1/*
2* Copyright (C) 2012 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.contacts.common.database;
18
19import android.database.AbstractCursor;
20import android.database.CursorIndexOutOfBoundsException;
21
22/**
23 * A cursor that is empty.
24 * <p>
25 * If you want an empty cursor, this class is better than a MatrixCursor because it has less
26 * overhead.
27 */
28final public class EmptyCursor extends AbstractCursor {
29
30    private String[] mColumns;
31
32    public EmptyCursor(String[] columns) {
33        this.mColumns = columns;
34    }
35
36    @Override
37    public int getCount() {
38        return 0;
39    }
40
41    @Override
42    public String[] getColumnNames() {
43        return mColumns;
44    }
45
46    @Override
47    public String getString(int column) {
48        throw cursorException();
49    }
50
51    @Override
52    public short getShort(int column) {
53        throw cursorException();
54    }
55
56    @Override
57    public int getInt(int column) {
58        throw cursorException();
59    }
60
61    @Override
62    public long getLong(int column) {
63        throw cursorException();
64    }
65
66    @Override
67    public float getFloat(int column) {
68        throw cursorException();
69    }
70
71    @Override
72    public double getDouble(int column) {
73        throw cursorException();
74    }
75
76    @Override
77    public boolean isNull(int column) {
78        throw cursorException();
79    }
80
81    private CursorIndexOutOfBoundsException cursorException() {
82        return new CursorIndexOutOfBoundsException("Operation not permitted on an empty cursor.");
83    }
84}
85