CODEWITHSUNDEEP
androidmultithreadingandroid-recyclerviewandroid-handler
Aditya Vyas-Lakhan
Aditya Vyas-Lakhan

Reputation: 13555

How to show recyclerview items in time interval?

I want to display recyclerview items after every 10 seconds. For instance, I have 8 items in my arraylist. Initially I want to display 3 items, then after waiting for 10 seconds first three visible items will disappear and next 3 items will show. how to achieve it ?

private void addList(){
        ItemAdapter itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.cachua);
        itemAdapter.setText("Tomato");
        mList.add(itemAdapter);

        itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.bo);
        itemAdapter.setText("butter");
        mList.add(itemAdapter);

        itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.cam);
        itemAdapter.setText("oranges");
        mList.add(itemAdapter);

        mAdapter = new ListAdapter(mList, this);
        mRecycleview.setAdapter(mAdapter);
        mRecycleview.setLayoutManager(new LinearLayoutManager(this));
        mAdapter.notifyDataSetChanged();
        Log.d("anhtt","mlist : " +mList.size());
        mList.clear();


        itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.quaxoai);
        itemAdapter.setText("mango");
        mList.add(itemAdapter);

        itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.dau);
        itemAdapter.setText("strawberry");
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        mAdapter = new ListAdapter(mList, this);
        mRecycleview.setAdapter(mAdapter);
        mRecycleview.setLayoutManager(new LinearLayoutManager(this));
        mAdapter.notifyDataSetChanged();
        Log.d("anhtt","mlist : " +mList.size());
        mList.add(itemAdapter);
        itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.tao);
        itemAdapter.setText("Apple");
        mList.add(itemAdapter);

        mList.add(itemAdapter);
        itemAdapter = new ItemAdapter();
        itemAdapter.setImage(R.drawable.oi);
        itemAdapter.setText("guava fruit");
        mList.add(itemAdapter);
    }

Upvotes: 1

Views: 817

Answers (2)

rahul.taicho
rahul.taicho

Reputation: 1379

You should absolutely avoid using Thread.sleep() on the UI thread to keep it unblocked.

Blocking the UI thread will stop event dispatch (input, drawing events) and to a user the application appears to be frozen. If you end up blocking the UI thread for >5 seconds then the user will see an Application Not Responding dialog which makes for a very poor UX.

For your use-case you could use a Handler to dispatch events to the UI thread in a delayed manner

Here's a rough skeleton that might be resourceful:

public final class ScratchActivity extends AppCompatActivity {

    private static final int INTERVAL_IN_MILLIS = 10000;
    private static final int STEP = 3;

    private Handler mHandler;

    // Backing list of models to update the recycler view
    private final List<Object> mItems = new ArrayList<>();

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mHandler = new Handler(Looper.getMainLooper());
    
        /*
            Set content view for activity etc.
            Initialize recycler view, layout manager and adapter
         */
    
        updateItems(0);
    }

    // Loop periodically to derive a sublist of items to update the recycler view adapter
    private void updateItems(int index) {
        if (index >= mItems.size()) return;
    
        notifyRecyclerView(mItems.subList(index, Math.min(index + STEP, mItems.size())));
        mHandler.postDelayed(() -> updateItems(index + STEP), INTERVAL_IN_MILLIS);
    }

    private void notifyRecyclerView(List<Object> data) {
        // Replace data within the recycler view
    }
}

Upvotes: 1

Muhammad Zahab
Muhammad Zahab

Reputation: 1105

Interesting scenario. I think instead of adding time delays in adapter you should do that stuff in your class where you are passing data to adapter. Try to load first 3 items which you want to show then use handler to make delay of 10 seconds.

Like this :

 final Handler handler = new Handler(Looper.getMainLooper());
    handler.postDelayed(new Runnable() {
      @Override
      public void run() {
        //Do your code to clear list and adding next 3 items and notify your adapter
      }
    }, 10000);

After this you need to clear your list and add next 3 items in list and notify your adapter that data has been updated. With this approach you can achieve your use case.

Upvotes: 2

Related Questions