AttachmentLoader.java revision 7f375ff8e57165bf7ad7a50131eabeaf602f09bf 
1/*
2 * Copyright (C) 2012 Google Inc.
3 * Licensed to The Android Open Source Project.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 *      http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18package com.android.mail.browse;
19
20import com.google.common.collect.Maps;
21
22import android.content.Context;
23import android.content.CursorLoader;
24import android.database.Cursor;
25import android.database.CursorWrapper;
26import android.net.Uri;
27
28import com.android.mail.providers.Attachment;
29import com.android.mail.providers.UIProvider;
30
31import java.util.Map;
32
33public class AttachmentLoader extends CursorLoader {
34
35    public AttachmentLoader(Context c, Uri uri) {
36        super(c, uri, UIProvider.ATTACHMENT_PROJECTION, null, null, null);
37    }
38
39    @Override
40    public Cursor loadInBackground() {
41        return new AttachmentCursor(super.loadInBackground());
42    }
43
44    public static class AttachmentCursor extends CursorWrapper {
45
46        private Map<String, Attachment> mCache = Maps.newHashMap();
47
48        private AttachmentCursor(Cursor inner) {
49            super(inner);
50        }
51
52        public Attachment get() {
53            final String uri = getWrappedCursor().getString(UIProvider.ATTACHMENT_URI_COLUMN);
54            Attachment m = mCache.get(uri);
55            if (m == null) {
56                m = new Attachment(this);
57                mCache.put(uri, m);
58            }
59            return m;
60        }
61    }
62}
63