I’m attempting to make a layout such that it is a ...

# compose

[Justin Breitfeller]

I’m attempting to make a layout such that it is a row if the enclosed children will fit in the horizontal space given to the composable. If not, I wanted to swap to a column where each child is assigned a minWidth of the constrained horizontal space. I was able to get this working with a SubcomposeLayout by:
1. Call subcompose with the passed in width constraints
2. If the resulting placeables are too wide, call subcompose with constraints that has a minWidth of what was passed to the SubcomposeLayout.
3. I then only place either the horizontal or vertical placeables.
The one problem I’m having with this approach is the semantics tree still knows about the horizontal subcomposition even though I never placed them. Is there a way to remove them or perhaps another way to approach this problem?

[Adam Powell]

Use the Layout composable and avoid subcomposition for this. Use intrinsic sizes to determine whether things fit and then perform final measurement once you've decided the orientation

[Justin Breitfeller]

Thanks! Is there a good link on instric sizes?

[Adam Powell]

start from the api docs, you can ask a Measurable for its minimum intrinsic width given a certain available height, for example

[Justin Breitfeller]

Awesome. https://developer.android.com/jetpack/compose/layouts/intrinsic-measurements this seems to be the resource to start with!

[Adam Powell]

hmm, the custom layout snippet there looks wrong but the basic idea is there. It'll involve a call to the Layout composable rather than returning an object directly like that

[Oleksandr Balan]

You can check how minIntrinsicWidth() is used in this sample:
https://kotlinlang.slack.com/archives/CJLTWPH7S/p1648551227037639?thread_ts=1648467352.438719&cid=CJLTWPH7S

As for me it would be useful to mention this approach in docs you linked.

[Justin Breitfeller]

Layout(modifier = modifier, content = content) { measurables, constraints ->
        val totalWidth = measurables.sumOf {
            it.minIntrinsicWidth(constraints.maxHeight)
        }

        if (totalWidth > constraints.maxWidth) {
            columnLayout(measurables, constraints)
        } else {
            rowLayout(measurables, constraints)
        }
    }

I ended up doing this which seems to work! Thanks!