1 files changed, 65 insertions, 0 deletions
diff --git a/src/com/android/dialer/TransactionSafeActivity.java b/src/com/android/dialer/TransactionSafeActivity.java
new file mode 100644
index 000000000..81e50128d
--- /dev/null
+++ b/src/com/android/dialer/TransactionSafeActivity.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.dialer;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+
+/**
+ * A common superclass that keeps track of whether an {@link Activity} has saved its state yet or
+ * not.
+ */
+public abstract class TransactionSafeActivity extends AppCompatActivity {
+
+    private boolean mIsSafeToCommitTransactions;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        mIsSafeToCommitTransactions = true;
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        mIsSafeToCommitTransactions = true;
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        mIsSafeToCommitTransactions = true;
+    }
+
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        mIsSafeToCommitTransactions = false;
+    }
+
+    /**
+     * Returns true if it is safe to commit {@link FragmentTransaction}s at this time, based on
+     * whether {@link Activity#onSaveInstanceState} has been called or not.
+     *
+     * Make sure that the current activity calls into
+     * {@link super.onSaveInstanceState(Bundle outState)} (if that method is overridden),
+     * so the flag is properly set.
+     */
+    public boolean isSafeToCommitTransactions() {
+        return mIsSafeToCommitTransactions;
+    }
+}