src/com/android/car/media/BrowseFragment.java - platform/packages/apps/Car/Media - Git at Google

 /*
  * Copyright 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.car.media;

 import static com.android.car.apps.common.FragmentUtils.checkParent;
 import static com.android.car.apps.common.FragmentUtils.requireParent;
 import static com.android.car.arch.common.LiveDataFunctions.ifThenElse;

 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Handler;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.ImageView;
 import android.widget.TextView;

 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModelProviders;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;

 import com.android.car.apps.common.util.ViewUtils;
 import com.android.car.arch.common.FutureData;
 import com.android.car.media.browse.BrowseAdapter;
 import com.android.car.media.common.GridSpacingItemDecoration;
 import com.android.car.media.common.MediaItemMetadata;
 import com.android.car.media.common.browse.MediaBrowserViewModel;
 import com.android.car.media.common.source.MediaSourceViewModel;

 import java.util.ArrayList;
 import java.util.List;
 import java.util.Stack;

 /**
  * A {@link Fragment} that implements the content forward browsing experience.
  *
  * This can be used to display either search or browse results at the root level. Deeper levels will
  * be handled the same way between search and browse, using a backstack to return to the root.
  */
 public class BrowseFragment extends Fragment {
     private static final String TAG = "BrowseFragment";
     private static final String TOP_MEDIA_ITEM_KEY = "top_media_item";
     private static final String SEARCH_KEY = "search_config";
     private static final String BROWSE_STACK_KEY = "browse_stack";

     private RecyclerView mBrowseList;
     private ImageView mErrorIcon;
     private TextView mMessage;
     private BrowseAdapter mBrowseAdapter;
     private MediaItemMetadata mTopMediaItem;
     private String mSearchQuery;
     private int mFadeDuration;
     private int mLoadingIndicatorDelay;
     private boolean mIsSearchFragment;
     private boolean mPlaybackControlsVisible = false;
     // todo(b/130760002): Create new browse fragments at deeper levels.
     private MutableLiveData<Boolean> mShowSearchResults = new MutableLiveData<>();
     private Handler mHandler = new Handler();
     private Stack<MediaItemMetadata> mBrowseStack = new Stack<>();
     private MediaBrowserViewModel.WithMutableBrowseId mMediaBrowserViewModel;
     private BrowseAdapter.Observer mBrowseAdapterObserver = new BrowseAdapter.Observer() {

         @Override
         protected void onPlayableItemClicked(MediaItemMetadata item) {
             hideKeyboard();
             getParent().onPlayableItemClicked(item);
         }

         @Override
         protected void onBrowsableItemClicked(MediaItemMetadata item) {
             navigateInto(item);
         }
     };

     /**
      * Fragment callbacks (implemented by the hosting Activity)
      */
     public interface Callbacks {
         /**
          * Method invoked when the back stack changes (for example, when the user moves up or down
          * the media tree)
          */
         void onBackStackChanged();

         /**
          * Method invoked when the user clicks on a playable item
          *
          * @param item item to be played.
          */
         void onPlayableItemClicked(MediaItemMetadata item);
     }

     /**
      * Moves the user one level up in the browse tree. Returns whether that was possible.
      */
     boolean navigateBack() {
         boolean result = false;
         if (!mBrowseStack.empty()) {
             mBrowseStack.pop();
             mMediaBrowserViewModel.search(mSearchQuery);
             mMediaBrowserViewModel.setCurrentBrowseId(getCurrentMediaItemId());
             getParent().onBackStackChanged();
             adjustBrowseTopPadding();
             result = true;
         }
         if (mBrowseStack.isEmpty()) {
             mShowSearchResults.setValue(mIsSearchFragment);
         }
         return result;
     }

     @NonNull
     private Callbacks getParent() {
         return requireParent(this, Callbacks.class);
     }

     /**
      * @return whether the user is at the top of the browsing stack.
      */
     public boolean isAtTopStack() {
         return mBrowseStack.isEmpty();
     }

     /**
      * Creates a new instance of this fragment. The root browse id will be the one provided to this
      * method.
      *
      * @param item media tree node to display on this fragment.
      * @return a fully initialized {@link BrowseFragment}
      */
     public static BrowseFragment newInstance(MediaItemMetadata item) {
         BrowseFragment fragment = new BrowseFragment();
         Bundle args = new Bundle();
         args.putParcelable(TOP_MEDIA_ITEM_KEY, item);
         fragment.setArguments(args);
         return fragment;
     }

     /**
      * Creates a new instance of this fragment, meant to display search results. The root browse
      * screen will be the search results for the provided query.
      *
      * @return a fully initialized {@link BrowseFragment}
      */
     public static BrowseFragment newSearchInstance() {
         BrowseFragment fragment = new BrowseFragment();
         Bundle args = new Bundle();
         args.putBoolean(SEARCH_KEY, true);
         fragment.setArguments(args);
         return fragment;
     }

     public void updateSearchQuery(@Nullable String query) {
         mSearchQuery = query;
         mMediaBrowserViewModel.search(query);
     }

     /**
      * Clears search state from this fragment, removes any UI elements from previous results.
      */
     public void resetSearchState() {
         updateSearchQuery(null);
         mBrowseAdapter.submitItems(null, null);
         stopLoadingIndicator();
         ViewUtils.hideViewAnimated(mErrorIcon, mFadeDuration);
         ViewUtils.hideViewAnimated(mMessage, mFadeDuration);
     }

     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         Bundle arguments = getArguments();
         if (arguments != null) {
             mTopMediaItem = arguments.getParcelable(TOP_MEDIA_ITEM_KEY);
             mIsSearchFragment = arguments.getBoolean(SEARCH_KEY, false);
             mShowSearchResults.setValue(mIsSearchFragment);
         }
         if (savedInstanceState != null) {
             List<MediaItemMetadata> savedStack =
                     savedInstanceState.getParcelableArrayList(BROWSE_STACK_KEY);
             mBrowseStack.clear();
             if (savedStack != null) {
                 mBrowseStack.addAll(savedStack);
             }
         }

         // Get the MediaBrowserViewModel tied to the lifecycle of this fragment, but using the
         // MediaSourceViewModel of the activity. This means the media source is consistent across
         // all fragments, but the fragment contents themselves will vary
         // (e.g. between different browse tabs, search)
         mMediaBrowserViewModel = MediaBrowserViewModel.Factory.getInstanceWithMediaBrowser(
                 ViewModelProviders.of(this),
                 MediaSourceViewModel.get(
                         requireActivity().getApplication()).getConnectedMediaBrowser());

         MediaActivity.ViewModel viewModel = ViewModelProviders.of(requireActivity()).get(
                 MediaActivity.ViewModel.class);
         viewModel.getMiniControlsVisible().observe(this, (visible) -> {
             mPlaybackControlsVisible = visible;
             adjustBrowseTopPadding();
         });

     }

     @Override
     public View onCreateView(@NonNull LayoutInflater inflater, final ViewGroup container,
             Bundle savedInstanceState) {
         int viewId = mIsSearchFragment ? R.layout.fragment_search : R.layout.fragment_browse;
         View view = inflater.inflate(viewId, container, false);
         mLoadingIndicatorDelay = view.getContext().getResources()
                 .getInteger(R.integer.progress_indicator_delay);
         mBrowseList = view.findViewById(R.id.browse_list);
         mErrorIcon = view.findViewById(R.id.error_icon);
         mMessage = view.findViewById(R.id.error_message);
         mFadeDuration = view.getContext().getResources().getInteger(
                 R.integer.new_album_art_fade_in_duration);
         int numColumns = view.getContext().getResources().getInteger(R.integer.num_browse_columns);
         GridLayoutManager gridLayoutManager = new GridLayoutManager(getContext(), numColumns);

         mBrowseList.setLayoutManager(gridLayoutManager);
         mBrowseList.addItemDecoration(new GridSpacingItemDecoration(
                 getResources().getDimensionPixelSize(R.dimen.grid_item_spacing)));

         mBrowseAdapter = new BrowseAdapter(mBrowseList.getContext());
         mBrowseList.setAdapter(mBrowseAdapter);
         mBrowseAdapter.registerObserver(mBrowseAdapterObserver);

         if (savedInstanceState == null) {
             mMediaBrowserViewModel.search(mSearchQuery);
             mMediaBrowserViewModel.setCurrentBrowseId(getCurrentMediaItemId());
         }
         mMediaBrowserViewModel.rootBrowsableHint().observe(this, hint ->
                 mBrowseAdapter.setRootBrowsableViewType(hint));
         mMediaBrowserViewModel.rootPlayableHint().observe(this, hint ->
                 mBrowseAdapter.setRootPlayableViewType(hint));
         LiveData<FutureData<List<MediaItemMetadata>>> mediaItems = ifThenElse(mShowSearchResults,
                 mMediaBrowserViewModel.getSearchedMediaItems(),
                 mMediaBrowserViewModel.getBrowsedMediaItems());

         mediaItems.observe(getViewLifecycleOwner(), futureData ->
         {
             // Prevent showing loading spinner or any error messages if search is uninitialized
             if (mIsSearchFragment && TextUtils.isEmpty(mSearchQuery)) {
                 return;
             }
             boolean isLoading = futureData.isLoading();
             if (isLoading) {
                 ViewUtils.hideViewAnimated(mBrowseList, mFadeDuration);
                 startLoadingIndicator();
                 mBrowseAdapter.submitItems(null, null);
                 return;
             }
             stopLoadingIndicator();
             List<MediaItemMetadata> items = futureData.getData();
             mBrowseAdapter.submitItems(getCurrentMediaItem(), items);
             if (items == null) {
                 mMessage.setText(R.string.unknown_error);
                 ViewUtils.hideViewAnimated(mBrowseList, mFadeDuration);
                 ViewUtils.showViewAnimated(mMessage, mFadeDuration);
                 ViewUtils.showViewAnimated(mErrorIcon, mFadeDuration);
             } else if (items.isEmpty()) {
                 mMessage.setText(R.string.nothing_to_play);
                 ViewUtils.hideViewAnimated(mBrowseList, mFadeDuration);
                 ViewUtils.hideViewAnimated(mErrorIcon, mFadeDuration);
                 ViewUtils.showViewAnimated(mMessage, mFadeDuration);
             } else {
                 ViewUtils.showViewAnimated(mBrowseList, mFadeDuration);
                 ViewUtils.hideViewAnimated(mErrorIcon, mFadeDuration);
                 ViewUtils.hideViewAnimated(mMessage, mFadeDuration);
             }
         });
         return view;
     }

     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
         checkParent(this, Callbacks.class);
     }

     private Runnable mLoadingIndicatorRunnable = new Runnable() {
         @Override
         public void run() {
             mMessage.setText(R.string.browser_loading);
             ViewUtils.showViewAnimated(mMessage, mFadeDuration);
         }
     };

     private void startLoadingIndicator() {
         // Display the indicator after a certain time, to avoid flashing the indicator constantly,
         // even when performance is acceptable.
         mHandler.postDelayed(mLoadingIndicatorRunnable, mLoadingIndicatorDelay);
     }

     private void stopLoadingIndicator() {
         mHandler.removeCallbacks(mLoadingIndicatorRunnable);
         ViewUtils.hideViewAnimated(mMessage, mFadeDuration);
     }

     @Override
     public void onSaveInstanceState(@NonNull Bundle outState) {
         super.onSaveInstanceState(outState);
         ArrayList<MediaItemMetadata> stack = new ArrayList<>(mBrowseStack);
         outState.putParcelableArrayList(BROWSE_STACK_KEY, stack);
     }

     private void navigateInto(MediaItemMetadata item) {
         hideKeyboard();
         mBrowseStack.push(item);
         mShowSearchResults.setValue(false);
         mMediaBrowserViewModel.setCurrentBrowseId(item.getId());
         getParent().onBackStackChanged();
         adjustBrowseTopPadding();
     }

     /**
      * @return the current item being displayed
      */
     @Nullable
     MediaItemMetadata getCurrentMediaItem() {
         if (mBrowseStack.isEmpty()) {
             return mTopMediaItem;
         } else {
             return mBrowseStack.lastElement();
         }
     }

     @Nullable
     private String getCurrentMediaItemId() {
         MediaItemMetadata currentItem = getCurrentMediaItem();
         return currentItem != null ? currentItem.getId() : null;
     }

     private void adjustBrowseTopPadding() {
         if(mBrowseList == null) {
             return;
         }

         int topPadding = isAtTopStack()
                 ? getResources().getDimensionPixelOffset(R.dimen.browse_fragment_top_padding)
                 : getResources().getDimensionPixelOffset(
                         R.dimen.browse_fragment_top_padding_stacked);
         int bottomPadding = mPlaybackControlsVisible
                 ? getResources().getDimensionPixelOffset(R.dimen.browse_fragment_bottom_padding)
                 : 0;

         mBrowseList.setPadding(mBrowseList.getPaddingLeft(), topPadding,
                 mBrowseList.getPaddingRight(), bottomPadding);
     }

     private void hideKeyboard() {
         InputMethodManager in =
                 (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
         in.hideSoftInputFromWindow(getView().getWindowToken(), 0);
     }
 }
	/*
	* Copyright 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.car.media;

	import static com.android.car.apps.common.FragmentUtils.checkParent;
	import static com.android.car.apps.common.FragmentUtils.requireParent;
	import static com.android.car.arch.common.LiveDataFunctions.ifThenElse;

	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.content.Context;
	import android.os.Bundle;
	import android.os.Handler;
	import android.text.TextUtils;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.ViewGroup;
	import android.view.inputmethod.InputMethodManager;
	import android.widget.ImageView;
	import android.widget.TextView;

	import androidx.fragment.app.Fragment;
	import androidx.lifecycle.LiveData;
	import androidx.lifecycle.MutableLiveData;
	import androidx.lifecycle.ViewModelProviders;
	import androidx.recyclerview.widget.GridLayoutManager;
	import androidx.recyclerview.widget.RecyclerView;

	import com.android.car.apps.common.util.ViewUtils;
	import com.android.car.arch.common.FutureData;
	import com.android.car.media.browse.BrowseAdapter;
	import com.android.car.media.common.GridSpacingItemDecoration;
	import com.android.car.media.common.MediaItemMetadata;
	import com.android.car.media.common.browse.MediaBrowserViewModel;
	import com.android.car.media.common.source.MediaSourceViewModel;

	import java.util.ArrayList;
	import java.util.List;
	import java.util.Stack;

	/**
	* A {@link Fragment} that implements the content forward browsing experience.
	*
	* This can be used to display either search or browse results at the root level. Deeper levels will
	* be handled the same way between search and browse, using a backstack to return to the root.
	*/
	public class BrowseFragment extends Fragment {
	private static final String TAG = "BrowseFragment";
	private static final String TOP_MEDIA_ITEM_KEY = "top_media_item";
	private static final String SEARCH_KEY = "search_config";
	private static final String BROWSE_STACK_KEY = "browse_stack";

	private RecyclerView mBrowseList;
	private ImageView mErrorIcon;
	private TextView mMessage;
	private BrowseAdapter mBrowseAdapter;
	private MediaItemMetadata mTopMediaItem;
	private String mSearchQuery;
	private int mFadeDuration;
	private int mLoadingIndicatorDelay;
	private boolean mIsSearchFragment;
	private boolean mPlaybackControlsVisible = false;
	// todo(b/130760002): Create new browse fragments at deeper levels.
	private MutableLiveData<Boolean> mShowSearchResults = new MutableLiveData<>();
	private Handler mHandler = new Handler();
	private Stack<MediaItemMetadata> mBrowseStack = new Stack<>();
	private MediaBrowserViewModel.WithMutableBrowseId mMediaBrowserViewModel;
	private BrowseAdapter.Observer mBrowseAdapterObserver = new BrowseAdapter.Observer() {

	@Override
	protected void onPlayableItemClicked(MediaItemMetadata item) {
	hideKeyboard();
	getParent().onPlayableItemClicked(item);
	}

	@Override
	protected void onBrowsableItemClicked(MediaItemMetadata item) {
	navigateInto(item);
	}
	};

	/**
	* Fragment callbacks (implemented by the hosting Activity)
	*/
	public interface Callbacks {
	/**
	* Method invoked when the back stack changes (for example, when the user moves up or down
	* the media tree)
	*/
	void onBackStackChanged();

	/**
	* Method invoked when the user clicks on a playable item
	*
	* @param item item to be played.
	*/
	void onPlayableItemClicked(MediaItemMetadata item);
	}

	/**
	* Moves the user one level up in the browse tree. Returns whether that was possible.
	*/
	boolean navigateBack() {
	boolean result = false;
	if (!mBrowseStack.empty()) {
	mBrowseStack.pop();
	mMediaBrowserViewModel.search(mSearchQuery);
	mMediaBrowserViewModel.setCurrentBrowseId(getCurrentMediaItemId());
	getParent().onBackStackChanged();
	adjustBrowseTopPadding();
	result = true;
	}
	if (mBrowseStack.isEmpty()) {
	mShowSearchResults.setValue(mIsSearchFragment);
	}
	return result;
	}

	@NonNull
	private Callbacks getParent() {
	return requireParent(this, Callbacks.class);
	}

	/**
	* @return whether the user is at the top of the browsing stack.
	*/
	public boolean isAtTopStack() {
	return mBrowseStack.isEmpty();
	}

	/**
	* Creates a new instance of this fragment. The root browse id will be the one provided to this
	* method.
	*
	* @param item media tree node to display on this fragment.
	* @return a fully initialized {@link BrowseFragment}
	*/
	public static BrowseFragment newInstance(MediaItemMetadata item) {
	BrowseFragment fragment = new BrowseFragment();
	Bundle args = new Bundle();
	args.putParcelable(TOP_MEDIA_ITEM_KEY, item);
	fragment.setArguments(args);
	return fragment;
	}

	/**
	* Creates a new instance of this fragment, meant to display search results. The root browse
	* screen will be the search results for the provided query.
	*
	* @return a fully initialized {@link BrowseFragment}
	*/
	public static BrowseFragment newSearchInstance() {
	BrowseFragment fragment = new BrowseFragment();
	Bundle args = new Bundle();
	args.putBoolean(SEARCH_KEY, true);
	fragment.setArguments(args);
	return fragment;
	}

	public void updateSearchQuery(@Nullable String query) {
	mSearchQuery = query;
	mMediaBrowserViewModel.search(query);
	}

	/**
	* Clears search state from this fragment, removes any UI elements from previous results.
	*/
	public void resetSearchState() {
	updateSearchQuery(null);
	mBrowseAdapter.submitItems(null, null);
	stopLoadingIndicator();
	ViewUtils.hideViewAnimated(mErrorIcon, mFadeDuration);
	ViewUtils.hideViewAnimated(mMessage, mFadeDuration);
	}

	@Override
	public void onCreate(@Nullable Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	Bundle arguments = getArguments();
	if (arguments != null) {
	mTopMediaItem = arguments.getParcelable(TOP_MEDIA_ITEM_KEY);
	mIsSearchFragment = arguments.getBoolean(SEARCH_KEY, false);
	mShowSearchResults.setValue(mIsSearchFragment);
	}
	if (savedInstanceState != null) {
	List<MediaItemMetadata> savedStack =
	savedInstanceState.getParcelableArrayList(BROWSE_STACK_KEY);
	mBrowseStack.clear();
	if (savedStack != null) {
	mBrowseStack.addAll(savedStack);
	}
	}

	// Get the MediaBrowserViewModel tied to the lifecycle of this fragment, but using the
	// MediaSourceViewModel of the activity. This means the media source is consistent across
	// all fragments, but the fragment contents themselves will vary
	// (e.g. between different browse tabs, search)
	mMediaBrowserViewModel = MediaBrowserViewModel.Factory.getInstanceWithMediaBrowser(
	ViewModelProviders.of(this),
	MediaSourceViewModel.get(
	requireActivity().getApplication()).getConnectedMediaBrowser());

	MediaActivity.ViewModel viewModel = ViewModelProviders.of(requireActivity()).get(
	MediaActivity.ViewModel.class);
	viewModel.getMiniControlsVisible().observe(this, (visible) -> {
	mPlaybackControlsVisible = visible;
	adjustBrowseTopPadding();
	});

	}

	@Override
	public View onCreateView(@NonNull LayoutInflater inflater, final ViewGroup container,
	Bundle savedInstanceState) {
	int viewId = mIsSearchFragment ? R.layout.fragment_search : R.layout.fragment_browse;
	View view = inflater.inflate(viewId, container, false);
	mLoadingIndicatorDelay = view.getContext().getResources()
	.getInteger(R.integer.progress_indicator_delay);
	mBrowseList = view.findViewById(R.id.browse_list);
	mErrorIcon = view.findViewById(R.id.error_icon);
	mMessage = view.findViewById(R.id.error_message);
	mFadeDuration = view.getContext().getResources().getInteger(
	R.integer.new_album_art_fade_in_duration);
	int numColumns = view.getContext().getResources().getInteger(R.integer.num_browse_columns);
	GridLayoutManager gridLayoutManager = new GridLayoutManager(getContext(), numColumns);

	mBrowseList.setLayoutManager(gridLayoutManager);
	mBrowseList.addItemDecoration(new GridSpacingItemDecoration(
	getResources().getDimensionPixelSize(R.dimen.grid_item_spacing)));

	mBrowseAdapter = new BrowseAdapter(mBrowseList.getContext());
	mBrowseList.setAdapter(mBrowseAdapter);
	mBrowseAdapter.registerObserver(mBrowseAdapterObserver);

	if (savedInstanceState == null) {
	mMediaBrowserViewModel.search(mSearchQuery);
	mMediaBrowserViewModel.setCurrentBrowseId(getCurrentMediaItemId());
	}
	mMediaBrowserViewModel.rootBrowsableHint().observe(this, hint ->
	mBrowseAdapter.setRootBrowsableViewType(hint));
	mMediaBrowserViewModel.rootPlayableHint().observe(this, hint ->
	mBrowseAdapter.setRootPlayableViewType(hint));
	LiveData<FutureData<List<MediaItemMetadata>>> mediaItems = ifThenElse(mShowSearchResults,
	mMediaBrowserViewModel.getSearchedMediaItems(),
	mMediaBrowserViewModel.getBrowsedMediaItems());

	mediaItems.observe(getViewLifecycleOwner(), futureData ->
	{
	// Prevent showing loading spinner or any error messages if search is uninitialized
	if (mIsSearchFragment && TextUtils.isEmpty(mSearchQuery)) {
	return;
	}
	boolean isLoading = futureData.isLoading();
	if (isLoading) {
	ViewUtils.hideViewAnimated(mBrowseList, mFadeDuration);
	startLoadingIndicator();
	mBrowseAdapter.submitItems(null, null);
	return;
	}
	stopLoadingIndicator();
	List<MediaItemMetadata> items = futureData.getData();
	mBrowseAdapter.submitItems(getCurrentMediaItem(), items);
	if (items == null) {
	mMessage.setText(R.string.unknown_error);
	ViewUtils.hideViewAnimated(mBrowseList, mFadeDuration);
	ViewUtils.showViewAnimated(mMessage, mFadeDuration);
	ViewUtils.showViewAnimated(mErrorIcon, mFadeDuration);
	} else if (items.isEmpty()) {
	mMessage.setText(R.string.nothing_to_play);
	ViewUtils.hideViewAnimated(mBrowseList, mFadeDuration);
	ViewUtils.hideViewAnimated(mErrorIcon, mFadeDuration);
	ViewUtils.showViewAnimated(mMessage, mFadeDuration);
	} else {
	ViewUtils.showViewAnimated(mBrowseList, mFadeDuration);
	ViewUtils.hideViewAnimated(mErrorIcon, mFadeDuration);
	ViewUtils.hideViewAnimated(mMessage, mFadeDuration);
	}
	});
	return view;
	}

	@Override
	public void onAttach(Context context) {
	super.onAttach(context);
	checkParent(this, Callbacks.class);
	}

	private Runnable mLoadingIndicatorRunnable = new Runnable() {
	@Override
	public void run() {
	mMessage.setText(R.string.browser_loading);
	ViewUtils.showViewAnimated(mMessage, mFadeDuration);
	}
	};

	private void startLoadingIndicator() {
	// Display the indicator after a certain time, to avoid flashing the indicator constantly,
	// even when performance is acceptable.
	mHandler.postDelayed(mLoadingIndicatorRunnable, mLoadingIndicatorDelay);
	}

	private void stopLoadingIndicator() {
	mHandler.removeCallbacks(mLoadingIndicatorRunnable);
	ViewUtils.hideViewAnimated(mMessage, mFadeDuration);
	}

	@Override
	public void onSaveInstanceState(@NonNull Bundle outState) {
	super.onSaveInstanceState(outState);
	ArrayList<MediaItemMetadata> stack = new ArrayList<>(mBrowseStack);
	outState.putParcelableArrayList(BROWSE_STACK_KEY, stack);
	}

	private void navigateInto(MediaItemMetadata item) {
	hideKeyboard();
	mBrowseStack.push(item);
	mShowSearchResults.setValue(false);
	mMediaBrowserViewModel.setCurrentBrowseId(item.getId());
	getParent().onBackStackChanged();
	adjustBrowseTopPadding();
	}

	/**
	* @return the current item being displayed
	*/
	@Nullable
	MediaItemMetadata getCurrentMediaItem() {
	if (mBrowseStack.isEmpty()) {
	return mTopMediaItem;
	} else {
	return mBrowseStack.lastElement();
	}
	}

	@Nullable
	private String getCurrentMediaItemId() {
	MediaItemMetadata currentItem = getCurrentMediaItem();
	return currentItem != null ? currentItem.getId() : null;
	}

	private void adjustBrowseTopPadding() {
	if(mBrowseList == null) {
	return;
	}

	int topPadding = isAtTopStack()
	? getResources().getDimensionPixelOffset(R.dimen.browse_fragment_top_padding)
	: getResources().getDimensionPixelOffset(
	R.dimen.browse_fragment_top_padding_stacked);
	int bottomPadding = mPlaybackControlsVisible
	? getResources().getDimensionPixelOffset(R.dimen.browse_fragment_bottom_padding)
	: 0;

	mBrowseList.setPadding(mBrowseList.getPaddingLeft(), topPadding,
	mBrowseList.getPaddingRight(), bottomPadding);
	}

	private void hideKeyboard() {
	InputMethodManager in =
	(InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
	in.hideSoftInputFromWindow(getView().getWindowToken(), 0);
	}
	}