java/com/android/dialer/contactsfragment/ContactsFragment.java - LeafOS-Project/android_packages_apps_Dialer - Gitiles

 /*
  * Copyright (C) 2017 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.contactsfragment;

 import static android.Manifest.permission.READ_CONTACTS;

 import android.app.Fragment;
 import android.app.LoaderManager.LoaderCallbacks;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.Loader;
 import android.content.pm.PackageManager;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.IntDef;
 import android.support.annotation.Nullable;
 import android.support.v13.app.FragmentCompat;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.Recycler;
 import android.support.v7.widget.RecyclerView.State;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnScrollChangeListener;
 import android.view.ViewGroup;
 import android.widget.ImageView;
 import android.widget.TextView;
 import com.android.dialer.common.Assert;
 import com.android.dialer.common.FragmentUtils;
 import com.android.dialer.common.LogUtil;
 import com.android.dialer.performancereport.PerformanceReport;
 import com.android.dialer.util.DialerUtils;
 import com.android.dialer.util.IntentUtil;
 import com.android.dialer.util.PermissionsUtil;
 import com.android.dialer.widget.EmptyContentView;
 import com.android.dialer.widget.EmptyContentView.OnEmptyViewActionButtonClickedListener;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.Arrays;

 /** Fragment containing a list of all contacts. */
 public class ContactsFragment extends Fragment
     implements LoaderCallbacks<Cursor>,
         OnScrollChangeListener,
         OnEmptyViewActionButtonClickedListener {

   /** An enum for the different types of headers that be inserted at position 0 in the list. */
   @Retention(RetentionPolicy.SOURCE)
   @IntDef({Header.NONE, Header.ADD_CONTACT})
   public @interface Header {
     int NONE = 0;
     /** Header that allows the user to add a new contact. */
     int ADD_CONTACT = 1;
   }

   public static final int READ_CONTACTS_PERMISSION_REQUEST_CODE = 1;

   private static final String EXTRA_HEADER = "extra_header";
   private static final String EXTRA_HAS_PHONE_NUMBERS = "extra_has_phone_numbers";

   /**
    * Listen to broadcast events about permissions in order to be notified if the READ_CONTACTS
    * permission is granted via the UI in another fragment.
    */
   private final BroadcastReceiver readContactsPermissionGrantedReceiver =
       new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
           loadContacts();
         }
       };

   private FastScroller fastScroller;
   private TextView anchoredHeader;
   private RecyclerView recyclerView;
   private LinearLayoutManager manager;
   private ContactsAdapter adapter;
   private EmptyContentView emptyContentView;

   private @Header int header;

   private boolean hasPhoneNumbers;
   private String query;

   /**
    * Used to get a configured instance of ContactsFragment.
    *
    * <p>Current example of this fragment are the contacts tab and in creating a new favorite
    * contact. For example, the contacts tab we use:
    *
    * <ul>
    *   <li>{@link Header#ADD_CONTACT} to insert a header that allows users to add a contact
    *   <li>Open contact cards on click
    * </ul>
    *
    * And for the add favorite contact screen we might use:
    *
    * <ul>
    *   <li>{@link Header#NONE} so that all rows are contacts (i.e. no header inserted)
    *   <li>Send a selected contact to the parent activity.
    * </ul>
    *
    * @param header determines the type of header inserted at position 0 in the contacts list
    */
   public static ContactsFragment newInstance(@Header int header) {
     ContactsFragment fragment = new ContactsFragment();
     Bundle args = new Bundle();
     args.putInt(EXTRA_HEADER, header);
     fragment.setArguments(args);
     return fragment;
   }

   /**
    * Returns {@link ContactsFragment} with a list of contacts such that:
    *
    * <ul>
    *   <li>Each contact has a phone number
    *   <li>Contacts are filterable via {@link #updateQuery(String)}
    *   <li>There is no list header (i.e. {@link Header#NONE}
    *   <li>Clicking on a contact notifies the parent activity via {@link
    *       OnContactSelectedListener#onContactSelected(ImageView, Uri, long)}.
    * </ul>
    */
   public static ContactsFragment newAddFavoritesInstance() {
     ContactsFragment fragment = new ContactsFragment();
     Bundle args = new Bundle();
     args.putInt(EXTRA_HEADER, Header.NONE);
     args.putBoolean(EXTRA_HAS_PHONE_NUMBERS, true);
     fragment.setArguments(args);
     return fragment;
   }

   @SuppressWarnings("WrongConstant")
   @Override
   public void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     header = getArguments().getInt(EXTRA_HEADER);
     hasPhoneNumbers = getArguments().getBoolean(EXTRA_HAS_PHONE_NUMBERS);
     if (savedInstanceState == null) {
       // The onHiddenChanged callback does not get called the first time the fragment is
       // attached, so call it ourselves here.
       onHiddenChanged(false);
     }
   }

   @Override
   public void onStart() {
     super.onStart();
     PermissionsUtil.registerPermissionReceiver(
         getActivity(), readContactsPermissionGrantedReceiver, READ_CONTACTS);
   }

   @Override
   public void onStop() {
     PermissionsUtil.unregisterPermissionReceiver(
         getActivity(), readContactsPermissionGrantedReceiver);
     super.onStop();
   }

   @Nullable
   @Override
   public View onCreateView(
       LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
     View view = inflater.inflate(R.layout.fragment_contacts, container, false);
     fastScroller = view.findViewById(R.id.fast_scroller);
     anchoredHeader = view.findViewById(R.id.header);
     recyclerView = view.findViewById(R.id.recycler_view);
     adapter =
         new ContactsAdapter(
             getContext(), header, FragmentUtils.getParent(this, OnContactSelectedListener.class));
     recyclerView.setAdapter(adapter);
     manager =
         new LinearLayoutManager(getContext()) {
           @Override
           public void onLayoutChildren(Recycler recycler, State state) {
             super.onLayoutChildren(recycler, state);
             int itemsShown = findLastVisibleItemPosition() - findFirstVisibleItemPosition() + 1;
             if (adapter.getItemCount() > itemsShown) {
               fastScroller.setVisibility(View.VISIBLE);
               recyclerView.setOnScrollChangeListener(ContactsFragment.this);
             } else {
               fastScroller.setVisibility(View.GONE);
             }
           }
         };
     recyclerView.setLayoutManager(manager);

     emptyContentView = view.findViewById(R.id.empty_list_view);
     emptyContentView.setImage(R.drawable.empty_contacts);
     emptyContentView.setActionClickedListener(this);

     if (PermissionsUtil.hasContactsReadPermissions(getContext())) {
       loadContacts();
     } else {
       emptyContentView.setDescription(R.string.permission_no_contacts);
       emptyContentView.setActionLabel(R.string.permission_single_turn_on);
       emptyContentView.setVisibility(View.VISIBLE);
       recyclerView.setVisibility(View.GONE);
     }

     return view;
   }

   @Override
   public void onResume() {
     super.onResume();
     if (getActivity() != null
         && isAdded()
         && PermissionsUtil.hasContactsReadPermissions(getContext())) {
       getLoaderManager().restartLoader(0, null, this);
     }
   }

   /** @return a loader according to sort order and display order. */
   @Override
   public Loader<Cursor> onCreateLoader(int id, Bundle args) {
     ContactsCursorLoader cursorLoader = new ContactsCursorLoader(getContext(), hasPhoneNumbers);
     cursorLoader.setQuery(query);
     return cursorLoader;
   }

   public void updateQuery(String query) {
     this.query = query;
     getLoaderManager().restartLoader(0, null, this);
   }

   @Override
   public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
     LogUtil.enterBlock("ContactsFragment.onLoadFinished");
     if (cursor == null || cursor.getCount() == 0) {
       emptyContentView.setDescription(R.string.all_contacts_empty);
       emptyContentView.setActionLabel(R.string.all_contacts_empty_add_contact_action);
       emptyContentView.setVisibility(View.VISIBLE);
       recyclerView.setVisibility(View.GONE);
     } else {
       emptyContentView.setVisibility(View.GONE);
       recyclerView.setVisibility(View.VISIBLE);
       adapter.updateCursor(cursor);

       PerformanceReport.logOnScrollStateChange(recyclerView);
       fastScroller.setup(adapter, manager);
     }
   }

   @Override
   public void onLoaderReset(Loader<Cursor> loader) {
     recyclerView.setAdapter(null);
     recyclerView.setOnScrollChangeListener(null);
     adapter = null;
   }

   /*
    * When our recycler view updates, we need to ensure that our row headers and anchored header
    * are in the correct state.
    *
    * The general rule is, when the row headers are shown, our anchored header is hidden. When the
    * recycler view is scrolling through a sublist that has more than one element, we want to show
    * out anchored header, to create the illusion that our row header has been anchored. In all
    * other situations, we want to hide the anchor because that means we are transitioning between
    * two sublists.
    */
   @Override
   public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
     fastScroller.updateContainerAndScrollBarPosition(recyclerView);
     int firstVisibleItem = manager.findFirstVisibleItemPosition();
     int firstCompletelyVisible = manager.findFirstCompletelyVisibleItemPosition();
     if (firstCompletelyVisible == RecyclerView.NO_POSITION) {
       // No items are visible, so there are no headers to update.
       return;
     }
     String anchoredHeaderString = adapter.getHeaderString(firstCompletelyVisible);

     OnContactsListScrolledListener listener =
         FragmentUtils.getParent(this, OnContactsListScrolledListener.class);
     if (listener != null) {
       listener.onContactsListScrolled(
           recyclerView.getScrollState() == RecyclerView.SCROLL_STATE_DRAGGING
               || fastScroller.isDragStarted());
     }

     // If the user swipes to the top of the list very quickly, there is some strange behavior
     // between this method updating headers and adapter#onBindViewHolder updating headers.
     // To overcome this, we refresh the headers to ensure they are correct.
     if (firstVisibleItem == firstCompletelyVisible && firstVisibleItem == 0) {
       adapter.refreshHeaders();
       anchoredHeader.setVisibility(View.INVISIBLE);
     } else if (firstVisibleItem != 0) { // skip the add contact row
       if (adapter.getHeaderString(firstVisibleItem).equals(anchoredHeaderString)) {
         anchoredHeader.setText(anchoredHeaderString);
         anchoredHeader.setVisibility(View.VISIBLE);
         getContactHolder(firstVisibleItem).getHeaderView().setVisibility(View.INVISIBLE);
         getContactHolder(firstCompletelyVisible).getHeaderView().setVisibility(View.INVISIBLE);
       } else {
         anchoredHeader.setVisibility(View.INVISIBLE);
         getContactHolder(firstVisibleItem).getHeaderView().setVisibility(View.VISIBLE);
         getContactHolder(firstCompletelyVisible).getHeaderView().setVisibility(View.VISIBLE);
       }
     }
   }

   private ContactViewHolder getContactHolder(int position) {
     return ((ContactViewHolder) recyclerView.findViewHolderForAdapterPosition(position));
   }

   @Override
   public void onEmptyViewActionButtonClicked() {
     if (emptyContentView.getActionLabel() == R.string.permission_single_turn_on) {
       String[] deniedPermissions =
           PermissionsUtil.getPermissionsCurrentlyDenied(
               getContext(), PermissionsUtil.allContactsGroupPermissionsUsedInDialer);
       if (deniedPermissions.length > 0) {
         LogUtil.i(
             "ContactsFragment.onEmptyViewActionButtonClicked",
             "Requesting permissions: " + Arrays.toString(deniedPermissions));
         FragmentCompat.requestPermissions(
             this, deniedPermissions, READ_CONTACTS_PERMISSION_REQUEST_CODE);
       }

     } else if (emptyContentView.getActionLabel()
         == R.string.all_contacts_empty_add_contact_action) {
       // Add new contact
       DialerUtils.startActivityWithErrorToast(
           getContext(), IntentUtil.getNewContactIntent(), R.string.add_contact_not_available);
     } else {
       throw Assert.createIllegalStateFailException("Invalid empty content view action label.");
     }
   }

   @Override
   public void onRequestPermissionsResult(
       int requestCode, String[] permissions, int[] grantResults) {
     if (requestCode == READ_CONTACTS_PERMISSION_REQUEST_CODE) {
       if (grantResults.length >= 1 && PackageManager.PERMISSION_GRANTED == grantResults[0]) {
         // Force a refresh of the data since we were missing the permission before this.
         PermissionsUtil.notifyPermissionGranted(getContext(), permissions[0]);
       }
     }
   }

   @Override
   public void onHiddenChanged(boolean hidden) {
     super.onHiddenChanged(hidden);
     OnContactsFragmentHiddenChangedListener listener =
         FragmentUtils.getParent(this, OnContactsFragmentHiddenChangedListener.class);
     if (listener != null) {
       listener.onContactsFragmentHiddenChanged(hidden);
     }
   }

   private void loadContacts() {
     getLoaderManager().initLoader(0, null, this);
     recyclerView.setVisibility(View.VISIBLE);
     emptyContentView.setVisibility(View.GONE);
   }

   /** Listener for contacts list scroll state. */
   public interface OnContactsListScrolledListener {
     void onContactsListScrolled(boolean isDragging);
   }

   /** Listener to notify parents when a contact is selected. */
   public interface OnContactSelectedListener {

     /** Called when a contact is selected in {@link ContactsFragment}. */
     void onContactSelected(ImageView photo, Uri contactUri, long contactId);
   }

   /** Listener for contacts fragment hidden state */
   public interface OnContactsFragmentHiddenChangedListener {
     void onContactsFragmentHiddenChanged(boolean hidden);
   }
 }
	/*
	* Copyright (C) 2017 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.contactsfragment;

	import static android.Manifest.permission.READ_CONTACTS;

	import android.app.Fragment;
	import android.app.LoaderManager.LoaderCallbacks;
	import android.content.BroadcastReceiver;
	import android.content.Context;
	import android.content.Intent;
	import android.content.Loader;
	import android.content.pm.PackageManager;
	import android.database.Cursor;
	import android.net.Uri;
	import android.os.Bundle;
	import android.support.annotation.IntDef;
	import android.support.annotation.Nullable;
	import android.support.v13.app.FragmentCompat;
	import android.support.v7.widget.LinearLayoutManager;
	import android.support.v7.widget.RecyclerView;
	import android.support.v7.widget.RecyclerView.Recycler;
	import android.support.v7.widget.RecyclerView.State;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.View.OnScrollChangeListener;
	import android.view.ViewGroup;
	import android.widget.ImageView;
	import android.widget.TextView;
	import com.android.dialer.common.Assert;
	import com.android.dialer.common.FragmentUtils;
	import com.android.dialer.common.LogUtil;
	import com.android.dialer.performancereport.PerformanceReport;
	import com.android.dialer.util.DialerUtils;
	import com.android.dialer.util.IntentUtil;
	import com.android.dialer.util.PermissionsUtil;
	import com.android.dialer.widget.EmptyContentView;
	import com.android.dialer.widget.EmptyContentView.OnEmptyViewActionButtonClickedListener;
	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;
	import java.util.Arrays;

	/** Fragment containing a list of all contacts. */
	public class ContactsFragment extends Fragment
	implements LoaderCallbacks<Cursor>,
	OnScrollChangeListener,
	OnEmptyViewActionButtonClickedListener {

	/** An enum for the different types of headers that be inserted at position 0 in the list. */
	@Retention(RetentionPolicy.SOURCE)
	@IntDef({Header.NONE, Header.ADD_CONTACT})
	public @interface Header {
	int NONE = 0;
	/** Header that allows the user to add a new contact. */
	int ADD_CONTACT = 1;
	}

	public static final int READ_CONTACTS_PERMISSION_REQUEST_CODE = 1;

	private static final String EXTRA_HEADER = "extra_header";
	private static final String EXTRA_HAS_PHONE_NUMBERS = "extra_has_phone_numbers";

	/**
	* Listen to broadcast events about permissions in order to be notified if the READ_CONTACTS
	* permission is granted via the UI in another fragment.
	*/
	private final BroadcastReceiver readContactsPermissionGrantedReceiver =
	new BroadcastReceiver() {
	@Override
	public void onReceive(Context context, Intent intent) {
	loadContacts();
	}
	};

	private FastScroller fastScroller;
	private TextView anchoredHeader;
	private RecyclerView recyclerView;
	private LinearLayoutManager manager;
	private ContactsAdapter adapter;
	private EmptyContentView emptyContentView;

	private @Header int header;

	private boolean hasPhoneNumbers;
	private String query;

	/**
	* Used to get a configured instance of ContactsFragment.
	*
	* <p>Current example of this fragment are the contacts tab and in creating a new favorite
	* contact. For example, the contacts tab we use:
	*
	* <ul>
	* <li>{@link Header#ADD_CONTACT} to insert a header that allows users to add a contact
	* <li>Open contact cards on click
	* </ul>
	*
	* And for the add favorite contact screen we might use:
	*
	* <ul>
	* <li>{@link Header#NONE} so that all rows are contacts (i.e. no header inserted)
	* <li>Send a selected contact to the parent activity.
	* </ul>
	*
	* @param header determines the type of header inserted at position 0 in the contacts list
	*/
	public static ContactsFragment newInstance(@Header int header) {
	ContactsFragment fragment = new ContactsFragment();
	Bundle args = new Bundle();
	args.putInt(EXTRA_HEADER, header);
	fragment.setArguments(args);
	return fragment;
	}

	/**
	* Returns {@link ContactsFragment} with a list of contacts such that:
	*
	* <ul>
	* <li>Each contact has a phone number
	* <li>Contacts are filterable via {@link #updateQuery(String)}
	* <li>There is no list header (i.e. {@link Header#NONE}
	* <li>Clicking on a contact notifies the parent activity via {@link
	* OnContactSelectedListener#onContactSelected(ImageView, Uri, long)}.
	* </ul>
	*/
	public static ContactsFragment newAddFavoritesInstance() {
	ContactsFragment fragment = new ContactsFragment();
	Bundle args = new Bundle();
	args.putInt(EXTRA_HEADER, Header.NONE);
	args.putBoolean(EXTRA_HAS_PHONE_NUMBERS, true);
	fragment.setArguments(args);
	return fragment;
	}

	@SuppressWarnings("WrongConstant")
	@Override
	public void onCreate(@Nullable Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	header = getArguments().getInt(EXTRA_HEADER);
	hasPhoneNumbers = getArguments().getBoolean(EXTRA_HAS_PHONE_NUMBERS);
	if (savedInstanceState == null) {
	// The onHiddenChanged callback does not get called the first time the fragment is
	// attached, so call it ourselves here.
	onHiddenChanged(false);
	}
	}

	@Override
	public void onStart() {
	super.onStart();
	PermissionsUtil.registerPermissionReceiver(
	getActivity(), readContactsPermissionGrantedReceiver, READ_CONTACTS);
	}

	@Override
	public void onStop() {
	PermissionsUtil.unregisterPermissionReceiver(
	getActivity(), readContactsPermissionGrantedReceiver);
	super.onStop();
	}

	@Nullable
	@Override
	public View onCreateView(
	LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
	View view = inflater.inflate(R.layout.fragment_contacts, container, false);
	fastScroller = view.findViewById(R.id.fast_scroller);
	anchoredHeader = view.findViewById(R.id.header);
	recyclerView = view.findViewById(R.id.recycler_view);
	adapter =
	new ContactsAdapter(
	getContext(), header, FragmentUtils.getParent(this, OnContactSelectedListener.class));
	recyclerView.setAdapter(adapter);
	manager =
	new LinearLayoutManager(getContext()) {
	@Override
	public void onLayoutChildren(Recycler recycler, State state) {
	super.onLayoutChildren(recycler, state);
	int itemsShown = findLastVisibleItemPosition() - findFirstVisibleItemPosition() + 1;
	if (adapter.getItemCount() > itemsShown) {
	fastScroller.setVisibility(View.VISIBLE);
	recyclerView.setOnScrollChangeListener(ContactsFragment.this);
	} else {
	fastScroller.setVisibility(View.GONE);
	}
	}
	};
	recyclerView.setLayoutManager(manager);

	emptyContentView = view.findViewById(R.id.empty_list_view);
	emptyContentView.setImage(R.drawable.empty_contacts);
	emptyContentView.setActionClickedListener(this);

	if (PermissionsUtil.hasContactsReadPermissions(getContext())) {
	loadContacts();
	} else {
	emptyContentView.setDescription(R.string.permission_no_contacts);
	emptyContentView.setActionLabel(R.string.permission_single_turn_on);
	emptyContentView.setVisibility(View.VISIBLE);
	recyclerView.setVisibility(View.GONE);
	}

	return view;
	}

	@Override
	public void onResume() {
	super.onResume();
	if (getActivity() != null
	&& isAdded()
	&& PermissionsUtil.hasContactsReadPermissions(getContext())) {
	getLoaderManager().restartLoader(0, null, this);
	}
	}

	/** @return a loader according to sort order and display order. */
	@Override
	public Loader<Cursor> onCreateLoader(int id, Bundle args) {
	ContactsCursorLoader cursorLoader = new ContactsCursorLoader(getContext(), hasPhoneNumbers);
	cursorLoader.setQuery(query);
	return cursorLoader;
	}

	public void updateQuery(String query) {
	this.query = query;
	getLoaderManager().restartLoader(0, null, this);
	}

	@Override
	public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
	LogUtil.enterBlock("ContactsFragment.onLoadFinished");
	if (cursor == null \|\| cursor.getCount() == 0) {
	emptyContentView.setDescription(R.string.all_contacts_empty);
	emptyContentView.setActionLabel(R.string.all_contacts_empty_add_contact_action);
	emptyContentView.setVisibility(View.VISIBLE);
	recyclerView.setVisibility(View.GONE);
	} else {
	emptyContentView.setVisibility(View.GONE);
	recyclerView.setVisibility(View.VISIBLE);
	adapter.updateCursor(cursor);

	PerformanceReport.logOnScrollStateChange(recyclerView);
	fastScroller.setup(adapter, manager);
	}
	}

	@Override
	public void onLoaderReset(Loader<Cursor> loader) {
	recyclerView.setAdapter(null);
	recyclerView.setOnScrollChangeListener(null);
	adapter = null;
	}

	/*
	* When our recycler view updates, we need to ensure that our row headers and anchored header
	* are in the correct state.
	*
	* The general rule is, when the row headers are shown, our anchored header is hidden. When the
	* recycler view is scrolling through a sublist that has more than one element, we want to show
	* out anchored header, to create the illusion that our row header has been anchored. In all
	* other situations, we want to hide the anchor because that means we are transitioning between
	* two sublists.
	*/
	@Override
	public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
	fastScroller.updateContainerAndScrollBarPosition(recyclerView);
	int firstVisibleItem = manager.findFirstVisibleItemPosition();
	int firstCompletelyVisible = manager.findFirstCompletelyVisibleItemPosition();
	if (firstCompletelyVisible == RecyclerView.NO_POSITION) {
	// No items are visible, so there are no headers to update.
	return;
	}
	String anchoredHeaderString = adapter.getHeaderString(firstCompletelyVisible);

	OnContactsListScrolledListener listener =
	FragmentUtils.getParent(this, OnContactsListScrolledListener.class);
	if (listener != null) {
	listener.onContactsListScrolled(
	recyclerView.getScrollState() == RecyclerView.SCROLL_STATE_DRAGGING
	\|\| fastScroller.isDragStarted());
	}

	// If the user swipes to the top of the list very quickly, there is some strange behavior
	// between this method updating headers and adapter#onBindViewHolder updating headers.
	// To overcome this, we refresh the headers to ensure they are correct.
	if (firstVisibleItem == firstCompletelyVisible && firstVisibleItem == 0) {
	adapter.refreshHeaders();
	anchoredHeader.setVisibility(View.INVISIBLE);
	} else if (firstVisibleItem != 0) { // skip the add contact row
	if (adapter.getHeaderString(firstVisibleItem).equals(anchoredHeaderString)) {
	anchoredHeader.setText(anchoredHeaderString);
	anchoredHeader.setVisibility(View.VISIBLE);
	getContactHolder(firstVisibleItem).getHeaderView().setVisibility(View.INVISIBLE);
	getContactHolder(firstCompletelyVisible).getHeaderView().setVisibility(View.INVISIBLE);
	} else {
	anchoredHeader.setVisibility(View.INVISIBLE);
	getContactHolder(firstVisibleItem).getHeaderView().setVisibility(View.VISIBLE);
	getContactHolder(firstCompletelyVisible).getHeaderView().setVisibility(View.VISIBLE);
	}
	}
	}

	private ContactViewHolder getContactHolder(int position) {
	return ((ContactViewHolder) recyclerView.findViewHolderForAdapterPosition(position));
	}

	@Override
	public void onEmptyViewActionButtonClicked() {
	if (emptyContentView.getActionLabel() == R.string.permission_single_turn_on) {
	String[] deniedPermissions =
	PermissionsUtil.getPermissionsCurrentlyDenied(
	getContext(), PermissionsUtil.allContactsGroupPermissionsUsedInDialer);
	if (deniedPermissions.length > 0) {
	LogUtil.i(
	"ContactsFragment.onEmptyViewActionButtonClicked",
	"Requesting permissions: " + Arrays.toString(deniedPermissions));
	FragmentCompat.requestPermissions(
	this, deniedPermissions, READ_CONTACTS_PERMISSION_REQUEST_CODE);
	}

	} else if (emptyContentView.getActionLabel()
	== R.string.all_contacts_empty_add_contact_action) {
	// Add new contact
	DialerUtils.startActivityWithErrorToast(
	getContext(), IntentUtil.getNewContactIntent(), R.string.add_contact_not_available);
	} else {
	throw Assert.createIllegalStateFailException("Invalid empty content view action label.");
	}
	}

	@Override
	public void onRequestPermissionsResult(
	int requestCode, String[] permissions, int[] grantResults) {
	if (requestCode == READ_CONTACTS_PERMISSION_REQUEST_CODE) {
	if (grantResults.length >= 1 && PackageManager.PERMISSION_GRANTED == grantResults[0]) {
	// Force a refresh of the data since we were missing the permission before this.
	PermissionsUtil.notifyPermissionGranted(getContext(), permissions[0]);
	}
	}
	}

	@Override
	public void onHiddenChanged(boolean hidden) {
	super.onHiddenChanged(hidden);
	OnContactsFragmentHiddenChangedListener listener =
	FragmentUtils.getParent(this, OnContactsFragmentHiddenChangedListener.class);
	if (listener != null) {
	listener.onContactsFragmentHiddenChanged(hidden);
	}
	}

	private void loadContacts() {
	getLoaderManager().initLoader(0, null, this);
	recyclerView.setVisibility(View.VISIBLE);
	emptyContentView.setVisibility(View.GONE);
	}

	/** Listener for contacts list scroll state. */
	public interface OnContactsListScrolledListener {
	void onContactsListScrolled(boolean isDragging);
	}

	/** Listener to notify parents when a contact is selected. */
	public interface OnContactSelectedListener {

	/** Called when a contact is selected in {@link ContactsFragment}. */
	void onContactSelected(ImageView photo, Uri contactUri, long contactId);
	}

	/** Listener for contacts fragment hidden state */
	public interface OnContactsFragmentHiddenChangedListener {
	void onContactsFragmentHiddenChanged(boolean hidden);
	}
	}