Android Endless List

Question

How can I create a list where when you reach the end of the list I am notified so I can load more items

User · Answer

You can detect end of the list with help of onScrollListener, working code is presented below:

@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
    if (view.getAdapter() != null && ((firstVisibleItem + visibleItemCount) >= totalItemCount) && totalItemCount != mPrevTotalItemCount) {
        Log.v(TAG, "onListEnd, extending list");
        mPrevTotalItemCount = totalItemCount;
        mAdapter.addMoreData();
    }
}

Another way to do that (inside adapter) is as following:

    public View getView(int pos, View v, ViewGroup p) {
            if(pos==getCount()-1){
                addMoreData(); //should be asynctask or thread
            }
            return view;
    }

Be aware that this method will be called many times, so you need to add another condition to block multiple calls of addMoreData().

When you add all elements to the list, please call notifyDataSetChanged() inside yours adapter to update the View (it should be run on UI thread - runOnUiThread)

User · Answer

Just wanted to contribute a solution that I used for my app   It is also based on the OnScrollListener interface  but I found it to have a much better scrolling performance on low-end devices  since none of the visible total count calculations are carried out during the scroll operations    Let your ListFragment or ListActivity implement OnScrollListener Add the following methods to that class    Override public void onScroll AbsListView view  int firstVisibleItem          int visibleItemCount  int totalItemCount          leave this empty     Override public void onScrollStateChanged AbsListView listView  int scrollState        if  scrollState    SCROLL STATE IDLE            if  listView getLastVisiblePosition    gt   listView getCount   - 1 - threshold                currentPage                  load more list items              loadElements currentPage                       where currentPage is the page of your datasource that should be added to your list  and threshold is the number of list items  counted from the end  that should  if visible  trigger the loading process  If you set threshold to 0  for instance  the user has to scroll to the very end of the list in order to load more items   optional  As you can see  the  load-more check  is only called when the user stops scrolling  To improve usability  you may inflate and add a loading indicator to the end of the list via listView addFooterView yourFooterView   One example for such a footer view    lt  xml version  1 0  encoding  utf-8   gt    lt RelativeLayout xmlns android  http   schemas android com apk res android      android id    id footer layout      android layout width  fill parent      android layout height  wrap content      android padding  10dp   gt        lt ProgressBar         android id    id progressBar1          android layout width  wrap content          android layout height  wrap content          android layout centerVertical  true          android layout gravity  center vertical    gt        lt TextView         android layout width  wrap content          android layout height  wrap content          android layout centerVertical  true          android layout toRightOf    id progressBar1          android padding  5dp          android text   string loading text    gt    lt  RelativeLayout gt    optional  Finally  remove that loading indicator by calling listView removeFooterView yourFooterView  if there are no more items or pages

User · Answer

I know its an old question and the Android world has mostly moved on to RecyclerViews  but for anyone interested  you may find this library very interesting   It uses the BaseAdapter used with the ListView to detect when the list has been scrolled to the last item or when it is being scrolled away from the last item   It comes with an example project barely 100 lines of Activity code  that can be used to quickly understand how it works   Simple usage   class Boy   private String name  private double height  private int age    Other code      An adapter to hold Boy objects would look like    public class BoysAdapter extends EndlessAdapter lt Boy gt               ViewHolder holder   null            if  convertView    null                LayoutInflater inflater   LayoutInflater from parent                      getContext                  holder   new ViewHolder                 convertView   inflater inflate                      R layout list cell  parent  false                 holder nameView   convertView findViewById R id cell                   minimize the default image              convertView setTag holder             else               holder    ViewHolder  convertView getTag                       Boy boy   getItem position            try               holder nameView setText boy getName                     Other data rendering codes             catch  Exception e                e printStackTrace                       return super getView position convertView parent        Notice how the BoysAdapter s getView method returns a call to the EndlessAdapter superclass s getView method  This is 100  essential   Now to create the adapter  do      adapter   new ModelAdapter                  Override             public void onScrollToBottom int bottomIndex  boolean moreItemsCouldBeAvailable                     if  moreItemsCouldBeAvailable                         makeYourServerCallForMoreItems                      else                       if  loadMore getVisibility      View VISIBLE                            loadMore setVisibility View VISIBLE                                                                       Override             public void onScrollAwayFromBottom int currentIndex                     loadMore setVisibility View GONE                               Override             public void onFinishedLoading boolean moreItemsReceived                     if   moreItemsReceived                        loadMore setVisibility View VISIBLE                                                The loadMore item is a button or other ui element that may be clicked to fetch more data from the url  When placed as described in the code  the adapter knows exactly when to show that button and when to disable it  Just create the button in your xml and place it as shown in the adapter code above   Enjoy

User · Answer

At Ognyan Bankov GitHub i found a simple and working solution  It makes use of  the Volley HTTP library that makes networking for Android apps easier and most importantly  faster  Volley is available through the open AOSP repository  The given code demonstrates   ListView which is populated by HTTP paginated requests  Usage of    NetworkImageView   quot Endless quot  ListView pagination with read-ahead   For future consistence i forked Bankov s repo

User · Answer

Here is a solution that also makes it easy to show a loading view in the end of the ListView while it s loading   You can see the classes here   https   github com CyberEagle OpenProjects blob master android-projects widgets src main java br com cybereagle androidwidgets helper ListViewWithLoadingIndicatorHelper java - Helper to make it possible to use the features without extending from SimpleListViewWithLoadingIndicator   https   github com CyberEagle OpenProjects blob master android-projects widgets src main java br com cybereagle androidwidgets listener EndlessScrollListener java - Listener that starts loading data when the user is about to reach the bottom of the ListView   https   github com CyberEagle OpenProjects blob master android-projects widgets src main java br com cybereagle androidwidgets view SimpleListViewWithLoadingIndicator java - The EndlessListView  You can use this class directly or extend from it

User · Answer

One solution is to implement an OnScrollListener and make changes  like adding items  etc   to the ListAdapter at a convenient state in its onScroll method   The following ListActivity shows a list of integers  starting with 40  adding items when the user scrolls to the end of the list   public class Test extends ListActivity implements OnScrollListener        Aleph0 adapter   new Aleph0         protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setListAdapter adapter            getListView   setOnScrollListener this              public void onScroll AbsListView view          int firstVisible  int visibleCount  int totalCount             boolean loadMore      maybe add a padding                firstVisible   visibleCount  gt   totalCount           if loadMore                adapter count    visibleCount     or any other amount             adapter notifyDataSetChanged                         public void onScrollStateChanged AbsListView v  int s               class Aleph0 extends BaseAdapter           int count   40     starting amount             public int getCount     return count            public Object getItem int pos    return pos            public long getItemId int pos    return pos             public View getView int pos  View v  ViewGroup p                    TextView view   new TextView Test this                   view setText  entry     pos                   return view                      You should obviously use separate threads for long running actions  like loading web-data   and might want to indicate progress in the last list item  like the market or gmail apps do

User · Answer

Best solution so far that I have seen is in FastAdapter library for recycler views  It has a EndlessRecyclerOnScrollListener    Here is an example usage  EndlessScrollListActivity  Once I used it for endless scrolling list I have realised that the setup is a very robust  I d definitely recommend it

User · Answer

May be a little late but the following solution happened very useful in my case  In a way all you need to do is add to your ListView a Footer and create for it addOnLayoutChangeListener   http   developer android com reference android widget ListView html addFooterView android view View   For example   ListView listView1    ListView  v findViewById R id dialogsList      Your listView View loadMoreView   getActivity   getLayoutInflater   inflate R layout list load more  null      Getting your layout of FooterView  which will always be at the bottom of your listview  E g  you may place on it the ProgressBar or leave it empty-layout  listView1 addFooterView loadMoreView      Adding your View to your listview        loadMoreView addOnLayoutChangeListener new View OnLayoutChangeListener          Override     public void onLayoutChange View v  int left  int top  int right  int bottom  int oldLeft  int oldTop  int oldRight  int oldBottom             Log d  Hey     Your list has reached bottom                This event fires once when a footer becomes visible and works like a charm

User · Answer

The key of this problem is to detect the load-more event  start an async request for data and then update the list  Also an adapter with loading indicator and other decorators is needed  In fact  the problem is very complicated in some corner cases  Just a OnScrollListener implementation is not enough  because sometimes the items do not fill the screen   I have written a personal package which support endless list for RecyclerView  and also provide a async loader implementation AutoPagerFragment which makes it very easy to get data from a multi-page source  It can load any page you want into a RecyclerView on a custom event  not only the next page   Here is the address  https   github com SphiaTower AutoPagerRecyclerManager

User · Answer

I ve been working in another solution very similar to that  but  I am using a footerView to give the possibility to the user download more elements clicking the footerView  I am using a  menu  which is shown above the ListView and in the bottom of the parent view  this  menu  hides the bottom of the ListView  so  when the listView is scrolling the menu disappear and when scroll state is idle  the menu appear again  but when the user scrolls to the end of the listView  I  ask  to know if the footerView is shown in that case  the menu doesn t appear and the user can see the footerView to load more content  Here the code   Regards   listView setOnScrollListener new OnScrollListener           Override     public void onScrollStateChanged AbsListView view  int scrollState               TODO Auto-generated method stub         if scrollState    SCROLL STATE IDLE                if footerView isShown                      bottomView setVisibility LinearLayout INVISIBLE                 else                   bottomView setVisibility LinearLayout VISIBLE                 else                   bottomView setVisibility LinearLayout INVISIBLE                                       Override     public void onScroll AbsListView view  int firstVisibleItem              int visibleItemCount  int totalItemCount

[android] Android Endless List

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