1/* 2 * Copyright (C) 2011 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.dx.io.instructions; 18 19/** 20 * Base implementation of {@link CodeCursor}. 21 */ 22public abstract class BaseCodeCursor implements CodeCursor { 23 /** base address map */ 24 private final AddressMap baseAddressMap; 25 26 /** next index within {@link #baseAddressMap} to read from or write to */ 27 private int cursor; 28 29 /** 30 * Constructs an instance. 31 */ 32 public BaseCodeCursor() { 33 this.baseAddressMap = new AddressMap(); 34 this.cursor = 0; 35 } 36 37 /** {@inheritDoc} */ 38 @Override 39 public final int cursor() { 40 return cursor; 41 } 42 43 /** {@inheritDoc} */ 44 @Override 45 public final int baseAddressForCursor() { 46 int mapped = baseAddressMap.get(cursor); 47 return (mapped >= 0) ? mapped : cursor; 48 } 49 50 /** {@inheritDoc} */ 51 @Override 52 public final void setBaseAddress(int targetAddress, int baseAddress) { 53 baseAddressMap.put(targetAddress, baseAddress); 54 } 55 56 /** 57 * Advance the cursor by the indicated amount. 58 */ 59 protected final void advance(int amount) { 60 cursor += amount; 61 } 62} 63