Android: Multiple simultaneous count-down timers in a ListView

Question

I am creating an app that requires a ListView with an undetermined number of elements, each of which has a timer that counts down from a variable number. I am able to succes

Answer 1

This is an example of the way I do it and it works perfect:

public class TestCounterActivity extends ListActivity
{
    TestAdapter adapter;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        // Example values
        ArrayList values = new ArrayList();
        values.add(new Date(1482464366239L));
        values.add(new Date(1480464366239L));
        values.add(new Date(1470464366239L));
        values.add(new Date(1460464366239L));
        values.add(new Date(1450464366239L));
        values.add(new Date(1440464366239L));
        values.add(new Date(1430464366239L));
        values.add(new Date(1420464366239L));
        values.add(new Date(1410464366239L));
        values.add(new Date(1490464366239L));

        adapter = new TestAdapter(this, values);

        setListAdapter(adapter);
    }

    @Override
    protected void onStop()
    {
        super.onStop();

        // Dont forget to cancel the running timers
        adapter.cancelAllTimers();
    }
}

And this is the adapter

public class TestAdapter extends ArrayAdapter 
{
    private final Activity context;
    private final List values;
    private HashMap counters;

    static class TestViewHolder 
    {
        public TextView tvCounter;
    }

    public TestAdapter(Activity context, List values) 
    {
        super(context, R.layout.test_row, values);
        this.context = context;
        this.values = values;
        this.counters = new HashMap();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
    {
        View rowView = convertView;

        if(rowView == null)
        {
            LayoutInflater inflater = context.getLayoutInflater();
            rowView = inflater.inflate(R.layout.test_row, null);
            final TestViewHolder viewHolder = new TestViewHolder();
            viewHolder.tvCounter = (TextView) rowView.findViewById(R.id.tvCounter);

            rowView.setTag(viewHolder);
        }

        TestViewHolder holder = (TestViewHolder) rowView.getTag();
        final TextView tv = holder.tvCounter;

        CountDownTimer cdt = counters.get(holder.tvCounter);
        if(cdt!=null)
        {
            cdt.cancel();
            cdt=null;
        }

        Date date = values.get(position);
        long currentDate = Calendar.getInstance().getTime().getTime();
        long limitDate = date.getTime();
        long difference = limitDate - currentDate;

        cdt = new CountDownTimer(difference, 1000)
        {
            @Override
            public void onTick(long millisUntilFinished) 
            {
                int days = 0;
                int hours = 0;
                int minutes = 0;
                int seconds = 0;
                String sDate = "";

                if(millisUntilFinished > DateUtils.DAY_IN_MILLIS)
                {
                    days = (int) (millisUntilFinished / DateUtils.DAY_IN_MILLIS);
                    sDate += days+"d";
                }

                millisUntilFinished -= (days*DateUtils.DAY_IN_MILLIS);

                if(millisUntilFinished > DateUtils.HOUR_IN_MILLIS)
                {
                    hours = (int) (millisUntilFinished / DateUtils.HOUR_IN_MILLIS);
                }

                millisUntilFinished -= (hours*DateUtils.HOUR_IN_MILLIS);

                if(millisUntilFinished > DateUtils.MINUTE_IN_MILLIS)
                {
                    minutes = (int) (millisUntilFinished / DateUtils.MINUTE_IN_MILLIS);
                }

                millisUntilFinished -= (minutes*DateUtils.MINUTE_IN_MILLIS);

                if(millisUntilFinished > DateUtils.SECOND_IN_MILLIS)
                {
                    seconds = (int) (millisUntilFinished / DateUtils.SECOND_IN_MILLIS);
                }

                sDate += " "+String.format("%02d",hours)+":"+String.format("%02d",minutes)+":"+String.format("%02d",seconds);
                tv.setText(sDate.trim());
            }

            @Override
            public void onFinish() {
                tv.setText("Finished");
            }
        };

        counters.put(tv, cdt);
        cdt.start();

        return rowView;
    }

    public void cancelAllTimers()
    {
        Set> s = counters.entrySet();
        Iterator it = s.iterator();
        while(it.hasNext())
        {
            try
            {
                Map.Entry pairs = (Map.Entry)it.next();
                CountDownTimer cdt = (CountDownTimer)pairs.getValue();

                cdt.cancel();
                cdt = null;
            }
            catch(Exception e){}
        }

        it=null;
        s=null;
        counters.clear();
    }
}