1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package org.apache.harmony.luni.lang.reflect;
18
19import java.lang.reflect.Constructor;
20import java.lang.reflect.GenericDeclaration;
21import java.lang.reflect.Method;
22import java.lang.reflect.Type;
23import java.lang.reflect.TypeVariable;
24
25
26public final class ImplForVariable<D extends GenericDeclaration>
27        implements TypeVariable<D> {
28    private ImplForVariable<D> formalVar;
29    private final GenericDeclaration declOfVarUser;
30    private final String name;
31    private D genericDeclaration;
32    private ListOfTypes bounds;
33
34
35    @Override
36    public boolean equals(Object o) {
37        if(!(o instanceof TypeVariable)) {
38            return false;
39        }
40        TypeVariable<?> that = (TypeVariable<?>) o;
41        return getName().equals(that.getName()) &&
42                getGenericDeclaration().equals(that.getGenericDeclaration());
43    }
44
45
46    @Override
47    public int hashCode() {
48        return 31 * getName().hashCode() + getGenericDeclaration().hashCode();
49    }
50
51    /**
52     * @param genericDecl declaration where a type variable is declared
53     * @param name type variable name
54     * @param bounds class and interface bounds
55     * @api2vm
56     */
57    ImplForVariable(D genericDecl, String name, ListOfTypes bounds) {
58        this.genericDeclaration = genericDecl;
59        this.name = name;
60        this.bounds = bounds;
61        this.formalVar = this;
62        this.declOfVarUser = null;
63    }
64
65    /**
66     * @param genericDecl declaration where a type variable is used
67     * @param name type variable name
68     * @api2vm
69     */
70    ImplForVariable(D genericDecl, String name) {
71        this.name = name;
72        this.declOfVarUser = genericDecl;
73    }
74
75    static TypeVariable findFormalVar(GenericDeclaration layer, String name) {
76        TypeVariable[] formalVars = layer.getTypeParameters();
77        for (TypeVariable var : formalVars) {
78            if (name.equals(var.getName())) {
79                return var;
80            }
81        }
82        // resolve() looks up the next level only, if null is returned
83        return null;
84    }
85
86    static GenericDeclaration nextLayer(GenericDeclaration decl) {
87            if (decl instanceof Class) {
88                // FIXME: Is the following hierarchy correct?:
89                Class cl = (Class)decl;
90                decl = cl.getEnclosingMethod();
91                if (decl != null) {
92                    return decl;
93                }
94                decl = cl.getEnclosingConstructor();
95                if (decl != null) {
96                    return decl;
97                }
98                return cl.getEnclosingClass();
99            } else if (decl instanceof Method) {
100                return ((Method)decl).getDeclaringClass();
101            } else if (decl instanceof Constructor) {
102                return ((Constructor)decl).getDeclaringClass();
103            }
104            throw new RuntimeException("unknown GenericDeclaration2: "
105                    + decl.toString());
106    }
107
108    void resolve() {
109        if (formalVar == null) {
110            GenericDeclaration curLayer = declOfVarUser;
111            TypeVariable var = null;
112            do {
113                var = findFormalVar(curLayer, name);
114                if (var != null) break;
115                else {
116                    curLayer = nextLayer(curLayer);
117                    if (curLayer == null) break; // FIXME: SHOULD NEVER HAPPEN!
118                                                 // throw exception: illegal
119                                                 // type variable reference.
120                }
121            } while (true);
122            formalVar = (ImplForVariable<D>)var;
123            this.genericDeclaration = formalVar.genericDeclaration;
124            this.bounds = formalVar.bounds;
125        }
126    }
127
128    public Type[] getBounds() {
129        resolve();
130        return bounds.getResolvedTypes().clone();
131    }
132
133    public D getGenericDeclaration() {
134        resolve();
135        return genericDeclaration;
136    }
137
138    public String getName() {
139        return name;
140    }
141
142    @Override
143    public String toString() {
144        return name;
145    }
146}
147