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.dex.file; 18 19 /** 20 * An item in a Dalvik file which is referenced by index. 21 */ 22 public abstract class IndexedItem extends Item { 23 /** {@code >= -1;} assigned index of the item, or {@code -1} if not 24 * yet assigned */ 25 private int index; 26 27 /** 28 * Constructs an instance. The index is initially unassigned. 29 */ IndexedItem()30 public IndexedItem() { 31 index = -1; 32 } 33 34 /** 35 * Gets whether or not this instance has been assigned an index. 36 * 37 * @return {@code true} iff this instance has been assigned an index 38 */ hasIndex()39 public final boolean hasIndex() { 40 return (index >= 0); 41 } 42 43 /** 44 * Gets the item index. 45 * 46 * @return {@code >= 0;} the index 47 * @throws RuntimeException thrown if the item index is not yet assigned 48 */ getIndex()49 public final int getIndex() { 50 if (index < 0) { 51 throw new RuntimeException("index not yet set"); 52 } 53 54 return index; 55 } 56 57 /** 58 * Sets the item index. This method may only ever be called once 59 * per instance, and this will throw a {@code RuntimeException} if 60 * called a second (or subsequent) time. 61 * 62 * @param index {@code >= 0;} the item index 63 */ setIndex(int index)64 public final void setIndex(int index) { 65 if (this.index != -1) { 66 throw new RuntimeException("index already set"); 67 } 68 69 this.index = index; 70 } 71 72 /** 73 * Gets the index of this item as a string, suitable for including in 74 * annotations. 75 * 76 * @return {@code non-null;} the index string 77 */ indexString()78 public final String indexString() { 79 return '[' + Integer.toHexString(index) + ']'; 80 } 81 } 82