pullRefreshIndicatorTransform

@ExperimentalMaterialApi
fun Modifier.pullRefreshIndicatorTransform(state: PullRefreshState, scale: Boolean = false) =
    drawWithContent {
            clipRect(
                top = 0f,
                left = -Float.MAX_VALUE,
                right = Float.MAX_VALUE,
                bottom = Float.MAX_VALUE,
            ) {
                this@drawWithContent.drawContent()
            }
        }
        .graphicsLayer {
            translationY = state.position - size.height

            if (scale && !state.refreshing) {
                val scaleFraction =
                    LinearOutSlowInEasing.transform(state.position / state.threshold)
                        .fastCoerceIn(0f, 1f)
                scaleX = scaleFraction
                scaleY = scaleFraction
            }
        }

A modifier for translating the position and scaling the size of a pull-to-refresh indicator based on the given PullRefreshState.

Parameters

Code Examples

PullRefreshIndicatorTransformSample

/**
 * An example to show how [pullRefreshIndicatorTransform] can be given custom contents to create a
 * custom indicator.
 */
@Composable
@OptIn(ExperimentalMaterialApi::class)
fun PullRefreshIndicatorTransformSample() {
    val refreshScope = rememberCoroutineScope()
    var refreshing by remember { mutableStateOf(false) }
    var itemCount by remember { mutableStateOf(15) }
    fun refresh() =
        refreshScope.launch {
            refreshing = true
            delay(1500)
            itemCount += 5
            refreshing = false
        }
    val state = rememberPullRefreshState(refreshing, ::refresh)
    val rotation = animateFloatAsState(state.progress * 120)
    Box(Modifier.fillMaxSize().pullRefresh(state)) {
        LazyColumn {
            if (!refreshing) {
                items(itemCount) { ListItem { Text(text = "Item ${itemCount - it}") } }
            }
        }
        Surface(
            modifier =
                Modifier.size(40.dp)
                    .align(Alignment.TopCenter)
                    .pullRefreshIndicatorTransform(state)
                    .rotate(rotation.value),
            shape = RoundedCornerShape(10.dp),
            color = Color.DarkGray,
            elevation = if (state.progress > 0 || refreshing) 20.dp else 0.dp,
        ) {
            Box {
                if (refreshing) {
                    CircularProgressIndicator(
                        modifier = Modifier.align(Alignment.Center).size(25.dp),
                        color = Color.White,
                        strokeWidth = 3.dp,
                    )
                }
            }
        }
    }
}