WkWebView inside a UIKit View is not displayed when height is fixed and used inside a LazyColumn Item

[Vaibhav2002]

Describe the bug When using a WkWebView inside a UIKit view without setting a fixed height using Modifier.height() inside a LazyColumn Item, it is not displayed When a fixed height it set, it is displayed.

Affected platforms

• iOS

Versions

• Libraries:
  • Compose Multiplatform version: 1.6.10
• Kotlin version: 2.0.0

To Reproduce Steps to reproduce the behavior:

1. Run this code snippet:

   LazyColumn(
       modifier = Modifier.fillMaxSize(),
       verticalArrangement = Arrangement.spacedBy(8.dp),
       contentPadding = PaddingValues(16.dp),
   ) {
       items(30, contentType = { it }) {
           ListItem(modifier = Modifier.fillParentMaxWidth())
       }
   }
   
   @Composable
   fun ListItem(modifier: Modifier = Modifier) {
       Column(modifier = modifier, verticalArrangement = Arrangement.spacedBy(8.dp)) {
           Box(modifier = Modifier.fillMaxWidth().background(Color.Red).height(30.dp))
           Box(modifier = Modifier.fillMaxWidth().background(Color.Green).height(64.dp))
           NativeWebView(
               url="https://youtube.com"
               modifier = Modifier.fillMaxWidth(),
           )
           Box(modifier = Modifier.fillMaxWidth().background(Color.Blue).height(30.dp))
       }
   }
   
   @OptIn(ExperimentalForeignApi::class)
   @Composable
   actual fun NativeWebView(url: String, modifier: Modifier) {
       UIKitView(
           factory = {
               val config =
                   WKWebViewConfiguration().apply {
                       allowsInlineMediaPlayback = true
                       defaultWebpagePreferences.allowsContentJavaScript = true
                       preferences.javaScriptEnabled = true
                   }
               WKWebView(
                   frame = CGRectZero.readValue(),
                   configuration = config,
               ).apply {
                   setOpaque(false)
               }
           },
           modifier = modifier,
           onRelease = {},
           update = {
              it.loadRequest(NSMutableURLRequest.requestWithURL(URL = NSURL(string = url)))
           }
       )
   }

Screenshots

When fixed height Modifier.height(400.dp) applied to NativeWebView, It looks fine

Without fixed height:

Additional context

My use case is to embed Tweets, Reddit Post, Yt Videos and other embeddable html in a LazyColumn Item

[elijah-semyonov]

Interop views don't support sizing based on intrinsic content size of native views (and most likely won't be, Compose and UIKit have different layout systems). Moreover, WKWebView doesn't have any intrinsic size. These closest you can get to mimic it is - https://stackoverflow.com/questions/27515236/how-to-determine-the-content-size-of-a-wkwebview and provide it explicitly.