Merge "Fix race condition in rememberPageStateFixed" into udc-dev

import androidx.compose.foundation.layout.padding

import androidx.compose.foundation.pager.HorizontalPager

import androidx.compose.foundation.pager.PagerState

import androidx.compose.foundation.pager.rememberPagerState

import androidx.compose.material3.TabRow

import androidx.compose.runtime.Composable

import androidx.compose.runtime.LaunchedEffect

import androidx.compose.runtime.SideEffect

import androidx.compose.runtime.State

import androidx.compose.runtime.getValue

import androidx.compose.runtime.mutableStateOf

import androidx.compose.runtime.remember

import androidx.compose.runtime.rememberCoroutineScope

import androidx.compose.runtime.saveable.rememberSaveable

import androidx.compose.runtime.setValue

    Column {

        val coroutineScope = rememberCoroutineScope()

        val pagerState by rememberPageStateFixed()

        val pagerState = rememberPageStateFixed()

        TabRow(

            selectedTabIndex = pagerState.currentPage,

 */

@Composable

@OptIn(ExperimentalFoundationApi::class)

private fun rememberPageStateFixed(): State<PagerState> {

private fun rememberPageStateFixed(): PagerState {

    var currentPage by rememberSaveable { mutableStateOf(0) }

    val pagerStateHolder = remember { mutableStateOf(PagerState(currentPage)) }

    LaunchedEffect(LocalConfiguration.current.orientation) {

    var targetPage by rememberSaveable { mutableStateOf(-1) }

    val pagerState = rememberPagerState()

    val configuration = LocalConfiguration.current

    var lastScreenWidthDp by rememberSaveable { mutableStateOf(-1) }

    val screenWidthDp = configuration.screenWidthDp

    LaunchedEffect(screenWidthDp) {

        // Reset pager state to fix an issue after configuration change.

        // When we declare android:configChanges="orientation" in the manifest, the pager state is

        // in a weird state after configuration change.

        pagerStateHolder.value = PagerState(currentPage)

        // When we declare android:configChanges in the manifest, the pager state is in a weird

        // state after configuration change.

        targetPage = currentPage

        lastScreenWidthDp = screenWidthDp

    }

    LaunchedEffect(targetPage) {

        if (targetPage != -1) {

            pagerState.scrollToPage(targetPage)

            targetPage = -1

        }

    }

    SideEffect {

        currentPage = pagerStateHolder.value.currentPage

        if (lastScreenWidthDp == screenWidthDp) {

            currentPage = pagerState.currentPage

        }

    }

    return pagerStateHolder

    return pagerState

}