ObservableArrayList.java revision 9784c9aaedeb863018f5fcaa0a598e8e2f8ed2f3 
1/*
2 * Copyright (C) 2015 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 */
16package android.databinding;
17
18import java.util.ArrayList;
19import java.util.Collection;
20
21/**
22 * An {@link ObservableList} implementation using ArrayList as an implementation.
23 */
24public class ObservableArrayList<T> extends ArrayList<T> implements ObservableList<T> {
25    private transient ListChangeRegistry mListeners = new ListChangeRegistry();
26
27    @Override
28    public void addOnListChangedCallback(OnListChangedCallback listener) {
29        if (mListeners == null) {
30            mListeners = new ListChangeRegistry();
31        }
32        mListeners.add(listener);
33    }
34
35    @Override
36    public void removeOnListChangedCallback(OnListChangedCallback listener) {
37        if (mListeners != null) {
38            mListeners.remove(listener);
39        }
40    }
41
42    @Override
43    public boolean add(T object) {
44        super.add(object);
45        notifyAdd(size() - 1, 1);
46        return true;
47    }
48
49    @Override
50    public void add(int index, T object) {
51        super.add(index, object);
52        notifyAdd(index, 1);
53    }
54
55    @Override
56    public boolean addAll(Collection<? extends T> collection) {
57        int oldSize = size();
58        boolean added = super.addAll(collection);
59        if (added) {
60            notifyAdd(oldSize, size() - oldSize);
61        }
62        return added;
63    }
64
65    @Override
66    public boolean addAll(int index, Collection<? extends T> collection) {
67        boolean added = super.addAll(index, collection);
68        if (added) {
69            notifyAdd(index, collection.size());
70        }
71        return added;
72    }
73
74    @Override
75    public void clear() {
76        int oldSize = size();
77        super.clear();
78        if (oldSize != 0) {
79            notifyRemove(0, oldSize);
80        }
81    }
82
83    @Override
84    public T remove(int index) {
85        T val = super.remove(index);
86        notifyRemove(index, 1);
87        return val;
88    }
89
90    @Override
91    public boolean remove(Object object) {
92        int index = indexOf(object);
93        if (index >= 0) {
94            remove(index);
95            return true;
96        } else {
97            return false;
98        }
99    }
100
101    @Override
102    public T set(int index, T object) {
103        T val = super.set(index, object);
104        if (mListeners != null) {
105            mListeners.notifyChanged(this, index, 1);
106        }
107        return val;
108    }
109
110    @Override
111    protected void removeRange(int fromIndex, int toIndex) {
112        super.removeRange(fromIndex, toIndex);
113        notifyRemove(fromIndex, toIndex - fromIndex);
114    }
115
116    private void notifyAdd(int start, int count) {
117        if (mListeners != null) {
118            mListeners.notifyInserted(this, start, count);
119        }
120    }
121
122    private void notifyRemove(int start, int count) {
123        if (mListeners != null) {
124            mListeners.notifyRemoved(this, start, count);
125        }
126    }
127}
128