src/com/android/deskclock/ClockFragment.java - LeafOS-Project/android_packages_apps_DeskClock - Gitiles

 /*
  * Copyright (C) 2012 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.deskclock;

 import static android.app.AlarmManager.ACTION_NEXT_ALARM_CLOCK_CHANGED;
 import static android.view.View.GONE;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static com.android.deskclock.uidata.UiDataModel.Tab.CLOCKS;
 import static java.util.Calendar.DAY_OF_WEEK;

 import android.app.Activity;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.Bundle;
 import android.text.format.DateUtils;
 import android.view.GestureDetector;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.TextClock;
 import android.widget.TextView;

 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;

 import com.android.deskclock.data.City;
 import com.android.deskclock.data.CityListener;
 import com.android.deskclock.data.DataModel;
 import com.android.deskclock.events.Events;
 import com.android.deskclock.uidata.UiDataModel;
 import com.android.deskclock.worldclock.CitySelectionActivity;

 import java.util.Calendar;
 import java.util.List;
 import java.util.TimeZone;

 /**
  * Fragment that shows the clock (analog or digital), the next alarm info and the world clock.
  */
 public final class ClockFragment extends DeskClockFragment {

     // Updates dates in the UI on every quarter-hour.
     private final Runnable mQuarterHourUpdater = new QuarterHourRunnable();

     // Updates the UI in response to changes to the scheduled alarm.
     private BroadcastReceiver mAlarmChangeReceiver;

     private TextClock mDigitalClock;
     private AnalogClock mAnalogClock;
     private View mClockFrame;
     private SelectedCitiesAdapter mCityAdapter;
     private RecyclerView mCityList;
     private String mDateFormat;
     private String mDateFormatForAccessibility;

     /**
      * The public no-arg constructor required by all fragments.
      */
     public ClockFragment() {
         super(CLOCKS);
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         mAlarmChangeReceiver = new AlarmChangedBroadcastReceiver();
     }

     @Override
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle icicle) {
         super.onCreateView(inflater, container, icicle);

         final View fragmentView = inflater.inflate(R.layout.clock_fragment, container, false);

         mDateFormat = getString(R.string.abbrev_wday_month_day_no_year);
         mDateFormatForAccessibility = getString(R.string.full_wday_month_day_no_year);

         mCityAdapter = new SelectedCitiesAdapter(getActivity(), mDateFormat,
                 mDateFormatForAccessibility);

         mCityList = fragmentView.findViewById(R.id.cities);
         mCityList.setLayoutManager(new LinearLayoutManager(getActivity()));
         mCityList.setAdapter(mCityAdapter);
         mCityList.setItemAnimator(null);
         DataModel.getDataModel().addCityListener(mCityAdapter);

         final ScrollPositionWatcher scrollPositionWatcher = new ScrollPositionWatcher();
         mCityList.addOnScrollListener(scrollPositionWatcher);

         final Context context = container.getContext();
         mCityList.setOnTouchListener(new CityListOnLongClickListener(context));
         fragmentView.setOnLongClickListener(new StartScreenSaverListener());

         // On tablet landscape, the clock frame will be a distinct view. Otherwise, it'll be added
         // on as a header to the main listview.
         mClockFrame = fragmentView.findViewById(R.id.main_clock_left_pane);
         if (mClockFrame != null) {
             mDigitalClock = mClockFrame.findViewById(R.id.digital_clock);
             mAnalogClock = mClockFrame.findViewById(R.id.analog_clock);
             Utils.setClockIconTypeface(mClockFrame);
             Utils.updateDate(mDateFormat, mDateFormatForAccessibility, mClockFrame);
             Utils.setClockStyle(mDigitalClock, mAnalogClock);
             Utils.setClockSecondsEnabled(mDigitalClock, mAnalogClock);
             Utils.updateDateGravity(mClockFrame);
         }

         // Schedule a runnable to update the date every quarter hour.
         UiDataModel.getUiDataModel().addQuarterHourCallback(mQuarterHourUpdater);

         return fragmentView;
     }

     @Override
     public void onResume() {
         super.onResume();

         final Activity activity = getActivity();

         mDateFormat = getString(R.string.abbrev_wday_month_day_no_year);
         mDateFormatForAccessibility = getString(R.string.full_wday_month_day_no_year);

         // Watch for system events that effect clock time or format.
         if (activity != null && mAlarmChangeReceiver != null) {
             final IntentFilter filter = new IntentFilter(ACTION_NEXT_ALARM_CLOCK_CHANGED);
             activity.registerReceiver(mAlarmChangeReceiver, filter, Context.RECEIVER_NOT_EXPORTED);
         }

         // Resume can be invoked after changing the clock style or seconds display.
         if (mDigitalClock != null && mAnalogClock != null) {
             Utils.setClockStyle(mDigitalClock, mAnalogClock);
             Utils.setClockSecondsEnabled(mDigitalClock, mAnalogClock);
             Utils.updateDateGravity(mClockFrame);
         }

         final View view = getView();
         if (view != null && view.findViewById(R.id.main_clock_left_pane) != null) {
             // Center the main clock frame by hiding the world clocks when none are selected.
             mCityList.setVisibility(mCityAdapter.getItemCount() == 0 ? GONE : VISIBLE);
         }
         // force refresh so clock style changes apply immediately
         mCityAdapter.citiesChanged();

         refreshAlarm();
     }

     @Override
     public void onPause() {
         super.onPause();

         final Activity activity = getActivity();
         if (activity != null && mAlarmChangeReceiver != null) {
             activity.unregisterReceiver(mAlarmChangeReceiver);
         }
     }

     @Override
     public void onDestroyView() {
         super.onDestroyView();
         UiDataModel.getUiDataModel().removePeriodicCallback(mQuarterHourUpdater);
         DataModel.getDataModel().removeCityListener(mCityAdapter);
     }

     @Override
     public void onFabClick(@NonNull ImageView fab) {
         startActivity(new Intent(getActivity(), CitySelectionActivity.class));
     }

     @Override
     public void onUpdateFab(@NonNull ImageView fab) {
         fab.setVisibility(VISIBLE);
         fab.setImageResource(R.drawable.ic_public);
         fab.setContentDescription(fab.getResources().getString(R.string.button_cities));
     }

     @Override
     public void onUpdateFabButtons(@NonNull ImageView left, @NonNull ImageView right) {
         left.setVisibility(INVISIBLE);
         right.setVisibility(INVISIBLE);
     }

     @Override
     public int getFabTargetVisibility() {
         return View.VISIBLE;
     }

     /**
      * Refresh the next alarm time.
      */
     private void refreshAlarm() {
         if (mClockFrame != null) {
             Utils.refreshAlarm(getActivity(), mClockFrame);
         } else {
             mCityAdapter.refreshAlarm();
         }
     }

     /**
      * Long pressing over the main clock starts the screen saver.
      */
     private final class StartScreenSaverListener implements View.OnLongClickListener {

         @Override
         public boolean onLongClick(View view) {
             startActivity(new Intent(getActivity(), ScreensaverActivity.class)
                     .setFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
                     .putExtra(Events.EXTRA_EVENT_LABEL, R.string.label_deskclock));
             return true;
         }
     }

     /**
      * Long pressing over the city list starts the screen saver.
      */
     private final class CityListOnLongClickListener extends GestureDetector.SimpleOnGestureListener
             implements View.OnTouchListener {

         private final GestureDetector mGestureDetector;

         private CityListOnLongClickListener(Context context) {
             mGestureDetector = new GestureDetector(context, this);
         }

         @Override
         public void onLongPress(MotionEvent e) {
             final View view = getView();
             if (view != null) {
                 view.performLongClick();
             }
         }

         @Override
         public boolean onDown(MotionEvent e) {
             return true;
         }

         @Override
         public boolean onTouch(View v, MotionEvent event) {
             return mGestureDetector.onTouchEvent(event);
         }
     }

     /**
      * This runnable executes at every quarter-hour (e.g. 1:00, 1:15, 1:30, 1:45, etc...) and
      * updates the dates displayed within the UI. Quarter-hour increments were chosen to accommodate
      * the "weirdest" timezones (e.g. Nepal is UTC/GMT +05:45).
      */
     private final class QuarterHourRunnable implements Runnable {
         @Override
         public void run() {
             mCityAdapter.notifyDataSetChanged();
         }
     }

     /**
      * Update the display of the scheduled alarm as it changes.
      */
     private final class AlarmChangedBroadcastReceiver extends BroadcastReceiver {
         @Override
         public void onReceive(Context context, Intent intent) {
             refreshAlarm();
         }
     }

     /**
      * Updates the vertical scroll state of this tab in the {@link UiDataModel} as the user scrolls
      * the recyclerview or when the size/position of elements within the recyclerview changes.
      */
     private final class ScrollPositionWatcher extends RecyclerView.OnScrollListener
             implements View.OnLayoutChangeListener {
         @Override
         public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
             setTabScrolledToTop(Utils.isScrolledToTop(mCityList));
         }

         @Override
         public void onLayoutChange(View v, int left, int top, int right, int bottom,
                 int oldLeft, int oldTop, int oldRight, int oldBottom) {
             setTabScrolledToTop(Utils.isScrolledToTop(mCityList));
         }
     }

     /**
      * This adapter lists all of the selected world clocks. Optionally, it also includes a clock at
      * the top for the home timezone if "Automatic home clock" is turned on in settings and the
      * current time at home does not match the current time in the timezone of the current location.
      * If the phone is in portrait mode it will also include the main clock at the top.
      */
     private static final class SelectedCitiesAdapter extends RecyclerView.Adapter
             implements CityListener {

         private final static int MAIN_CLOCK = R.layout.main_clock_frame;
         private final static int WORLD_CLOCK = R.layout.world_clock_item;

         private final LayoutInflater mInflater;
         private final Context mContext;
         private final boolean mIsPortrait;
         private final boolean mShowHomeClock;
         private final String mDateFormat;
         private final String mDateFormatForAccessibility;

         private SelectedCitiesAdapter(Context context, String dateFormat,
                 String dateFormatForAccessibility) {
             mContext = context;
             mDateFormat = dateFormat;
             mDateFormatForAccessibility = dateFormatForAccessibility;
             mInflater = LayoutInflater.from(context);
             mIsPortrait = Utils.isPortrait(context);
             mShowHomeClock = DataModel.getDataModel().getShowHomeClock();
         }

         @Override
         public int getItemViewType(int position) {
             if (position == 0 && mIsPortrait) {
                 return MAIN_CLOCK;
             }
             return WORLD_CLOCK;
         }

         @NonNull
         @Override
         public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
             final View view = mInflater.inflate(viewType, parent, false);
             switch (viewType) {
                 case WORLD_CLOCK:
                     return new CityViewHolder(view);
                 case MAIN_CLOCK:
                     return new MainClockViewHolder(view);
                 default:
                     throw new IllegalArgumentException("View type not recognized");
             }
         }

         @Override
         public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
             final int viewType = getItemViewType(position);
             switch (viewType) {
                 case WORLD_CLOCK:
                     // Retrieve the city to bind.
                     final City city;
                     // If showing home clock, put it at the top
                     if (mShowHomeClock && position == (mIsPortrait ? 1 : 0)) {
                         city = getHomeCity();
                     } else {
                         final int positionAdjuster = (mIsPortrait ? 1 : 0)
                                 + (mShowHomeClock ? 1 : 0);
                         city = getCities().get(position - positionAdjuster);
                     }
                     ((CityViewHolder) holder).bind(mContext, city);
                     break;
                 case MAIN_CLOCK:
                     ((MainClockViewHolder) holder).bind(mContext, mDateFormat,
                             mDateFormatForAccessibility);
                     break;
                 default:
                     throw new IllegalArgumentException("Unexpected view type: " + viewType);
             }
         }

         @Override
         public int getItemCount() {
             final int mainClockCount = mIsPortrait ? 1 : 0;
             final int homeClockCount = mShowHomeClock ? 1 : 0;
             final int worldClockCount = getCities().size();
             return mainClockCount + homeClockCount + worldClockCount;
         }

         private City getHomeCity() {
             return DataModel.getDataModel().getHomeCity();
         }

         private List<City> getCities() {
             return DataModel.getDataModel().getSelectedCities();
         }

         private void refreshAlarm() {
             if (mIsPortrait && getItemCount() > 0) {
                 notifyItemChanged(0);
             }
         }

         @Override
         public void citiesChanged() {
             notifyDataSetChanged();
         }

         private static final class CityViewHolder extends RecyclerView.ViewHolder {

             private final TextView mName;
             private final TextClock mDigitalClock;
             private final AnalogClock mAnalogClock;
             private final TextView mHoursAhead;

             private CityViewHolder(View itemView) {
                 super(itemView);

                 mName = itemView.findViewById(R.id.city_name);
                 mDigitalClock = itemView.findViewById(R.id.digital_clock);
                 mAnalogClock = itemView.findViewById(R.id.analog_clock);
                 mHoursAhead = itemView.findViewById(R.id.hours_ahead);
             }

             private void bind(Context context, City city) {
                 final String cityTimeZoneId = city.getTimeZone().getID();

                 // Configure the digital clock or analog clock depending on the user preference.
                 if (DataModel.getDataModel().getClockStyle() == DataModel.ClockStyle.ANALOG) {
                     mDigitalClock.setVisibility(GONE);
                     mAnalogClock.setVisibility(VISIBLE);
                     mAnalogClock.setTimeZone(cityTimeZoneId);
                     mAnalogClock.enableSeconds(false);
                 } else {
                     mAnalogClock.setVisibility(GONE);
                     mDigitalClock.setVisibility(VISIBLE);
                     mDigitalClock.setTimeZone(cityTimeZoneId);
                     mDigitalClock.setFormat12Hour(Utils.get12ModeFormat(0.3f /* amPmRatio */,
                             false));
                     mDigitalClock.setFormat24Hour(Utils.get24ModeFormat(false));
                 }

                 // Bind the city name.
                 mName.setText(city.getName());

                 // Compute if the city week day matches the weekday of the current timezone.
                 final Calendar localCal = Calendar.getInstance(TimeZone.getDefault());
                 final Calendar cityCal = Calendar.getInstance(city.getTimeZone());
                 final boolean displayDayOfWeek =
                         localCal.get(DAY_OF_WEEK) != cityCal.get(DAY_OF_WEEK);

                 // Compare offset from UTC time on today's date (daylight savings time, etc.)
                 final TimeZone currentTimeZone = TimeZone.getDefault();
                 final TimeZone cityTimeZone = TimeZone.getTimeZone(cityTimeZoneId);
                 final long currentTimeMillis = System.currentTimeMillis();
                 final long currentUtcOffset = currentTimeZone.getOffset(currentTimeMillis);
                 final long cityUtcOffset = cityTimeZone.getOffset(currentTimeMillis);
                 final long offsetDelta = cityUtcOffset - currentUtcOffset;

                 final int hoursDifferent = (int) (offsetDelta / DateUtils.HOUR_IN_MILLIS);
                 final int minutesDifferent = (int) (offsetDelta / DateUtils.MINUTE_IN_MILLIS) % 60;
                 final boolean displayMinutes = offsetDelta % DateUtils.HOUR_IN_MILLIS != 0;
                 final boolean isAhead = hoursDifferent > 0 || (hoursDifferent == 0
                         && minutesDifferent > 0);
                 // Bind the number of hours ahead or behind, or hide if the time is the same.
                 final boolean displayDifference = hoursDifferent != 0 || displayMinutes;
                 mHoursAhead.setVisibility(displayDifference ? VISIBLE : GONE);
                 final String timeString = Utils.createHoursDifferentString(
                         context, displayMinutes, isAhead, hoursDifferent, minutesDifferent);
                 mHoursAhead.setText(displayDayOfWeek ?
                         (context.getString(isAhead ? R.string.world_hours_tomorrow
                                 : R.string.world_hours_yesterday, timeString))
                         : timeString);
             }
         }

         private static final class MainClockViewHolder extends RecyclerView.ViewHolder {

             private final TextClock mDigitalClock;
             private final AnalogClock mAnalogClock;

             private MainClockViewHolder(View itemView) {
                 super(itemView);

                 mDigitalClock = itemView.findViewById(R.id.digital_clock);
                 mAnalogClock = itemView.findViewById(R.id.analog_clock);
                 Utils.setClockIconTypeface(itemView);
             }

             private void bind(Context context, String dateFormat,
                               String dateFormatForAccessibility) {
                 Utils.refreshAlarm(context, itemView);

                 Utils.updateDate(dateFormat, dateFormatForAccessibility, itemView);
                 Utils.setClockStyle(mDigitalClock, mAnalogClock);
                 Utils.setClockSecondsEnabled(mDigitalClock, mAnalogClock);
                 Utils.updateDateGravity(itemView);
             }
         }
     }
 }
	/*
	* Copyright (C) 2012 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.deskclock;

	import static android.app.AlarmManager.ACTION_NEXT_ALARM_CLOCK_CHANGED;
	import static android.view.View.GONE;
	import static android.view.View.INVISIBLE;
	import static android.view.View.VISIBLE;
	import static com.android.deskclock.uidata.UiDataModel.Tab.CLOCKS;
	import static java.util.Calendar.DAY_OF_WEEK;

	import android.app.Activity;
	import android.content.BroadcastReceiver;
	import android.content.Context;
	import android.content.Intent;
	import android.content.IntentFilter;
	import android.os.Bundle;
	import android.text.format.DateUtils;
	import android.view.GestureDetector;
	import android.view.LayoutInflater;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.ImageView;
	import android.widget.TextClock;
	import android.widget.TextView;

	import androidx.annotation.NonNull;
	import androidx.recyclerview.widget.LinearLayoutManager;
	import androidx.recyclerview.widget.RecyclerView;

	import com.android.deskclock.data.City;
	import com.android.deskclock.data.CityListener;
	import com.android.deskclock.data.DataModel;
	import com.android.deskclock.events.Events;
	import com.android.deskclock.uidata.UiDataModel;
	import com.android.deskclock.worldclock.CitySelectionActivity;

	import java.util.Calendar;
	import java.util.List;
	import java.util.TimeZone;

	/**
	* Fragment that shows the clock (analog or digital), the next alarm info and the world clock.
	*/
	public final class ClockFragment extends DeskClockFragment {

	// Updates dates in the UI on every quarter-hour.
	private final Runnable mQuarterHourUpdater = new QuarterHourRunnable();

	// Updates the UI in response to changes to the scheduled alarm.
	private BroadcastReceiver mAlarmChangeReceiver;

	private TextClock mDigitalClock;
	private AnalogClock mAnalogClock;
	private View mClockFrame;
	private SelectedCitiesAdapter mCityAdapter;
	private RecyclerView mCityList;
	private String mDateFormat;
	private String mDateFormatForAccessibility;

	/**
	* The public no-arg constructor required by all fragments.
	*/
	public ClockFragment() {
	super(CLOCKS);
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);

	mAlarmChangeReceiver = new AlarmChangedBroadcastReceiver();
	}

	@Override
	public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle icicle) {
	super.onCreateView(inflater, container, icicle);

	final View fragmentView = inflater.inflate(R.layout.clock_fragment, container, false);

	mDateFormat = getString(R.string.abbrev_wday_month_day_no_year);
	mDateFormatForAccessibility = getString(R.string.full_wday_month_day_no_year);

	mCityAdapter = new SelectedCitiesAdapter(getActivity(), mDateFormat,
	mDateFormatForAccessibility);

	mCityList = fragmentView.findViewById(R.id.cities);
	mCityList.setLayoutManager(new LinearLayoutManager(getActivity()));
	mCityList.setAdapter(mCityAdapter);
	mCityList.setItemAnimator(null);
	DataModel.getDataModel().addCityListener(mCityAdapter);

	final ScrollPositionWatcher scrollPositionWatcher = new ScrollPositionWatcher();
	mCityList.addOnScrollListener(scrollPositionWatcher);

	final Context context = container.getContext();
	mCityList.setOnTouchListener(new CityListOnLongClickListener(context));
	fragmentView.setOnLongClickListener(new StartScreenSaverListener());

	// On tablet landscape, the clock frame will be a distinct view. Otherwise, it'll be added
	// on as a header to the main listview.
	mClockFrame = fragmentView.findViewById(R.id.main_clock_left_pane);
	if (mClockFrame != null) {
	mDigitalClock = mClockFrame.findViewById(R.id.digital_clock);
	mAnalogClock = mClockFrame.findViewById(R.id.analog_clock);
	Utils.setClockIconTypeface(mClockFrame);
	Utils.updateDate(mDateFormat, mDateFormatForAccessibility, mClockFrame);
	Utils.setClockStyle(mDigitalClock, mAnalogClock);
	Utils.setClockSecondsEnabled(mDigitalClock, mAnalogClock);
	Utils.updateDateGravity(mClockFrame);
	}

	// Schedule a runnable to update the date every quarter hour.
	UiDataModel.getUiDataModel().addQuarterHourCallback(mQuarterHourUpdater);

	return fragmentView;
	}

	@Override
	public void onResume() {
	super.onResume();

	final Activity activity = getActivity();

	mDateFormat = getString(R.string.abbrev_wday_month_day_no_year);
	mDateFormatForAccessibility = getString(R.string.full_wday_month_day_no_year);

	// Watch for system events that effect clock time or format.
	if (activity != null && mAlarmChangeReceiver != null) {
	final IntentFilter filter = new IntentFilter(ACTION_NEXT_ALARM_CLOCK_CHANGED);
	activity.registerReceiver(mAlarmChangeReceiver, filter, Context.RECEIVER_NOT_EXPORTED);
	}

	// Resume can be invoked after changing the clock style or seconds display.
	if (mDigitalClock != null && mAnalogClock != null) {
	Utils.setClockStyle(mDigitalClock, mAnalogClock);
	Utils.setClockSecondsEnabled(mDigitalClock, mAnalogClock);
	Utils.updateDateGravity(mClockFrame);
	}

	final View view = getView();
	if (view != null && view.findViewById(R.id.main_clock_left_pane) != null) {
	// Center the main clock frame by hiding the world clocks when none are selected.
	mCityList.setVisibility(mCityAdapter.getItemCount() == 0 ? GONE : VISIBLE);
	}
	// force refresh so clock style changes apply immediately
	mCityAdapter.citiesChanged();

	refreshAlarm();
	}

	@Override
	public void onPause() {
	super.onPause();

	final Activity activity = getActivity();
	if (activity != null && mAlarmChangeReceiver != null) {
	activity.unregisterReceiver(mAlarmChangeReceiver);
	}
	}

	@Override
	public void onDestroyView() {
	super.onDestroyView();
	UiDataModel.getUiDataModel().removePeriodicCallback(mQuarterHourUpdater);
	DataModel.getDataModel().removeCityListener(mCityAdapter);
	}

	@Override
	public void onFabClick(@NonNull ImageView fab) {
	startActivity(new Intent(getActivity(), CitySelectionActivity.class));
	}

	@Override
	public void onUpdateFab(@NonNull ImageView fab) {
	fab.setVisibility(VISIBLE);
	fab.setImageResource(R.drawable.ic_public);
	fab.setContentDescription(fab.getResources().getString(R.string.button_cities));
	}

	@Override
	public void onUpdateFabButtons(@NonNull ImageView left, @NonNull ImageView right) {
	left.setVisibility(INVISIBLE);
	right.setVisibility(INVISIBLE);
	}

	@Override
	public int getFabTargetVisibility() {
	return View.VISIBLE;
	}

	/**
	* Refresh the next alarm time.
	*/
	private void refreshAlarm() {
	if (mClockFrame != null) {
	Utils.refreshAlarm(getActivity(), mClockFrame);
	} else {
	mCityAdapter.refreshAlarm();
	}
	}

	/**
	* Long pressing over the main clock starts the screen saver.
	*/
	private final class StartScreenSaverListener implements View.OnLongClickListener {

	@Override
	public boolean onLongClick(View view) {
	startActivity(new Intent(getActivity(), ScreensaverActivity.class)
	.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
	.putExtra(Events.EXTRA_EVENT_LABEL, R.string.label_deskclock));
	return true;
	}
	}

	/**
	* Long pressing over the city list starts the screen saver.
	*/
	private final class CityListOnLongClickListener extends GestureDetector.SimpleOnGestureListener
	implements View.OnTouchListener {

	private final GestureDetector mGestureDetector;

	private CityListOnLongClickListener(Context context) {
	mGestureDetector = new GestureDetector(context, this);
	}

	@Override
	public void onLongPress(MotionEvent e) {
	final View view = getView();
	if (view != null) {
	view.performLongClick();
	}
	}

	@Override
	public boolean onDown(MotionEvent e) {
	return true;
	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
	return mGestureDetector.onTouchEvent(event);
	}
	}

	/**
	* This runnable executes at every quarter-hour (e.g. 1:00, 1:15, 1:30, 1:45, etc...) and
	* updates the dates displayed within the UI. Quarter-hour increments were chosen to accommodate
	* the "weirdest" timezones (e.g. Nepal is UTC/GMT +05:45).
	*/
	private final class QuarterHourRunnable implements Runnable {
	@Override
	public void run() {
	mCityAdapter.notifyDataSetChanged();
	}
	}

	/**
	* Update the display of the scheduled alarm as it changes.
	*/
	private final class AlarmChangedBroadcastReceiver extends BroadcastReceiver {
	@Override
	public void onReceive(Context context, Intent intent) {
	refreshAlarm();
	}
	}

	/**
	* Updates the vertical scroll state of this tab in the {@link UiDataModel} as the user scrolls
	* the recyclerview or when the size/position of elements within the recyclerview changes.
	*/
	private final class ScrollPositionWatcher extends RecyclerView.OnScrollListener
	implements View.OnLayoutChangeListener {
	@Override
	public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
	setTabScrolledToTop(Utils.isScrolledToTop(mCityList));
	}

	@Override
	public void onLayoutChange(View v, int left, int top, int right, int bottom,
	int oldLeft, int oldTop, int oldRight, int oldBottom) {
	setTabScrolledToTop(Utils.isScrolledToTop(mCityList));
	}
	}

	/**
	* This adapter lists all of the selected world clocks. Optionally, it also includes a clock at
	* the top for the home timezone if "Automatic home clock" is turned on in settings and the
	* current time at home does not match the current time in the timezone of the current location.
	* If the phone is in portrait mode it will also include the main clock at the top.
	*/
	private static final class SelectedCitiesAdapter extends RecyclerView.Adapter
	implements CityListener {

	private final static int MAIN_CLOCK = R.layout.main_clock_frame;
	private final static int WORLD_CLOCK = R.layout.world_clock_item;

	private final LayoutInflater mInflater;
	private final Context mContext;
	private final boolean mIsPortrait;
	private final boolean mShowHomeClock;
	private final String mDateFormat;
	private final String mDateFormatForAccessibility;

	private SelectedCitiesAdapter(Context context, String dateFormat,
	String dateFormatForAccessibility) {
	mContext = context;
	mDateFormat = dateFormat;
	mDateFormatForAccessibility = dateFormatForAccessibility;
	mInflater = LayoutInflater.from(context);
	mIsPortrait = Utils.isPortrait(context);
	mShowHomeClock = DataModel.getDataModel().getShowHomeClock();
	}

	@Override
	public int getItemViewType(int position) {
	if (position == 0 && mIsPortrait) {
	return MAIN_CLOCK;
	}
	return WORLD_CLOCK;
	}

	@NonNull
	@Override
	public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
	final View view = mInflater.inflate(viewType, parent, false);
	switch (viewType) {
	case WORLD_CLOCK:
	return new CityViewHolder(view);
	case MAIN_CLOCK:
	return new MainClockViewHolder(view);
	default:
	throw new IllegalArgumentException("View type not recognized");
	}
	}

	@Override
	public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
	final int viewType = getItemViewType(position);
	switch (viewType) {
	case WORLD_CLOCK:
	// Retrieve the city to bind.
	final City city;
	// If showing home clock, put it at the top
	if (mShowHomeClock && position == (mIsPortrait ? 1 : 0)) {
	city = getHomeCity();
	} else {
	final int positionAdjuster = (mIsPortrait ? 1 : 0)
	+ (mShowHomeClock ? 1 : 0);
	city = getCities().get(position - positionAdjuster);
	}
	((CityViewHolder) holder).bind(mContext, city);
	break;
	case MAIN_CLOCK:
	((MainClockViewHolder) holder).bind(mContext, mDateFormat,
	mDateFormatForAccessibility);
	break;
	default:
	throw new IllegalArgumentException("Unexpected view type: " + viewType);
	}
	}

	@Override
	public int getItemCount() {
	final int mainClockCount = mIsPortrait ? 1 : 0;
	final int homeClockCount = mShowHomeClock ? 1 : 0;
	final int worldClockCount = getCities().size();
	return mainClockCount + homeClockCount + worldClockCount;
	}

	private City getHomeCity() {
	return DataModel.getDataModel().getHomeCity();
	}

	private List<City> getCities() {
	return DataModel.getDataModel().getSelectedCities();
	}

	private void refreshAlarm() {
	if (mIsPortrait && getItemCount() > 0) {
	notifyItemChanged(0);
	}
	}

	@Override
	public void citiesChanged() {
	notifyDataSetChanged();
	}

	private static final class CityViewHolder extends RecyclerView.ViewHolder {

	private final TextView mName;
	private final TextClock mDigitalClock;
	private final AnalogClock mAnalogClock;
	private final TextView mHoursAhead;

	private CityViewHolder(View itemView) {
	super(itemView);

	mName = itemView.findViewById(R.id.city_name);
	mDigitalClock = itemView.findViewById(R.id.digital_clock);
	mAnalogClock = itemView.findViewById(R.id.analog_clock);
	mHoursAhead = itemView.findViewById(R.id.hours_ahead);
	}

	private void bind(Context context, City city) {
	final String cityTimeZoneId = city.getTimeZone().getID();

	// Configure the digital clock or analog clock depending on the user preference.
	if (DataModel.getDataModel().getClockStyle() == DataModel.ClockStyle.ANALOG) {
	mDigitalClock.setVisibility(GONE);
	mAnalogClock.setVisibility(VISIBLE);
	mAnalogClock.setTimeZone(cityTimeZoneId);
	mAnalogClock.enableSeconds(false);
	} else {
	mAnalogClock.setVisibility(GONE);
	mDigitalClock.setVisibility(VISIBLE);
	mDigitalClock.setTimeZone(cityTimeZoneId);
	mDigitalClock.setFormat12Hour(Utils.get12ModeFormat(0.3f /* amPmRatio */,
	false));
	mDigitalClock.setFormat24Hour(Utils.get24ModeFormat(false));
	}

	// Bind the city name.
	mName.setText(city.getName());

	// Compute if the city week day matches the weekday of the current timezone.
	final Calendar localCal = Calendar.getInstance(TimeZone.getDefault());
	final Calendar cityCal = Calendar.getInstance(city.getTimeZone());
	final boolean displayDayOfWeek =
	localCal.get(DAY_OF_WEEK) != cityCal.get(DAY_OF_WEEK);

	// Compare offset from UTC time on today's date (daylight savings time, etc.)
	final TimeZone currentTimeZone = TimeZone.getDefault();
	final TimeZone cityTimeZone = TimeZone.getTimeZone(cityTimeZoneId);
	final long currentTimeMillis = System.currentTimeMillis();
	final long currentUtcOffset = currentTimeZone.getOffset(currentTimeMillis);
	final long cityUtcOffset = cityTimeZone.getOffset(currentTimeMillis);
	final long offsetDelta = cityUtcOffset - currentUtcOffset;

	final int hoursDifferent = (int) (offsetDelta / DateUtils.HOUR_IN_MILLIS);
	final int minutesDifferent = (int) (offsetDelta / DateUtils.MINUTE_IN_MILLIS) % 60;
	final boolean displayMinutes = offsetDelta % DateUtils.HOUR_IN_MILLIS != 0;
	final boolean isAhead = hoursDifferent > 0 \|\| (hoursDifferent == 0
	&& minutesDifferent > 0);
	// Bind the number of hours ahead or behind, or hide if the time is the same.
	final boolean displayDifference = hoursDifferent != 0 \|\| displayMinutes;
	mHoursAhead.setVisibility(displayDifference ? VISIBLE : GONE);
	final String timeString = Utils.createHoursDifferentString(
	context, displayMinutes, isAhead, hoursDifferent, minutesDifferent);
	mHoursAhead.setText(displayDayOfWeek ?
	(context.getString(isAhead ? R.string.world_hours_tomorrow
	: R.string.world_hours_yesterday, timeString))
	: timeString);
	}
	}

	private static final class MainClockViewHolder extends RecyclerView.ViewHolder {

	private final TextClock mDigitalClock;
	private final AnalogClock mAnalogClock;

	private MainClockViewHolder(View itemView) {
	super(itemView);

	mDigitalClock = itemView.findViewById(R.id.digital_clock);
	mAnalogClock = itemView.findViewById(R.id.analog_clock);
	Utils.setClockIconTypeface(itemView);
	}

	private void bind(Context context, String dateFormat,
	String dateFormatForAccessibility) {
	Utils.refreshAlarm(context, itemView);

	Utils.updateDate(dateFormat, dateFormatForAccessibility, itemView);
	Utils.setClockStyle(mDigitalClock, mAnalogClock);
	Utils.setClockSecondsEnabled(mDigitalClock, mAnalogClock);
	Utils.updateDateGravity(itemView);
	}
	}
	}
	}