Duplicate menu items shown on ViewPager2 fragment creation [144442240]

Fixed

Bug

Status Update

No update yet.

Description

ch...@beyls.net

created issue #1

Nov 13, 2019 10:54PM

When FragmentStateAdapter calls createFragment() then adds the new fragment to the FragmentManager, it doesn't set the initial menu visibility of that fragment to false.

As a result, between the time the fragment is added and the time it becomes the new primary fragment of the ViewPager2, its menu is briefly shown at the same time as the menu of the current primary fragment, creating a visual glitch of duplicate menu items.

Fix: update the code of FragmentStateAdapter to call newFragment.setMenuItemVisible(false) right after creating the fragment using createFragment(position)

Comments

er...@gmail.com <er...@gmail.com> #2Dec 3, 2019 02:42PM

Hi, thanks for reporting. Should be an easy fix!

I'm guessing it should work find until ~ 2^23 items = ~ 8M items. How did you come across this bug? Do you have a ViewPager2 with that many items?

ViewPager2FragMenuBug.zip

14 MB

Download

er...@gmail.com <er...@gmail.com> #3Dec 3, 2019 02:44PM

Hi, good to hear that.

We have an implementation of RecyclerView.Adapter that supports "infinite looping". So when the infinite looping is enabled, the adapter's getItemCount() reports Int.MAX_VALUE items. We also call setCurrentItem to somewhere in the middle of item count on the ViewPager2, so that's how we got that far.

jg...@google.com <jg...@google.com> #4Dec 17, 2019 12:23PM

For future reference: first item for which it fails is probably when mCurrentItem = (1 << 25) + 2

jg...@google.com <jg...@google.com> #5Dec 17, 2019 12:26PM

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

commit 2e9f35536432bed0677171c8ae59b4f67850915a
Author: Jelle Fresen <jellefresen@google.com>
Date: Fri Jul 12 14:26:10 2019

Use double instead of float for decimal positions

A position ranges from 0 to Integer.MAX_VALUE, but floats only have a 23
bit mantissa. Values over 2^23 are rounded to a nearby value.

Solve this by using double instead of float when we need to represent a
position with a fractional component. A double has a mantissa of 52 bit
and can therefore represent all 2^32 possible int values.

Bug: 134858960
Test: ./gradlew viewpager2:cC
Change-Id: I08b97df6fac600caa83366ccab8671541e2c1e7f

A viewpager2/src/androidTest/java/androidx/viewpager2/test/ui/SparseAdapter.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/FakeDragTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/OffscreenPageLimitTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/PageChangeCallbackTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/PageTransformerTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/SetItemWhileScrollInProgressTest.kt
M viewpager2/src/main/java/androidx/viewpager2/widget/ScrollEventAdapter.java
M viewpager2/src/main/java/androidx/viewpager2/widget/ViewPager2.java

https://android-review.googlesource.com/1014538

https://goto.google.com/android-sha1/2e9f35536432bed0677171c8ae59b4f67850915a

ch...@beyls.net <ch...@beyls.net> #6Dec 18, 2019 09:34AM

Fixed in now released beta03 -

https://developer.android.com/jetpack/androidx/releases/viewpager2#1.0.0-beta03

jg...@google.com <jg...@google.com> Dec 20, 2019 03:37PM

Assigned to je...@google.com.

je...@google.com <je...@google.com> Jan 17, 2020 02:35PM

Accepted by je...@google.com.

ap...@google.com <ap...@google.com> #7Feb 4, 2020 05:34PM

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

commit dca177316c5d2771759641d01f956b0f49892ca7
Author: Jelle Fresen <jellefresen@google.com>
Date: Fri Jan 17 17:32:28 2020

Fix for Fragment menu visibility issue in FSA

The fragment's menu visibility is directly related to the fragment's max
lifecycle. When the max lifecycle is STARTED, the menu should not be
visible. When the max lifecycle is RESUMED, the menu should be visible.

This CL fixes the bug where a fragment that is added to the fragment
manager by FragmentStateAdapter did set the max lifecycle to STARTED,
but did not set the menu visibility to false.

Relnote: "Fixed `FragmentStateAdapter` issue with initial fragment menu
visibility when adding a fragment to the `FragmentManager`."

Bug: 144442240
Test: ./gradlew viewpager2:viewpager2:cC \
-Pandroid.testInstrumentationRunnerArguments.class=\
androidx.viewpager2.widget.FragmentLifecycleTest

Change-Id: I9d2ffa0efcb03b63eeca25f2d4e74c81446a5774

M viewpager2/viewpager2/src/androidTest/java/androidx/viewpager2/widget/FragmentLifecycleTest.kt
M viewpager2/viewpager2/src/main/java/androidx/viewpager2/adapter/FragmentStateAdapter.java

https://android-review.googlesource.com/1211984

je...@google.com <je...@google.com> Feb 28, 2020 02:27PM

Marked as fixed.

v....@gmail.com <v....@gmail.com> #8Apr 1, 2020 10:56PM

I think this issue relates to

https://issuetracker.google.com/issues/147550812 as well and that other issue can be marked as fixed too.
Checked on 1.1.0-alpha01 and can confirm the fix.

ni...@gmail.com <ni...@gmail.com> #9Nov 24, 2021 11:25AM

Comment has been deleted.

Message last modified on Nov 24, 2021 11:25AM

14...@gmail.com <14...@gmail.com> #10Jan 20, 2022 12:49AM

Still having issue in alpha, when you slide very fast, icon will disappear for a while!

je...@google.com <je...@google.com> #11Jan 20, 2022 11:04AM

Can you file a new bug for that? It sounds like that is a separate issue where for a brief period of time there none of the fragments is in RESUMED state. We'd need to figure out if that is a bug or working as intended.