Removal of visible item may result in showing an unexpected item [154124815]

Fixed

Bug

Status Update

No update yet.

Description

je...@google.com

created issue #1

Apr 15, 2020 06:07PM

When items are same size as the viewport, and RV is currently laid out such that the viewport shows exactly one complete item, and you remove that item from the dataset, it can't find a reference child that is in the viewport. It defaults to using the first child it found in the hierarchy (getChild(0) for regular LTR RVs) as the reference child. But then it doesn't seem to use that child's old position as the anchor position, but just places that child at the start of the viewport.

That is a problem if you are looking at the last item (item N) and have two extra items laid out before the visible one. You'd expect that if you remove item N, you will look at item N-1 after that. But, it will actually go to item N-2.

I didn't check the behavior if you're not looking at the last item, but that might be affected as well.

Comments

sh...@google.com <sh...@google.com> #2Apr 15, 2020 10:09PM

since these are in public API (:/) we need to do this in 1.2

sh...@google.com <sh...@google.com> #3Apr 15, 2020 10:09PM

Reassigned to je...@google.com.

since it is already marked as deprecated, we can probably do it by now.

sh...@google.com <sh...@google.com> #4Apr 15, 2020 10:11PM

Opening diff shortly

je...@google.com <je...@google.com> #5Apr 16, 2020 09:40AM

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

commit d576cbdc911cba16638a44fd8223391a90a07ef7
Author: Mike Nakhimovich <digitalbuddha@users.noreply.github.com>
Date: Tue Aug 11 09:30:34 2020

[GH] Hide deprecated internal API.

## Proposed Changes

* `RoomDatabase.java` has protected `mCallbacks` field which is leaking in the API docs, we should @Hide it.

## Testing

Test: Ran unit tests locally

## Issues Fixed

Fixes: 76109329

This is an imported pull request from

https://github.com/androidx/androidx/pull/61.

Resolves #61
Github-Pr-Head-Sha: 6440daa3a63752c7f9d5ba2a390248cd85bc634f
GitOrigin-RevId: fe92d8466a59b44b218b6ca3cbd57dcda17992f7

Change-Id: Id599cdf5b02b32bdae0166266fb7da967598fe92

A room/runtime/api/current.ignore
M room/runtime/api/current.txt
M room/runtime/api/public_plus_experimental_current.txt
M room/runtime/api/restricted_current.txt
M room/runtime/src/main/java/androidx/room/RoomDatabase.java

https://android-review.googlesource.com/1396827

ap...@google.com <ap...@google.com> #6May 4, 2020 11:13PM

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

commit fe867028214a364167c893083065eddcd709e223
Author: Shep Shapard <shepshapard@google.com>
Date: Wed Apr 15 14:02:59 2020

Improve out of bounds anchor.

Bug fixes involve a behavior change where
if all in bounds children are removed from a
LinearLayoutManager, and out of bounds children
are found to become potential anchors, out of bounds
children that are "further down in the scroll direction"
are moved to fill in the RV.

Bug: 154124815
Test: ./gradlew recyclerview:recyclerview:connectedCheck --info --daemon -Pandroid.testInstrumentationRunnerArguments.class=androidx.recyclerview.widget.LinearLayoutManagerRemoveShownItemsTest

Change-Id: I63b177d1bedd8016125bc6aa619fb12714797252

M recyclerview/recyclerview/src/androidTest/java/androidx/recyclerview/widget/LinearLayoutManagerFindReferenceChildTest.kt
M recyclerview/recyclerview/src/androidTest/java/androidx/recyclerview/widget/LinearLayoutManagerFindZeroPxReferenceChildTest.kt
A recyclerview/recyclerview/src/androidTest/java/androidx/recyclerview/widget/LinearLayoutManagerRemoveShownItemsTest.kt
M recyclerview/recyclerview/src/main/java/androidx/recyclerview/widget/GridLayoutManager.java
M recyclerview/recyclerview/src/main/java/androidx/recyclerview/widget/LinearLayoutManager.java
M samples/Support7Demos/src/main/AndroidManifest.xml
A samples/Support7Demos/src/main/java/com/example/android/supportv7/widget/RemoveLargeItemsDemo.java
A samples/Support7Demos/src/main/res/layout/remove_large_items_demo.xml
A samples/Support7Demos/src/main/res/layout/remove_large_items_demo_item.xml

https://android-review.googlesource.com/1286717

sh...@google.com <sh...@google.com> May 8, 2020 08:40PM

Marked as fixed.

ch...@gmail.com <ch...@gmail.com> #7Jan 6, 2021 04:13PM

i think this bug doesn't fix. when i clear the mainAdapter and then update footerAdapter, sometimes it will jump to the bottom