Maintain Save Restore scroll position when returning to a ListView

Question

I have a long ListView that the user can scroll around before returning to the previous screen  When the user opens this ListView again  I want the list to be scrolled to the same point that it was previously  Any ideas on how to achieve this

User · Answer

My answer is for Firebase and position 0 is a workaround

Parcelable state;

DatabaseReference everybody = db.getReference("Everybody Room List");
    everybody.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            state = listView.onSaveInstanceState(); // Save
            progressBar.setVisibility(View.GONE);
            arrayList.clear();
            for (DataSnapshot messageSnapshot : dataSnapshot.getChildren()) {
                Messages messagesSpacecraft = messageSnapshot.getValue(Messages.class);
                arrayList.add(messagesSpacecraft);
            }
            listView.setAdapter(convertView);
            listView.onRestoreInstanceState(state); // Restore
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {
        }
    });

and convertView

position 0 a add a blank item that you are not using

public class Chat_ConvertView_List_Room extends BaseAdapter {

private ArrayList<Messages> spacecrafts;
private Context context;

@SuppressLint("CommitPrefEdits")
Chat_ConvertView_List_Room(Context context, ArrayList<Messages> spacecrafts) {
    this.context = context;
    this.spacecrafts = spacecrafts;
}

@Override
public int getCount() {
    return spacecrafts.size();
}

@Override
public Object getItem(int position) {
    return spacecrafts.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@SuppressLint({"SetTextI18n", "SimpleDateFormat"})
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        convertView = LayoutInflater.from(context).inflate(R.layout.message_model_list_room, parent, false);
    }

    final Messages s = (Messages) this.getItem(position);

    if (position == 0) {
        convertView.getLayoutParams().height = 1; // 0 does not work
    } else {
        convertView.getLayoutParams().height = RelativeLayout.LayoutParams.WRAP_CONTENT;
    }

    return convertView;
}
}

I have seen this work temporarily without disturbing the user, I hope it works for you

User · Answer

Neither of the solutions offered here seemed to work for me  In my case  I have a ListView in a Fragment which I m replacing in a FragmentTransaction  so a new Fragment instance is created each time the fragment is shown  which means that the ListView state can not be stored as a member of the Fragment   Instead  I ended up storing the state in my custom Application class  The code below should give you an idea how this works   public class MyApplication extends Application       public static HashMap lt String  Parcelable gt  parcelableCache   new HashMap lt  gt                  code omitted for brevity             nbsp   public class MyFragment extends Fragment      private ListView mListView   null      private MyAdapter mAdapter   null         Override     public void onViewCreated View view   Nullable Bundle savedInstanceState            super onViewCreated view  savedInstanceState            mAdapter   new MyAdapter getActivity    null  0           mListView     ListView  view findViewById R id myListView             Parcelable listViewState   MyApplication parcelableCache get  my listview state            if  listViewState    null               mListView onRestoreInstanceState listViewState                Override     public void onPause             MyApplication parcelableCache put  my listview state   mListView onSaveInstanceState             super onPause                      code omitted for brevity             The basic idea is that you store the state outside the fragment instance  If you don t like the idea of having a static field in your application class  I guess you could do it by implementing a fragment interface and storing the state in your activity   Another solution would be to store it in SharedPreferences  but it gets a bit more complicated  and you would need to make sure you clear it on application launch unless you want the state to be persisted across app launches    nbsp   Also  to avoid the  scroll position not saved when first item is visible   you can display a dummy first item with 0px height  This can be achieved by overriding getView   in your adapter  like this    Override public View getView int position  View convertView  ViewGroup parent        if  position    0             View zeroHeightView   new View parent getContext             zeroHeightView setLayoutParams new ViewGroup LayoutParams 0  0            return zeroHeightView            else         return super getView position  convertView  parent

User · Answer

Am posting this because I am surprised nobody had mentioned this   After user clicks the back button he will return to the listview in the same state as he went out of it    This code will override the  up  button to behave the same way as the back button so in the case of Listview -  Details -  Back to Listview  and no other options  this is the simplest code to maintain the scrollposition and the content in the listview    public boolean onOptionsItemSelected MenuItem item         switch  item getItemId               case android R id home               onBackPressed                 return true               return super onOptionsItemSelected item        Caution  If you can go to another activity from the details activity the up button will return you back to that activity so you will have to manipulate the backbutton history in order for this to work

User · Answer

I adopted the solution suggested by   Kirk Woll   and it works for me  I have also seen in the Android source code for the  Contacts  app  that they use a similar technique  I would like to add some more details  On top on my ListActivity-derived class   private static final String LIST STATE    listState   private Parcelable mListState   null    Then  some method overrides    Override protected void onRestoreInstanceState Bundle state        super onRestoreInstanceState state       mListState   state getParcelable LIST STATE       Override protected void onResume         super onResume        loadData        if  mListState    null          getListView   onRestoreInstanceState mListState       mListState   null      Override protected void onSaveInstanceState Bundle state        super onSaveInstanceState state       mListState   getListView   onSaveInstanceState        state putParcelable LIST STATE  mListState       Of course  loadData  is my function to retrieve data from the DB and put it onto the list   On my Froyo device  this works both when you change the phone orientation  and when you edit an item and go back to the list

User · Answer

If you re using fragments hosted on an activity you can do something like this   public abstract class BaseFragment extends Fragment        private boolean mSaveView   false       private SoftReference lt View gt  mViewReference         Override      public View onCreateView LayoutInflater inflater  ViewGroup container  Bundle savedInstanceState              if  mSaveView                   if  mViewReference    null                        final View savedView   mViewReference get                        if  savedView    null                             if  savedView getParent      null                                    ViewGroup  savedView getParent    removeView savedView                                 return savedView                                                                                           final View view   inflater inflate getFragmentResource    container  false             mViewReference   new SoftReference lt View gt  view             return view               protected void setSaveView boolean value               mSaveView   value            public class MyFragment extends BaseFragment         Override      public View onCreateView LayoutInflater inflater  ViewGroup container  Bundle savedInstanceState              setSaveView true             final View view   super onCreateView inflater  container  savedInstanceState             ListView placesList    ListView  view findViewById R id places list             if  placesList getAdapter      null                   placesList setAdapter createAdapter

User · Answer

BEST SOLUTION IS      save index and top position int index   mList getFirstVisiblePosition    View v   mList getChildAt 0   int top    v    null    0    v getTop   - mList getPaddingTop                 restore index and position mList post new Runnable          Override     public void run           mList setSelectionFromTop index  top              YOU MUST CALL IN POST AND IN THREAD

User · Answer

Try this      save index and top position int index   mList getFirstVisiblePosition    View v   mList getChildAt 0   int top    v    null    0    v getTop   - mList getPaddingTop                 restore index and position mList setSelectionFromTop index  top     Explanation  ListView getFirstVisiblePosition   returns the top visible list item  But this item may be partially scrolled out of view  and if you want to restore the exact scroll position of the list you need to get this offset  So ListView getChildAt 0  returns the View for the top list item  and then View getTop   - mList getPaddingTop   returns its relative offset from the top of the ListView  Then  to restore the ListView s scroll position  we call ListView setSelectionFromTop   with the index of the item we want and an offset to position its top edge from the top of the ListView

User · Answer

use this below code     int index top    Override protected void onPause         super onPause        index   mList getFirstVisiblePosition         View v   challengeList getChildAt 0       top    v    null    0    v getTop   - mList getPaddingTop         and whenever your refresh your data use this below code     adapter notifyDataSetChanged    mList setSelectionFromTop index  top

User · Answer

For an activity derived from ListActivity that implements LoaderManager LoaderCallbacks using a SimpleCursorAdapter it did not work to restore the position in onReset    because the activity was almost always restarted and the adapter was reloaded when the details view was closed  The trick was to restore the position in onLoadFinished     in onListItemClick        save the selected item position when an item was clicked    to open the details index   getListView   getFirstVisiblePosition    View v   getListView   getChildAt 0   top    v    null    0    v getTop   - getListView   getPaddingTop       in onLoadFinished        restore the selected item which was saved on item click    when details are closed and list is shown again getListView   setSelectionFromTop index  top     in onBackPressed        Show the top item at next start of the app index   0  top   0

User · Answer

Parcelable state    Override public void onPause                Save ListView state   onPause     Log d TAG   saving listview state        state   listView onSaveInstanceState        super onPause            Override public void onViewCreated final View view  Bundle savedInstanceState        super onViewCreated view  savedInstanceState          Set new items     listView setAdapter adapter                  Restore previous state  including selected item index and scroll position      if state    null            Log d TAG   trying to restore listview state            listView onRestoreInstanceState state

User · Answer

If you are saving restoring scroll position of ListView yourself you are essentially duplicating the functionality already implemented in android framework  The ListView restores fine scroll position just well on its own except one caveat  as  aaronvargas mentioned there is a bug in AbsListView that won t let to restore fine scroll position for the first list item  Nevertheless the best way to restore scroll position is not to restore it  Android framework will do it better for you  Just make sure you have met the following conditions    make sure you have not called setSaveEnabled false  method and not set android saveEnabled  false  attribute for the list in the xml layout file for ExpandableListView override long getCombinedChildId long groupId  long childId  method so that it returns positive long number  default implementation in class BaseExpandableListAdapter returns negative number   Here are examples        Override public long getChildId int groupPosition  int childPosition        return 0L   groupPosition  lt  lt  12   childPosition      Override public long getCombinedChildId long groupId  long childId        return groupId  lt  lt  32   childId  lt  lt  1   1      Override public long getGroupId int groupPosition        return groupPosition      Override public long getCombinedGroupId long groupId        return  groupId  amp  0x7FFFFFFF   lt  lt  32       if ListView or ExpandableListView is used in a fragment do not recreate the fragment on activity recreation  after screen rotation for example   Obtain the fragment with findFragmentByTag String tag  method  make sure the ListView has an android id and it is unique    To avoid aforementioned caveat with first list item you can craft your adapter the way it returns special dummy zero pixels height view for the ListView at position 0  Here is the simple example project shows ListView and ExpandableListView restore their fine scroll positions whereas their scroll positions are not explicitly saved restored  Fine scroll position is restored perfectly even for the complex scenarios with temporary switching to some other application  double screen rotation and switching back to the test application  Please note  if you are explicitly exiting the application  by pressing the Back button  the scroll position won t be saved  as well as all other Views won t save their state   https   github com voromto RestoreScrollPosition releases

User · Answer

I found something interesting about this   I tried setSelection and scrolltoXY but it did not work at all  the list remained in the same position  after some trial and error I got the following code that does work  final ListView list    ListView  findViewById R id list   list post new Runnable                      Override     public void run             list setSelection 0               If instead of posting the Runnable you try runOnUiThread it does not work either  at least on some devices   This is a very strange workaround for something that should be straight forward

User · Answer

For some looking for a solution to this problem  the root of the issue may be where you are setting your list views adapter  After you set the adapter on the listview  it resets the scroll position  Just something to consider  I moved setting the adapter into my onCreateView after we grab the reference to the listview  and it solved the problem for me

User · Answer

A very simple way       Save the position     int currentPosition   listView getFirstVisiblePosition       Here u should save the currentPosition anywhere      Restore the previus saved position     listView setSelection savedPosition     The method setSelection will reset the list to the supplied item  If not in touch mode the item will actually be selected if in touch mode the item will only be positioned on screen   A more complicated approach   listView setOnScrollListener this      Implements the interface   Override public void onScroll AbsListView view  int firstVisibleItem              int visibleItemCount  int totalItemCount        mCurrentX   view getScrollX        mCurrentY   view getScrollY        Override public void onScrollStateChanged AbsListView view  int scrollState          Save anywere the x and the y      Restore      listView scrollTo savedX  savedY

User · Answer

To clarify the excellent answer of Ryan Newsom and to adjust it for fragments and for the usual case that we want to navigate from a  master  ListView fragment to a  details  fragment and then back to the  master       private View root      public View onCreateView LayoutInflater inflater  ViewGroup container  Bundle savedInstanceState                       if root    null                root   inflater inflate R layout myfragmentid container false                InitializeView                              return root                  public void InitializeView                 ListView listView    ListView root findViewById R id listviewid           BaseAdapter adapter   CreateAdapter     Create your adapter here         listView setAdpater adapter             other initialization code         The  magic  here is that when we navigate back from the details fragment to the ListView fragment  the view is not recreated  we don t set the ListView s adapter  so everything stays as we left it

User · Answer

private Parcelable state   Override public void onPause         state   mAlbumListView onSaveInstanceState        super onPause        Override public void onResume         super onResume         if  getAdapter      null            mAlbumListView setAdapter getAdapter             if  state    null               mAlbumListView requestFocus                mAlbumListView onRestoreInstanceState state                       That s enough

User · Answer

CAUTION   There is a bug in AbsListView that doesn t allow the onSaveState   to work correctly if the ListView getFirstVisiblePosition   is 0    So If you have large images that take up most of the screen  and you scroll to the second image  but a little of the first is showing  the scroll position Won t be saved      from AbsListView java 1650  comments mine      this will be false when the firstPosition IS 0 if  haveChildren  amp  amp  mFirstPosition  gt  0              else       ss viewTop   0      ss firstId   INVALID POSITION      ss position   0      But in this situation  the  top  in the code below will be a negative number which causes other issues that prevent the state to be restored correctly  So when the  top  is negative  get the next child     save index and top position int index   getFirstVisiblePosition    View v   getChildAt 0   int top    v    null    0   v getTop     if  top  lt  0  amp  amp  getChildAt 1     null        index        v   getChildAt 1       top   v getTop         parcel the index and top     when restoring  unparcel index and top listView setSelectionFromTop index  top

User · Answer

You can maintain the scroll state after a reload if you save the state before you reload and restore it after  In my case I made a asynchronous network request and reloaded the list in a callback after it completed  This is where I restore state  Code sample is Kotlin   val state   myList layoutManager onSaveInstanceState    getNewThings     newThings  List lt Thing gt  - gt       myList adapter things   newThings     myList layoutManager onRestoreInstanceState state

User · Answer

Isn t simply android saveEnabled  true  in the ListView xml declaration enough

User · Answer

I m using FirebaseListAdapter and couldn t get any of the solutions to work  I ended up doing this  I m guessing there are more elegant ways but this is a complete and working solution   Before onCreate   private int reset  private int top  private int index    Inside of the FirebaseListAdapter    Override public void onDataChanged          super onDataChanged             Only do this on first change  when starting         activity or coming back to it       if reset    0              mListView setSelectionFromTop index  top             reset                 onStart    Override protected void onStart         super onStart        if adapter    null            adapter startListening            index   0          top   0             Get position from SharedPrefs         SharedPreferences sharedPref   PreferenceManager getDefaultSharedPreferences this           top   sharedPref getInt  TOP POSITION   0           index   sharedPref getInt  INDEX POSITION   0              Set reset to 0 to allow change to last position         reset   0            onStop    Override protected void onStop         super onStop        if adapter    null            adapter stopListening               Set position         index   mListView getFirstVisiblePosition            View v   mListView getChildAt 0           top    v    null    0    v getTop   - mListView getPaddingTop                Save position to SharedPrefs         SharedPreferences sharedPref   PreferenceManager getDefaultSharedPreferences this           sharedPref edit   putInt  TOP POSITION        top  apply            sharedPref edit   putInt  INDEX POSITION        index  apply              Since I also had to solve this for FirebaseRecyclerAdapter I m posting the solution here for that too   Before onCreate   private int reset  private int top  private int index    Inside of the FirebaseRecyclerAdapter    Override public void onDataChanged            Only do this on first change  when starting        activity or coming back to it      if reset    0            linearLayoutManager scrollToPositionWithOffset index  top           reset              onStart    Override protected void onStart         super onStart        if adapter    null            adapter startListening            index   0          top   0             Get position from SharedPrefs         SharedPreferences sharedPref   PreferenceManager getDefaultSharedPreferences this           top   sharedPref getInt  TOP POSITION   0           index   sharedPref getInt  INDEX POSITION   0              Set reset to 0 to allow change to last position         reset   0            onStop    Override protected void onStop         super onStop        if adapter    null            adapter stopListening               Set position         index   linearLayoutManager findFirstVisibleItemPosition            View v   linearLayoutManager getChildAt 0           top    v    null    0    v getTop   - linearLayoutManager getPaddingTop                Save position to SharedPrefs         SharedPreferences sharedPref   PreferenceManager getDefaultSharedPreferences this           sharedPref edit   putInt  TOP POSITION        top  apply            sharedPref edit   putInt  INDEX POSITION        index  apply

[android] Maintain/Save/Restore scroll position when returning to a ListView

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