I updated my project from dev03 to dev04 and get t...

# compose

[amar_1995]

I updated my project from dev03 to dev04 and get this error.
java.lang.ClassCastException: androidx.compose.GroupStart cannot be cast to androidx.ui.foundation.ScrollerPosition
It was working fine in dev03.
Can anyone help me to resolve this error and why this is occuring ??

[Ian Warwick]

not had this one yet, did it link to where in the code its failing? did you update the dependencies with new compiler etc?

[amar_1995]

https://pastebin.com/zk0huWc9
Error code

[amar_1995]

And, I believe that, I have updated dependencies with new compiler.

[Ian Warwick]

cool I had a look but can't see anything I am familiar with 😞

[amar_1995]

https://kotlinlang.slack.com/archives/CJLTWPH7S/p1580466795175100
Above is the link to my code(dev03)

[Ian Warwick]

cool, is that with dev04 because I think +MaterialTheme is no longer needed

[Ian Warwick]

MaterialTheme.colors().surface

can be this now

[amar_1995]

Yes, That code is in dev03

[amar_1995]

var internationalState = observer(newArticleModel.internationalHeadline)
Surface(color = (MaterialTheme.colors()).surface, modifier = LayoutSize.Fill) {
    if (internationalState == null) {
        ShowLoading()
    } else if (internationalState.isEmpty()) {
        NoContentMore()
    } else {
        val scrollerPosition: ScrollerPosition = remember { ScrollerPosition(0f) }
        println("MainActivity data here : " + internationalState)

        Observe {
            onCommit(scrollerPosition.isAtEndOfList) {
                println("Is commit entered")
                if(scrollerPosition.isAtEndOfList)
                    newArticleModel.loadMoreData()
            }
        }
        VerticalScroller(scrollerPosition = scrollerPosition) {
            Column(modifier = LayoutSize.Fill) {
                println("Page rendering size " + PageSize.topHeadlineInternationalPageNo)
                internationalState!!.forEach {
                    Ripple(bounded = true) {
                        Clickable() {
                            ArticleTicket(
                                backgroundColor = (MaterialTheme.colors()).background,
                                article = it
                            )
                        }
                    }

                }
            }
        }
    }
}

Dev04 code

[Ian Warwick]

aha I see but are you using dev04 now in your project?

[Ian Warwick]

cool

[Ian Warwick]

did you add this?

composeOptions {
        kotlinCompilerExtensionVersion "$compose_version"
    }

to your gradle files?

[amar_1995]

Yes

[Ian Warwick]

awesome

[Ian Warwick]

seems the error complains about this line val scrollerPosition: ScrollerPosition = remember { ScrollerPosition(0f) }

[amar_1995]

I think so
But don't know what is going wrong

[matvei]

ScrollerPosition() is a composable function now that does memorization for you

[matvei]

Just remove outer remember and it will work 🙂

[Ian Warwick]

nice 😄

[matvei]

remember {
    remember {
    }
}

[Adam Powell]

Matvei beat me to it. 🙂 We're not correctly detecting that you're trying to make a composable call in the non-composable body of remember there. Ideally fixed in the next release

[matvei]

This won't work and should ideally be a compiler error or a warning

[Adam Powell]

The reason for the change is that ScrollerPosition reads the current density ambient so that it can use the native android fling motion now

[amar_1995]

nice, It is working now