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 com.android.camera.data;
18 
19 import android.content.ContentResolver;
20 import android.database.Cursor;
21 import android.net.Uri;
22 import android.provider.MediaStore;
23 
24 import com.android.camera.Storage;
25 import com.android.camera.debug.Log;
26 
27 import java.util.ArrayList;
28 import java.util.List;
29 
30 /**
31  * A set of queries for loading data from a content resolver.
32  */
33 public class FilmstripContentQueries {
34     private static final Log.Tag TAG = new Log.Tag("LocalDataQuery");
35 
36     public interface CursorToFilmstripItemFactory<I extends FilmstripItem> {
37 
38         /**
39          * Convert a cursor at a given location to a Local Data object.
40          *
41          * @param cursor the current cursor state.
42          * @return a LocalData object that represents the current cursor state.
43          */
get(Cursor cursor)44         public I get(Cursor cursor);
45     }
46 
47     /**
48      * Query the camera storage directory and convert it to local data
49      * objects.
50      *
51      * @param contentResolver to resolve content with.
52      * @param contentUri to resolve an item at
53      * @param projection the columns to extract
54      * @param minimumId the lower bound of results
55      * @param orderBy the order by clause
56      * @param factory an object that can turn a given cursor into a LocalData object.
57      * @return A list of LocalData objects that satisfy the query.
58      */
forCameraPath(ContentResolver contentResolver, Uri contentUri, String[] projection, long minimumId, String orderBy, CursorToFilmstripItemFactory<I> factory)59     public static <I extends FilmstripItem> List<I> forCameraPath(ContentResolver contentResolver,
60           Uri contentUri, String[] projection, long minimumId, String orderBy,
61           CursorToFilmstripItemFactory<I> factory) {
62         String selection = MediaStore.MediaColumns._ID + " > ?";
63         String[] selectionArgs = new String[] { Long.toString(minimumId) };
64 
65         Cursor cursor = contentResolver.query(contentUri, projection,
66               selection, selectionArgs, orderBy);
67         List<I> result = new ArrayList<>();
68         if (cursor != null) {
69             while (cursor.moveToNext()) {
70                 I item = factory.get(cursor);
71                 if (item != null) {
72                     result.add(item);
73                 } else {
74                     final int dataIndex = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
75                     Log.e(TAG, "Error loading data:" + cursor.getString(dataIndex));
76                 }
77             }
78 
79             cursor.close();
80         }
81         return result;
82     }
83 }
84