this.maximumCategoryCount = maxColumns;
085 }
086
087 /**
088 * Returns the underlying dataset that was supplied to the constructor.
089 *
090 * @return The underlying dataset (never <code>null</code>).
091 */
092 public CategoryDataset getUnderlyingDataset() {
093 return this.underlying;
094 }
095
096 /**
097 * Returns the index of the first visible category.
098 *
099 * @return The index.
100 *
101 * @see #setFirstCategoryIndex(int)
102 */
103 public int getFirstCategoryIndex() {
104 return this.firstCategoryIndex;
105 }
106
107 /**
108 * Sets the index of the first category that should be used from the
109 * underlying dataset, and sends a {@link DatasetChangeEvent} to all
110 * registered listeners.
111 *
112 * @param first the index.
113 *
114 * @see #getFirstCategoryIndex()
115 */
116 public void setFirstCategoryIndex(int first) {
117 if (first < 0 || first >= this.underlying.getColumnCount()) {
118 throw new IllegalArgumentException("Invalid index.");
119 }
120 this.firstCategoryIndex = first;
121 fireDatasetChanged();
122 }
123
124 /**
125 * Returns the maximum category count.
126 *
127 * @return The maximum category count.
128 *
129 * @see #setMaximumCategoryCount(int)
130 */
131 public int getMaximumCategoryCount() {
132 return this.maximumCategoryCount;
133 }
134
135 /**
136 * Sets the maximum category count and sends a {@link DatasetChangeEvent}
137 * to all registered listeners.
138 *
139 * @param max the maximum.
140 *
141 * @see #getMaximumCategoryCount()
142 */
143 public void setMaximumCategoryCount(int max) {
144 if (max < 0) {
145 throw new IllegalArgumentException("Requires 'max' >= 0.");
146 }
147 this.maximumCategoryCount = max;
148 fireDatasetChanged();
149 }
150
151 /**
152 * Returns the index of the last column for this dataset, or -1.
153 *
154 * @return The index.
155 */
156 private int lastCategoryIndex() {
157 if (this.maximumCategoryCount == 0) {
158 return -1;
159 }
160 return Math.min(this.firstCategoryIndex + this.maximumCategoryCount,
161 this.underlying.getColumnCount()) - 1;
162 }
163
164 /**
165 * Returns the index for the specified column key.
166 *
167 * @param key the key.
168 *
169 * @return The column index, or -1 if the key is not recognised.
170 */
171 public int getColumnIndex(Comparable key) {
172 int index = this.underlying.getColumnIndex(key);
173 if (index >= this.firstCategoryIndex && index <= lastCategoryIndex()) {
174 return index - this.firstCategoryIndex;
175 }
176 return -1; // we didn't find the key
177 }
178
179 /**
180 * Returns the column key for a given index.
181 *
182 * @param column the column index (zero-based).
183 *
184 * @return The column key.
185 *
186 * @throws IndexOutOfBoundsException if <code>row</code> is out of bounds.
187 */
188 public Comparable getColumnKey(int column) {
189 return this.underlying.getColumnKey(column + this.firstCategoryIndex);
190 }
191
192 /**
193 * Returns the column keys.
194 *
195 * @return The keys.
196 *
197 * @see #getColumnKey(int)
198 */
199 public List getColumnKeys() {
200 List result = new java.util.ArrayList();
201 int last = lastCategoryIndex();
202 for (int i = this.firstCategoryIndex; i < last; i++) {
203 result.add(this.underlying.getColumnKey(i));
204 }
205 return Collections.unmodifiableList(result);
206 }
207
208 /**
209 * Returns the row index for a given key.
210 *
211 * @param key the row key.
212 *
213 * @return The row index, or <code>-1</code> if the key is unrecognised.
214 */
215 public int getRowIndex(Comparable key) {
216 return this.underlying.getRowIndex(key);
217 }
218
219 /**
220 * Returns the row key for a given index.
221 *
222 * @param row the row index (zero-based).
223 *
224 * @return The row key.
225 *
226 * @throws IndexOutOfBoundsException if <code>row</code> is out of bounds.
227 */
228 public Comparable getRowKey(int row) {
229 return this.underlying.getRowKey(row);
230 }
231
232 /**
233 * Returns the row keys.
234 *
235 * @return The keys.
236 */
237 public List getRowKeys() {
238 return this.underlying.getRowKeys();
239 }
240
241 /**
242 * Returns the value for a pair of keys.
243 *
244 * @param rowKey the row key (<code>null</code> not permitted).
245 * @param columnKey the column key (<code>null</code> not permitted).
246 *
247 * @return The value (possibly <code>null</code>).
248 *
249 * @throws UnknownKeyException if either key is not defined in the dataset.
250 */
251 public Number getValue(Comparable rowKey, Comparable columnKey) {
252 int r = getRowIndex(rowKey);
253 int c = getColumnIndex(columnKey);
254 if (c != -1) {
255 return this.underlying.getValue(r, c + this.firstCategoryIndex);
256 }
257 else {
258 throw new UnknownKeyException("Unknown columnKey: " + columnKey);
259 }
260 }
261
262 /**
263 * Returns the number of columns in the table.
264 *
265 * @return The column count.
266 */
267 public int getColumnCount() {
268 int last = lastCategoryIndex();
269 if (last == -1) {
270 return 0;
271 }
272 else {
273 return Math.max(last - this.firstCategoryIndex + 1, 0);
274 }
275 }
276
277 /**
278 * Returns the number of rows in the table.
279 *
280 * @return The row count.
281 */
282 public int getRowCount() {
283 return this.underlying.getRowCount();
284 }
285
286 /**
287 * Returns a value from the table.
288 *
289 * @param row the row index (zero-based).
290 * @param column the column index (zero-based).
291 *
292 * @return The value (possibly <code>null</code>).
293 */
294 public Number getValue(int row, int column) {
295 return this.underlying.getValue(row, column + this.firstCategoryIndex);
296 }
297
298 /**
299 * Tests this <code>SlidingCategoryDataset</code> for equality with an
300 * arbitrary object.
301 *
302 * @param obj the object (<code>null</code> permitted).
303 *
304 * @return A boolean.
305 */
306 public boolean equals(Object obj) {
307 if (obj == this) {
308 return true;
309 }
310 if (!(obj instanceof SlidingCategoryDataset)) {
311 return false;
312 }
313 SlidingCategoryDataset that = (SlidingCategoryDataset) obj;
314 if (this.firstCategoryIndex != that.firstCategoryIndex) {
315 return false;
316 }
317 if (this.maximumCategoryCount != that.maximumCategoryCount) {
318 return false;
319 }
320 if (!this.underlying.equals(that.underlying)) {
321 return false;
322 }
323 return true;
324 }
325
326 /**
327 * Returns an independent copy of the dataset. Note that:
328 * <ul>
329 * <li>the underlying dataset is only cloned if it implements the
330 * {@link PublicCloneable} interface;</li>
331 * <li>the listeners registered with this dataset are not carried over to
332 * the cloned dataset.</li>
333 * </ul>
334 *
335 * @return An independent copy of the dataset.
336 *
337 * @throws CloneNotSupportedException if the dataset cannot be cloned for
338 * any reason.
339 */
340 public Object clone() throws CloneNotSupportedException {
341 SlidingCategoryDataset clone = (SlidingCategoryDataset) super.clone();
342 if (this.underlying instanceof PublicCloneable) {
343 PublicCloneable pc = (PublicCloneable) this.underlying;
344 clone.underlying = (CategoryDataset) pc.clone();
345 }
346 return clone;
347 }
348
349 }