Add workaround for Robolectric not posting requestApplyInsets() [137201343]

Fixed

Bug

Status Update

No update yet.

Description

il...@google.com

created issue #1

Jul 10, 2019 05:44PM

Component used: Fragment
Version used: 1.2.0-alpha01

When running a test in Robolectric, the new behavior introduced in

https://issuetracker.google.com/issues/135945162 causes issues when you have a ViewPager since Robolectric, instead of properly posting the requestApplyInsets (and the subsequent measure/layout) runs it inline, causing an IllegalStateException when FragmentPagerAdapter / FragmentStatePagerAdapter use commitNowAllowingStateLoss() when the FragmentManager is in the middle of processing transactions.

We should continue to use commitNowAllowingStateLoss(), but catch the IllegalStateException and fall back to commitAllowingStateLoss() specifically in the case where we're already performing transactions.

Comments

il...@google.com <il...@google.com> Jul 10, 2019 06:13PM

Accepted by il...@google.com.

ap...@google.com <ap...@google.com> #2Jul 10, 2019 07:59PM

Marked as fixed.

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

commit c7782e3df384027df9484f615880a22d26975f18
Author: Ian Lake <ilake@google.com>
Date: Wed Jul 10 10:53:39 2019

Fall back to commitAllowingStateLoss() on ISE

When FragmentPagerAdapter or FragmentStatePagerAdapter
runs finishUpdate() in response to a measure/layout
pass, it runs commitNowAllowingStateLoss() as all
normal devices don't do measure/layout while processing
pending FragmentTransactions.

However, with

b/135945162

, FragmentManager does call
requestApplyInsets() as part of processing Fragments.
This gets posted on real devices, but Robolectric will
run it inline, causing this to throw an
IllegalStateException. To ensure that Robolectric
continues to work, we can call commitAllowingStateLoss()
in this particular case to ensure that it runs even
while pending FragmentTransactions are being processed.

Test: manual testing
Fixes: 137201343
Change-Id: I62b6312ffbd754af6c6bedf0f1adc30c40641575

M fragment/fragment/src/main/java/androidx/fragment/app/FragmentPagerAdapter.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentStatePagerAdapter.java

https://android-review.googlesource.com/1013911

https://goto.google.com/android-sha1/c7782e3df384027df9484f615880a22d26975f18

om...@gmail.com <om...@gmail.com> #3Jan 6, 2020 09:24PM

Using version: fragmentx: 1.2.0-rc4

If multiple finishUpdate() calls are made, it is possible that commitNowAllowingStateLoss() can throw multiple IllegalStateExceptions, which will cause an NPE since mCurTransaction is set to null after the try/catch method. See the stacktrace below:

java.lang.NullPointerException
at androidx.fragment.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:267)
at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1244)
at androidx.viewpager.widget.ViewPager.populate(ViewPager.java:1092)
at androidx.viewpager.widget.ViewPager.onMeasure(ViewPager.java:1622)
at android.view.View.measure(View.java:22071)
at androidx.constraintlayout.widget.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:1227)
at androidx.constraintlayout.widget.ConstraintLayout.onMeasure(ConstraintLayout.java:1572)
at android.view.View.measure(View.java:22071)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.view.View.measure(View.java:22071)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at androidx.appcompat.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
at android.view.View.measure(View.java:22071)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
at android.view.View.measure(View.java:22071)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.view.View.measure(View.java:22071)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:806)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:685)
at android.view.View.measure(View.java:22071)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at com.android.internal.policy.DecorView.onMeasure(DecorView.java:724)
at android.view.View.measure(View.java:22071)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2422)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1504)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1761)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1392)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6752)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at org.robolectric.shadows.ShadowMessageQueue.dispatchMessage(ShadowMessageQueue.java:148)
at org.robolectric.shadows.ShadowMessageQueue.access$200(ShadowMessageQueue.java:38)
at org.robolectric.shadows.ShadowMessageQueue$1.run(ShadowMessageQueue.java:126)
at org.robolectric.util.Scheduler$ScheduledRunnable.run(Scheduler.java:386)
at org.robolectric.util.Scheduler.runOneTask(Scheduler.java:278)
at org.robolectric.util.Scheduler.advanceTo(Scheduler.java:260)
at org.robolectric.util.Scheduler.advanceBy(Scheduler.java:243)
at org.robolectric.util.Scheduler.advanceBy(Scheduler.java:233)
at org.robolectric.util.Scheduler.setIdleState(Scheduler.java:88)
at org.robolectric.util.Scheduler.unPause(Scheduler.java:123)
at org.robolectric.shadows.ShadowLooper.unPause(ShadowLooper.java:347)
at org.robolectric.shadows.ShadowLooper.runPaused(ShadowLooper.java:398)
at org.robolectric.android.controller.ActivityController.visible(ActivityController.java:161)

ap...@google.com <ap...@google.com> #4Jan 21, 2020 09:34PM

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

commit eb154034645a875304797a38995baac5ddd3346d
Author: Jeremy Woods <jbwoods@google.com>
Date: Tue Jan 14 12:40:54 2020

Avoid try/catching exceptions in FragmentPagerAdapters

When FragmentPagerAdapter or FragmentStatePagerAdapter
runs finishUpdate() in response to a measure/layout
pass, it runs commitNowAllowingStateLoss() as all
normal devices don't do measure/layout while processing
pending FragmentTransactions, but Robolectric will. In
order to ensure that Robolectric continued to work,

b/137201343

provided behavior to fallback to
commitAllowingStateLoss() when processing pending
FragmentTransactions. It used a try/catch for
IllegalStateExceptions, which means valid exceptions
could be ignored.

This change drops any transactions that attempt to be
committed while the FragmentManager is already executing
transactions.

Test: FragmentPagerAdapterRoboTest
Fixes: 147359544

Change-Id: I21ebbfe67d349980003b6df77704f005e693e664

M fragment/fragment/src/main/java/androidx/fragment/app/FragmentPagerAdapter.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentStatePagerAdapter.java
A fragment/fragment/src/test/java/androidx/fragment/app/FragmentPagerActivity.kt
A fragment/fragment/src/test/java/androidx/fragment/app/FragmentPagerAdapterRoboTest.kt

https://android-review.googlesource.com/1208711

an...@google.com <an...@google.com> #5Jan 22, 2020 12:10AM

The following changes were cherrypicked through Coastguard (

https://android-build.googleplex.com/coastguard/)
Release Track: (

https://android-build.googleplex.com/coastguard/dashboard/6552735953321984/#/history/all)
Created: 2020-01-22 00:07:09.044119+00:00
Changes: aosp/1208711

Issue 137201343