IssueTracker

Component used: Fragment

Version used: 1.6.0-alpha02 (starting from 1.5.0-alpha01)

Devices/Android versions reproduced on: Pixel 6 (Android 13), Pixel 5 (Android 12)

Problem description:
onConfigurationChanged() of Fragments, within Activities which handle the orientation change themself, is called multiple times in certain cases.

Project sample setup:

• Activity handles orientation change itself
• Activity attaches Fragment 1 using the supportFragmentManager
• Fragment 1 attaches Fragment 2 using its childFragmentManager

When the device orientation changes onConfigurationChanged() is called once for the Activity and Fragment 1, but twice for Fragment 2.

Technical details:
The behaviour change was introduced in androidx.fragment:fragment-ktx:1.5.0-alpha01 in the following commit: https://android.googlesource.com/platform/frameworks/support/+/327c6affed80e7117144f9e0bf6cb0a9015a5d91
An OnConfigurationChangedProvider was added to the ComponentActivity which is used in the FragmentManager to notify the Fragments about configuration changes.

The problem of this change is the following:
Each Fragment that is added gets registered on an orientation change in the Activity. On orientation change the FragmentManager of the Activity notifies each Fragment about the orientation change while each Fragment itself also notifies its own FragmentManager about the notification change which again notifies each child Fragment.
This ends up in the following notify calls in an example where 3 Fragments are attached in each other:

Activity
  --> Fragment 1
      --> Fragment 2
          --> Fragment 3
  --> Fragment 2
      --> Fragment 3
  --> Fragment 3

Sample project:
The sample shows the issue described above using 2 Fragments. It uses the latest AppCompat version 1.5.1 together with Fragment 1.6.0-alpha02. Added logging to onConfigurationChanged() of all Fragments and the Activity.
The output for an orientation change is the following:

2022-09-20 14:01:28.485 VERIFY_TAG  com.example.orientationchange  E  Fragment 1: onConfigurationChanged
2022-09-20 14:01:28.485 VERIFY_TAG  com.example.orientationchange  E  Fragment 2: onConfigurationChanged
2022-09-20 14:01:28.485 VERIFY_TAG  com.example.orientationchange  E  Fragment 2: onConfigurationChanged
2022-09-20 14:01:28.485 VERIFY_TAG  com.example.orientationchange  E  MainActivity: onConfigurationChanged