Provider interop between SavedStateHandle and Compose Saver/SaveableStateRegistry [195689777]

Fixed

Feature Request

Status Update

No update yet.

Description

va...@google.com

created issue #1

Aug 5, 2021 10:14PM

Compose provides rememberSaveable, along with accompanying tools like Saver and SaveableStateRegistry as its mechanisms for storing saved instance state. Currently, there isn't a provided interoperability layer between these tools and SavedStateHandle.

If SavedStateHandle isn't used in the ViewModel, state that is hoisted from @Composables to ViewModels won't be stored to saved instance state. This might either cause bugs due to state loss upon process death, or act as a barrier to hoisting state sufficiently if it seems like rememberSaveable has to be used to remember state across process recreation.

The proposal is to provide the necessary hooks for SavedStateHandle with Saver so that any state holder that is being saved via rememberSaveable could also be saved with SavedStateHandle.

Comments

il...@google.com <il...@google.com> Nov 18, 2021 10:12PM

Status: New

il...@google.com <il...@google.com> #2Jan 5, 2022 09:42PM

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

commit b90079595f33f58fece04026a97faa0d243acdb1
Author: Yuichi Araki <yaraki@google.com>
Date: Wed Sep 18 16:55:49 2019

Change the way to detect mismatch between POJO and query

This fixes cursor mismatch warnings with expandProjection.

Bug: 140759491
Test: QueryMethodProcessorTest
Change-Id: I7659002e5e0d1ef60fc1af2a625c0c36da0664d8

M room/compiler/src/main/kotlin/androidx/room/processor/QueryMethodProcessor.kt
M room/compiler/src/main/kotlin/androidx/room/solver/TypeAdapterStore.kt
M room/compiler/src/main/kotlin/androidx/room/solver/query/result/PojoRowAdapter.kt
M room/compiler/src/test/kotlin/androidx/room/processor/QueryMethodProcessorTest.kt
M room/compiler/src/test/kotlin/androidx/room/testing/TestProcessor.kt

https://android-review.googlesource.com/1123258

https://goto.google.com/android-sha1/b90079595f33f58fece04026a97faa0d243acdb1

va...@google.com <va...@google.com> #3Jan 5, 2022 10:22PM

The following changes were cherrypicked through Coastguard (

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

https://android-build.googleplex.com/coastguard/dashboard/6093116828680192/#/cherrypickHistory/all)
Created: 2019-10-14 17:23:42.610596+00:00
Changes: aosp/1123258

il...@google.com <il...@google.com> Feb 17, 2022 07:20PM

Assigned to jb...@google.com.

al...@gmail.com <al...@gmail.com> #4Mar 11, 2022 10:38AM

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

commit bdde5a1a970ddc9007b28de4aa29d60ffa588f08
Author: Yigit Boyar <yboyar@google.com>
Date: Thu Apr 16 16:47:05 2020

Re-factor how errors are dismissed when query is re-written

This CL changes how we handle errors/warnings if query is
re-written.
There was a bug in expandProjection where we would report warnings
for things that Room already fixes automatically (

b/140759491

).
The solution to that problem (I7659002e5e0d1ef60fc1af2a625c0c36da0664d8)
solved it by deferring validating of columns until after re-write
decision is made. Unfortunately, this required changing PojoRowAdapter
to have a dummy mapping until it is validating, make it hard to use
as it does have a non-null mapping which is not useful.

This CL partially reverts that change and instead rely on the log
deferring logic we have in Context. This way, we don't need to break
the stability of PojoRowAdapter while still having the ability to
drop warnings that room fixes. This will also play nicer when we
have different query re-writing options that can use more information
about the query results.

Bug: 153387066
Bug: 140759491
Test: existing tests pass
Change-Id: I2ec967c763d33d7a3ff02c1a13c6953b460d1e5f

M room/compiler/src/main/kotlin/androidx/room/log/RLog.kt
M room/compiler/src/main/kotlin/androidx/room/processor/QueryMethodProcessor.kt
M room/compiler/src/main/kotlin/androidx/room/solver/TypeAdapterStore.kt
M room/compiler/src/main/kotlin/androidx/room/solver/query/result/PojoRowAdapter.kt

https://android-review.googlesource.com/1288456

va...@google.com <va...@google.com> #5Mar 14, 2022 05:59PM

No, the states would follow the same lifetime as other state stored in SavedStateHandle, which follows the same rules as Saved instance state from that table (serialized to disk, survives process death, only supports simple, small objects).

The goal isn't to all state to survive user completion of the activity, but to allow using the same Saver abstraction for rememberSaveable and SavedStateHandle.

ap...@google.com <ap...@google.com> #6Mar 16, 2022 06:22PM

Project: platform/frameworks/support
Branch: androidx-main

commit 0d614efac51fd8308d3a8d1a4ac3a86fd89caa03
Author: Jeremy Woods <jbwoods@google.com>
Date: Tue Mar 01 17:01:49 2022

Add experimental SavedStateHandle Saver support

Added an experimental API at the lifecycle level to provide a temporary
hook for SavedStateHandle into compose Saver while we work on a longer
term integration plan.

RelNote: "The `lifecycle-viewmodel-compose` module now provides
`SavedStateHandleSaver`, an experimental API that ensures values in a
`SavedStateHandle` are integrated correctly with the same saved instance
state that `rememberSaveable` uses."
Test: N/A
Bug: 195689777

Change-Id: Ia88b79c56a5f82263ddaf436777dfc1c4ab73704

M lifecycle/lifecycle-viewmodel-compose/api/restricted_current.txt
M lifecycle/lifecycle-viewmodel-savedstate/src/main/java/androidx/lifecycle/SavedStateHandle.kt
M lifecycle/lifecycle-viewmodel-compose/api/current.txt
M lifecycle/lifecycle-viewmodel-compose/api/public_plus_experimental_current.txt
M lifecycle/lifecycle-viewmodel-compose/build.gradle
A lifecycle/lifecycle-viewmodel-compose/src/main/java/androidx/lifecycle/viewmodel/compose/SavedStateHandleSaveableApi.kt
A lifecycle/lifecycle-viewmodel-compose/src/androidTest/java/androidx/lifecycle/viewmodel/compose/SavedStateHandleSaverTest.kt
A lifecycle/lifecycle-viewmodel-compose/src/main/java/androidx/lifecycle/viewmodel/compose/SavedStateHandleSaver.kt

https://android-review.googlesource.com/2005170

jb...@google.com <jb...@google.com> #7Mar 17, 2022 03:58AM

Marked as fixed.

This has been added internally and will be in the Lifecycle 2.5.0-alpha05 release.