1 files changed, 117 insertions, 0 deletions
diff --git a/java/com/android/dialer/phonelookup/emergency/EmergencyPhoneLookup.java b/java/com/android/dialer/phonelookup/emergency/EmergencyPhoneLookup.java
new file mode 100644
index 000000000..3f675d35f
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+++ b/java/com/android/dialer/phonelookup/emergency/EmergencyPhoneLookup.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2018 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.phonelookup.emergency;
+
+import android.content.Context;
+import com.android.dialer.DialerPhoneNumber;
+import com.android.dialer.common.concurrent.Annotations.BackgroundExecutor;
+import com.android.dialer.inject.ApplicationContext;
+import com.android.dialer.phonelookup.PhoneLookup;
+import com.android.dialer.phonelookup.PhoneLookupInfo;
+import com.android.dialer.phonelookup.PhoneLookupInfo.EmergencyInfo;
+import com.android.dialer.phonenumberutil.PhoneNumberHelper;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import javax.inject.Inject;
+
+/**
+ * PhoneLookup implementation for checking if a number is an emergency number.
+ *
+ * <p>The check has to be done in a PhoneLookup as it involves detecting the user's location and
+ * obtaining SIM info, which are expensive operations. Doing it in the main thread will make the UI
+ * super janky.
+ */
+public class EmergencyPhoneLookup implements PhoneLookup<EmergencyInfo> {
+
+  private final Context appContext;
+  private final ListeningExecutorService backgroundExecutorService;
+
+  @Inject
+  EmergencyPhoneLookup(
+      @ApplicationContext Context appContext,
+      @BackgroundExecutor ListeningExecutorService backgroundExecutorService) {
+    this.appContext = appContext;
+    this.backgroundExecutorService = backgroundExecutorService;
+  }
+
+  @Override
+  public ListenableFuture<EmergencyInfo> lookup(DialerPhoneNumber dialerPhoneNumber) {
+    return backgroundExecutorService.submit(
+        () ->
+            EmergencyInfo.newBuilder()
+                .setIsEmergencyNumber(
+                    PhoneNumberHelper.isLocalEmergencyNumber(
+                        appContext, dialerPhoneNumber.getNormalizedNumber()))
+                .build());
+  }
+
+  @Override
+  public ListenableFuture<Boolean> isDirty(ImmutableSet<DialerPhoneNumber> phoneNumbers) {
+    return Futures.immediateFuture(false);
+  }
+
+  @Override
+  public ListenableFuture<ImmutableMap<DialerPhoneNumber, EmergencyInfo>> getMostRecentInfo(
+      ImmutableMap<DialerPhoneNumber, EmergencyInfo> existingInfoMap) {
+    // We can update EmergencyInfo for all numbers in the provided map, but the negative impact on
+    // performance is intolerable as checking a single number involves detecting the user's location
+    // and obtaining SIM info, which will take more than 100ms (see
+    // android.telephony.PhoneNumberUtils#isLocalEmergencyNumber(Context, int, String) for details).
+    //
+    // As emergency numbers won't change in a country, the only case we will miss is that
+    //   (1) a number is an emergency number in country A but not in country B,
+    //   (2) a user has an emergency call entry when they are in country A, and
+    //   (3) they travel from A to B,
+    // which is a rare event.
+    //
+    // We can update the implementation if telecom supports batch check in the future.
+    return Futures.immediateFuture(existingInfoMap);
+  }
+
+  @Override
+  public void setSubMessage(PhoneLookupInfo.Builder destination, EmergencyInfo subMessage) {
+    destination.setEmergencyInfo(subMessage);
+  }
+
+  @Override
+  public EmergencyInfo getSubMessage(PhoneLookupInfo phoneLookupInfo) {
+    return phoneLookupInfo.getEmergencyInfo();
+  }
+
+  @Override
+  public ListenableFuture<Void> onSuccessfulBulkUpdate() {
+    return Futures.immediateFuture(null);
+  }
+
+  @Override
+  public void registerContentObservers() {
+    // No content observer to register.
+  }
+
+  @Override
+  public void unregisterContentObservers() {
+    // Nothing to be done as no content observer is registered.
+  }
+
+  @Override
+  public ListenableFuture<Void> clearData() {
+    return Futures.immediateFuture(null);
+  }
+}