[Serialization] Support Compose's `MutableState` in `saved` [378895074]

Fixed

Feature

Status Update

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Description

mg...@google.com

created issue #1

Nov 13, 2024 05:12PM

saveable has built-in support for Compose's MutableState, supporting this use case:

val state by saveable { mutableStateOf(...) }

It does this by providing an overloaded function that handles MutableState.value and serializes it when needed.

To help people migrate from saveable to saved, we want to support MutableState in our KotlinX serialization support.

While working on getMutableState, I experimented with this and created a naive KSerializer implementation to handle MutableState.

Here’s what it could look like:

private class StateSerializer<T : Any>(val valueSerializer: KSerializer<T>)

public inline fun <reified T : Any> stateSerializer(): KSerializer<MutableState<T>>

For serialization, we'd use (value as MutableState<T>).value + valueSerializer to serialize the content. Deserialization works in the opposite direction.

Here’s a usage example:

val state by saved(serializer = stateSerializer<Int>()) { mutableStateOf(1) }

However, calling this without the serializer would cause an exception.

Our variant should work like saveable: if T (the generic type in saved) is serializable, it should work without needing the serializer.

The goal is to find the best way to support MutableState in saved (using a KSerializer, overloads, or another method).

Related to b/378895070.

Comments

mg...@google.com <mg...@google.com> #2Nov 13, 2024 05:13PM

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

commit c60f33e229e31ab328ef6b59dab63b264954831c
Author: Alexandre Elias <aelias@google.com>
Date: Fri Jul 10 16:23:09 2020

Semantics no-op cleanups

Partly in response to lmr's broad code review, I did a pass of
superficial API/implementation cleanup. The main changes are:

- I changed each Boolean SemanticsProperty where false is equivalent to
not being present to take "Unit" instead. This is conceptually
clearer: it avoids questions like "can I cancel out a semantics from a
merged child by setting it to false?" Because "property = Unit" looks
weird, I also changed the style of these to "property()".

- I moved the Semantics id generator closer to where it's used, in
SemanticsModifierCore. I made it internal and an AtomicInt.
(Note that integer ids are heavily used in the Android
AccessibilityNodeInfo APIs so I can't simply remove them entirely.)

- I deleted dead code. Some examples include SemanticsHintOverrides,
a public API not connected to anything, and SemanticsPropertyKey
merge() open method which is never called. (In both cases I have
a different plan in mind for accessibility.)

Fixes: 145951226
Fixes: 145955412
Test: existing tests
Relnote: "Single-value semantics properties now use a calling style.
For example, 'semantics { hidden = true }' is now written as:
'semantics { hidden() }'."

Change-Id: Ic1afd12ea22c926babc9662f1804d80b33aa0cfc

M ui/integration-tests/benchmark/src/androidTest/java/androidx/ui/benchmark/test/LayoutNodeModifierBenchmark.kt
M ui/ui-core/api/0.1.0-dev15.txt
M ui/ui-core/api/current.txt
M ui/ui-core/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-core/api/public_plus_experimental_current.txt
M ui/ui-core/api/restricted_0.1.0-dev15.txt
M ui/ui-core/api/restricted_current.txt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/graphics/vector/VectorTest.kt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/semantics/SemanticsTests.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidActuals.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeView.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeViewAccessibilityDelegateCompat.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidPopup.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/Expect.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsConfiguration.kt
D ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsHintOverrides.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsModifier.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsNode.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsOwner.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsWrapper.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/semantics/SemanticsProperties.kt
M ui/ui-foundation/api/0.1.0-dev15.txt
M ui/ui-foundation/api/current.txt
M ui/ui-foundation/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-foundation/api/public_plus_experimental_current.txt
M ui/ui-foundation/api/restricted_0.1.0-dev15.txt
M ui/ui-foundation/api/restricted_current.txt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Clickable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Dialog.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Scroller.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Selectable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Toggleable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/semantics/FoundationSemanticsProperties.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ButtonTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CardTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CheckboxScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/RadioButtonScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ScaffoldTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SnackbarTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SurfaceTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ripple/RippleIndicationTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/textfield/TextFieldScreenshotTest.kt
M ui/ui-material/src/main/java/androidx/ui/material/AppBar.kt
M ui/ui-material/src/main/java/androidx/ui/material/TextFieldImpl.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/AssertsTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/CallSemanticsActionTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ErrorMessagesTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/FindersTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/PrintToStringTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ScrollToTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/TextActionsTest.kt
M ui/ui-test/src/main/java/androidx/ui/test/Actions.kt
M ui/ui-test/src/main/java/androidx/ui/test/Filters.kt
M ui/ui-text/api/0.1.0-dev15.txt
M ui/ui-text/api/current.txt
M ui/ui-text/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-text/api/public_plus_experimental_current.txt
M ui/ui-text/api/restricted_0.1.0-dev15.txt
M ui/ui-text/api/restricted_current.txt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/CoreTextField.kt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/TextSemanticsProperties.kt

https://android-review.googlesource.com/1360099

ap...@google.com <ap...@google.com> #3Jan 22, 2025 11:15AM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3454247

Add MutableStateSerializer for serializing MutableState

Expand for full commit details

Add `MutableStateSerializer` for serializing `MutableState` 
 
- Introduced an inline `MutableStateSerializer` function to infer and retrieve the appropriate `KSerializer` for `MutableState` of a serializable type. 
- Added an overload of `MutableStateSerializer` that accepts an explicit `KSerializer` for the wrapped type, allowing for customizing the `KSerializer`. 
- Implemented `MutableStateSerializerImpl`, a private class that handles the serialization and deserialization logic for `MutableState`, delegating inner value processing to the provided `KSerializer`. 
- Only `KSerializer<MutableState<T>>` is exposed; the `MutableStateSerializerImpl` remains private. 
 
RelNote: "Add `MutableStateSerializer` for serializing `androidx.compose.runtime.MutableState`." 
Test: MutableStateSerializerTest 
Bug: 378895074 
Change-Id: Idfc489d9313461bddd0046052d0f6a41644e7712

Files:

M lifecycle/lifecycle-viewmodel-compose/api/current.txt
M lifecycle/lifecycle-viewmodel-compose/api/restricted_current.txt
M lifecycle/lifecycle-viewmodel-compose/build.gradle
A lifecycle/lifecycle-viewmodel-compose/src/androidInstrumentedTest/kotlin/androidx/lifecycle/viewmodel/compose/serialization/serializers/MutableStateSerializerTest.android.kt
A lifecycle/lifecycle-viewmodel-compose/src/commonMain/kotlin/androidx/lifecycle/viewmodel/compose/serialization/serializers/MutableStateSerializer.kt

Hash: d628386123647d7f90b6efb2ddde93621c7cc7db
Date: Fri Jan 17 11:18:40 2025

ap...@google.com <ap...@google.com> #4Jan 22, 2025 11:15AM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3454246

Move KMP compatible test dependencies to commonTest

Expand for full commit details

Move KMP compatible test dependencies to `commonTest` 
 
Test: N/A 
Bug: 378895074 
Change-Id: I77d03d1da41808e03d5e2978b768dc3ef6649211

Files:

M lifecycle/lifecycle-viewmodel-compose/build.gradle

Hash: e266fa197c54fe55955b2de9acc1c1d9894e6376
Date: Fri Jan 17 14:25:48 2025

mg...@google.com <mg...@google.com> Jan 22, 2025 05:34PM

Marked as fixed.

ap...@google.com <ap...@google.com> #5Jan 29, 2025 05:37PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3463875

Move MutableStateSerializer to savedstate-compose

Expand for full commit details

Move `MutableStateSerializer` to `savedstate-compose` 
 
- This change moves `MutableStateSerializer` from `lifecycle-viewmodel-compose` to `savedstate-compose`.  This corrects its previous misplacement and aligns with the design outlined in go/savedstate-compose, which specifies that all `savedstate-compose` related APIs should reside within the `savedstate-compose` module. 
 
RelNote: "Move `MutableStateSerializer` to `savedstate-compose`." 
Test: MutableStateSerializerTest 
Bug: 378895074 
Change-Id: I4f690e41dc5619d185784409170943abeb0f0550

Files:

M lifecycle/lifecycle-viewmodel-compose/api/current.txt
M lifecycle/lifecycle-viewmodel-compose/api/restricted_current.txt
M savedstate/savedstate-compose/api/current.txt
M savedstate/savedstate-compose/api/restricted_current.txt
M savedstate/savedstate-compose/src/androidInstrumentedTest/kotlin/androidx/savedstate/compose/serialization/serializers/MutableStateSerializerTest.android.kt
M savedstate/savedstate-compose/src/commonMain/kotlin/androidx/savedstate/compose/serialization/serializers/MutableStateSerializer.kt

Hash: f845eabb6c5e3b138059839e59f383f70304d792
Date: Wed Jan 29 11:31:04 2025

pr...@google.com <pr...@google.com> #6Feb 12, 2025 06:40PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.lifecycle:lifecycle-viewmodel-compose:2.9.0-alpha10
androidx.lifecycle:lifecycle-viewmodel-compose-android:2.9.0-alpha10
androidx.lifecycle:lifecycle-viewmodel-compose-desktop:2.9.0-alpha10
androidx.savedstate:savedstate-compose:1.3.0-alpha08
androidx.savedstate:savedstate-compose-android:1.3.0-alpha08
androidx.savedstate:savedstate-compose-jvmstubs:1.3.0-alpha08
androidx.savedstate:savedstate-compose-linuxx64stubs:1.3.0-alpha08

ap...@google.com <ap...@google.com> #7Feb 24, 2025 07:24PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3500735

Add SnapshotStateMapSerializer

Expand for full commit details

Add `SnapshotStateMapSerializer` 
 
- Add `SnapshotStateMapSerializer` to support `mutableStateMapOf`. 
 
RelNote: "Add `SnapshotStateMapSerializer` to support `mutableStateMapOf`." 
Bug: 378895074 
Test: SnapshotStateMapSerializerTest 
Change-Id: Ie6f1905cb2004c75efc4e962a6a6275773259af8

Files:

M savedstate/savedstate-compose/api/current.txt
M savedstate/savedstate-compose/api/restricted_current.txt
M savedstate/savedstate-compose/bcv/native/current.txt
A savedstate/savedstate-compose/src/androidInstrumentedTest/kotlin/androidx/savedstate/compose/serialization/serializers/SnapshotStateMapSerializerTest.kt
A savedstate/savedstate-compose/src/commonMain/kotlin/androidx/savedstate/compose/serialization/serializers/SnapshotStateMapSerializer.kt

Hash: 88190ed6a4e2b4a6b18f5b8ac4e6f16aa65a51dd
Date: Thu Feb 20 14:13:23 2025

ap...@google.com <ap...@google.com> #8Feb 24, 2025 07:24PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3500734

Add SnapshotStateListSerializer

Expand for full commit details

Add `SnapshotStateListSerializer` 
 
- Add `SnapshotStateListSerializer` to support `mutableStateListOf`. 
 
RelNote: "Add `SnapshotStateListSerializer` to support `mutableStateListOf`." 
Bug: 378895074 
Test: SnapshotStateListSerializerTest 
Change-Id: I4d888f709797a1b2f87490af0758baa4da78660d

Files:

M savedstate/savedstate-compose/api/current.txt
M savedstate/savedstate-compose/api/restricted_current.txt
M savedstate/savedstate-compose/bcv/native/current.txt
A savedstate/savedstate-compose/src/androidInstrumentedTest/kotlin/androidx/savedstate/compose/serialization/serializers/SnapshotStateListSerializerTest.kt
A savedstate/savedstate-compose/src/commonMain/kotlin/androidx/savedstate/compose/serialization/serializers/SnapshotStateListSerializer.kt

Hash: 97fa891fa692abb5e574c1c42d21a7a0d626768c
Date: Wed Feb 19 18:46:34 2025

ap...@google.com <ap...@google.com> #9Feb 24, 2025 07:24PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3500349

Clean-up MutableStateSerializer

Expand for full commit details

Clean-up `MutableStateSerializer` 
 
Bug: 378895074 
Test: MutableStateSerializerTest 
Change-Id: I429cff7fb9947da4cfd3c12b4411773f89151e65

Files:

M savedstate/savedstate-compose/src/commonMain/kotlin/androidx/savedstate/compose/serialization/serializers/MutableStateSerializer.kt

Hash: 74e185a819ed398f68d21f68d41c69efaca97105
Date: Thu Feb 20 20:27:08 2025

ap...@google.com <ap...@google.com> #10Feb 24, 2025 07:25PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Marcello Galhardo <mgalhardo@google.com>
Link: https://android-review.googlesource.com/3501338

Clean-up MutableStateFlowSerializer

Expand for full commit details

Clean-up `MutableStateFlowSerializer` 
 
Bug: 378895074 
Test: MutableStateFlowSerializerTest 
Change-Id: Ied12e735a56d1b64122f404a6e323da250e7856f

Files:

M savedstate/savedstate/src/commonMain/kotlin/androidx/savedstate/serialization/serializers/MutableStateFlowSerializer.kt

Hash: 67a3a5bb0bea13142f2585932d66b1970938975b
Date: Thu Feb 20 21:25:57 2025

Issue 378895074

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mg...@google.com <mg...@google.com> #2Nov 13, 2024 05:13PM

ap...@google.com <ap...@google.com> #3Jan 22, 2025 11:15AM

ap...@google.com <ap...@google.com> #4Jan 22, 2025 11:15AM

mg...@google.com <mg...@google.com> Jan 22, 2025 05:34PM

ap...@google.com <ap...@google.com> #5Jan 29, 2025 05:37PM

pr...@google.com <pr...@google.com> #6Feb 12, 2025 06:40PM

ap...@google.com <ap...@google.com> #7Feb 24, 2025 07:24PM

ap...@google.com <ap...@google.com> #8Feb 24, 2025 07:24PM

ap...@google.com <ap...@google.com> #9Feb 24, 2025 07:24PM

ap...@google.com <ap...@google.com> #10Feb 24, 2025 07:25PM

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