After adding an `AbstractComposeView` to our app I m noticin

Question

After adding an `AbstractComposeView` to our app I m noticing that my states aren t getting saved using `rememberSaveable` when the view is detached from window I m trying to investigate this for some time but I haven t reached anywhere How can I investigate what might be happening

saket · Answer

I haven t changed the default `setViewCompositionStrategy` which is `DisposeOnDetachedFromWindow`

Andrey Kulikov · Answer

if you have multiple `AbstractComposeView`s in one Fragment Activity they should have unique ids so they can save their states in a bundle correctly

saket · Answer

yep I m already setting a unique ID to my `AbstractComposeView`

saket · Answer

fwiw state restoration is working as expected when my screen is recreated due to a config change like the system theme but not when I navigate to another screen which makes me suspect if there s something our navigation system is messing up but I m finding it hard to find out what

Ian Lake · Answer

Is your navigation system fragment based Or custom view based

Ian Lake · Answer

Because if it is fragment based `DisposeOnDetachedFromWindow` is always too early as per the docs <https developer android com jetpack compose interop interop apis composition strategy>

Ian Lake · Answer

Same for if you are using `Transition`

Ian Lake · Answer

If it is custom view based then it would be up to you to manually save the state of the View before detaching it from the window then manually restore the view state when you return to that screen this is what fragments does for you FWIW

saket · Answer

Our navigation system is view based and state restoration is working as expected for all non composable screens so far For instance I ve verified that my `AbstractComposeView` implementation s `onSaveInstanceState ` is getting called Is there anything else I can check

saket · Answer

we re still using compose 1 0 1 if it matters

Zach Klippenstein (he/him) [MOD] · Answer

Does your navigation system support SavedStateRegistry Compose uses that instead of instance state

Zach Klippenstein (he/him) [MOD] · Answer

We had to do a <https developer squareup com blog jetpack compose support in workflow |ton of work> to support compose state restoration in workflow which is also view based

saket · Answer

gt Does your navigation system support SavedStateRegistry Compose uses that instead of instance state I think it does because `LocalSaveableStateRegistry current` is non null

saket · Answer

why did workflow require special changes for state restoration to work if the host Activity already provides a saved state registry

Zach Klippenstein (he/him) [MOD] · Answer

Because the activity s saved state registry saves state when the activity goes away and restores it when the activity comes back Your navigation framework probably makes manual calls to save restoreHierarchyState it needs to also manually save and restore child registries for each of its screens Technically it saves it more often but since it s only restored when the activity is restored it effectively only hangs onto the last saved state before it goes away

saket · Answer

oooh that makes sense I think I understand the problem now We ll have to manually dispatch state saves then Your article was very useful thank you

saket · Answer

on a second thought I checked that my composition is getting disposed when my view is detached from window shouldn t that trigger a state save or are disposals and state saves decoupled from each other

Ian Lake · Answer

The whole thing is that you need to save state before the composition gets disposed

saket · Answer

got it thanks both of you