Scalebar

A composable UI component to display a Scalebar. A Scalebar displays the representation of an accurate linear measurement on the map. It provides a visual indication through which users can determine the size of features or the distance between features on a map.

The required parameters to display a Scalebar are the maximum width of the Scalebar in device independent pixels (dp), the current unitsPerDip of the MapView, and the current ViewpointType.CenterAndScale of the MapView and the SpatialReference of the MapView. The current value of unitsPerDip can be obtained from the Composable MapView's onUnitsPerDipChanged callback. The Viewpoint can be obtained from the Composable MapView's onViewpointChangedForCenterAndScale callback and the SpatialReference can be obtained from the Composable MapView's onSpatialReferenceChanged callback.

The Scalebar will be automatically updated when the Viewpoint changes.

Workflow example:

    var viewpoint: Viewpoint? by remember { mutableStateOf(null) }
    var unitsPerDip by remember { mutableDoubleStateOf(Double.NaN) }
    var spatialReference: SpatialReference? by remember { mutableStateOf(null) }
    // show composable MapView with a Scalebar
    Box(
        modifier = modifier.fillMaxSize()
    ) {
        MapView(
            modifier = Modifier.fillMaxSize(),
            arcGISMap = arcGISMap,
            onSpatialReferenceChanged = { spatialReference = it },
            onUnitsPerDipChanged = { unitsPerDip = it },
            onViewpointChangedForCenterAndScale = { viewpoint = it }
        )
        Scalebar(
            modifier = Modifier
                .padding(25.dp)
                .align(Alignment.BottomStart),
            maxWidth = 175.dp,
            unitsPerDip = unitsPerDip,
            viewpoint = viewpoint,
            spatialReference = spatialReference,
        )
    }

Parameters