CollapsableParallaxImageCompletedParallaxImage.kt

import androidx.compose.foundation.Image
import androidx.compose.foundation.ScrollState
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ImageBitmap
import androidx.compose.ui.graphics.asImageBitmap
import androidx.compose.ui.graphics.graphicsLayer
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.unit.dp
import coil.ImageLoader
import com.google.accompanist.systemuicontroller.rememberSystemUiController
import yourApp.rememberCoilTarget
import yourApp.rememberDefaultImageRequest
import yourApp.computeDominantTopSectionColor
import kotlinx.coroutines.launch
import kotlin.math.min

@Composable
fun ParallaxImage(
    modifier: Modifier = Modifier,
    url: String,
    scrollState: ScrollState,
) {
    val coroutineScope = rememberCoroutineScope()

    val systemUiController = rememberSystemUiController()
    var parallaxColor by remember { mutableStateOf(Color.Transparent) }

    var image by remember { mutableStateOf(ImageBitmap(1, 1)) }
    val loader = ImageLoader(LocalContext.current)
    val target = rememberCoilTarget { bitmap ->
        image = bitmap.asImageBitmap()
        coroutineScope.launch {
            val (color, isLight) = bitmap
                .computeDominantTopSectionColor()
            parallaxColor = color
            systemUiController.setStatusBarColor(color, isLight)
        }
    }

    val request = rememberDefaultImageRequest(url = url, target = target)
    LaunchedEffect(url) {
        loader.execute(request)
    }

    Image(
        modifier = modifier
            .height(250.dp)
            .fillMaxWidth()
            .background(parallaxColor)
            .graphicsLayer { alpha = min(1f, 1 - (scrollState.value / 400f)) },
        bitmap = image,
        contentScale = ContentScale.FillWidth,
        contentDescription = null,
    )
}