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1
11 package org.eclipse.core.internal.expressions;
12
13 import java.util.Collection  ;
14
15 import org.w3c.dom.Element ;
16
17 import org.eclipse.core.runtime.CoreException;
18 import org.eclipse.core.runtime.IConfigurationElement;
19
20 import org.eclipse.core.expressions.EvaluationResult;
21 import org.eclipse.core.expressions.Expression;
22 import org.eclipse.core.expressions.ExpressionInfo;
23 import org.eclipse.core.expressions.ICountable;
24 import org.eclipse.core.expressions.IEvaluationContext;
25
26
27 public class CountExpression extends Expression {
28
29 private static final int ANY_NUMBER= 5;
30 private static final int EXACT= 4;
31 private static final int ONE_OR_MORE= 3;
32 private static final int NONE_OR_ONE= 2;
33 private static final int NONE= 1;
34 private static final int UNKNOWN= 0;
35
36
39 private static final int HASH_INITIAL= CountExpression.class.getName().hashCode();
40
41 private int fMode;
42 private int fSize;
43
44 public CountExpression(IConfigurationElement configElement) {
45 String size = configElement.getAttribute(ATT_VALUE);
46 initializeSize(size);
47 }
48
49 public CountExpression(Element element) {
50 String size = element.getAttribute(ATT_VALUE);
51 initializeSize(size.length() > 0 ? size : null);
52 }
53
54 public CountExpression(String size) {
55 initializeSize(size);
56 }
57
58 private void initializeSize(String size) {
59 if (size == null)
60 size= "*"; if (size.equals("*")) fMode= ANY_NUMBER;
63 else if (size.equals("?")) fMode= NONE_OR_ONE;
65 else if (size.equals("!")) fMode= NONE;
67 else if (size.equals("+")) fMode= ONE_OR_MORE;
69 else {
70 try {
71 fSize= Integer.parseInt(size);
72 fMode= EXACT;
73 } catch (NumberFormatException e) {
74 fMode= UNKNOWN;
75 }
76 }
77 }
78
79 public EvaluationResult evaluate(IEvaluationContext context) throws CoreException {
80 Object var= context.getDefaultVariable();
81 int size;
82 if (var instanceof Collection ) {
83 size= ((Collection )var).size();
84 } else {
85 ICountable countable= Expressions.getAsICountable(var, this);
86 if (countable == null)
87 return EvaluationResult.NOT_LOADED;
88 size= countable.count();
89 }
90 switch (fMode) {
91 case UNKNOWN:
92 return EvaluationResult.FALSE;
93 case NONE:
94 return EvaluationResult.valueOf(size == 0);
95 case NONE_OR_ONE:
96 return EvaluationResult.valueOf(size == 0 || size == 1);
97 case ONE_OR_MORE:
98 return EvaluationResult.valueOf(size >= 1);
99 case EXACT:
100 return EvaluationResult.valueOf(fSize == size);
101 case ANY_NUMBER:
102 return EvaluationResult.TRUE;
103 }
104 return EvaluationResult.FALSE;
105 }
106
107 public void collectExpressionInfo(ExpressionInfo info) {
108 info.markDefaultVariableAccessed();
109 }
110
111 public boolean equals(final Object object) {
112 if (!(object instanceof CountExpression))
113 return false;
114
115 final CountExpression that= (CountExpression)object;
116 return (this.fMode == that.fMode) && (this.fSize == that.fSize);
117 }
118
119 protected int computeHashCode() {
120 return HASH_INITIAL * HASH_FACTOR + fMode
121 * HASH_FACTOR + fSize;
122 }
123 }
124 |
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