CountDown Timer not working properly while scrolling?

Question

CountDownTimer is not showing while scrolling

Below is my code;

public void onBindViewHolder(final RecyclerView.ViewHolder viewHolder, final int position) {
{

   if (holder.timer != null) {
        holder.timer.cancel();
    }



  if (!resturantDetails.getRemainingTime().equalsIgnoreCase("") && holder.timer == null) {

            Log.e("AAAAAAAAAAAAAAAAAAAAAAAAA", "" + resturantDetails.getRemainingTime());
            holder.timer = new CountDownTimer(Long.parseLong(resturantDetails.getRemainingTime()), 1000) {
                @Override
                public void onTick(long millisUntilFinished) {

                    long seconds = (millisUntilFinished / 1000) % 60;
                    long minutes = ((millisUntilFinished / (1000 * 60)) % 60);
                    long hours = ((millisUntilFinished / (1000 * 60 * 60)) % 24);

                    holder.tvHour.setText(String.format("%02d", hours));
                    holder.tvMinutes.setText(String.format("%02d", minutes));
                    holder.tvSeconds.setText(String.format("%02d", seconds));
                }

                @Override

                public void onFinish() {

                }
            }.start();
        } 
}

Below is my ViewHolder class;

  public class ResturantDashboardViewHolder extends RecyclerView.ViewHolder {


        CountDownTimer timer;

        public ResturantDashboardViewHolder(View itemView) {
            super(itemView);

        }
    }

`RecyclerView` recycles the view on scroll... that's why `onBindViewHolder` only called when view is visible ... after that view is recycled so it's bad practice to initialize `CountDownTimer `in `onBindViewHolder` that will be initialize again and again — Hanzala, Jan 17 '19 at 05:42
Can you please give me example...I will upvote your answer...plz help me — Vishal Vaishnav, Jan 17 '19 at 05:44
Hii @Hanzala plz show my edited code and give me best solution for this — Vishal Vaishnav, Jan 17 '19 at 05:49
you want to show Remaining Time of something in every item in recyclerView right? — Hanzala, Jan 17 '19 at 05:51
Yupp @Hanzala... Not every item but which time has remaining time flag from api in that item only...bt it not working while scrolling — Vishal Vaishnav, Jan 17 '19 at 05:53
initialize `CountDownTimer` in your activity and add it's reference to adapter so calculate remaining time in `onBindViewHolder` and only call `notifyDataSetChanged()` in `onTick()` method — Hanzala, Jan 17 '19 at 05:56
Can you give me example for this so that I can upvote your answer @Hanzala — Vishal Vaishnav, Jan 17 '19 at 05:58
off the topic, don't use countdown timer as it is never 100% accurate, go for handler — hemen, Jan 17 '19 at 06:39
Can you tell what can use for showing timer on behalf of CountDownTimer in Recyclerview @notTdar — Vishal Vaishnav, Jan 17 '19 at 06:45
https://stackoverflow.com/questions/6242268/repeat-a-task-with-a-time-delay — hemen, Jan 17 '19 at 06:53

score 1 · Answer 1 · answered Jan 17 '19 at 06:03

This problem is simple.

RecyclerView reuses the holders, calling bind each time to update the data in them.

Since you create a CountDownTimer each time any data is bound, you will end up with multiple timers updating the same ViewHolder.

The best thing here would be to cancel it before binding the data (if started) and rescheduling to the desired duration.

public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
    ...
    if (holder.timer != null) {
        holder.timer.cancel();
    }
    holder.timer = new CountDownTimer(expiryTime, 500) {
        ...
    }.start();
}

public static class ResturantDashboardViewHolder extends RecyclerView.ViewHolder {
    ...
    CountDownTimer timer;

    public FeedViewHolder(View itemView) {
        ...
    }
}

This way you will cancel any current timer instance for that ViewHolder prior to starting another timer.

I tried this code...but this is only start counter when visible item in recyclerview... it does not start timer by default at loading recyclerview — Vishal Vaishnav, Jan 17 '19 at 06:16

score 0 · Accepted Answer · answered Jan 17 '19 at 09:55

Finally I got best solution;

Below is adapter code for count down timer

    public class RestaurantListDetailAdapter extends RecyclerView.Adapter<RestaurantListDetailAdapter.ResturantDashboardViewHolder> implements Filterable {

    ArrayList<RestaurantListDetail.DataModel.ResultList> resturantList = new ArrayList<>();
    Context mContext;
    Utils utils;
    String latitude, longitude;
    OffersAdapter offersAdapter;
    private ArrayList<RestaurantListDetail.DataModel.ResultList> mFilteredList;

    public RestaurantListDetailAdapter(ArrayList res, Context mContext, String latitude, String longitude) {
        this.resturantList = res;
        this.mContext = mContext;
        this.latitude = latitude;
        this.longitude = longitude;

        long maxTime = 0;
        for (RestaurantListDetail.DataModel.ResultList item : resturantList) {
            if (!item.getRemainingTime().equalsIgnoreCase("")) {
                maxTime = Long.parseLong(item.getRemainingTime());
            }
        }

        new CountDownTimer(maxTime, 1000) {
            @Override
            public void onTick(long l) {

                for (int i = 0, dataLength = resturantList.size(); i < dataLength; i++) {
                    RestaurantListDetail.DataModel.ResultList item = resturantList.get(i);
                    if (!item.getRemainingTime().equalsIgnoreCase("")) {
                        item.setRemainingTime(String.valueOf(Long.parseLong(item.getRemainingTime())-1000)) ;
                    }
                }

                //remove the expired items
                //Iterator<RestaurantListDetail.DataModel.ResultList> dataIterator = resturantList.iterator();
                //while (dataIterator.hasNext()) {
                //RestaurantListDetail.DataModel.ResultList rd = dataIterator.next();
                //if (rd.getRemainingTime().equalsIgnoreCase("")) {
                //          dataIterator.remove();
                //                        }
                //                    }
                notifyDataSetChanged();
            }

            @Override
            public void onFinish() {
            // resturantList.clear();
            // notifyDataSetChanged();
            }
        }.start();

    }

    @Override
    public ResturantDashboardViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.dashboard_search_item, parent, false);
        ResturantDashboardViewHolder viewHolder = new ResturantDashboardViewHolder(v);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(final ResturantDashboardViewHolder holder, final int position) {
        final RestaurantListDetail.DataModel.ResultList resturantDetails = resturantList.get(position);

        if (!resturantDetails.getRemainingTime().equalsIgnoreCase(""))
        {
            long seconds = Long.parseLong(resturantDetails.getRemainingTime()) / 1000;
            long minutes = seconds / 60;

            holder.tvHour   .setText(String.format("%02d", TimeUnit.MILLISECONDS.toHours(Long.parseLong(resturantDetails.getRemainingTime()))));
            holder.tvMinutes.setText(String.format("%02d",minutes % 60));
            holder.tvSeconds.setText(String.format("%02d",seconds % 60));
        }

    }

    @Override
    public int getItemCount() {
        return resturantList.size();
    }


    public class ResturantDashboardViewHolder extends RecyclerView.ViewHolder {


        LinearLayout llBookingTable, ll_timer_slot, llOfferLayout, llOffers, rl_offer;
        TextView tv_resturantname, tvSeatLeft, tvListsTags, tvOffers, textView, tvHour, tvMinutes, tvSeconds, tvOutlets, tv_distance, tv_place, tv_rating, tvClosed, tvCostForTwo, tvOffer, tvSuburb;


        public ResturantDashboardViewHolder(View itemView) {
            super(itemView);

            tvOffers = itemView.findViewById(R.id.tvOffers);
            rl_offer = itemView.findViewById(R.id.rl_offer);
            tvSeatLeft = itemView.findViewById(R.id.tvSeatLeft);
            tvListsTags = itemView.findViewById(R.id.tvListsTags);
            textView = itemView.findViewById(R.id.textView);
            llOfferLayout = itemView.findViewById(R.id.llOfferLayout);

            llBookingTable = itemView.findViewById(R.id.llBookingTable);
            ll_timer_slot = itemView.findViewById(R.id.ll_timer_slot);
            tvHour = itemView.findViewById(R.id.tvHour);
            tvMinutes = itemView.findViewById(R.id.tvMinutes);
            tvSeconds = itemView.findViewById(R.id.tvSeconds);
            tvOutlets = itemView.findViewById(R.id.tvOutlets);
            llOffers = itemView.findViewById(R.id.llOffers);
            tvSuburb = itemView.findViewById(R.id.tvSuburb);
            tv_distance = itemView.findViewById(R.id.tv_distance);
            tv_place = itemView.findViewById(R.id.tv_resturant_place);
            tv_resturantname = itemView.findViewById(R.id.tv_resturant_item);
            tv_rating = itemView.findViewById(R.id.tv_rating);
            tvClosed = itemView.findViewById(R.id.tvClosed);
            tvCostForTwo = itemView.findViewById(R.id.tvCostForTwo);
            tvOffer = itemView.findViewById(R.id.tvOffer);
        }
    }

}

CountDown Timer not working properly while scrolling?

2 Answers2