Is it possible to prevent an AndroidView from recomposing if a parent node recomposes? I have an And...

# compose

[aoriani]

Is it possible to prevent an AndroidView from recomposing if a parent node recomposes? I have an AndroidView wrapping a camera2 PreviewView to display the camera feed. When a parent node recomposes I see that the PreviewView blinks black, which tells me that the view is being recreated.

[Arjun Achatz]

Just spit-balling here, but you might be able to wrap the composable definition in a key(x){} where x is something contextual, or unit 😬

[Adam Powell]

can you show your code? generally recomposing an AndroidView composable does not recreate the view. There may be something else going on there.

[aoriani]

@Adam Powell I was lazy. I only read the doc for the update param which says "The callback to be invoked after the layout is inflated.", so I thought it was an adequate place to set the preview surface. Reading the docs for AndroidView a bit further I found "The update block can be run multiple times (on the UI thread as well) due to recomposition, and it is the right place to set View properties depending on state". Then I realized what was my mistake, and I moved everything to factory.

I guess the doc for update should be changed to something like the callback to update the view when there is a recomposition . Should I create a PR to update the docs?

[Adam Powell]

Since this led to some confusion for you I think it's important that the docs are especially precise here. The update block will be run if:
1. the view is initially created by the supplied factory
2. a new update is provided through recomposition (e.g. recomposed with a new/different lambda capture)
3. snapshot state accessed by update was invalidated

[Adam Powell]

I purposely have not used the word, "when" in this description; the promise of this API contract only calls for running update after one of the above conditions has been met and before any upcoming frame performs layout and drawing

[aoriani]

Thanks @Adam Powell