ArrayObjectAdapter.java revision 8b068ddbbf22a246eab49ec25a2f7c3abfbdca51 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14package android.support.v17.leanback.widget;
15
16import java.util.ArrayList;
17import java.util.Collection;
18
19/**
20 * Adapter implemented with an {@link ArrayList}.
21 */
22public class ArrayObjectAdapter extends ObjectAdapter {
23
24    private ArrayList<Object> mItems = new ArrayList<Object>();
25
26    public ArrayObjectAdapter(PresenterSelector presenterSelector) {
27        super(presenterSelector);
28    }
29
30    public ArrayObjectAdapter(Presenter presenter) {
31        super(presenter);
32    }
33
34    public ArrayObjectAdapter() {
35        super();
36    }
37
38    @Override
39    public int size() {
40        return mItems.size();
41    }
42
43    @Override
44    public Object get(int index) {
45        return mItems.get(index);
46    }
47
48    /**
49     * Adds an item to the end of the list.
50     *
51     * @param item The item to add to the end of the list.
52     */
53    public void add(Object item) {
54        add(mItems.size(), item);
55    }
56
57    /**
58     * Inserts an item into this list at the specified index.
59     *
60     * @param index The index at which the item should be inserted.
61     * @param item The item to insert into the list.
62     */
63    public void add(int index, Object item) {
64        mItems.add(index, item);
65        notifyItemRangeInserted(index, 1);
66    }
67
68    /**
69     * Adds the objects in the given collection to the list, starting at the
70     * given index.
71     *
72     * @param index The index at which the items should be inserted.
73     * @param items A {@link Collection} of items to insert.
74     */
75    public void addAll(int index, Collection<Object> items) {
76        int itemsCount = items.size();
77        mItems.addAll(index, items);
78        notifyItemRangeInserted(index, itemsCount);
79    }
80
81    /**
82     * Removes the first occurrence of the given item from the list.
83     *
84     * @param item The item to remove from the list.
85     * @return True if the item was found and thus removed from the list.
86     */
87    public boolean remove(Object item) {
88        int index = mItems.indexOf(item);
89        if (index >= 0) {
90            mItems.remove(index);
91            notifyItemRangeRemoved(index, 1);
92        }
93        return index >= 0;
94    }
95
96    /**
97     * Removes a range of items from the list. The range is specified by giving
98     * the starting position and the number of elements to remove.
99     *
100     * @param position The index of the first item to remove.
101     * @param count The number of items to remove.
102     * @return The number of items removed.
103     */
104    public int removeItems(int position, int count) {
105        int itemsToRemove = Math.min(count, mItems.size() - position);
106
107        for (int i = 0; i < itemsToRemove; i++) {
108            mItems.remove(position);
109        }
110        notifyItemRangeRemoved(position, itemsToRemove);
111        return itemsToRemove;
112    }
113
114    /**
115     * Removes all items from this list, leaving it empty.
116     */
117    public void clear() {
118        int itemCount = mItems.size();
119        mItems.clear();
120        notifyItemRangeRemoved(0, itemCount);
121    }
122}
123