Show pop-up banner when Location is off and user tries to enable GeoTZ.

As of now GeoTZ state remains unchanged even if user enables
Location toggle.

Bug: 152746236
Test: m -j30 RunSettingsRoboTests ROBOTEST_FILTER="com.android.settings.datetime.LocationTimeZoneDetectionPreferenceControllerTest"
Test: checked manually that dialog opens Location settings page
Change-Id: I5fd3288e9d5a7aac3bc82da6944b4ccd6bb9e0f5

src/com/android/settings/datetime/DateTimeSettings.java

@@ -59,6 +59,7 @@ public class DateTimeSettings extends DashboardFragment implements
     public void onAttach(Context context) {
         super.onAttach(context);
         getSettingsLifecycle().addObserver(new TimeChangeListenerMixin(context, this));
+        use(LocationTimeZoneDetectionPreferenceController.class).setFragment(this);
     }
 
     @Override
@@ -77,6 +78,7 @@ public class DateTimeSettings extends DashboardFragment implements
         final AutoTimeFormatPreferenceController autoTimeFormatPreferenceController =
                 new AutoTimeFormatPreferenceController(
                         activity, this /* UpdateTimeAndDateCallback */);
+
         controllers.add(autoTimeZonePreferenceController);
         controllers.add(autoTimePreferenceController);
         controllers.add(autoTimeFormatPreferenceController);

src/com/android/settings/datetime/LocationTimeZoneDetectionPreferenceController.java

@@ -31,6 +31,7 @@ import androidx.preference.Preference;
 import androidx.preference.PreferenceScreen;
 
 import com.android.settings.R;
+import com.android.settings.core.InstrumentedPreferenceFragment;
 import com.android.settings.core.TogglePreferenceController;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
 import com.android.settingslib.core.lifecycle.events.OnStart;
@@ -46,17 +47,24 @@ public class LocationTimeZoneDetectionPreferenceController
         extends TogglePreferenceController
         implements LifecycleObserver, OnStart, OnStop, TimeManager.TimeZoneDetectorListener {
 
+    private static final String TAG = "location_time_zone_detection";
+
     private final TimeManager mTimeManager;
     private final LocationManager mLocationManager;
     private TimeZoneCapabilitiesAndConfig mTimeZoneCapabilitiesAndConfig;
+    private InstrumentedPreferenceFragment mFragment;
     private Preference mPreference;
 
-    public LocationTimeZoneDetectionPreferenceController(Context context, String key) {
-        super(context, key);
+    public LocationTimeZoneDetectionPreferenceController(Context context) {
+        super(context, TAG);
         mTimeManager = context.getSystemService(TimeManager.class);
         mLocationManager = context.getSystemService(LocationManager.class);
     }
 
+    void setFragment(InstrumentedPreferenceFragment fragment) {
+        mFragment = fragment;
+    }
+
     @Override
     public boolean isChecked() {
         TimeZoneCapabilitiesAndConfig capabilitiesAndConfig =
@@ -67,10 +75,17 @@ public class LocationTimeZoneDetectionPreferenceController
 
     @Override
     public boolean setChecked(boolean isChecked) {
-        TimeZoneConfiguration configuration = new TimeZoneConfiguration.Builder()
-                .setGeoDetectionEnabled(isChecked)
-                .build();
-        return mTimeManager.updateTimeZoneConfiguration(configuration);
+        if (isChecked && !mLocationManager.isLocationEnabled()) {
+            new LocationToggleDisabledDialogFragment(mContext)
+                    .show(mFragment.getFragmentManager(), TAG);
+            // Toggle status is not updated.
+            return false;
+        } else {
+            TimeZoneConfiguration configuration = new TimeZoneConfiguration.Builder()
+                    .setGeoDetectionEnabled(isChecked)
+                    .build();
+            return mTimeManager.updateTimeZoneConfiguration(configuration);
+        }
     }
 
     @Override

src/com/android/settings/datetime/LocationToggleDisabledDialogFragment.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2021 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.settings.datetime;
+
+import android.app.AlertDialog;
+import android.app.Dialog;
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.provider.Settings;
+
+import com.android.settings.R;
+import com.android.settings.core.instrumentation.InstrumentedDialogFragment;
+
+/**
+ * Dialog shown when user tries to enable GeoTZ with Location toggle disabled.
+ */
+public class LocationToggleDisabledDialogFragment extends InstrumentedDialogFragment {
+
+    private final Context mContext;
+
+    public LocationToggleDisabledDialogFragment(Context context) {
+        mContext = context;
+    }
+
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+        return new AlertDialog.Builder(getActivity())
+                .setTitle(R.string.location_time_zone_detection_location_is_off_dialog_title)
+                .setIcon(R.drawable.ic_warning_24dp)
+                .setMessage(R.string.location_time_zone_detection_location_is_off_dialog_message)
+                .setPositiveButton(
+                        R.string.location_time_zone_detection_location_is_off_dialog_ok_button,
+                        (dialog, which) -> {
+                            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
+                            mContext.startActivity(intent);
+                        })
+                .setNegativeButton(
+                        R.string.location_time_zone_detection_location_is_off_dialog_cancel_button,
+                        (dialog, which) -> {})
+                .create();
+    }
+
+    @Override
+    public int getMetricsCategory() {
+        return SettingsEnums.DIALOG_DATE_TIME_ENABLE_GEOTZ_WITH_DISABLED_LOCATION;
+    }
+}