How to Know Whether a Recyclerview/Linearlayoutmanager Is Scrolled to Top or Bottom

Detect the top of RecyclerView?

If you have a LinearLayoutManager set on your RecyclerView you can use it to find the first visible item:

LinearLayoutManager layoutManager = new LinearLayoutManager(this);
recyclerview.setLayoutManager(layoutManager);

if (layoutManager.firstCompletelyVisibleItemPosition() == 0) {
    //this is the top of the RecyclerView
    //Do Something
}

How to detect when user have scrolled to the top most item in a RecyclerView

I have solved my question by myself. I used the code below instead

private boolean isUserScrolling = false;
private boolean isListGoingUp = true;

Then in the RecyclerView OnScrollListener

@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
    super.onScrollStateChanged(recyclerView, newState);
    //detect is the topmost item visible and is user scrolling? if true then only execute
    if(newState ==  RecyclerView.SCROLL_STATE_DRAGGING){
        isUserScrolling = true;
        if(isListGoingUp){
            //my recycler view is actually inverted so I have to write this condition instead
            if(linearLayoutManager.findLastCompletelyVisibleItemPosition() + 1 == list.size()){
                Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        if(isListGoingUp) {
                            if (linearLayoutManager.findLastCompletelyVisibleItemPosition() + 1 == list.size()) {
                                Toast.makeText(getContext(),"exeute something", Toast.LENGTH_SHORT).show();
                            }
                        }
                    }
                },50);
                //waiting for 50ms because when scrolling down from top, the variable isListGoingUp is still true until the onScrolled method is executed
            }
        }
    }
}

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
    if(isUserScrolling){
        if(dy > 0){
            //means user finger is moving up but the list is going down
            isListGoingUp = false;
        }
        else{
            //means user finger is moving down but the list is going up
            isListGoingUp = true;
        }
    }
}

Scroll to top in RecyclerView with LinearLayoutManager

Continuing from above comments, ideally, replacing

mRecyclerView.smoothScrollToPosition(0);

in the onClick of the floating action button with

mLayoutManager.scrollToPositionWithOffset(0, 0);

should work. You can also remove the SnackBar code, because you don't need it anyways. So, all in all your above method should look like

public void setFloatingActionButton(final View view) {
    float actionButton = (android.support.design.widget.FloatingActionButton) getActivity()
            .findViewById(R.id.float);
    actionButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView
                    .getLayoutManager();
            layoutManager.scrollToPositionWithOffset(0, 0);
        }
    });
}

And if you say that the above doesnt work, then test if the onClick() is even being called or not. Try adding a log message in it and see if its printed.

How programmatically know that recyclerview is scrolled position is bottom of recyclerview to execute following function

first / last visible child depends on the LayoutManager.
If you are using LinearLayoutManager or GridLayoutManager, you can use

int findFirstVisibleItemPosition();
int findFirstCompletelyVisibleItemPosition();
int findLastVisibleItemPosition();
int findLastCompletelyVisibleItemPosition();

For example:

GridLayoutManager layoutManager = ((GridLayoutManager)mRecyclerView.getLayoutManager());
int firstVisiblePosition = layoutManager.findLastCompletelyVisibleItemPosition();

For LinearLayoutManager, first/last depends on the adapter ordering. Don't query children from RecyclerView; LayoutManager may be prefered to layout more items than visible for caching.

Android recyclerview scroll to top

Did you try taskRecyclerView.getLayoutManager().scrollToPosition(0) or taskRecyclerView.scrollToPosition(your_position)?

RecyclerView does not implement any scrolling logic in taskRecyclerView.scrollToPosition(your_position) and taskRecyclerView.getLayoutManager().scrollToPosition(0) is more specific and it goes to specific index depending implemented layout, in your case is linear.

Check if RecyclerView is scrollable

There you go:

public boolean isRecyclerScrollable() {
  LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
  RecyclerView.Adapter adapter = recyclerView.getAdapter();
  if (layoutManager == null || adapter == null) return false;

  return layoutManager.findLastCompletelyVisibleItemPosition() < adapter.getItemCount() - 1;
}

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