ComposeUiViewController with nested scrollable column shrinks Column with UIModalPresentationFormSheet

[nilufer32]

Describe the bug A clear and concise description of what the bug is. When using ComposeUiViewController, and setting the modalPresentationStyle of the view controller to UIModalPresentationFormSheet, dragging the form sheet updwards/downwards causes shrinking/stretching of the nested composable scrollable column I place inside it. Also im not able to vertically scroll my column.

Affected platforms

IOS

Versions

• Libraries:
  • Compose Multiplatform version: 1.6.10
• Kotlin version: 2.0.0-RC1

To reproduce:

val bottomSheetUIViewController =
        ComposeUIViewController {
            VerticalScrollWithIndependentHorizontalRows()
        }
        bottomSheetUIViewController.modalPresentationStyle = UIModalPresentationFormSheet
        bottomSheetUIViewController.sheetPresentationController?.setDetents(
        listOf(
                    UISheetPresentationControllerDetent.mediumDetent(),
                    UISheetPresentationControllerDetent.largeDetent(),
                )
                )

                UIApplication.sharedApplication.keyWindow?.rootViewController?.presentViewController(
            viewControllerToPresent = bottomSheetUIViewController,
            animated = true,
            completion = {},
        )

 @Composable
fun VerticalScrollWithIndependentHorizontalRows() {
    Column(
        modifier =
            Modifier.fillMaxSize().verticalScroll(verticalScrollState, enabled = true),
    ) {
        repeat(10) { rowIndex ->
            val horizontalScrollState = rememberScrollState()

            Spacer(Modifier.height(30.dp).background(Color.DarkGray))
            Row(
                modifier =
                    Modifier
                        .padding(start = 16.dp, end = 16.dp)
                        .horizontalScroll(horizontalScrollState),
            ) {
                repeat(5) {
                    Box(
                        modifier =
                            Modifier
                                .size(100.dp)
                                .background(Color.Gray),
                    ) {
                        Text("Item $it in row $rowIndex")
                    }
                }
            }
        }
    }
}

Video depicting the bug :

https://github.com/JetBrains/compose-multiplatform/assets/151455263/924b9ce3-0c92-4aca-b55b-5338c5e90431

Additional Warning: When attempting to scroll in my nested vertically scrollable column, I receive the following logs in Xcode: DidReceiveMemoryWarning

[nilufer32]

any updates on this issue?

[elijah-semyonov]

I'll have a look at it soon.

[elijah-semyonov]

The nested scrolling issue is a separate one: https://github.com/JetBrains/compose-multiplatform/issues/3806

[nilufer32]

But is the scrolling issue related to the shrinking/stretching of the content?

[elijah-semyonov]

Not really

[elijah-semyonov]

Memory warning doesn't seem to be related to the repro you posted. Most likely you have a retain cycle between Kotlin and ObjC with a strong reference inside ObjC API that Kotlin can't break.

[nilufer32]

@elijah-semyonov I dont really see how could that be the case as the prototype app I used to reproduce the bug uses the standard architecture of a multiplatform app where I simply use a ComposeUIViewController from swift, and to this view controller I add the sample code above

[elijah-semyonov]

Do you mind sharing the whole solution? "DidReceiveMemoryWarning" means something went terribly wrong.

[nilufer32]

all I do to trigger the memory warning is attempt to scroll inside the column in my bottom sheet by scrolling multiple times consecutively. this actually does scroll inside my column but at an extremely slow pace as in every scroll event scrolls the column by 1 pixel roughly

[elijah-semyonov]

Can you record it? I fail to reproduce this behavior.

[nilufer32]

sure ill record it right now

[nilufer32]

Here's the repo containing the reproduction code: https://github.com/nilufer32/test

https://github.com/JetBrains/compose-multiplatform/assets/151455263/472c9299-9d61-4987-af14-dcde8d95db49

[elijah-semyonov]

@nilufer32 You've got wrong Compose Version in repro 🌚 compose = "1.5.11"

[elijah-semyonov]

Reproduced memory spike though

[nilufer32]

the issue is 100% reproducible using compose 1.6.10 and kotlin 2.0.0. I just seem to have forgotten to update the library versions when I was creating a sample app to post for you onto github :)

[elijah-semyonov]

A memory spike part of the issue should be fixed in https://github.com/JetBrains/compose-multiplatform-core/pull/1390