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I'm having this issue too.

Steps to reproduce:
* create a recyclerview which is a vertical list of about 2000 items.
* enable fast scroll on the recyclerview by adding the xml attributes described in the support library release notes.

Expected output: the thumb drawable should be visible and large enough to be able to tap on it.

Current output: the thumb drawable is so tiny it's impossible to tap on.

Sdk version :
Target 26
Support library 26.0.1

Frequency: 100 percent of the time when the list is large (couple thousand items)

Here's a sample project to illustrate the issue: https://github.com/caarmen/RecyclerViewBug

The small list has 250 items, and the large list has 5000 items.
The scroll thumb on the small list is easy to grab.
The scroll thumb on the large list is impossible to grab.

For info, in my github sample project linked in #5, I've created a branch called "hack" with a commit which works around this issue, to ensure a minimum height for the vertical thumb drawable.  

It's not pretty: it creates a custom class in the android.support.v7.widget package, it access private resources, and it accesses classes and methods which are only exposed for testing.

But it illustrates what could be fixed.

We have passed this to the development team and will update this issue with more information as it becomes available.

While we wait for a fix (or if there won't be a fix), is there another recommended way to use RecyclerView and have fast scroll enabled, for large lists?

Hello?

Any updates?

I too have large data sets >500 and thumb size and scrollbar width make the fast scrollbar usless!
The list also has a mixture of Longclickable and Clickable rows.

I would therefore like to add two three options to the Issue.

to be able to set:-

a) the scrollbar width
b) the thumb minimum height
c) be able to disable clicks on list whilst scrollbar is visible.

I haven't yet issued this version to users but I can already hear their crys of scrollbar unusable!

Steve Hall

Further thoughts:-

The minimum thumb height could easily be set to 2 or 3 times scrollbar width.
Also where scrollbar height is a minimum the thumb width could be set to twice scrollbar width to provide a bigger target.

Almost one year and still like that? Come on...

I'm not surprised. It's Google's issue tracker, after all.

Forget waiting for fix, you can use attached fast scrollbar that I made and successfully use. It's inspired by some unknown source, and is written in Kotlin. Small, elegant, and works just fine.
It scrolls fast also on large collections (important) where some other libraries fail badly.
Of course, minimal height is assured.
Dimensions can be changed directly in code.

Usage (in Kotlin):
```
val rlist = root.findViewById<RecyclerView>(R.id.rlist)
RFastScroller(rlist,
                    ContextCompat.getColor(this, R.color.fast_scroll_normal),
                    ContextCompat.getColor(this, R.color.fast_scroll_pressed))
```

+1 for this issue. It's been 1 year and fast scroll is still unusable because of this... I still have to resort to old 3rd-party libs...
The whole point of fast scroll is to scroll fast through large data sets, and that's the one thing it's not doing properly. I'm even wondering how this feature has been tested and approved as is in the first place.

A workaround would be extending layout manager and overriding computeScroll, but it do affects the scroll positions and stuff. There is no use of fast scroll in recyclerview because of this issue. its pending from a long time!

I am facing the same issue.

With a large enough list the size of the thumb drawable is scaled down to 0 making it impossible to see, let alone grab.
For reference, I’m currently accessing a DB table with over 300,000 entries.

The problem code is in:
        androidx.recyclerview.widget.FastScroller (an internal class)
in the method:
        void updateScrollPosition(int offsetX, int offsetY)

specifically the lines (comments by me):
        if (mNeedVerticalScrollbar) {
            float middleScreenPos = offsetY + verticalVisibleLength / 2.0f;
            mVerticalThumbCenterY =
                (int) ((verticalVisibleLength * middleScreenPos) / verticalContentLength);
                // - - - This calculation tends to 0 as the number of items in the recyclerview gets larger.
            mVerticalThumbHeight = Math.min(verticalVisibleLength,
                (verticalVisibleLength * verticalVisibleLength) / verticalContentLength);

                // - - - We should add something like
                // mVerticalThumbHeight = Math.max(mVerticalThumbHeight, MINIMUM_THUMB_HEIGHT);
                // - - - where the value of MINIMUM_THUMB_HEIGHT is determined from
                //     1) A minimum size suggested by Material Design.
                //     2) A custom value passed by the developer in the XML file:
                //        eg. app:fastScrollMinimumVerticalThumbSize=“???”
        }

        if (mNeedHorizontalScrollbar) {
            float middleScreenPos = offsetX + horizontalVisibleLength / 2.0f;
            mHorizontalThumbCenterX =
                (int) ((horizontalVisibleLength * middleScreenPos) / horizontalContentLength);
                // - - - This calculation tends to 0 as the number of items in the recyclerview gets larger, if set up as a horizontal scroller.
            mHorizontalThumbWidth = Math.min(horizontalVisibleLength,
                (horizontalVisibleLength * horizontalVisibleLength) / horizontalContentLength);
                // - - - create a similar change as for Vertical
        }

when list has more than 2000 items, the scrollbar thumb too small and unable to tap or drag it., useless

It certainly needs a minimum height, but making it a little wider would be nice as well. Even on a short list where the thumb is tall, it's still very tricky to get a hold of the thumb because it's glued to the right edge. Phones with cases make this a tricky task, and you certainly can't use a thumb to thumb it around. If it were a just a little bit wider that would love that issue. Making it variable would be best.

no status here ?

Any updates?

2 years later, and I still can't migrate my contacts list from ListView to RecyclerView.

Can you raise the priority of this issue, please?

Can google at least tell us what the blocking issue 65438556 is about ?

Any update ?

This library was released under Google's license: https://github.com/zhanghai/AndroidFastScroll

A Google employee released a solution as an external library under their personal github account? Would like to see the fix directly in the official libraries: in androidx.

Why prevents it to be integrated in AndroidX?

Changing the width of the scrollbar would be useful too!

Same issue. Google needs to fix this as it is very common use case to have long scrolling lists.

+1 looking forward to a fix for this.

Still no fix. Embarassing.

Well, until there is official fix, then I will be using https://github.com/quiph/RecyclerView-FastScroller, which seems to work pretty good.

Three years and no update for an issue flagged with P1 priority... Congratulations, Google

When John Spartan from "Demolition Man" wakes up in a utopian future society in the year 2032, Google will still not have gotten around to this P1 issue.

Hey! Are there any Updates on this?

Any updates?

@15 Seems to work, but there isn't the same functionality as what we have today. Do you have a more updated version of this, that supports more? Like fastScrollHorizontalThumbDrawable, fastScrollHorizontalTrackDrawable ?

@28 This library has minSdkVersion 21 , which is higher than what RecyclerView supports.

@36 This library has issues of putting the thumb in the wrong location:
https://github.com/quiph/RecyclerView-FastScroller/issues/45

@15 Actually it has some issues sadly. :(

Made a library that fixes it, based on the solutions I've read:
https://github.com/AndroidDeveloperLB/FastScrollerAndRecyclerViewFixes
Supports API 16 and above.

@44 How exactly? Is there a way to set a minimal size for it?
Please explain what has changed in the API.

@46 I requested here to be able to set the minimal size, offered a solution on Github to have such a control, and it was marked as duplicate to here, and then you set it to a fixed minimal size...

Why did you mark my request as a duplicate:
https://issuetracker.google.com/issues/177670978

?
Please re-consider.

I'm having this issue too.

@48 For now you can use my solution here:
https://issuetracker.google.com/issues/64729576#comment43

@50 Frankly it's good enough for me, for now. On my app I had it set to 50dp, but I guess 48dp is fine too :)

Just that others might want it differently.
Is it a hard thing to have?

@52 You can release the one without customization now, and customized one (with default value as you've decided - 48dp) a bit later.

@49 I can't use libraries for fast scrolling, because then I have another problem: I need to correctly calculate vertical_scroll_range. Because the vertical size of each element is different. This cannot be done with libraries.
It turns out that today it's impossible to use RecyclerView for large lists with fast scrolling.

@google Why aren't you doing anything?

@55 And how do you calculate the total scroll height? If the height of the elements is different?

I think you misunderstood the RecyclerView problem.

@58 I need a regular scroll bar design. I don't want much. Thought we wouldn't have these problems in 2021.

Moreover, I think that since RecyclerView doesn't create all elements at startup, it's impossible to calculate the scroll height. That's why I have to return to ListView.

RV 1.3.0 development has started as RV 1.3.0-alpha01 has been released, any chance  https://android-review.googlesource.com/c/platform/frameworks/support/+/1621939 will land soon?

Bump - still an issue...

Sill an issue in 2024!

Still not merged!

Still not resolved? Hire me if you have shortage of software engineers.