IssueTracker

Verified library version is `1.0.0-beta02`

More information on this in:
http://issuetracker.google.com/124042228#comment3
http://issuetracker.google.com/124042228#comment7

> More information on this in:
> http://issuetracker.google.com/124042228#comment3
> http://issuetracker.google.com/124042228#comment7

I think that is probably the same problem.

I investigated the sample: https://github.com/marbat87/ScrollingViewPager2.git

See attached video:
1) no scrolling issues as long as angle is kept very close to x or y axis (0 -- 13s)
2) when scroll angle changes during a scroll, that is respected; if you remove NestedScrollView from the layout hierarchy (in fragment_main.xml) and have RecyclerView there directly, scroll orientation locking happens and makes for a better user experience
3) threshold / angle exploration (29s -- end) -- clearly the threshold angle is too narrow (touch slop not respected); it's worse with AppBarLayout collapsed than when it's expanded -- it confirms the issue; we'll investigate further

Project: platform/frameworks/support
Branch: androidx-master-dev

commit fb1c82582399043b149eb2630f524c75de9c88dc
Author: Jelle Fresen <jellefresen@google.com>
Date:   Thu Aug 15 11:34:36 2019

    Disallow intercept, touch slop and canScroll in nestedPreScroll
   
    * Disallow intercept (requestDisallowInterceptTouchEvent(true))
    When scroll delta is consumed by dispatchNestedPreScroll, the parent
    should be requested not to intercept subsequent touch events, just as
    when scroll is consumed by the widget itself or dispatchNestedScroll.
   
    * Touch slop
    NestedScrollingChild implementations should only call
    dispatchNestedPreScroll after the delta x/y has exceeded the touch slop.
   
    * canScroll (canScrollHorizontally/canScrollVertically)
    The dx/dy values passed to dispatchNestedPreScroll should be zero if the
    child can't scroll in that direction.
   
    Fixed in:
    - RecyclerView
    - NestedScrollView
   
    Bug: 138668210
    Bug: 139530818
    Test: ./gradlew connectedCheck
    Change-Id: I85b327ad096fbbd204adb92f630770ec7fad5990

M       core/core/src/androidTest/java/androidx/core/widget/NestedScrollViewNestedScrollingChildTest.java
M       core/core/src/main/java/androidx/core/widget/NestedScrollView.java
M       recyclerview/recyclerview/src/androidTest/java/androidx/recyclerview/widget/RecyclerViewNestedScrolling3RequestDisallowInterceptTouchTest.java
M       recyclerview/recyclerview/src/androidTest/java/androidx/recyclerview/widget/RecyclerViewNestedScrollingChildTest.java
M       recyclerview/recyclerview/src/main/java/androidx/recyclerview/widget/RecyclerView.java

https://android-review.googlesource.com/1105373
https://goto.google.com/android-sha1/fb1c82582399043b149eb2630f524c75de9c88dc