Simple Android RecyclerView example

Question

I ve made a list of items a few times using Android s RecyclerView  but it is a rather complicated process  Going through one of the numerous tutorials online works  this  this  and this are good   but I am looking a bare bones example that I can copy and paste to get up and running quickly  Only the following features are necessary    Vertical layout A single TextView on each row Responds to click events   Because I have wished for this several times  I finally decided to make the answer below for my future reference and yours

User · Answer

Here s a much newer Kotlin solution for this which is much simpler than many of the answers written here  it uses anonymous class   val items   mutableListOf lt String gt     inner class ItemHolder view  View   RecyclerView ViewHolder view        var textField  TextView   view findViewById android R id text1  as TextView    override fun onViewCreated view  View  savedInstanceState  Bundle         rvitems layoutManager   LinearLayoutManager context      rvitems adapter   object   RecyclerView Adapter lt ItemHolder gt               override fun onCreateViewHolder parent  ViewGroup  viewType  Int   ItemHolder               return ItemHolder LayoutInflater from parent context  inflate android R layout simple list item 1  parent  false                      override fun getItemCount    Int               return items size                    override fun onBindViewHolder holder  ItemHolder  position  Int                holder textField text   items position              holder textField setOnClickListener                   Toast makeText context   Clicked  position   Toast LENGTH SHORT  show                                     I took the liberty to use android R layout simple list item 1 as it s simpler  I wanted to simplify it even further and put ItemHolder as an inner class but couldn t quite figure out how to reference it in a type in the outer class parameter

User · Answer

Based on different sources I have created Simple Implementation of RecyclerView using a Simple Library   Add this line in build gradle  implementation  com hereshem lib awesomelib 2 0 1    AddCreate a RecyclerView by adding MyRecyclerView in activity main xml with   lt com hereshem lib recycler MyRecyclerView         android id    id recycler          app layoutManager  LinearLayoutManager          android layout width  match parent          android layout height  match parent   gt    Now in the MainActivity  Create a ViewHolder by passing the name of Class that needs to bind  public static class EVHolder extends MyViewHolder lt Events gt        TextView date  title  summary      public EVHolder View v            super v           date   v findViewById R id date           title   v findViewById R id title           summary   v findViewById R id summary              Override     public void bindView Events c            date setText c date           title setText c title           summary setText c summary             Create Items list variable and adapters with very few lines by passing items  class and layout in the adapter  List lt Events gt  items   new ArrayList lt  gt     MyRecyclerView recycler   findViewById R id recycler   RecyclerViewAdapter adapter   new RecyclerViewAdapter this  items  EVHolder class  R layout row event   recycler setAdapter adapter     ClickListener can be added with following lines  recycler setOnItemClickListener new MyRecyclerView OnItemClickListener          Override     public void onItemClick int position            Toast makeText MainActivity this   Recycler Item Clicked     position  Toast LENGTH SHORT  show                Its all done   More example and implementation can be found here   Hope this helps

User · Answer

Minimal Recycler view ready to use Kotlin template for    Vertical layout A single TextView on each row Responds to click events  Single and LongPress    I know this is an old thread and so are answers here  Adding this answer for future reference   Add a recycle view in your layout      lt android support v7 widget RecyclerView             android id    id wifiList              android layout width  match parent              android layout height  match parent               gt     Create a layout to display list items  list item xml    lt  xml version  1 0  encoding  utf-8   gt   lt android support v7 widget CardView     xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  wrap content  gt       lt LinearLayout         android padding  5dp          android layout width  match parent          android orientation  vertical          android layout height  wrap content  gt            lt android support v7 widget AppCompatTextView             android id    id ssid              android text   string app name              android layout width  match parent              android textSize  17sp              android layout height  wrap content    gt        lt  LinearLayout gt    lt  android support v7 widget CardView gt    Now create a minimal Adapter to hold data  code here is self explanatory   class WifiAdapter private val wifiList  ArrayList lt ScanResult gt     RecyclerView Adapter lt WifiAdapter ViewHolder gt               holder class to hold reference     inner class ViewHolder view  View    RecyclerView ViewHolder view              get view reference         var ssid  TextView   view findViewById R id ssid  as TextView             override fun onCreateViewHolder parent  ViewGroup  viewType  Int   ViewHolder               create view holder to hold reference          return ViewHolder  LayoutInflater from parent context  inflate R layout list item  parent  false               override fun onBindViewHolder holder  ViewHolder  position  Int              set values         holder ssid text    wifiList position  SSID            override fun getItemCount    Int           return wifiList size                update your data      fun updateData scanResult  ArrayList lt ScanResult gt              wifiList clear            notifyDataSetChanged            wifiList addAll scanResult           notifyDataSetChanged                Add this class to handle Single click and long click events on List Items  import android content Context  import android support v7 widget RecyclerView  import android view GestureDetector  import android view MotionEvent  import android view View   public class RecyclerTouchListener implements RecyclerView OnItemTouchListener        public interface ClickListener           void onClick View view  int position            void onLongClick View view  RecyclerView recyclerView  int position              private GestureDetector gestureDetector      private ClickListener clickListener       public RecyclerTouchListener Context context  final RecyclerView recyclerView  final ClickListener clickListener            this clickListener   clickListener          gestureDetector   new GestureDetector context  new GestureDetector SimpleOnGestureListener                  Override             public boolean onSingleTapUp MotionEvent e                    return true                              Override             public void onLongPress MotionEvent e                    View child   recyclerView findChildViewUnder e getX    e getY                     if  child    null  amp  amp  clickListener    null                        clickListener onLongClick child recyclerView   recyclerView getChildPosition child                                                             Override     public boolean onInterceptTouchEvent RecyclerView rv  MotionEvent e            View child   rv findChildViewUnder e getX    e getY             if  child    null  amp  amp  clickListener    null  amp  amp  gestureDetector onTouchEvent e                 clickListener onClick child  rv getChildPosition child                      return false              Override     public void onTouchEvent RecyclerView rv  MotionEvent e                 Override     public void onRequestDisallowInterceptTouchEvent boolean disallowIntercept             Lastly Set your adapter to Recycler View and add Touch Listener to start intercepting touch event for single or double tap on list items      wifiAdapter   WifiAdapter ArrayList         wifiList apply              vertical layout         layoutManager   LinearLayoutManager applicationContext             set adapter         adapter   wifiAdapter             Touch handling         wifiList addOnItemTouchListener RecyclerTouchListener applicationContext  wifiList  object   RecyclerTouchListener ClickListener               override fun onClick view  View   position  Int                    Toast makeText applicationContext   RV OnCLickj     position  Toast LENGTH SHORT  show                              override fun onLongClick view  View  recyclerView  RecyclerView  position  Int                    Toast makeText applicationContext   RV OnLongCLickj     position  Toast LENGTH SHORT  show                                              Bonus   Update Data  wifiAdapter updateData mScanResults as ArrayList lt ScanResult gt     Result

User · Answer

Now you need 1 adapter for all RecyclerView   One adapter can be used in for all RecyclerView  So NO onBindViewHolder  No onCreateViewHolder handling  No code for setting adapter from Java Kotlin class  Check sample class  You can set events and custom data for every list by using Binding Adapters      I show here setting two different RecyclerView by 1 adapter -   activity home xml   lt  xml version  1 0  encoding  utf-8   gt   lt layout xmlns android  http   schemas android com apk res android          xmlns app  http   schemas android com apk res-auto  gt        lt data gt            lt variable             name  listOne              type  java util List   gt            lt variable             name  listTwo              type  java util List   gt            lt variable             name  onItemClickListenerOne              type  com ks nestedrecyclerbindingexample callbacks OnItemClickListener   gt            lt variable             name  onItemClickListenerTwo              type  com ks nestedrecyclerbindingexample callbacks OnItemClickListener   gt        lt  data gt        lt LinearLayout         android layout width  match parent          android layout height  match parent          android orientation  vertical  gt            lt android support v7 widget RecyclerView             rvItemLayout     layout row one               rvList    listOne               rvOnItemClick    onItemClickListenerOne               android layout width  match parent              android layout height  wrap content              app layoutManager  android support v7 widget LinearLayoutManager                gt            lt android support v7 widget RecyclerView             rvItemLayout     layout row two               rvList    listTwo               rvOnItemClick    onItemClickListenerTwo               android layout width  match parent              android layout height  wrap content              app layoutManager  android support v7 widget LinearLayoutManager                gt        lt  LinearLayout gt    lt  layout gt    You can see I pass list  item layout id and click listener from layout   rvItemLayout     layout row one   rvList    listOne   rvOnItemClick    onItemClickListenerOne     This custom attributes are created by BindingAdapter   public class BindingAdapters        BindingAdapter value     rvItemLayout    rvList    rvOnItemClick    requireAll   false      public static void setRvAdapter RecyclerView recyclerView  int rvItemLayout  List rvList   Nullable OnItemClickListener onItemClickListener            if  rvItemLayout    0  amp  amp  rvList    null  amp  amp  rvList size    gt  0              recyclerView setAdapter new GeneralAdapter rvItemLayout  rvList  onItemClickListener              Now from Activity  you pass list  click listener like  HomeActivity java  public class HomeActivity extends AppCompatActivity       ActivityHomeBinding binding        Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           binding   DataBindingUtil setContentView this  R layout activity home           binding setListOne new ArrayList        pass your list or set list from response of API         binding setListTwo new ArrayList             binding setOnItemClickListenerOne new OnItemClickListener                  Override             public void onItemClick View view  Object object                    if  object instanceof ModelParent                           TODO  your action here                                                     binding setOnItemClickListenerTwo new OnItemClickListener                  Override             public void onItemClick View view  Object object                    if  object instanceof ModelChild                           TODO  your action here                                                         You don t want read too much  directly clone download full example on from my github repo  And try it yourself   You can see GeneralAdapter java in above repo   If you have problems while setting up data binding  please see this answer

User · Answer

You can use abstract adapter with diff utils and filter  SimpleAbstractAdapter kt  abstract class SimpleAbstractAdapter lt T gt  private var items  ArrayList lt T gt    arrayListOf      RecyclerView Adapter lt SimpleAbstractAdapter VH gt         protected var listener  OnViewHolderListener lt T gt     null    private val filter   ArrayFilter      private val lock   Any      protected abstract fun getLayout    Int    protected abstract fun bindView item  T  viewHolder  VH     protected abstract fun getDiffCallback    DiffCallback lt T gt      private var onFilterObjectCallback  OnFilterObjectCallback    null    private var constraint  CharSequence        override fun onBindViewHolder vh  VH  position  Int        getItem position   let   bindView it  vh       override fun onCreateViewHolder parent  ViewGroup  viewType  Int   VH       return VH parent  getLayout       override fun getItemCount    Int   items size  protected abstract class DiffCallback lt T gt    DiffUtil Callback         private val mOldItems   ArrayList lt T gt        private val mNewItems   ArrayList lt T gt         fun setItems oldItems  List lt T gt   newItems  List lt T gt             mOldItems clear           mOldItems addAll oldItems          mNewItems clear           mNewItems addAll newItems             override fun getOldListSize    Int           return mOldItems size            override fun getNewListSize    Int           return mNewItems size            override fun areItemsTheSame oldItemPosition  Int  newItemPosition  Int   Boolean           return areItemsTheSame                  mOldItems oldItemPosition                   mNewItems newItemPosition                       abstract fun areItemsTheSame oldItem  T  newItem  T   Boolean      override fun areContentsTheSame oldItemPosition  Int  newItemPosition  Int   Boolean           return areContentsTheSame                  mOldItems oldItemPosition                   mNewItems newItemPosition                       abstract fun areContentsTheSame oldItem  T  newItem  T   Boolean    class VH parent  ViewGroup   LayoutRes layout  Int    RecyclerView ViewHolder LayoutInflater from parent context  inflate layout  parent  false    interface OnViewHolderListener lt T gt        fun onItemClick position  Int  item  T     fun getItem position  Int   T        return items getOrNull position     fun getItems    ArrayList lt T gt        return items    fun setViewHolderListener listener  OnViewHolderListener lt T gt         this listener   listener    fun addAll list  List lt T gt         val diffCallback   getDiffCallback       when           diffCallback    null  amp  amp   items isEmpty   - gt                diffCallback setItems items  list              val diffResult   DiffUtil calculateDiff diffCallback              items clear               items addAll list              diffResult dispatchUpdatesTo this                    diffCallback    null  amp  amp   items isEmpty   - gt                items clear               items addAll list              notifyDataSetChanged                     else - gt                items addAll list              notifyDataSetChanged                      fun add item  T        items add item      notifyDataSetChanged      fun add position Int  item  T        items add position item      notifyItemInserted position     fun remove position  Int        items removeAt position      notifyItemRemoved position     fun remove item  T        items remove item      notifyDataSetChanged      fun clear notify  Boolean false        items clear       if  notify            notifyDataSetChanged            fun setFilter filter  SimpleAdapterFilter lt T gt    ArrayFilter       return this filter setFilter filter     interface SimpleAdapterFilter lt T gt        fun onFilterItem contains  CharSequence  item  T   Boolean    fun convertResultToString resultValue  Any   CharSequence       return filter convertResultToString resultValue     fun filter constraint  CharSequence        this constraint   constraint     filter filter constraint     fun filter constraint  CharSequence  listener  Filter FilterListener        this constraint   constraint     filter filter constraint  listener     fun getFilter    Filter       return filter    interface OnFilterObjectCallback       fun handle countFilterObject  Int     fun setOnFilterObjectCallback objectCallback  OnFilterObjectCallback        onFilterObjectCallback   objectCallback    inner class ArrayFilter   Filter         private var original  ArrayList lt T gt    arrayListOf       private var filter  SimpleAdapterFilter lt T gt    DefaultFilter       private var list  ArrayList lt T gt    arrayListOf       private var values  ArrayList lt T gt    arrayListOf         fun setFilter filter  SimpleAdapterFilter lt T gt    ArrayFilter           original   items         this filter   filter         return this            override fun performFiltering constraint  CharSequence    Filter FilterResults           val results   Filter FilterResults           if  constraint    null    constraint isBlank                  synchronized lock                    list   original                           results values   list             results count   list size           else               synchronized lock                    values   original                           val result   ArrayList lt T gt                for  value in values                    if  constraint  null  amp  amp  constraint trim   isNotEmpty    amp  amp  value    null                        if  filter onFilterItem constraint  value                             result add value                                          else                       value  let   result add it                                                results values   result             results count   result size                   return results            override fun publishResults constraint  CharSequence  results  Filter FilterResults            items   results values as  ArrayList lt T gt     arrayListOf           notifyDataSetChanged           onFilterObjectCallback  handle results count            class DefaultFilter lt T gt    SimpleAdapterFilter lt T gt        override fun onFilterItem contains  CharSequence  item  T   Boolean           val valueText   item toString   toLowerCase           if  valueText startsWith contains toString                   return true           else               val words   valueText split     toRegex    dropLastWhile   it isEmpty     toTypedArray               for  word in words                    if  word contains contains                         return true                                                   return false               And extend abstract adapter with implements methods  TasksAdapter kt  import android annotation SuppressLint   import kotlinx android synthetic main task item layout view    class TasksAdapter private val listener TasksListener    null    SimpleAbstractAdapter lt Task gt      override fun getLayout    Int       return R layout task item layout    override fun getDiffCallback    DiffCallback lt Task gt         return object   DiffCallback lt Task gt              override fun areItemsTheSame oldItem  Task  newItem  Task   Boolean               return oldItem id    newItem id                    override fun areContentsTheSame oldItem  Task  newItem  Task   Boolean               return oldItem items    newItem items                     SuppressLint  SetTextI18n   override fun bindView item  Task  viewHolder  VH        viewHolder itemView apply           val position   viewHolder adapterPosition         val customer   item customer         val customerName   if  customer    null  customer name else            tvTaskCommentTitle text   customerName           item id         tvCommentContent text   item taskAddress         ivCall setOnClickListener               listener  onCallClick position  item                    setOnClickListener               listener  onItemClick position  item                      interface TasksListener   SimpleAbstractAdapter OnViewHolderListener lt Task gt        fun onCallClick position  Int  item  Task         Init adapter  mAdapter   TasksAdapter object   TasksAdapter TasksListener               override fun onCallClick position  Int  item Task                               override fun onItemClick position  Int  item Task                              rvTasks adapter   mAdapter   and fill  mAdapter  addAll tasks    add custom filter   mAdapter  setFilter object   SimpleAbstractAdapter SimpleAdapterFilter lt MoveTask gt                override fun onFilterItem contains  CharSequence  item Task   Boolean                   return contains toString   toLowerCase   contains item id  toLowerCase   toString                           filter data  mAdapter  filter  test

User · Answer

Start by adding recyclerview library   implementation  androidx recyclerview recyclerview 1 1 0    Create model class        public class UserModel implements Serializable        private String userName        public UserModel String userName            this userName   userName             public String getUserName             return userName             public void setUserName String userName            this userName   userName               create adapter class   public class UsersAdapter extends RecyclerView Adapter lt UsersAdapter UsersAdapterVh gt  implements Filterable        private List lt UserModel gt  userModelList      private List lt UserModel gt  getUserModelListFiltered      private Context context      private SelectedUser selectedUser       public UsersAdapter List lt UserModel gt  userModelList SelectedUser selectedUser            this userModelList   userModelList          this getUserModelListFiltered   userModelList          this selectedUser   selectedUser              NonNull      Override     public UsersAdapter UsersAdapterVh onCreateViewHolder  NonNull ViewGroup parent  int viewType            context   parent getContext             return new UsersAdapterVh LayoutInflater from context  inflate R layout row users null                Override     public void onBindViewHolder  NonNull UsersAdapter UsersAdapterVh holder  int position             UserModel userModel   userModelList get position            String username   userModel getUserName            String prefix   userModel getUserName   substring 0 1            holder tvUsername setText username           holder tvPrefix setText prefix                Override     public int getItemCount             return userModelList size                Override     public Filter getFilter              Filter filter   new Filter                  Override             protected FilterResults performFiltering CharSequence charSequence                    FilterResults filterResults   new FilterResults                     if charSequence    null   charSequence length      0                       filterResults count   getUserModelListFiltered size                        filterResults values   getUserModelListFiltered                    else                      String searchChr   charSequence toString   toLowerCase                         List lt UserModel gt  resultData   new ArrayList lt  gt                          for UserModel userModel  getUserModelListFiltered                           if userModel getUserName   toLowerCase   contains searchChr                                resultData add userModel                                                                       filterResults count   resultData size                        filterResults values   resultData                                      return filterResults                              Override             protected void publishResults CharSequence charSequence  FilterResults filterResults                     userModelList    List lt UserModel gt   filterResults values                  notifyDataSetChanged                                      return filter              public interface SelectedUser           void selectedUser UserModel userModel               public class UsersAdapterVh extends RecyclerView ViewHolder            TextView tvPrefix          TextView tvUsername          ImageView imIcon          public UsersAdapterVh  NonNull View itemView                super itemView               tvPrefix   itemView findViewById R id prefix               tvUsername   itemView findViewById R id username               imIcon   itemView findViewById R id imageView                itemView setOnClickListener new View OnClickListener                      Override                 public void onClick View view                        selectedUser selectedUser userModelList get getAdapterPosition                                                              create layout row uses xml       lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout xmlns android  http   schemas android com apk res android      android orientation  vertical  android layout width  match parent      android layout height  match parent  gt        lt RelativeLayout         android layout width  match parent          android padding  10dp          android layout height  wrap content  gt            lt RelativeLayout             android layout width  50dp              android background   drawable users bg              android layout height  50dp  gt               lt TextView                 android id    id prefix                  android layout width  wrap content                  android textSize  16sp                  android textColor   color headerColor                  android text  T                  android layout centerInParent  true                  android layout height  wrap content   gt            lt  RelativeLayout gt           lt TextView             android id    id username              android layout width  wrap content              android textSize  16sp              android textColor   color headerColor              android text  username              android layout marginStart  90dp              android layout centerVertical  true              android layout height  wrap content   gt           lt ImageView             android layout width  wrap content              android id    id imageView              android layout margin  10dp              android layout alignParentEnd  true              android src   drawable ic navigate next black 24dp              android layout height  wrap content   gt       lt  RelativeLayout gt    lt  LinearLayout gt    Find recyclerview and populate data   Toolbar toolbar  RecyclerView recyclerView   List lt UserModel gt  userModelList   new ArrayList lt  gt      String   names     Richard   Alice   Hannah   David     UsersAdapter usersAdapter     Override protected void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout activity main        recyclerView   findViewById R id recyclerview       toolbar   findViewById R id toolbar        this setSupportActionBar toolbar       this getSupportActionBar   setTitle           recyclerView setLayoutManager new LinearLayoutManager this        recyclerView addItemDecoration new DividerItemDecoration this DividerItemDecoration VERTICAL         for String s names           UserModel userModel   new UserModel s            userModelList add userModel              usersAdapter   new UsersAdapter userModelList this        recyclerView setAdapter usersAdapter        find full tutorial and source code here   Android RecyclerView

User · Answer

implementation androidx recyclerview recyclerview      It is advised to update to the androidx libraries which are here   https   developer android com jetpack androidx releases recyclerview  The layout file Widget XML tag then must be updated to  androidx recyclerview widget RecyclerView

User · Answer

This will be the simplest version of the implementation of RecyclerView   activity main xml  lt  xml version  quot 1 0 quot  encoding  quot utf-8 quot   gt   lt FrameLayout xmlns android  quot http   schemas android com apk res android quot      xmlns app  quot http   schemas android com apk res-auto quot      xmlns tools  quot http   schemas android com tools quot      android layout width  quot match parent quot      android layout height  quot match parent quot      tools context  quot  MainActivity quot  gt        lt androidx recyclerview widget RecyclerView         android layout width  quot match parent quot          android layout height  quot match parent quot          android id  quot   id recycler view quot   gt    lt  FrameLayout gt   list item view xml  lt  xml version  quot 1 0 quot  encoding  quot utf-8 quot   gt   lt LinearLayout xmlns android  quot http   schemas android com apk res android quot      android layout width  quot match parent quot      android layout height  quot 46dp quot  gt        lt TextView         android layout width  quot wrap content quot          android layout height  quot wrap content quot          android id  quot   id textview quot          android text  quot TextView quot          android textSize  quot 16dp quot    gt    lt  LinearLayout gt   CustomAdapter java public class CustomAdapter extends RecyclerView Adapter lt CustomAdapter ViewHolder gt      private List lt String gt  data    public CustomAdapter  List lt String gt  data       this data   data          Override   public CustomAdapter ViewHolder onCreateViewHolder ViewGroup parent  int viewType        View rowItem   LayoutInflater from parent getContext    inflate R layout list item view  parent  false       return new ViewHolder rowItem           Override   public void onBindViewHolder CustomAdapter ViewHolder holder  int position        holder textView setText this data get position            Override   public int getItemCount         return this data size           public static class ViewHolder extends RecyclerView ViewHolder implements View OnClickListener       private TextView textView       public ViewHolder View view          super view         view setOnClickListener this         this textView   view findViewById R id textview               Override     public void onClick View view          Toast makeText view getContext     quot position    quot    getLayoutPosition      quot  text    quot    this textView getText    Toast LENGTH SHORT  show                 MainActivity java public class MainActivity extends AppCompatActivity       Override   protected void onCreate Bundle savedInstanceState        super onCreate savedInstanceState       setContentView R layout activity main        RecyclerView recyclerView   findViewById R id recycler view            recyclerView setLayoutManager new LinearLayoutManager this        recyclerView setAdapter new CustomAdapter generateData          recyclerView addItemDecoration new DividerItemDecoration this  DividerItemDecoration VERTICAL           private List lt String gt  generateData         List lt String gt  data   new ArrayList lt  gt         for  int i   0  i  lt  100  i            data add String valueOf i     quot th Element quot              return data

User · Answer

To get started   just to view something in Recycler view recycler view adapter can be something like this  class CustomAdapter  RecyclerView Adapter lt CustomAdapter ViewHolder gt          var data    listOf lt String gt            set value                field   value             notifyDataSetChanged                 override fun getItemCount    data size      override fun onBindViewHolder holder  ViewHolder  position  Int            holder txt text  data position            override fun onCreateViewHolder parent  ViewGroup  viewType  Int   ViewHolder           return ViewHolder              LayoutInflater from parent context  inflate R layout item view  parent  false                        class ViewHolder itemView  View    RecyclerView ViewHolder itemView           val txt  TextView   itemView findViewById R id item text view           and to attach the adapter to the recycler view and to attach data to adapter val view   findViewById lt RecyclerView gt  R id recycler view                                                val adapter   CustomAdapter                                                                             val data   listOf  quot text1 quot    quot text2 quot    quot text3 quot   adapter data   data                                                                              view layoutManager   LinearLayoutManager this  RecyclerView VERTICAL  false  view adapter   adapter

User · Answer

Dependencies compile  com android support appcompat-v7 25 3 1  compile  com android support design 25 3 1  compile  com android support multidex 1 0 1  compile  com android support cardview-v7 25 3 1  compile  com android support support-v4 25 3 1  compile  com lguipeng bubbleview library 1 0 0  compile  com larswerkman HoloColorPicker 1 5  compile  com mcxiaoke volley library-aar 1 0 0   One Class For Click Item import android content Context  import android support v7 widget RecyclerView  import android view GestureDetector  import android view MotionEvent  import android view View   public class RecyclerItemClickListener implements RecyclerView OnItemTouchListener       private OnItemClickListener mListener       public interface OnItemClickListener           public void onItemClick View view  int position              GestureDetector mGestureDetector       public RecyclerItemClickListener Context context  OnItemClickListener listener            mListener   listener          mGestureDetector   new GestureDetector context  new GestureDetector SimpleOnGestureListener                  Override             public boolean onSingleTapUp MotionEvent e                    return true                                        Override     public boolean onInterceptTouchEvent RecyclerView view  MotionEvent e            View childView   view findChildViewUnder e getX    e getY             if  childView    null  amp  amp  mListener    null  amp  amp  mGestureDetector onTouchEvent e                 mListener onItemClick childView  view getChildPosition childView                return true                    return false              Override     public void onTouchEvent RecyclerView view  MotionEvent motionEvent            Override     public void onRequestDisallowInterceptTouchEvent boolean disallowIntercept                Second Class RecyclerView import android annotation SuppressLint  import android app ProgressDialog  import android content BroadcastReceiver  import android content Context  import android content Intent  import android content IntentFilter  import android net Uri  import android os Bundle  import android support annotation Nullable  import android support v4 app Fragment  import android support v4 app FragmentTransaction  import android support v4 content LocalBroadcastManager  import android support v7 widget LinearLayoutManager  import android support v7 widget RecyclerView  import android util Log  import android view LayoutInflater  import android view View  import android view ViewGroup  import android widget Toast   import com android volley DefaultRetryPolicy  import com android volley Request  import com android volley RequestQueue  import com android volley Response  import com android volley VolleyError  import com android volley toolbox StringRequest  import com android volley toolbox Volley   import org json JSONArray  import org json JSONException  import org json JSONObject  import java util ArrayList   public class SLByTopics extends Fragment         public static ArrayList lt MByTopics gt  byTopicsMainArrayList new ArrayList lt  gt           TabRefreshReceiver tabRefreshReceiver      RecyclerView recyclerView      SAdpByTopics sAdpByTopics      public ArrayList lt MByTopics gt  mByTopicsArrayList new ArrayList lt  gt         ProgressDialog progressDialog       public SLByTopics                Override     public void onCreate  Nullable Bundle savedInstanceState            super onCreate savedInstanceState               Override     public View onCreateView LayoutInflater inflater   Nullable ViewGroup container   Nullable Bundle savedInstanceState            View view   inflater inflate R layout sl fragment by topics  container  false            progressDialog   new ProgressDialog getActivity             if  IsOnline isNetworkAvailable getActivity                   getCategoryTree              else              IsOnline showNoInterNetMessage getActivity                       tabRefreshReceiver   new TabRefreshReceiver           LocalBroadcastManager getInstance getContext    registerReceiver tabRefreshReceiver  new IntentFilter  quot BY TOPICS quot              setUpView view           return view             private void setUpView View view             recyclerView  RecyclerView view findViewById R id by topics list recyclerView           LinearLayoutManager linearLayoutManager new LinearLayoutManager getActivity             linearLayoutManager setOrientation LinearLayoutManager VERTICAL           recyclerView setLayoutManager linearLayoutManager               Override     public void onResume             super onResume             recyclerView addOnItemTouchListener new RecyclerItemClickListener getActivity    new RecyclerItemClickListener OnItemClickListener                  Override             public void onItemClick View view  final int position                     if  mByTopicsArrayList get position  getChild   size   gt 0                       Intent intent   new Intent getActivity    SByTopicCategory class                       intent putExtra  quot selectedCategoryName quot  mByTopicsArrayList get position  getCatname                         intent putExtra  quot jsonData quot  mByTopicsArrayList get position  getMainTopicJson                         startActivity intent                       getActivity   overridePendingTransition R anim activity in  R anim activity out                    else                       Intent intent   new Intent getActivity    SByCategoryQuestionList class                       intent putExtra  quot selectedSubCategoryName quot  mByTopicsArrayList get position  getCatname                         intent putExtra  quot catID quot  mByTopicsArrayList get position  getId                         startActivity intent                       getActivity   overridePendingTransition R anim activity in  R anim activity out                                                            private class TabRefreshReceiver extends BroadcastReceiver            Override         public void onReceive Context context  Intent intent                try                   FragmentTransaction ft   getFragmentManager   beginTransaction                    ft detach SLByTopics this  attach SLByTopics this  commit                    LocalBroadcastManager getInstance getContext    unregisterReceiver tabRefreshReceiver                 catch  Exception e                    e printStackTrace                                        private void getCategoryTree             progressDialog setMessage  quot Please Wait    quot            progressDialog setCancelable false           progressDialog show             StringRequest stringRequest   new StringRequest Request Method POST  Const HOSTNAME   Const STUDENT GET CATEGORY TREE                  new Response Listener lt String gt                           SuppressLint  quot LongLogTag quot                        Override                     public void onResponse String response                            try                               JSONObject object   new JSONObject response                               String status   object getString  quot status quot                                int i   Integer parseInt status                                switch  i                                     case 0                                      progressDialog dismiss                                          Toast makeText getActivity     quot getCategorySuccess quot   Toast LENGTH SHORT  show                                        Log e  quot getCategoryTree Response quot    quot getCategoryTree Response    quot    response                                        try                                               byTopicsMainArrayList clear                                            JSONArray info   object getJSONArray  quot info quot                                            if  info length    gt  0                                                for  i   0  i  lt  info length    i                                                      JSONObject data   info getJSONObject i                                                   MByTopics mByTopics   new MByTopics                                                    mByTopics setId data getString  quot id quot                                                     mByTopics setCatname data getString  quot catname quot                                                     mByTopics setMainTopicJson data toString                                                      JSONArray topicChildren   data getJSONArray  quot children quot                                                    ArrayList lt SMByTopicCategory gt  byChildrenArrayList   new ArrayList lt  gt                                                      for  int j   0  j  lt  topicChildren length    j                                                          JSONObject topicChildrenData   topicChildren getJSONObject j                                                       SMByTopicCategory smByTopicCategory   new SMByTopicCategory                                                        smByTopicCategory setId topicChildrenData getString  quot id quot                                                         smByTopicCategory setCatname topicChildrenData getString  quot catname quot                                                         smByTopicCategory setChildTopicJson topicChildrenData toString                                                          JSONArray topicChildrenQuestion   topicChildrenData getJSONArray  quot children quot                                                        ArrayList lt SMByTopicSubCategory gt  byChildrenSubArrayList   new ArrayList lt  gt                                                          for  int k   0  k  lt  topicChildrenQuestion length    k                                                              JSONObject topicChildrenSubData   topicChildrenQuestion getJSONObject k                                                           SMByTopicSubCategory smByTopicSubCategory   new SMByTopicSubCategory                                                            smByTopicSubCategory setId topicChildrenSubData getString  quot id quot                                                             smByTopicSubCategory setCatname topicChildrenSubData getString  quot catname quot                                                             smByTopicSubCategory setChildSubTopicJson topicChildrenSubData toString                                                              byChildrenSubArrayList add smByTopicSubCategory                                                                                                              smByTopicCategory setQuestions byChildrenSubArrayList                                                        byChildrenArrayList add smByTopicCategory                                                                                                     mByTopics setChild byChildrenArrayList                                                   byTopicsMainArrayList add mByTopics                                                                                               mByTopicsArrayList clear                                                mByTopicsArrayList byTopicsMainArrayList                                              sAdpByTopics new SAdpByTopics mByTopicsArrayList getActivity                                                 recyclerView setAdapter sAdpByTopics                                               sAdpByTopics notifyDataSetChanged                                                                                     catch  Exception e                                           e printStackTrace                                                                              break                                   default                                      progressDialog dismiss                                          Toast makeText getActivity     quot getCategoryError    quot    response  Toast LENGTH SHORT  show                                        Log e  quot getCategoryTree Not Response quot    quot getCategoryTree Uploading Not Response    quot    response                                                            catch  JSONException e                                e printStackTrace                                                                                       new Response ErrorListener                          Override                     public void onErrorResponse VolleyError error                            progressDialog dismiss                            Log e  quot getCategoryTree Error   quot   quot getCategoryTree Error   quot  error getMessage                               Toast makeText getActivity    error getMessage    Toast LENGTH LONG  show                                                                           Override             protected Map lt String  String gt  getParams   throws AuthFailureError                    Map lt String  String gt  map   new HashMap lt String  String gt                       map put  quot uid quot   String valueOf ConfigManager getUserId                      return map                                      stringRequest setRetryPolicy new DefaultRetryPolicy                  0                  DefaultRetryPolicy DEFAULT MAX RETRIES                  DefaultRetryPolicy DEFAULT BACKOFF MULT             RequestQueue requestQueue   Volley newRequestQueue getActivity             requestQueue add stringRequest            Adapter Class For Recycler Item import android app Activity  import android support v7 widget RecyclerView  import android view LayoutInflater  import android view View  import android view ViewGroup  import android widget TextView  import java util ArrayList   public class SAdpByTopics extends RecyclerView Adapter lt RecyclerView ViewHolder gt            ArrayList lt MByTopics gt  topicsArrayList new ArrayList lt  gt             Activity activity        public SAdpByTopics ArrayList lt MByTopics gt  topicsArrayList Activity activity           this topicsArrayList topicsArrayList          this activity activity                Override      public RecyclerView ViewHolder onCreateViewHolder ViewGroup parent  int viewType            View itemeView  LayoutInflater from parent getContext    inflate R layout list item by topic list parent false           RecyclerView ViewHolder holder new Holder itemeView           holder setIsRecyclable false           return holder                Override      public void onBindViewHolder RecyclerView ViewHolder holder  int position             final Holder classHolder    Holder  holder           try               classHolder txt topic name setText topicsArrayList get position  getCatname               catch  Exception e                e printStackTrace                             Override      public int getItemCount             return topicsArrayList size             class Holder extends RecyclerView ViewHolder implements View OnClickListener       TextView txt topic name       public Holder View itemView            super itemView           txt topic name    TextView  itemView findViewById R id txt topic name               Override     public void onClick View v                Module Class public class MByTopics        String id      String topicName      String catname      String MainTopicJson      ArrayList lt SMByTopicCategory gt  child      ArrayList lt SMByTopicSubCategory gt  questions       public void setId String id           this id id            public String getId            return  id             public void setCatname String catname            this catname   catname             public String getCatname             return catname             public void setTopicName String topicName            this topicName   topicName            public String getTopicName             return topicName             public void setChild ArrayList lt SMByTopicCategory gt  child            this child   child             public String getMainTopicJson             return MainTopicJson             public void setMainTopicJson String mainTopicJson            MainTopicJson   mainTopicJson             public ArrayList lt SMByTopicCategory gt  getChild             return child             public void setQuestions ArrayList lt SMByTopicSubCategory gt  questions            this questions   questions             public ArrayList lt SMByTopicSubCategory gt  getQuestions             return questions             public ArrayList lt MByTopics gt  getByTopicList             ArrayList lt MByTopics gt  mByTopicsArrayList   new ArrayList lt  gt              for  int i 0 i lt 11 i                 MByTopics mQuestionBankCategory new MByTopics                 if  i  1    i   5   i  9                   mQuestionBankCategory setTopicName  quot Microeconomics quot                 else  if  i  2    i   10   i  6                    mQuestionBankCategory setTopicName  quot Macroeconomics quot                 else                   mQuestionBankCategory setTopicName  quot Current Isssues quot                               mByTopicsArrayList add mQuestionBankCategory                      return mByTopicsArrayList

User · Answer

Since I cant comment yet im gonna post as an answer the link   I have found a simple  well organized tutorial on recyclerview http   www androiddeft com 2017 10 01 recyclerview-android   Apart from that when you are going to add a recycler view into you activity what you want to do is as below and how you should do this has been described on the link    add RecyclerView component into your layout file make a class which you are going to display as list rows make a layout file which is the layout of a row of you list now we need a custom adapter so create a custom adapter by extending from the parent class RecyclerView Adapter add recyclerview into your mainActivity oncreate adding separators adding Touch listeners

User · Answer

The following is a minimal example that will look like the following image     Start with an empty activity  You will perform the following tasks to add the RecyclerView  All you need to do is copy and paste the code in each section  Later you can customize it to fit your needs    Add dependencies to gradle Add the xml layout files for the activity and for the RecyclerView row Make the RecyclerView adapter Initialize the RecyclerView in your activity    Update Gradle dependencies  Make sure the following dependencies are in your app gradle build file   implementation  com android support appcompat-v7 28 0 0  implementation  com android support recyclerview-v7 28 0 0    You can update the version numbers to whatever is the most current  Use compile rather than implementation if you are still using Android Studio 2 x   Create activity layout  Add the RecyclerView to your xml layout   activity main xml   lt  xml version  1 0  encoding  utf-8   gt   lt RelativeLayout     xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  match parent  gt        lt android support v7 widget RecyclerView         android id    id rvAnimals          android layout width  match parent          android layout height  match parent   gt    lt  RelativeLayout gt    Create row layout  Each row in our RecyclerView is only going to have a single TextView  Create a new layout resource file   recyclerview row xml   lt  xml version  1 0  encoding  utf-8   gt   lt LinearLayout     xmlns android  http   schemas android com apk res android      android layout width  match parent      android layout height  wrap content      android orientation  horizontal      android padding  10dp  gt        lt TextView         android id    id tvAnimalName          android layout width  wrap content          android layout height  wrap content          android textSize  20sp   gt    lt  LinearLayout gt    Create the adapter  The RecyclerView needs an adapter to populate the views in each row with your data  Create a new java file   MyRecyclerViewAdapter java  public class MyRecyclerViewAdapter extends RecyclerView Adapter lt MyRecyclerViewAdapter ViewHolder gt         private List lt String gt  mData      private LayoutInflater mInflater      private ItemClickListener mClickListener          data is passed into the constructor     MyRecyclerViewAdapter Context context  List lt String gt  data            this mInflater   LayoutInflater from context           this mData   data                inflates the row layout from xml when needed      Override     public ViewHolder onCreateViewHolder ViewGroup parent  int viewType            View view   mInflater inflate R layout recyclerview row  parent  false           return new ViewHolder view                 binds the data to the TextView in each row      Override     public void onBindViewHolder ViewHolder holder  int position            String animal   mData get position           holder myTextView setText animal                 total number of rows      Override     public int getItemCount             return mData size                   stores and recycles views as they are scrolled off screen     public class ViewHolder extends RecyclerView ViewHolder implements View OnClickListener           TextView myTextView           ViewHolder View itemView                super itemView               myTextView   itemView findViewById R id tvAnimalName               itemView setOnClickListener this                       Override         public void onClick View view                if  mClickListener    null  mClickListener onItemClick view  getAdapterPosition                             convenience method for getting data at click position     String getItem int id            return mData get id                 allows clicks events to be caught     void setClickListener ItemClickListener itemClickListener            this mClickListener   itemClickListener                parent activity will implement this method to respond to click events     public interface ItemClickListener           void onItemClick View view  int position             Notes   Although not strictly necessary  I included the functionality for listening for click events on the rows  This was available in the old ListViews and is a common need  You can remove this code if you don t need it    Initialize RecyclerView in Activity  Add the following code to your main activity   MainActivity java  public class MainActivity extends AppCompatActivity implements MyRecyclerViewAdapter ItemClickListener        MyRecyclerViewAdapter adapter        Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity main               data to populate the RecyclerView with         ArrayList lt String gt  animalNames   new ArrayList lt  gt             animalNames add  Horse            animalNames add  Cow            animalNames add  Camel            animalNames add  Sheep            animalNames add  Goat                set up the RecyclerView         RecyclerView recyclerView   findViewById R id rvAnimals           recyclerView setLayoutManager new LinearLayoutManager this            adapter   new MyRecyclerViewAdapter this  animalNames           adapter setClickListener this           recyclerView setAdapter adapter               Override     public void onItemClick View view  int position            Toast makeText this   You clicked     adapter getItem position      on row number     position  Toast LENGTH SHORT  show              Notes   Notice that the activity implements the ItemClickListener that we defined in our adapter  This allows us to handle row click events in onItemClick    Finished  That s it  You should be able to run your project now and get something similar to the image at the top   Going on  Adding a divider between rows  You can add a simple divider like this  DividerItemDecoration dividerItemDecoration   new DividerItemDecoration recyclerView getContext        layoutManager getOrientation     recyclerView addItemDecoration dividerItemDecoration     If you want something a little more complex  see the following answers    How to add dividers and spaces between items in RecyclerView  How to indent the divider in a linear layout RecyclerView  ie  add padding  margin  or an inset only to the ItemDecoration    Changing row color on click  See this answer for how to change the background color and add the Ripple Effect when a row is clicked     Updating rows  See this answer for how to add  remove  and update rows     Further reading   CodePath YouTube tutorials Android RecyclerView Example  stacktips tutorial  RecyclerView in Android  Tutorial

[android] Simple Android RecyclerView example

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