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 com.android.tools.layoutlib.create;
18
19import org.objectweb.asm.ClassVisitor;
20
21/**
22 * This class visitor renames a class from a given old name to a given new name.
23 * The class visitor will also rename all inner classes and references in the methods.
24 * <p/>
25 *
26 * For inner classes, this handles only the case where the outer class name changes.
27 * The inner class name should remain the same.
28 */
29public class RenameClassAdapter extends AbstractClassAdapter {
30
31
32    private final String mOldName;
33    private final String mNewName;
34    private String mOldBase;
35    private String mNewBase;
36
37    /**
38     * Creates a class visitor that renames a class from a given old name to a given new name.
39     * The class visitor will also rename all inner classes and references in the methods.
40     * The names must be full qualified internal ASM names (e.g. com/blah/MyClass$InnerClass).
41     */
42    public RenameClassAdapter(ClassVisitor cv, String oldName, String newName) {
43        super(cv);
44        mOldBase = mOldName = oldName;
45        mNewBase = mNewName = newName;
46
47        int pos = mOldName.indexOf('$');
48        if (pos > 0) {
49            mOldBase = mOldName.substring(0, pos);
50        }
51        pos = mNewName.indexOf('$');
52        if (pos > 0) {
53            mNewBase = mNewName.substring(0, pos);
54        }
55
56        assert (mOldBase == null && mNewBase == null) || (mOldBase != null && mNewBase != null);
57    }
58
59    /**
60     * Renames an internal type name, e.g. "com.package.MyClass".
61     * If the type doesn't need to be renamed, returns the input string as-is.
62     * <p/>
63     * The internal type of some of the MethodVisitor turns out to be a type
64       descriptor sometimes so descriptors are renamed too.
65     */
66    @Override
67    protected String renameInternalType(String type) {
68        if (type == null) {
69            return null;
70        }
71
72        if (type.equals(mOldName)) {
73            return mNewName;
74        }
75
76        if (!mOldBase.equals(mOldName) && type.equals(mOldBase)) {
77            return mNewBase;
78        }
79
80        int pos = type.indexOf('$');
81        if (pos == mOldBase.length() && type.startsWith(mOldBase)) {
82            return mNewBase + type.substring(pos);
83        }
84        return type;
85    }
86
87}
88