1/*
2 * Copyright (C) 2011 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 android.database;
18
19import android.database.CrossProcessCursor;
20import android.database.Cursor;
21import android.database.CursorWindow;
22import android.database.CursorWrapper;
23
24/**
25 * Cursor wrapper that implements {@link CrossProcessCursor}.
26 * <p>
27 * If the wrapped cursor implements {@link CrossProcessCursor}, then the wrapper
28 * delegates {@link #fillWindow}, {@link #getWindow()} and {@link #onMove} to it.
29 * Otherwise, the wrapper provides default implementations of these methods that
30 * traverse the contents of the cursor similar to {@link AbstractCursor#fillWindow}.
31 * </p><p>
32 * This wrapper can be used to adapt an ordinary {@link Cursor} into a
33 * {@link CrossProcessCursor}.
34 * </p>
35 */
36public class CrossProcessCursorWrapper extends CursorWrapper implements CrossProcessCursor {
37    /**
38     * Creates a cross process cursor wrapper.
39     * @param cursor The underlying cursor to wrap.
40     */
41    public CrossProcessCursorWrapper(Cursor cursor) {
42        super(cursor);
43    }
44
45    @Override
46    public void fillWindow(int position, CursorWindow window) {
47        if (mCursor instanceof CrossProcessCursor) {
48            final CrossProcessCursor crossProcessCursor = (CrossProcessCursor)mCursor;
49            crossProcessCursor.fillWindow(position, window);
50            return;
51        }
52
53        DatabaseUtils.cursorFillWindow(mCursor, position, window);
54    }
55
56    @Override
57    public CursorWindow getWindow() {
58        if (mCursor instanceof CrossProcessCursor) {
59            final CrossProcessCursor crossProcessCursor = (CrossProcessCursor)mCursor;
60            return crossProcessCursor.getWindow();
61        }
62
63        return null;
64    }
65
66    @Override
67    public boolean onMove(int oldPosition, int newPosition) {
68        if (mCursor instanceof CrossProcessCursor) {
69            final CrossProcessCursor crossProcessCursor = (CrossProcessCursor)mCursor;
70            return crossProcessCursor.onMove(oldPosition, newPosition);
71        }
72
73        return true;
74    }
75}
76