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1
19
20 package org.apache.cayenne.util;
21
22 import java.util.AbstractList  ;
23 import java.util.ArrayList ;
24 import java.util.Collections ;
25 import java.util.Comparator ;
26 import java.util.List ;
27
28 import org.apache.cayenne.CayenneRuntimeException;
29 import org.apache.cayenne.ValueHolder;
30 import org.apache.cayenne.reflect.PropertyUtils;
31
32
46 public class IndexPropertyList extends AbstractList implements ValueHolder {
47
48
52 static final int DEFAULT_GAP = 3;
53
54
57 protected List list;
58 protected String indexProperty;
59
60 boolean dirty;
61 Comparator comparator;
62
63
66 public IndexPropertyList(String indexProperty) {
67 this(indexProperty, new ArrayList (), false);
68 }
69
70
75 public IndexPropertyList(String indexProperty, List objects, boolean sortNeeded) {
76
77 if (indexProperty == null) {
78 throw new IllegalArgumentException ("Null sortProperty");
79 }
80
81 if (objects == null) {
82 throw new IllegalArgumentException ("Null objects list.");
83 }
84
85 this.indexProperty = indexProperty;
86 this.list = objects;
87
88 this.dirty = sortNeeded;
91 }
92
93 ValueHolder getWrappedValueHolder() {
94 return (list instanceof ValueHolder) ? (ValueHolder) list : null;
95 }
96
97 public boolean isFault() {
98 ValueHolder h = getWrappedValueHolder();
99 return (h != null) ? h.isFault() : false;
100 }
101
102 public Object setValueDirectly(Object value) throws CayenneRuntimeException {
103 ValueHolder h = getWrappedValueHolder();
104 return h != null ? h.setValueDirectly(value) : null;
105 }
106
107 public Object setValue(Object value) throws CayenneRuntimeException {
108 ValueHolder h = getWrappedValueHolder();
109 return h != null ? h.setValue(value) : null;
110 }
111
112 public Object getValue() throws CayenneRuntimeException {
113 ValueHolder h = getWrappedValueHolder();
114 return h != null ? h.getValue() : null;
115 }
116
117 public Object getValueDirectly() throws CayenneRuntimeException {
118 ValueHolder h = getWrappedValueHolder();
119 return h != null ? h.getValueDirectly() : null;
120 }
121
122 public void invalidate() {
123 ValueHolder h = getWrappedValueHolder();
124 if (h != null) {
125 h.invalidate();
126 }
127 }
128
129
132 public void touch() {
133 this.dirty = true;
134 }
135
136 public Object get(int index) {
137 if (dirty) {
138 sort();
139 }
140
141 return list.get(index);
142 }
143
144 public int size() {
145 if (dirty) {
146 sort();
147 }
148
149 return list.size();
150 }
151
152 public Object set(int index, Object element) {
153 if (dirty) {
154 sort();
155 }
156
157 Object removed = list.set(index, element);
158
159 if (element != null) {
160 int indexValue = (removed != null)
161 ? getIndexValue(removed)
162 : calculateIndexValue(index);
163
164 setIndexValue(element, indexValue);
165 shift(index + 1, indexValue);
166 }
167
168 if (removed != null && removed != element) {
169 setIndexValue(removed, -1);
170 }
171
172 return removed;
173 }
174
175 public void add(int index, Object element) {
176 if (dirty) {
177 sort();
178 }
179
180 list.add(index, element);
181
182 if (element != null) {
183 int indexValue = calculateIndexValue(index);
184
185 setIndexValue(element, indexValue);
186 shift(index + 1, indexValue);
187 }
188 }
189
190 public Object remove(int index) {
191 if (dirty) {
192 sort();
193 }
194
195 Object removed = list.remove(index);
196
197 if (removed != null) {
198 setIndexValue(removed, -1);
199 }
200
201 return removed;
202 }
203
204
208
212 protected int calculateIndexValue(int listIndex) {
213 if (list.isEmpty()) {
214 throw new ArrayIndexOutOfBoundsException (listIndex);
215 }
216
217 if (list.size() == 1 && listIndex == 0) {
218 return 0;
219 }
220
221
223 if (listIndex == list.size() - 1) {
225 return getIndexValue(get(listIndex - 1)) + DEFAULT_GAP;
226 }
227
228 int from = (listIndex == 0) ? -1 : getIndexValue(get(listIndex - 1));
229 int to = getIndexValue(get(listIndex + 1));
230 return (to - from > 1) ? (to - from) / 2 + from : from + DEFAULT_GAP;
231 }
232
233 protected int getIndexValue(Object object) {
234 Number n = (Number ) PropertyUtils.getProperty(object, indexProperty);
235 if (n == null) {
236 throw new CayenneRuntimeException("Null index property '"
237 + indexProperty
238 + "' for object "
239 + object);
240 }
241
242 return n.intValue();
243 }
244
245 protected void setIndexValue(Object object, int index) {
246 PropertyUtils.setProperty(object, indexProperty, new Integer (index));
247 }
248
249 protected void shift(int startIndex, int afterIndexValue) {
250 int size = size();
251 for (int i = startIndex; i < size; i++) {
252 Object object = get(i);
253
254 int indexValue = getIndexValue(object);
255 if (indexValue > afterIndexValue) {
256 break;
257 }
258
259 int newValue = calculateIndexValue(i);
260 setIndexValue(object, newValue);
261 afterIndexValue = newValue;
262 }
263 }
264
265
268 protected void sort() {
269 if (!dirty) {
270 return;
271 }
272
273 Collections.sort(unwrapList(), getComparator());
276 dirty = false;
277 }
278
279 List unwrapList() {
280 if (list instanceof PersistentObjectList) {
281 return ((PersistentObjectList) list).resolvedObjectList();
282 }
283 else {
284 return list;
285 }
286 }
287
288
291 Comparator getComparator() {
292 if (comparator == null) {
293 comparator = new Comparator () {
294
295 public int compare(Object o1, Object o2) {
296 if ((o1 == null && o2 == null) || o1 == o2) {
297 return 0;
298 }
299 else if (o1 == null && o2 != null) {
300 return -1;
301 }
302 else if (o1 != null && o2 == null) {
303 return 1;
304 }
305
306 Comparable p1 = (Comparable ) PropertyUtils.getProperty(
307 o1,
308 indexProperty);
309 Comparable p2 = (Comparable ) PropertyUtils.getProperty(
310 o2,
311 indexProperty);
312 return (p1 == null) ? -1 : p1.compareTo(p2);
313 }
314 };
315 }
316 return comparator;
317 }
318 }
319 |
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