Home | History | Annotate | Download | only in create 
      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 
     17 package com.android.tools.layoutlib.create;
     18 
     19 import 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  */
     29 public 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