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 17 package com.android.contacts.common.activity; 18 19 import android.app.Activity; 20 import android.os.Bundle; 21 22 /** 23 * A common superclass that keeps track of whether an {@link Activity} has saved its state yet or 24 * not. 25 */ 26 public abstract class TransactionSafeActivity extends Activity { 27 28 private boolean mIsSafeToCommitTransactions; 29 30 @Override 31 protected void onCreate(Bundle savedInstanceState) { 32 super.onCreate(savedInstanceState); 33 mIsSafeToCommitTransactions = true; 34 } 35 36 @Override 37 protected void onStart() { 38 super.onStart(); 39 mIsSafeToCommitTransactions = true; 40 } 41 42 @Override 43 protected void onResume() { 44 super.onResume(); 45 mIsSafeToCommitTransactions = true; 46 } 47 48 @Override 49 protected void onSaveInstanceState(Bundle outState) { 50 super.onSaveInstanceState(outState); 51 mIsSafeToCommitTransactions = 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 * Make sure that the current activity calls into 59 * {@link super.onSaveInstanceState(Bundle outState)} (if that method is overridden), 60 * so the flag is properly set. 61 */ 62 public boolean isSafeToCommitTransactions() { 63 return mIsSafeToCommitTransactions; 64 } 65 } 66
