I think this has been asked before here

Question

I think this has been asked before here <https kotlinlang slack com archives CJLTWPH7S p1633949519417700> but I wanted to ask to see if there were any new discoveries How is it possible to determine the max height needed for the items in a LazyRow so that you can set that as the height of each item so that the vertical height of the LazyRow doesn t change as you scroll

Adam Powell · Answer

It isn t possible by design The Lazy layouts are made for exactly one use case when you have so many items that you don t want UI for all of them to exist at once If you can t have the UI structures for all of them exist at once you can t take the max min of their measurements If they don t all exist at once then you miss correctness cases where the size of one might change over time and you d have to update the min max in response

Adam Powell · Answer

If you have few enough items such that it s practical to do this use a plain Row or Column with a scrolling modifier instead then you can use the usual intrinsics measurements

dazza5000 · Answer

I think the challenge is that Row Column doesn t support snapping and the defacto library snapper doesn t seem to support Row Column or is there another way to get snapping on a Row

dazza5000 · Answer

also thank you for the quick timely response heart

Adam Powell · Answer

you can do anything you like re programmatic scrolling and snapping with the scroll state object passed to the associated modifier

Chris Sinco [G] · Answer

< dazza5000> It d also be helpful to get a mock of what you re trying to build to better understand your needs

dazza5000 · Answer

I would like something that could account for this circumstance

dazza5000 · Answer

right now I am attempting to resize the card based on how much the longest string will take based on the first cards text layout characteristics here is some imperfect logic that doesn t account for wrapping

dazza5000 · Answer

``` val largestTitleTextLength BasicCardModel = carouselModel maxByOrNull it title length 0 val textLayout TextLayoutResult gt Unit = Log d darran darran layout $it val textCharacterLength = it layoutInput text length val textLayoutWidth = it multiParagraph width val widthPerCharacter = textLayoutWidth textCharacterLength it lineCount Log d darran width per character $widthPerCharacter Log d darran lineCount $ it lineCount val maxWidth = it layoutInput constraints maxWidth val heightPerLine = it multiParagraph height it lineCount val totalWidthNeeded = largestTitleTextLength title length 1 widthPerCharacter val linesRequired Float = totalWidthNeeded maxWidth val lineCeiling = ceil linesRequired Log d darran linesCeiling $ lineCeiling val titleHeight = heightPerLine linesRequired Log d darran height calculated by textLayoutResult needed $ it multiParagraph height Log d darran height calculated by algo needed $titleHeight Log d darran height overflowhappened $ it didOverflowHeight Log d darran width overflowhappened $ it didOverflowWidth if it multiParagraph height gt titleHeightToSendDown 0f titleHeightToSendDown = it multiParagraph height if titleHeight gt titleHeightToSendDown 0f titleHeightToSendDown = titleHeight Log d darran title height to send down $titleHeightToSendDown ```

Zoltan Demant · Answer

Its not perfect but it will match the largest child that has been rendered thus far Im using a magic number of `224 dp` as the initial one you can do whatever you like there this works great for my use case ```var minHeight by remember mutableStateOf 224 dp Modifier onSizeChanged size gt val itemHeight = with density val height = size height height toDp if itemHeight gt minHeight minHeight = itemHeight heightIn min = minHeight ```

dazza5000 · Answer

< David Corrado> this bottom solution posted by < Zoltan Demant> is not perfect but will at least maintain a size of the largest rendered card

dazza5000 · Answer

came up with this

dazza5000 · Answer

``` var minHeight Dp by remember mutableStateOf null val density = LocalDensity current val cardSizeModifier = Modifier onSizeChanged size gt val itemHeight = with density val height = size height height toDp if itemHeight gt minHeight 0 dp minHeight = itemHeight defaultMinSize minHeight = minHeight Dp Unspecified ```

dazza5000 · Answer

thank you all for the help heart