ContextualFlowColumn

Deprecated ContextualFlowLayouts are no longer maintained

@Composable
@ExperimentalLayoutApi
fun ContextualFlowColumn(
    itemCount: Int,
    modifier: Modifier = Modifier,
    verticalArrangement: Arrangement.Vertical = Arrangement.Top,
    horizontalArrangement: Arrangement.Horizontal = Arrangement.Start,
    itemHorizontalAlignment: Alignment.Horizontal = Alignment.Start,
    maxItemsInEachColumn: Int = Int.MAX_VALUE,
    maxLines: Int = Int.MAX_VALUE,
    overflow: ContextualFlowColumnOverflow = ContextualFlowColumnOverflow.Clip,
    content: @Composable ContextualFlowColumnScope.(index: Int) -> Unit,
)

ContextualFlowColumn is a specialized version of the FlowColumn layout. It is designed to enable users to make contextual decisions during the construction of FlowColumn layouts.

This component is particularly advantageous when dealing with a large collection of items, allowing for efficient management and display. Unlike traditional FlowColumn that composes all items regardless of their visibility, ContextualFlowColumn smartly limits composition to only those items that are visible within its constraints, such as maxLines or maxWidth. This approach ensures optimal performance and resource utilization by composing fewer items than the total number available, based on the current context and display parameters.

While maintaining the core functionality of the standard FlowColumn, ContextualFlowColumn operates on an index-based system and composes items sequentially, one after another. This approach provides a perfect way to make contextual decisions and can be an easier way to handle problems such as dynamic see more buttons such as (N+ buttons).

Parameters

Code Examples

ContextualFlowColMaxLineDynamicSeeMore

@OptIn(ExperimentalLayoutApi::class)
@Composable
fun ContextualFlowColMaxLineDynamicSeeMore() {
    val totalCount = 300
    var maxLines by remember { mutableStateOf(2) }
    Text(
        modifier = Modifier.fillMaxWidth(1f).padding(20.dp),
        text =
            "ContextualFlowColumn (based on Subcompose)" +
                " is great for Large Items & +N dynamic labels",
        fontWeight = FontWeight.Bold,
    )
    val moreOrCollapseIndicator =
        @Composable { scope: ContextualFlowColumnOverflowScope ->
            val remainingItems = totalCount - scope.shownItemCount
            DynamicSeeMore(isHorizontal = true, remainingItems = remainingItems) {
                if (remainingItems == 0) {
                    maxLines = 2
                } else {
                    maxLines += 2
                }
            }
        }
    ContextualFlowColumn(
        modifier =
            Modifier.fillMaxWidth(1f)
                .horizontalScroll(rememberScrollState())
                .padding(20.dp)
                .height(200.dp)
                .wrapContentHeight(align = Alignment.Top),
        verticalArrangement = Arrangement.spacedBy(10.dp),
        horizontalArrangement = Arrangement.spacedBy(20.dp),
        maxLines = maxLines,
        overflow =
            ContextualFlowColumnOverflow.expandOrCollapseIndicator(
                minColumnsToShowCollapse = 4,
                expandIndicator = moreOrCollapseIndicator,
                collapseIndicator = moreOrCollapseIndicator,
            ),
        itemCount = totalCount,
    ) { index ->
        Box(
            modifier =
                Modifier.align(Alignment.CenterHorizontally)
                    .height(50.dp)
                    .width(50.dp)
                    .background(Color.Green)
        ) {
            Text(
                text = index.toString(),
                fontSize = 18.sp,
                modifier = Modifier.padding(3.dp).align(Alignment.Center),
            )
        }
    }
}