1 /*
2  * Copyright (C) 2013 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 android.util;
18 
19 import java.util.ArrayList;
20 import java.util.Collections;
21 
22 public class SparseArray<E> {
23     private final ArrayList<Integer> mKeys;
24     private final ArrayList<E> mValues;
25 
SparseArray()26     public SparseArray() {
27         this(10);
28     }
29 
SparseArray(final int initialCapacity)30     public SparseArray(final int initialCapacity) {
31         mKeys = new ArrayList<>(initialCapacity);
32         mValues = new ArrayList<>(initialCapacity);
33     }
34 
size()35     public int size() {
36         return mKeys.size();
37     }
38 
clear()39     public void clear() {
40         mKeys.clear();
41         mValues.clear();
42     }
43 
put(final int key, final E value)44     public void put(final int key, final E value) {
45         final int index = Collections.binarySearch(mKeys, key);
46         if (index >= 0) {
47             mValues.set(index, value);
48             return;
49         }
50         final int insertIndex = ~index;
51         mKeys.add(insertIndex, key);
52         mValues.add(insertIndex, value);
53     }
54 
get(final int key)55     public E get(final int key) {
56         return get(key, null);
57     }
58 
get(final int key, final E valueIfKeyNotFound)59     public E get(final int key, final E valueIfKeyNotFound) {
60         final int index = Collections.binarySearch(mKeys, key);
61         if (index >= 0) {
62             return mValues.get(index);
63         }
64         return valueIfKeyNotFound;
65     }
66 
indexOfKey(final int key)67     public int indexOfKey(final int key) {
68         return mKeys.indexOf(key);
69     }
70 
indexOfValue(final E value)71     public int indexOfValue(final E value) {
72         return mValues.indexOf(value);
73     }
74 
keyAt(final int index)75     public int keyAt(final int index) {
76         return mKeys.get(index);
77     }
78 
valueAt(final int index)79     public E valueAt(final int index) {
80         return mValues.get(index);
81     }
82 }
83