NullPointerException with null data in adapter

[timothyjc]

My data in my adapter is empty when the view is loaded and I get the following exception.

java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.ViewParent android.view.View.getParent()' on a null object reference
at android.support.v7.widget.RecyclerView.getChildViewHolder(RecyclerView.java:2567)
at xyz.danoz.recyclerviewfastscroller.calculation.progress.VerticalLinearLayoutManagerScrollProgressCalculator.calculateScrollProgress(VerticalLinearLayoutManagerScrollProgressCalculator.java:29)
at xyz.danoz.recyclerviewfastscroller.AbsRecyclerViewFastScroller.onLayout(AbsRecyclerViewFastScroller.java:202)
at android.view.View.layout(View.java:15596)
at android.view.ViewGroup.layout(ViewGroup.java:4966)

The problem is in VerticalLinearLayoutManagerScrollProgressCalculator:

@Override
public float calculateScrollProgress(RecyclerView recyclerView) {
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
    int lastFullyVisiblePosition = layoutManager.findLastCompletelyVisibleItemPosition();

    View visibleChild = recyclerView.getChildAt(0);
    ViewHolder holder = recyclerView.getChildViewHolder(visibleChild);

There is no child at index 0.

This method should handle the case when the RecyclerView has no children, such as when there is not yet any data.

[Maxr1998]

Can confirm. This also applies when a using a filter with no results.

[Maxr1998]

Fixed in master, please close.

[Komoi]

It seems still broken to me - It fails with same (similar) stacktrace when trying to use it with empty filtered adapter. I am using your lib via compile 'xyz.danoz:recyclerviewfastscroller:0.1.0' in gradle.

[Maxr1998]

Use the new 0.1.1 and report back ;)

[Komoi]

This fixes the issue, thank you for fast response :)

[Maxr1998]

@Komoi may I ask you what you did because I still get a crash on fastScroller.setRecyclerView()
It's a nullpointer exception, but I'm pretty sure the items aren't null :/
Look at my source: https://github.com/Maxr1998/MaxLock/blob/master/app/src/main/java/de/Maxr1998/xposed/maxlock/ui/settings/appslist/AppsListFragment.java#L131

Layout: https://github.com/Maxr1998/MaxLock/blob/master/app/src/main/res/layout-v14/fragment_appslist.xml

Don't mind the outcommented lines, they are no comments in my local sources..

[Komoi]

@Maxr1998 I actually implemented fast scroll without indicator, it seemed to hard to implement if fully for me, I got lost in examples explaining use of indicators. I checked your code and your problem might be unrelated to this issue and I really cant help you since I do not fully understand it. Is your backtrace similar as timothyjc's? Good luck with your project :)

[Maxr1998]

Thanks for looking into it :)
I don't believe the section indicator is the problem, I think I'll have to rewrite this whole stuff anyway...
Thanks and good luck for you too!

@danoz73 please close this issues as it's fixed.