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.incallui;
18
19import android.os.Bundle;
20import android.support.v4.app.FragmentActivity;
21
22/**
23 * A common superclass that keeps track of whether an {@link Activity} has saved its state yet or
24 * not.
25 */
26public abstract class TransactionSafeFragmentActivity extends FragmentActivity {
27
28  private boolean isSafeToCommitTransactions;
29
30  @Override
31  protected void onCreate(Bundle savedInstanceState) {
32    super.onCreate(savedInstanceState);
33    isSafeToCommitTransactions = true;
34  }
35
36  @Override
37  protected void onStart() {
38    super.onStart();
39    isSafeToCommitTransactions = true;
40  }
41
42  @Override
43  protected void onResume() {
44    super.onResume();
45    isSafeToCommitTransactions = true;
46  }
47
48  @Override
49  protected void onSaveInstanceState(Bundle outState) {
50    super.onSaveInstanceState(outState);
51    isSafeToCommitTransactions = false;
52  }
53
54  /**
55   * Returns true if it is safe to commit {@link FragmentTransaction}s at this time, based on
56   * whether {@link Activity#onSaveInstanceState} has been called or not.
57   *
58   * <p>Make sure that the current activity calls into {@link super.onSaveInstanceState(Bundle
59   * outState)} (if that method is overridden), so the flag is properly set.
60   */
61  public boolean isSafeToCommitTransactions() {
62    return isSafeToCommitTransactions;
63  }
64}
65