1 /* 2 * Copyright (C) 2007 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.dx.rop.code; 18 19 import com.android.dx.rop.cst.CstString; 20 21 /** 22 * A local variable item: either a name or a signature or both. 23 */ 24 public class LocalItem implements Comparable<LocalItem> { 25 /** {@code null-ok;} local variable name */ 26 private final CstString name; 27 28 /** {@code null-ok;} local variable signature */ 29 private final CstString signature; 30 31 /** 32 * Make a new item. If both name and signature are null, null is returned. 33 * 34 * TODO: intern these 35 * 36 * @param name {@code null-ok;} local variable name 37 * @param signature {@code null-ok;} local variable signature 38 * @return {@code non-null;} appropriate instance. 39 */ make(CstString name, CstString signature)40 public static LocalItem make(CstString name, CstString signature) { 41 if (name == null && signature == null) { 42 return null; 43 } 44 45 return new LocalItem (name, signature); 46 } 47 48 /** 49 * Constructs instance. 50 * 51 * @param name {@code null-ok;} local variable name 52 * @param signature {@code null-ok;} local variable signature 53 */ LocalItem(CstString name, CstString signature)54 private LocalItem(CstString name, CstString signature) { 55 this.name = name; 56 this.signature = signature; 57 } 58 59 /** {@inheritDoc} */ 60 @Override equals(Object other)61 public boolean equals(Object other) { 62 if (!(other instanceof LocalItem)) { 63 return false; 64 } 65 66 LocalItem local = (LocalItem) other; 67 68 return 0 == compareTo(local); 69 } 70 71 /** 72 * Compares two strings like String.compareTo(), excepts treats a null 73 * as the least-possible string value. 74 * 75 * @return negative integer, zero, or positive integer in accordance 76 * with Comparable.compareTo() 77 */ compareHandlesNulls(CstString a, CstString b)78 private static int compareHandlesNulls(CstString a, CstString b) { 79 if (a == b) { 80 return 0; 81 } else if (a == null) { 82 return -1; 83 } else if (b == null) { 84 return 1; 85 } else { 86 return a.compareTo(b); 87 } 88 } 89 90 /** {@inheritDoc} */ 91 @Override compareTo(LocalItem local)92 public int compareTo(LocalItem local) { 93 int ret; 94 95 ret = compareHandlesNulls(name, local.name); 96 97 if (ret != 0) { 98 return ret; 99 } 100 101 ret = compareHandlesNulls(signature, local.signature); 102 103 return ret; 104 } 105 106 107 /** {@inheritDoc} */ 108 @Override hashCode()109 public int hashCode() { 110 return (name == null ? 0 : name.hashCode()) * 31 111 + (signature == null ? 0 : signature.hashCode()); 112 } 113 114 /** {@inheritDoc} */ 115 @Override toString()116 public String toString() { 117 if (name != null && signature == null) { 118 return name.toQuoted(); 119 } else if (name == null && signature == null) { 120 return ""; 121 } 122 123 return "[" + (name == null ? "" : name.toQuoted()) 124 + "|" + (signature == null ? "" : signature.toQuoted()); 125 } 126 127 /** 128 * Gets name. 129 * 130 * @return {@code null-ok;} name 131 */ getName()132 public CstString getName() { 133 return name; 134 } 135 136 /** 137 * Gets signature. 138 * 139 * @return {@code null-ok;} signature 140 */ getSignature()141 public CstString getSignature() { 142 return signature; 143 } 144 } 145