RecyclerVIew auto scroll to display all the elements as in News Feed etc.,

Question

How to auto scroll RecyclerView smoothly so that user can see all the elements of the RecyclerView and scroll again from the start - as in News Feed etc.

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Answer 1

I think this is the best solution for this.

    final int speedScroll = 150;
    final Handler handler = new Handler();
    final Runnable runnable = new Runnable() {
        int count = 0;
        @Override
        public void run() {
            if(count < list.size()){
                recyclerView.scrollToPosition(count++);
                handler.postDelayed(this,speedScroll);
            }


        }
    };

    handler.postDelayed(runnable,speedScroll);

Answer 2

After Trial And Errors This Works Perfect For Me

    final RecyclerView mRecyclerViewr;
    final ArrayList<String> stringArrayData = new ArrayList<String>
    final LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayoutManager.HORIZONTAL, false);
    mRecyclerViewr.setLayoutManager(linearLayoutManager);
    CustomAdapter customAdapter = new CustomAdapter(getApplicationContext(), topPriceBarList);
    mRecyclerViewr.setAdapter(customAdapter);

        // Auto Scroll Left To Right
        final int scrollSpeed = 100;   // Scroll Speed in Milliseconds
        final Handler handler = new Handler();
        final Runnable runnable = new Runnable() {
            int x = 15;        // Pixels To Move/Scroll
            boolean flag = true;
            // Find Scroll Position By Accessing RecyclerView's LinearLayout's Visible Item Position
            int scrollPosition = linearLayoutManager.findLastCompletelyVisibleItemPosition();  
            int arraySize = stringArrayData.size();  // Gets RecyclerView's Adapter's Array Size

            @Override
            public void run() {
                if (scrollPosition < arraySize) {
                    if (scrollPosition == arraySize - 1) {
                        flag = false;
                    } else if (scrollPosition <= 1) {
                        flag = true;
                    }
                    if (!flag) {
                        try {
                            // Delay in Seconds So User Can Completely Read Till Last String
                            TimeUnit.SECONDS.sleep(1); 
                            mRecyclerViewr.scrollToPosition(0);  // Jumps Back Scroll To Start Point
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                    // Know The Last Visible Item
                    scrollPosition = linearLayoutManager.findLastCompletelyVisibleItemPosition();

                    mRecyclerViewr.smoothScrollBy(x, 0);
                    handler.postDelayed(this, scrollSpeed);
                }
            }
        };
        handler.postDelayed(runnable, scrollSpeed);

This Will Auto Scroll Your RecyclerView To The End, Wait For a Second (So User Can Read Till End) And Jumps/Scroll Back To First String In RecyclerView's Array List. If You Want To Auto Scroll in Posetive And Negative direction You Just Need To Change The Condition Instead Of Using if(!flag) You Need To Set Value Of x in it

    if (flag) x = 15;
    else x= -15;  // For Auto Scroll To Negative i.e Left Direction

Answer 3

Simplified in Kotlin:

 lifecycleScope.launch(Dispatchers.Main, start = CoroutineStart.DEFAULT) {
        var position = MINIMUM_POSITION
        repeat(AUTO_SCROLL_REPEATING_TIMES) {
            delay(SCROLL_DELAY)
            rvBanners.smoothScrollToPosition(position)
            when {
                position+1 == listSize -> position = 0
                position == 0 -> position = MINIMUM_POSITION
                else -> position++
            }
        }
    }

If you want to start the auto-scroll at a specific time:

val job = lifecycleScope.launch(Dispatchers.Main, start = CoroutineStart.LAZY) {
        var position = MINIMUM_POSITION
        repeat(AUTO_SCROLL_REPEATING_TIMES) {
            delay(SCROLL_DELAY)
            rvBanners.smoothScrollToPosition(position)
            when {
                position+1 == listSize -> position = 0
                position == 0 -> position = MINIMUM_POSITION
                else -> position++
            }
        }
    }
...
job.start()

Answer 4

This is the best way to Auto Scroll RecyclerView and its 100% working :

  RecyclerView recyclerView = findViewById(R.id.rv_id);

  final int time = 4000; // it's the delay time for sliding between items in recyclerview

    final Adapter adapter = new Adapter(dataItems);
    recyclerView.setAdapter(adapter);

    final LinearLayoutManager linearLayoutManager = new LinearLayoutManager(rootView.getContext(), LinearLayoutManager.HORIZONTAL, false);
    recyclerView.setLayoutManager(linearLayoutManager);

    //The LinearSnapHelper will snap the center of the target child view to the center of the attached RecyclerView , it's optional if you want , you can use it
    final LinearSnapHelper linearSnapHelper = new LinearSnapHelper();
    linearSnapHelper.attachToRecyclerView(recyclerView); 

    final Timer timer = new Timer();
    timer.schedule(new TimerTask() {

        @Override
        public void run() {

            if (linearLayoutManager.findLastCompletelyVisibleItemPosition() < (adapter.getItemCount() - 1)) {

                linearLayoutManager.smoothScrollToPosition(recyclerView, new RecyclerView.State(), linearLayoutManager.findLastCompletelyVisibleItemPosition() + 1);
            }

            else if (linearLayoutManager.findLastCompletelyVisibleItemPosition() == (adapter.getItemCount() - 1)) {

                linearLayoutManager.smoothScrollToPosition(recyclerView, new RecyclerView.State(), 0);
            }
        }
    }, 0, time);

Answer 5

Just to improve on the answer a little, it's auto scrolling infinity with smooth animation.

final int speedScroll = 1200;
final Handler handler = new Handler();
final Runnable runnable = new Runnable() {
    int count = 0;
    boolean flag = true;
    @Override
    public void run() {
        if(count < adapter.getItemCount()){
            if(count==adapter.getItemCount()-1){
                flag = false;
            }else if(count == 0){
                flag = true;
            }
            if(flag) count++;
            else count--;

            recyclerView.smoothScrollToPosition(count);
            handler.postDelayed(this,speedScroll);
        }
    }
};

handler.postDelayed(runnable,speedScroll);

This is exactly your answer but if you link to more smooth animation then use LayoutManager

recyclerView.setLayoutManager(new CustomLinearLayoutManager(mContext, LinearLayoutManager.HORIZONTAL, false));

Control you animation changing MILLISECONDS_PER_INCH value.

public class CustomLinearLayoutManager extends LinearLayoutManager {
    public CustomLinearLayoutManager(Context context) {
        super(context);
    }

    public CustomLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
    }

    public CustomLinearLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position) {
        final LinearSmoothScroller linearSmoothScroller =
                new LinearSmoothScroller(recyclerView.getContext()) {
                    private static final float MILLISECONDS_PER_INCH = 200f;

                    @Override
                    public PointF computeScrollVectorForPosition(int targetPosition) {
                        return CustomLinearLayoutManager.this
                                .computeScrollVectorForPosition(targetPosition);
                    }

                    @Override
                    protected float calculateSpeedPerPixel
                            (DisplayMetrics displayMetrics) {
                        return MILLISECONDS_PER_INCH / displayMetrics.densityDpi;
                    }
                };
        linearSmoothScroller.setTargetPosition(position);
        startSmoothScroll(linearSmoothScroller);
    }
}

Answer 6

private void hanldeAutoScroll() {


    int position=0;

    final int duration = 2000;
    //final int pixelsToMove = 90;

    final Handler mHandler = new Handler(Looper.getMainLooper());
     final Runnable SCROLLING_RUNNABLE = new Runnable() {

        @Override
        public void run() {

            position++;

            if (position<urls.size())
            {
                recyclerView.scrollToPosition(position);

            }else if (position==urls.size())
            {

                position=-1;

            }

           // recyclerView.smoothScrollBy(pixelsToMove, 0);
            mHandler.postDelayed(this, duration);
        }
    };
    mHandler.postDelayed(SCROLLING_RUNNABLE, 2000);




}