ListSuggestionCursor.java revision 7f6a94f1ad3e3ec2546fb59310f5c5481032ff0c 
1/*
2 * Copyright (C) 2009 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
17package com.android.quicksearchbox;
18
19import com.google.common.annotations.VisibleForTesting;
20
21import android.database.DataSetObservable;
22import android.database.DataSetObserver;
23
24import java.util.ArrayList;
25
26/**
27 * A SuggestionCursor that is backed by a list of Suggestions.
28 */
29public class ListSuggestionCursor extends AbstractSuggestionCursorWrapper {
30
31    private static final int DEFAULT_CAPACITY = 16;
32
33    private final DataSetObservable mDataSetObservable = new DataSetObservable();
34
35    private final ArrayList<Suggestion> mSuggestions;
36
37    private int mPos = 0;
38
39    public ListSuggestionCursor(String userQuery) {
40        this(userQuery, DEFAULT_CAPACITY);
41    }
42
43    @VisibleForTesting
44    public ListSuggestionCursor(String userQuery, Suggestion...suggestions) {
45        this(userQuery, suggestions.length);
46        for (Suggestion suggestion : suggestions) {
47            mSuggestions.add(suggestion);
48        }
49    }
50
51    public ListSuggestionCursor(String userQuery, int capacity) {
52        super(userQuery);
53        mSuggestions = new ArrayList<Suggestion>(capacity);
54    }
55
56    /**
57     * Adds a suggestion from another suggestion cursor.
58     *
59     * @return {@code true} if the suggestion was added.
60     */
61    public boolean add(Suggestion suggestion) {
62        mSuggestions.add(suggestion);
63        return true;
64    }
65
66    public void close() {
67        mSuggestions.clear();
68    }
69
70    public int getPosition() {
71        return mPos;
72    }
73
74    public void moveTo(int pos) {
75        mPos = pos;
76    }
77
78    public boolean moveToNext() {
79        int size = mSuggestions.size();
80        if (mPos >= size) {
81            // Already past the end
82            return false;
83        }
84        mPos++;
85        return mPos < size;
86    }
87
88    public void removeRow() {
89        mSuggestions.remove(mPos);
90    }
91
92    public void replaceRow(Suggestion suggestion) {
93        mSuggestions.set(mPos, suggestion);
94    }
95
96    public int getCount() {
97        return mSuggestions.size();
98    }
99
100    @Override
101    protected Suggestion current() {
102        return mSuggestions.get(mPos);
103    }
104
105    @Override
106    public String toString() {
107        return getClass().getSimpleName() + "{[" + getUserQuery() + "] " + mSuggestions + "}";
108    }
109
110    /**
111     * Register an observer that is called when changes happen to this data set.
112     *
113     * @param observer gets notified when the data set changes.
114     */
115    public void registerDataSetObserver(DataSetObserver observer) {
116        mDataSetObservable.registerObserver(observer);
117    }
118
119    /**
120     * Unregister an observer that has previously been registered with
121     * {@link #registerDataSetObserver(DataSetObserver)}
122     *
123     * @param observer the observer to unregister.
124     */
125    public void unregisterDataSetObserver(DataSetObserver observer) {
126        mDataSetObservable.unregisterObserver(observer);
127    }
128
129    protected void notifyDataSetChanged() {
130        mDataSetObservable.notifyChanged();
131    }
132}
133