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1
22
25
26 package ch.ethz.prose.engine;
27
28 import ch.ethz.prose.Insertable;
29
30 public class ListenerList
31 {
32
33
34 public JoinPointListener[] listenerArray;
35 public int nrOfListeners;
36 private int nearestPowerOfTwo;
37
38 public ListenerList()
39 {
40 listenerArray = new JoinPointListener[16];
41 nearestPowerOfTwo = 16;
42 }
43
44
45 private void ensureCapacity(int newCapacity)
46 {
47
48 if (listenerArray.length >= newCapacity)
50 return;
51
52 nearestPowerOfTwo = 2* nearestPowerOfTwo;
53
54 JoinPointListener[] newListenerArray = new JoinPointListener[nearestPowerOfTwo - 12];
56 System.arraycopy(listenerArray, 0, newListenerArray, 0, nrOfListeners);
57 listenerArray = newListenerArray;
58 }
59
60
61 public synchronized boolean contains(Object  elem)
62 {
63 for (int i = 0; i < nrOfListeners; i++)
64 if ( (elem == null && listenerArray[i] == null ) ||
65 (elem != null && elem.equals(listenerArray[i]) ) )
66 return true;
67
68 return false;
69 }
70
71 static class CrosscutComparator implements java.util.Comparator
72 {
73 public int compare(Object o1, Object o2)
74 {
75 if (o1 instanceof Insertable && o2 instanceof Insertable)
76 return ((Insertable)o1).getPriority() - ((Insertable)o2).getPriority();
77 else
78 return 0;
79 }
80
81 };
82
83
84 public synchronized boolean add(JoinPointListener element)
85 {
86 int index = nrOfListeners;
87 CrosscutComparator comparator = new CrosscutComparator();
88
89 for (index = 0; index < nrOfListeners &&
92 comparator.compare(listenerArray[index],element) < 0; index++);
93
94 ensureCapacity(nrOfListeners + 1);
95 System.arraycopy(listenerArray, index,
96 listenerArray, index + 1, nrOfListeners - index);
97
98 listenerArray[index] = element;
99 nrOfListeners++;
100
101 return true;
103 }
104
105
106
107
108 public synchronized boolean remove(Object element)
109 {
110 int indexToRemove = -1;
111 for (int i = 0; i < nrOfListeners; i++)
112 if (element != null && element.equals(listenerArray[i]) )
113 {
114 indexToRemove = i;
115 remove(indexToRemove);
116 i--;
117 }
118
119 return (indexToRemove == -1);
120 }
121
122 public synchronized boolean isEmpty()
123 {
124 return nrOfListeners == 0;
125 }
126
127 private Object remove(int index)
128 {
129 Object old = listenerArray[index]; if (index < 0 || index > nrOfListeners - 1)
131 throw new IndexOutOfBoundsException ();
132
133 System.arraycopy(listenerArray, index + 1,
134 listenerArray, index, nrOfListeners - index - 1);
135 nrOfListeners --;
136 return old;
137 }
138
139 public String toString()
140 {
141 StringBuffer result = new StringBuffer ();
142 for (int i = 0; i<nrOfListeners; i++)
143 {
144 result.append(listenerArray[i]);
145 if (i != (nrOfListeners -1) )
146 result.append(",");
147 }
148
149 return result.toString();
150 }
151 }
152
153 |
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