1 /* 2 * Copyright 2012, Google LLC 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google LLC nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 package com.android.tools.smali.util; 32 33 import javax.annotation.Nonnull; 34 import javax.annotation.Nullable; 35 import java.util.AbstractSequentialList; 36 import java.util.Iterator; 37 import java.util.ListIterator; 38 import java.util.NoSuchElementException; 39 40 public abstract class AbstractForwardSequentialList<T> extends AbstractSequentialList<T> { 41 iterator(int index)42 @Nonnull private Iterator<T> iterator(int index) { 43 if (index < 0) { 44 throw new NoSuchElementException(); 45 } 46 47 Iterator<T> it = iterator(); 48 for (int i=0; i<index; i++) { 49 it.next(); 50 } 51 return it; 52 } 53 iterator()54 @Override @Nonnull public abstract Iterator<T> iterator(); 55 listIterator(final int initialIndex)56 @Override @Nonnull public ListIterator<T> listIterator(final int initialIndex) { 57 58 final Iterator<T> initialIterator; 59 try { 60 initialIterator = iterator(initialIndex); 61 } catch (NoSuchElementException ex) { 62 throw new IndexOutOfBoundsException(); 63 } 64 65 return new AbstractListIterator<T>() { 66 private int index = initialIndex - 1; 67 @Nullable private Iterator<T> forwardIterator = initialIterator; 68 69 @Nonnull 70 private Iterator<T> getForwardIterator() { 71 if (forwardIterator == null) { 72 try { 73 forwardIterator = iterator(index+1); 74 } catch (IndexOutOfBoundsException ex) { 75 throw new NoSuchElementException(); 76 } 77 } 78 return forwardIterator; 79 } 80 81 @Override public boolean hasNext() { 82 return getForwardIterator().hasNext(); 83 } 84 85 @Override public boolean hasPrevious() { 86 return index >= 0; 87 } 88 89 @Override public T next() { 90 T ret = getForwardIterator().next(); 91 index++; 92 return ret; 93 } 94 95 @Override public int nextIndex() { 96 return index+1; 97 } 98 99 @Override public T previous() { 100 forwardIterator = null; 101 try { 102 return iterator(index--).next(); 103 } catch (IndexOutOfBoundsException ex) { 104 throw new NoSuchElementException(); 105 } 106 } 107 108 @Override public int previousIndex() { 109 return index; 110 } 111 }; 112 } 113 listIterator()114 @Override @Nonnull public ListIterator<T> listIterator() { 115 return listIterator(0); 116 } 117 } 118