Java tutorial
/******************************************************************************* * Copyright 2011 See AUTHORS file. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ package com.badlogic.gdx.utils; import java.util.Comparator; /** Queues any removals done after {@link #begin()} is called to occur once {@link #end()} is called. This can allow code out of * your control to remove items without affecting iteration. Between begin and end, most mutator methods will throw * IllegalStateException. Only {@link #removeIndex(int)}, {@link #removeValue(Object, boolean)}, and add methods are allowed. * <p> * Code using this class must not rely on items being removed immediately. Consider using {@link SnapshotArray} if this is a * problem.. * @author Nathan Sweet */ public class DelayedRemovalArray<T> extends Array<T> { private int iterating; private IntArray remove = new IntArray(0); public DelayedRemovalArray() { super(); } public DelayedRemovalArray(Array array) { super(array); } public DelayedRemovalArray(boolean ordered, int capacity, Class arrayType) { super(ordered, capacity, arrayType); } public DelayedRemovalArray(boolean ordered, int capacity) { super(ordered, capacity); } public DelayedRemovalArray(boolean ordered, T[] array, int startIndex, int count) { super(ordered, array, startIndex, count); } public DelayedRemovalArray(Class arrayType) { super(arrayType); } public DelayedRemovalArray(int capacity) { super(capacity); } public DelayedRemovalArray(T[] array) { super(array); } public void begin() { iterating++; } public void end() { if (iterating == 0) throw new IllegalStateException("begin must be called before end."); iterating--; if (iterating == 0) { for (int i = 0, n = remove.size; i < n; i++) removeIndex(remove.pop()); } } private void remove(int index) { for (int i = 0, n = remove.size; i < n; i++) { int removeIndex = remove.get(i); if (index == removeIndex) return; if (index < removeIndex) { remove.insert(i, index); return; } } remove.add(index); } public boolean removeValue(T value, boolean identity) { if (iterating > 0) { int index = indexOf(value, identity); if (index == -1) return false; remove(index); return true; } return super.removeValue(value, identity); } public T removeIndex(int index) { if (iterating > 0) { remove(index); return get(index); } return super.removeIndex(index); } public void removeRange(int start, int end) { if (iterating > 0) { for (int i = end; i >= start; i--) remove(i); } else super.removeRange(start, end); } public void set(int index, T value) { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.set(index, value); } public void insert(int index, T value) { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.insert(index, value); } public void swap(int first, int second) { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.swap(first, second); } public T pop() { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); return super.pop(); } public void clear() { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.clear(); } public void sort() { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.sort(); } public void sort(Comparator<? super T> comparator) { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.sort(comparator); } public void reverse() { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.reverse(); } public void shuffle() { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.shuffle(); } public void truncate(int newSize) { if (iterating > 0) throw new IllegalStateException("Invalid between begin/end."); super.truncate(newSize); } /** @see #DelayedRemovalArray(Object[]) */ static public <T> DelayedRemovalArray<T> with(T... array) { return new DelayedRemovalArray(array); } }