1 | /* |
2 | * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved. |
3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 | * |
5 | * This code is free software; you can redistribute it and/or modify it |
6 | * under the terms of the GNU General Public License version 2 only, as |
7 | * published by the Free Software Foundation. Sun designates this |
8 | * particular file as subject to the "Classpath" exception as provided |
9 | * by Sun in the LICENSE file that accompanied this code. |
10 | * |
11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | * version 2 for more details (a copy is included in the LICENSE file that |
15 | * accompanied this code). |
16 | * |
17 | * You should have received a copy of the GNU General Public License version |
18 | * 2 along with this work; if not, write to the Free Software Foundation, |
19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
20 | * |
21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
23 | * have any questions. |
24 | */ |
25 | |
26 | package com.sun.tools.javac.model; |
27 | |
28 | import com.sun.tools.javac.util.*; |
29 | import java.util.AbstractList; |
30 | import java.util.Iterator; |
31 | import java.util.NoSuchElementException; |
32 | import com.sun.tools.javac.code.Scope; |
33 | import com.sun.tools.javac.code.Symbol; |
34 | |
35 | import static com.sun.tools.javac.code.Flags.*; |
36 | |
37 | /** |
38 | * Utility to construct a view of a symbol's members, |
39 | * filtering out unwanted elements such as synthetic ones. |
40 | * This view is most efficiently accessed through its iterator() method. |
41 | * |
42 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
43 | * you write code that depends on this, you do so at your own risk. |
44 | * This code and its internal interfaces are subject to change or |
45 | * deletion without notice.</b> |
46 | */ |
47 | public class FilteredMemberList extends AbstractList<Symbol> { |
48 | |
49 | private final Scope scope; |
50 | |
51 | public FilteredMemberList(Scope scope) { |
52 | this.scope = scope; |
53 | } |
54 | |
55 | public int size() { |
56 | int cnt = 0; |
57 | for (Scope.Entry e = scope.elems; e != null; e = e.sibling) { |
58 | if (!unwanted(e.sym)) |
59 | cnt++; |
60 | } |
61 | return cnt; |
62 | } |
63 | |
64 | public Symbol get(int index) { |
65 | for (Scope.Entry e = scope.elems; e != null; e = e.sibling) { |
66 | if (!unwanted(e.sym) && (index-- == 0)) |
67 | return e.sym; |
68 | } |
69 | throw new IndexOutOfBoundsException(); |
70 | } |
71 | |
72 | // A more efficient implementation than AbstractList's. |
73 | public Iterator<Symbol> iterator() { |
74 | return new Iterator<Symbol>() { |
75 | |
76 | /** The next entry to examine, or null if none. */ |
77 | private Scope.Entry nextEntry = scope.elems; |
78 | |
79 | private boolean hasNextForSure = false; |
80 | |
81 | public boolean hasNext() { |
82 | if (hasNextForSure) { |
83 | return true; |
84 | } |
85 | while (nextEntry != null && unwanted(nextEntry.sym)) { |
86 | nextEntry = nextEntry.sibling; |
87 | } |
88 | hasNextForSure = (nextEntry != null); |
89 | return hasNextForSure; |
90 | } |
91 | |
92 | public Symbol next() { |
93 | if (hasNext()) { |
94 | Symbol result = nextEntry.sym; |
95 | nextEntry = nextEntry.sibling; |
96 | hasNextForSure = false; |
97 | return result; |
98 | } else { |
99 | throw new NoSuchElementException(); |
100 | } |
101 | } |
102 | |
103 | public void remove() { |
104 | throw new UnsupportedOperationException(); |
105 | } |
106 | }; |
107 | } |
108 | |
109 | /** |
110 | * Tests whether this is a symbol that should never be seen by |
111 | * clients, such as a synthetic class. Returns true for null. |
112 | */ |
113 | private static boolean unwanted(Symbol s) { |
114 | return s == null || (s.flags() & SYNTHETIC) != 0; |
115 | } |
116 | } |