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 com.android.providers.contacts;
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}, but will only behave as such if the
26 * cursor it is wrapping is itself a {@link CrossProcessCursor} or another wrapper around the same.
27 */
28public class CrossProcessCursorWrapper extends CursorWrapper implements CrossProcessCursor {
29
30    // The cross process cursor.  Only non-null if the wrapped cursor was a cross-process cursor.
31    private final CrossProcessCursor mCrossProcessCursor;
32
33    public CrossProcessCursorWrapper(Cursor cursor) {
34        super(cursor);
35        mCrossProcessCursor = getCrossProcessCursor(cursor);
36    }
37
38    private CrossProcessCursor getCrossProcessCursor(Cursor cursor) {
39        if (cursor instanceof CrossProcessCursor) {
40            return (CrossProcessCursor) cursor;
41        } else if (cursor instanceof CursorWrapper) {
42            return getCrossProcessCursor(((CursorWrapper) cursor).getWrappedCursor());
43        } else {
44            return null;
45        }
46    }
47
48    @Override
49    public void fillWindow(int pos, CursorWindow window) {
50        if (mCrossProcessCursor != null) {
51            mCrossProcessCursor.fillWindow(pos, window);
52        } else {
53            throw new UnsupportedOperationException("Wrapped cursor is not a cross-process cursor");
54        }
55    }
56
57    @Override
58    public CursorWindow getWindow() {
59        if (mCrossProcessCursor != null) {
60            return mCrossProcessCursor.getWindow();
61        } else {
62            throw new UnsupportedOperationException("Wrapped cursor is not a cross-process cursor");
63        }
64    }
65
66    @Override
67    public boolean onMove(int oldPosition, int newPosition) {
68        if (mCrossProcessCursor != null) {
69            return mCrossProcessCursor.onMove(oldPosition, newPosition);
70        } else {
71            throw new UnsupportedOperationException("Wrapped cursor is not a cross-process cursor");
72        }
73    }
74
75}
76