calculateCentroidSize

fun PointerEvent.calculateCentroidSize(useCurrent: Boolean = true): Float

Returns the average distance from the centroid for all pointers that are currently and were previously down. If no pointers are down, 0 is returned. If useCurrent is true, the size of the PointerInputChange.position is returned and if false, the size of PointerInputChange.previousPosition is returned. Only pointers that are down in both the previous and current state are used to calculate the centroid size.

Example Usage:

Code Examples

CalculateCentroidSize

@Composable
fun CalculateCentroidSize() {
    var centroidSize by remember { mutableStateOf(0f) }
    var position by remember { mutableStateOf(Offset.Zero) }
    Box(
        Modifier.drawBehind {
                // Draw a circle where the gesture is
                drawCircle(Color.Blue, centroidSize, center = position)
            }
            .pointerInput(Unit) {
                awaitEachGesture {
                    awaitFirstDown().also { position = it.position }
                    do {
                        val event = awaitPointerEvent()
                        val size = event.calculateCentroidSize()
                        if (size != 0f) {
                            centroidSize = event.calculateCentroidSize()
                        }
                        val centroid = event.calculateCentroid()
                        if (centroid != Offset.Unspecified) {
                            position = centroid
                        }
                    } while (event.changes.any { it.pressed })
                }
            }
            .fillMaxSize()
    )
}