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1
21
24 package org.lobobrowser.util;
25
26 import java.util.*;
27
28 public class FilteredCollection implements Collection {
29 private final ObjectFilter filter;
30 private final Collection sourceCollection;
31
32 public FilteredCollection(Collection sourceCollection, ObjectFilter filter) {
33 this.filter = filter;
34 this.sourceCollection = sourceCollection;
35 }
36
37 public int size() {
38 int count = 0;
39 Iterator i = this.sourceCollection.iterator();
40 while(i.hasNext()) {
41 if(this.filter.decode(i.next()) != null) {
42 count++;
43 }
44 }
45 return count;
46 }
47
48 public boolean isEmpty() {
49 Iterator i = this.sourceCollection.iterator();
50 while(i.hasNext()) {
51 if(this.filter.decode(i.next()) != null) {
52 return false;
53 }
54 }
55 return true;
56 }
57
58 public boolean contains(Object  o) {
59 return this.sourceCollection.contains(this.filter.encode(o));
60 }
61
62 public Iterator iterator() {
63 final Iterator sourceIterator = this.sourceCollection.iterator();
64 return new Iterator() {
65 private Boolean hasNext;
66 private Object next;
67
68 private void scanNext() {
69 while(sourceIterator.hasNext()) {
70 Object item = filter.decode(sourceIterator.next());
71 if(item != null) {
72 hasNext = Boolean.TRUE;
73 this.next = item;
74 }
75 }
76 hasNext = Boolean.FALSE;
77 }
78
79
82 public boolean hasNext() {
83 if(this.hasNext == null) {
84 scanNext();
85 }
86 return this.hasNext.booleanValue();
87 }
88
89
92 public Object next() {
93 if(this.hasNext == null) {
94 scanNext();
95 }
96 if(Boolean.FALSE.equals(this.hasNext)) {
97 throw new NoSuchElementException();
98 }
99 Object next = this.next;
100 this.hasNext = null;
101 return next;
102 }
103
104
107 public void remove() {
108 throw new UnsupportedOperationException ();
109 }
110 };
111 }
112
113 public Object [] toArray() {
114 return this.toArray(new Object [0]);
115 }
116
117 public Object [] toArray(Object [] a) {
118 Collection bucket = new ArrayList();
119 Iterator i = this.sourceCollection.iterator();
120 while(i.hasNext()) {
121 Object item = this.filter.decode(i.next());
122 if(item != null) {
123 bucket.add(item);
124 }
125 }
126 return bucket.toArray(a);
127 }
128
129 public boolean add(Object o) {
130 return this.sourceCollection.add(this.filter.encode(o));
131 }
132
133 public boolean remove(Object o) {
134 return this.sourceCollection.remove(this.filter.encode(o));
135 }
136
137 public boolean containsAll(Collection c) {
138 Iterator i = c.iterator();
139 while(i.hasNext()) {
140 if(!this.contains(i.next())) {
141 return false;
142 }
143 }
144 return true;
145 }
146
147 public boolean addAll(Collection c) {
148 boolean result = false;
149 Iterator i = c.iterator();
150 while(i.hasNext()) {
151 if(this.add(i.next())) {
152 result = true;
153 }
154 }
155 return result;
156 }
157
158 public boolean removeAll(Collection c) {
159 boolean result = false;
160 Iterator i = c.iterator();
161 while(i.hasNext()) {
162 if(this.remove(i.next())) {
163 result = true;
164 }
165 }
166 return result;
167 }
168
169 public boolean retainAll(Collection c) {
170 boolean result = false;
171 Object [] values = this.toArray();
172 for(int i = 0; i < values.length; i++) {
173 if(!c.contains(values[i])) {
174 if(this.remove(values[i])) {
175 result = true;
176 }
177 }
178 }
179 return result;
180 }
181
182 public void clear() {
183 Object [] values = this.toArray();
184 for(int i = 0; i < values.length; i++) {
185 this.sourceCollection.remove(this.filter.encode(values[i]));
186 }
187 }
188 }
189 |
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