SuggestionCursor.java revision b42184f1e6a1b7bb22797ff92cae696753aca770 
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 */
16package com.android.quicksearchbox;
17
18import com.android.quicksearchbox.util.QuietlyCloseable;
19
20import android.database.DataSetObserver;
21
22/**
23 * A sequence of suggestions, with a current position.
24 */
25public interface SuggestionCursor extends Suggestion, QuietlyCloseable {
26
27    /**
28     * Gets the query that the user typed to get this suggestion.
29     */
30    String getUserQuery();
31
32    /**
33     * Gets the number of suggestions in this result.
34     *
35     * @return The number of suggestions, or {@code 0} if this result represents a failed query.
36     */
37    int getCount();
38
39    /**
40     * Moves to a given suggestion.
41     *
42     * @param pos The position to move to.
43     * @throws IndexOutOfBoundsException if {@code pos < 0} or {@code pos >= getCount()}.
44     */
45    void moveTo(int pos);
46
47    /**
48     * Moves to the next suggestion, if there is one.
49     *
50     * @return {@code false} if there is no next suggestion.
51     */
52    boolean moveToNext();
53
54    /**
55     * Gets the current position within the cursor.
56     */
57    int getPosition();
58
59    /**
60     * Frees any resources used by this cursor.
61     */
62    void close();
63
64    /**
65     * Register an observer that is called when changes happen to this data set.
66     *
67     * @param observer gets notified when the data set changes.
68     */
69    void registerDataSetObserver(DataSetObserver observer);
70
71    /**
72     * Unregister an observer that has previously been registered with
73     * {@link #registerDataSetObserver(DataSetObserver)}
74     *
75     * @param observer the observer to unregister.
76     */
77    void unregisterDataSetObserver(DataSetObserver observer);
78}
79