/*******************************************************************************
* 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 com.badlogic.gdx.math.MathUtils;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* A resizable, ordered or unordered array of objects. If unordered, this class avoids a memory copy when removing
* elements (the last element is moved to the removed element's position).
*
* @author Nathan Sweet
*/
public class Array<T> implements Iterable<T> {
/**
* Provides direct access to the underlying array. If the Array's generic type is not Object, this field may only be
* accessed if the {@link Array#Array(boolean, int, Class)} constructor was used.
*/
public T[] items;
public int size;
public boolean ordered;
private ArrayIterator iterator;
/** Creates an ordered array with a capacity of 16. */
public Array() {
this(true, 16);
}
/** Creates an ordered array with the specified capacity. */
public Array(int capacity) {
this(true, capacity);
}
/**
* @param ordered
* If false, methods that remove elements may change the order of other elements in the array, which
* avoids a memory copy.
* @param capacity
* Any elements added beyond this will cause the backing array to be grown.
*/
public Array(boolean ordered, int capacity) {
this.ordered = ordered;
items = (T[]) new Object[capacity];
}
/**
* Creates a new array with {@link #items} of the specified type.
*
* @param ordered
* If false, methods that remove elements may change the order of other elements in the array, which
* avoids a memory copy.
* @param capacity
* Any elements added beyond this will cause the backing array to be grown.
*/
public Array(boolean ordered, int capacity, Class<T> arrayType) {
this.ordered = ordered;
items = (T[]) java.lang.reflect.Array.newInstance(arrayType, capacity);
}
/** Creates an ordered array with {@link #items} of the specified type and a capacity of 16. */
public Array(Class<T> arrayType) {
this(true, 16, arrayType);
}
/**
* Creates a new array containing the elements in the specified array. The new array will have the same type of
* backing array and will be ordered if the specified array is ordered. The capacity is set to the number of
* elements, so any subsequent elements added will cause the backing array to be grown.
*/
public Array(Array array) {
this(array.ordered, array.size, (Class<T>) array.items.getClass().getComponentType());
size = array.size;
System.arraycopy(array.items, 0, items, 0, size);
}
/**
* Creates a new ordered array containing the elements in the specified array. The new array will have the same type
* of backing array. The capacity is set to the number of elements, so any subsequent elements added will cause the
* backing array to be grown.
*/
public Array(T[] array) {
this(true, array);
}
/**
* Creates a new array containing the elements in the specified array. The new array will have the same type of
* backing array. The capacity is set to the number of elements, so any subsequent elements added will cause the
* backing array to be grown.
*
* @param ordered
* If false, methods that remove elements may change the order of other elements in the array, which
* avoids a memory copy.
*/
public Array(boolean ordered, T[] array) {
this(ordered, array.length, (Class) array.getClass().getComponentType());
size = array.length;
System.arraycopy(array, 0, items, 0, size);
}
public void add(T value) {
T[] items = this.items;
if (size == items.length)
items = resize(Math.max(8, (int) (size * 1.75f)));
items[size++] = value;
}
public void addAll(Array array) {
addAll(array, 0, array.size);
}
public void addAll(Array array, int offset, int length) {
if (offset + length > array.size)
throw new IllegalArgumentException("offset + length must be <= size: " + offset + " + " + length + " <= "
+ array.size);
addAll((T[]) array.items, offset, length);
}
public void addAll(T[] array) {
addAll(array, 0, array.length);
}
public void addAll(T[] array, int offset, int length) {
T[] items = this.items;
int sizeNeeded = size + length;
if (sizeNeeded > items.length)
items = resize(Math.max(8, (int) (sizeNeeded * 1.75f)));
System.arraycopy(array, offset, items, size, length);
size += length;
}
public T get(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
return items[index];
}
public void set(int index, T value) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
items[index] = value;
}
public void insert(int index, T value) {
T[] items = this.items;
if (size == items.length)
items = resize(Math.max(8, (int) (size * 1.75f)));
if (ordered)
System.arraycopy(items, index, items, index + 1, size - index);
else
items[size] = items[index];
size++;
items[index] = value;
}
public void swap(int first, int second) {
if (first >= size)
throw new IndexOutOfBoundsException(String.valueOf(first));
if (second >= size)
throw new IndexOutOfBoundsException(String.valueOf(second));
T[] items = this.items;
T firstValue = items[first];
items[first] = items[second];
items[second] = firstValue;
}
/**
* @param identity
* If true, == comparison will be used. If false, .equals() comaparison will be used.
*/
public boolean contains(T value, boolean identity) {
T[] items = this.items;
int i = size - 1;
if (identity || value == null) {
while (i >= 0)
if (items[i--] == value)
return true;
} else {
while (i >= 0)
if (value.equals(items[i--]))
return true;
}
return false;
}
public int indexOf(T value, boolean identity) {
T[] items = this.items;
if (identity || value == null) {
for (int i = 0, n = size; i < n; i++)
if (items[i] == value)
return i;
} else {
for (int i = 0, n = size; i < n; i++)
if (value.equals(items[i]))
return i;
}
return -1;
}
public int lastIndexOf(T value, boolean identity) {
T[] items = this.items;
if (identity || value == null) {
for (int i = size - 1; i >= 0; i--)
if (items[i] == value)
return i;
} else {
for (int i = size - 1; i >= 0; i--)
if (value.equals(items[i]))
return i;
}
return -1;
}
public boolean removeValue(T value, boolean identity) {
T[] items = this.items;
if (identity || value == null) {
for (int i = 0, n = size; i < n; i++) {
if (items[i] == value) {
removeIndex(i);
return true;
}
}
} else {
for (int i = 0, n = size; i < n; i++) {
if (value.equals(items[i])) {
removeIndex(i);
return true;
}
}
}
return false;
}
/** Removes and returns the item at the specified index. */
public T removeIndex(int index) {
if (index >= size)
throw new IndexOutOfBoundsException(String.valueOf(index));
T[] items = this.items;
T value = (T) items[index];
size--;
if (ordered)
System.arraycopy(items, index + 1, items, index, size - index);
else
items[index] = items[size];
items[size] = null;
return value;
}
/**
* Removes from this array all of elements contained in the specified array.
*
* @param identity
* True to use ==, false to use .equals().
* @return true if this array was modified.
*/
public boolean removeAll(Array<T> array, boolean identity) {
int size = this.size;
int startSize = size;
T[] items = this.items;
if (identity) {
for (int i = 0, n = array.size; i < n; i++) {
T item = array.get(i);
for (int ii = 0; ii < size; ii++) {
if (item.equals(items[ii])) {
removeIndex(ii);
size--;
break;
}
}
}
} else {
for (int i = 0, n = array.size; i < n; i++) {
T item = array.get(i);
for (int ii = 0; ii < size; ii++) {
if (item == items[ii]) {
removeIndex(ii);
size--;
break;
}
}
}
}
return size != startSize;
}
/** Removes and returns the last item. */
public T pop() {
--size;
T item = items[size];
items[size] = null;
return item;
}
/** Returns the last item. */
public T peek() {
return items[size - 1];
}
/** Returns the first item. */
public T first() {
return items[0];
}
public void clear() {
T[] items = this.items;
for (int i = 0, n = size; i < n; i++)
items[i] = null;
size = 0;
}
/**
* Reduces the size of the backing array to the size of the actual items. This is useful to release memory when many
* items have been removed, or if it is known that more items will not be added.
*/
public void shrink() {
resize(size);
}
/**
* Increases the size of the backing array to acommodate the specified number of additional items. Useful before
* adding many items to avoid multiple backing array resizes.
*
* @return {@link #items}
*/
public T[] ensureCapacity(int additionalCapacity) {
int sizeNeeded = size + additionalCapacity;
if (sizeNeeded >= items.length)
resize(Math.max(8, sizeNeeded));
return items;
}
/** Creates a new backing array with the specified size containing the current items. */
protected T[] resize(int newSize) {
T[] items = this.items;
T[] newItems = (T[]) java.lang.reflect.Array.newInstance(items.getClass().getComponentType(), newSize);
System.arraycopy(items, 0, newItems, 0, Math.min(size, newItems.length));
this.items = newItems;
return newItems;
}
/**
* Sorts this array. The array elements must implement {@link Comparable}. This method is not thread safe (uses
* {@link Sort#instance()}).
*/
public void sort() {
Sort.instance().sort(items, 0, size);
}
/** Sorts the array. This method is not thread safe (uses {@link Sort#instance()}). */
public void sort(Comparator<T> comparator) {
Sort.instance().sort(items, comparator, 0, size);
}
public void reverse() {
for (int i = 0, lastIndex = size - 1, n = size / 2; i < n; i++) {
int ii = lastIndex - i;
T temp = items[i];
items[i] = items[ii];
items[ii] = temp;
}
}
public void shuffle() {
for (int i = size - 1; i >= 0; i--) {
int ii = MathUtils.random(i);
T temp = items[i];
items[i] = items[ii];
items[ii] = temp;
}
}
/**
* Returns an iterator for the items in the array. Remove is supported. Note that the same iterator instance is
* returned each time this method is called. Use the {@link ArrayIterator} constructor for nested or multithreaded
* iteration.
*/
public Iterator<T> iterator() {
if (iterator == null)
iterator = new ArrayIterator(this);
else
iterator.index = 0;
return iterator;
}
/**
* Reduces the size of the array to the specified size. If the array is already smaller than the specified size, no
* action is taken.
*/
public void truncate(int newSize) {
if (size <= newSize)
return;
for (int i = newSize; i < size; i++)
items[i] = null;
size = newSize;
}
/** Returns a random item from the array, or null if the array is empty. */
public T random() {
if (size == 0)
return null;
return items[MathUtils.random(0, size - 1)];
}
public T[] toArray() {
return (T[]) toArray(items.getClass().getComponentType());
}
public <V> V[] toArray(Class<V> type) {
V[] result = (V[]) java.lang.reflect.Array.newInstance(type, size);
System.arraycopy(items, 0, result, 0, size);
return result;
}
public boolean equals(Object object) {
if (object == this)
return true;
if (!(object instanceof Array))
return false;
Array array = (Array) object;
int n = size;
if (n != array.size)
return false;
Object[] items1 = this.items;
Object[] items2 = array.items;
for (int i = 0; i < n; i++) {
Object o1 = items1[i];
Object o2 = items2[i];
if (!(o1 == null ? o2 == null : o1.equals(o2)))
return false;
}
return true;
}
public String toString() {
if (size == 0)
return "[]";
T[] items = this.items;
StringBuilder buffer = new StringBuilder(32);
buffer.append('[');
buffer.append(items[0]);
for (int i = 1; i < size; i++) {
buffer.append(", ");
buffer.append(items[i]);
}
buffer.append(']');
return buffer.toString();
}
public String toString(String separator) {
if (size == 0)
return "";
T[] items = this.items;
StringBuilder buffer = new StringBuilder(32);
buffer.append(items[0]);
for (int i = 1; i < size; i++) {
buffer.append(separator);
buffer.append(items[i]);
}
return buffer.toString();
}
static public class ArrayIterator<T> implements Iterator<T> {
private final Array<T> array;
int index;
public ArrayIterator(Array<T> array) {
this.array = array;
}
public boolean hasNext() {
return index < array.size;
}
public T next() {
if (index >= array.size)
throw new NoSuchElementException(String.valueOf(index));
return array.items[index++];
}
public void remove() {
index--;
array.removeIndex(index);
}
public void reset() {
index = 0;
}
}
static public class ArrayIterable<T> implements Iterable<T> {
private ArrayIterator<T> iterator;
public ArrayIterable(Array<T> array) {
iterator = new ArrayIterator<T>(array);
}
@Override
public Iterator<T> iterator() {
iterator.reset();
return iterator;
}
}
}