Change the working of groups

demo/maps/src/jvmMain/kotlin/Main.kt

@@ -22,6 +22,8 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
 import java.net.URL
 import java.nio.file.Path
 import kotlin.math.PI
@@ -64,13 +66,13 @@ fun App() {
 
             image(pointOne, Icons.Filled.Home)
 
-            val marker1 = rectangle(55.744 to 38.614, size = DpSize(10.dp, 10.dp), color = Color.Magenta)
+            val marker1 = rectangle(55.744 to 38.614, size = DpSize(10.dp, 10.dp)).color(Color.Magenta)
-            val marker2 = rectangle(55.8 to 38.5, size = DpSize(10.dp, 10.dp), color = Color.Magenta)
+            val marker2 = rectangle(55.8 to 38.5, size = DpSize(10.dp, 10.dp)).color(Color.Magenta)
-            val marker3 = rectangle(56.0 to 38.5, size = DpSize(10.dp, 10.dp), color = Color.Magenta)
+            val marker3 = rectangle(56.0 to 38.5, size = DpSize(10.dp, 10.dp)).color(Color.Magenta)
 
-            draggableLine(marker1, marker2, color = Color.Blue)
+            draggableLine(marker1, marker2).color(Color.Blue)
-            draggableLine(marker2, marker3, color = Color.Blue)
+            draggableLine(marker2, marker3).color(Color.Blue)
-            draggableLine(marker3, marker1, color = Color.Blue)
+            draggableLine(marker3, marker1).color(Color.Blue)
 
             points(
                 points = listOf(
@@ -85,13 +87,16 @@ fun App() {
             )
 
             //remember feature ID
-            circle(
+            val circleId = circle(
                 centerCoordinates = pointTwo,
-            ).updated(scope) {
+            )
+            scope.launch {
+                while (isActive) {
                     delay(200)
-                //Overwrite a feature with new color
+                    circleId.color(Color(Random.nextFloat(), Random.nextFloat(), Random.nextFloat()))
-                it.copy(color = Color(Random.nextFloat(), Random.nextFloat(), Random.nextFloat()))
                 }
+            }
+
 
 //            draw(position = pointThree) {
 //                drawLine(start = Offset(-10f, -10f), end = Offset(10f, 10f), color = Color.Red)
@@ -105,16 +110,20 @@ fun App() {
 
             centerCoordinates.filterNotNull().onEach {
                 group(id = "center") {
-                    circle(center = it, color = Color.Blue, id = "circle", size = 1.dp)
+                    circle(center = it, id = "circle", size = 1.dp).color(Color.Blue)
-                    text(position = it, it.toShortString(), id = "text", color = Color.Blue)
+                    text(position = it, it.toShortString(), id = "text").color(Color.Blue)
                 }
             }.launchIn(scope)
 
-            features.forEach { (id, feature) ->
+            visit { id, feature ->
                 if (feature is PolygonFeature) {
                     (id as FeatureId<PolygonFeature<Gmc>>).onHover {
                         println("Hover on $id")
-                        points(feature.points, color = Color.Blue, id = "selected", attributes = Attributes(ZAttribute, 10f))
+                        points(
+                            feature.points,
+                            id = "selected",
+                            attributes = Attributes(ZAttribute, 10f)
+                        ).color(Color.Blue)
                     }
                 }
             }

demo/scheme/src/jvmMain/kotlin/Main.kt

@@ -8,7 +8,7 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.window.Window
 import androidx.compose.ui.window.application
-import center.sciprog.maps.features.FeatureCollection
+import center.sciprog.maps.features.FeatureGroup
 import center.sciprog.maps.features.ViewConfig
 import center.sciprog.maps.features.ViewPoint
 import center.sciprog.maps.features.computeBoundingBox
@@ -29,7 +29,7 @@ fun App() {
     MaterialTheme {
         val scope = rememberCoroutineScope()
 
-        val schemeFeaturesState = FeatureCollection.remember(XYCoordinateSpace) {
+        val schemeFeaturesState = FeatureGroup.remember(XYCoordinateSpace) {
             background(1600f, 1200f) { painterResource("middle-earth.jpg") }
             circle(410.52737 to 868.7676, color = Color.Blue)
             text(410.52737 to 868.7676, "Shire", color = Color.Blue)
@@ -53,7 +53,7 @@ fun App() {
         }
 
         val initialViewPoint: ViewPoint<XY> = remember {
-            schemeFeaturesState.features.values.computeBoundingBox(XYCoordinateSpace, 1f)?.computeViewPoint()
+            schemeFeaturesState.features.computeBoundingBox(XYCoordinateSpace, 1f)?.computeViewPoint()
                 ?: XYViewPoint(XY(0f, 0f))
         }
 

maps-kt-compose/src/commonMain/kotlin/center/sciprog/maps/compose/MapView.kt

@@ -11,7 +11,7 @@ import center.sciprog.maps.features.*
 @Composable
 public expect fun MapView(
     mapState: MapViewScope,
-    featuresState: FeatureCollection<Gmc>,
+    featuresState: FeatureGroup<Gmc>,
     modifier: Modifier = Modifier.fillMaxSize(),
 )
 
@@ -29,7 +29,7 @@ public fun MapView(
 ) {
 
     val featureState = remember(featureMap) {
-        FeatureCollection.build(WebMercatorSpace) {
+        FeatureGroup.build(WebMercatorSpace) {
             featureMap.forEach { feature(it.key.id, it.value) }
         }
     }
@@ -38,7 +38,7 @@ public fun MapView(
         mapTileProvider,
         config,
         initialViewPoint = initialViewPoint,
-        initialRectangle = initialRectangle ?: featureState.features.values.computeBoundingBox(WebMercatorSpace, Float.MAX_VALUE),
+        initialRectangle = initialRectangle ?: featureState.features.computeBoundingBox(WebMercatorSpace, Float.MAX_VALUE),
     )
 
     MapView(mapState, featureState, modifier)
@@ -58,16 +58,16 @@ public fun MapView(
     initialRectangle: Rectangle<Gmc>? = null,
     config: ViewConfig<Gmc> = ViewConfig(),
     modifier: Modifier = Modifier.fillMaxSize(),
-    buildFeatures: FeatureCollection<Gmc>.() -> Unit = {},
+    buildFeatures: FeatureGroup<Gmc>.() -> Unit = {},
 ) {
 
-    val featureState = FeatureCollection.remember(WebMercatorSpace, buildFeatures)
+    val featureState = FeatureGroup.remember(WebMercatorSpace, buildFeatures)
 
     val mapState: MapViewScope = rememberMapState(
         mapTileProvider,
         config,
         initialViewPoint = initialViewPoint,
-        initialRectangle = initialRectangle ?: featureState.features.values.computeBoundingBox(WebMercatorSpace, Float.MAX_VALUE),
+        initialRectangle = initialRectangle ?: featureState.features.computeBoundingBox(WebMercatorSpace, Float.MAX_VALUE),
     )
 
     MapView(mapState, featureState, modifier)

maps-kt-compose/src/commonMain/kotlin/center/sciprog/maps/compose/mapFeatures.kt

@@ -1,6 +1,5 @@
 package center.sciprog.maps.compose
 
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.PointMode
 import androidx.compose.ui.graphics.drawscope.DrawScope
 import androidx.compose.ui.graphics.vector.ImageVector
@@ -11,73 +10,62 @@ import center.sciprog.maps.coordinates.*
 import center.sciprog.maps.features.*
 
 
-internal fun FeatureBuilder<Gmc>.coordinatesOf(pair: Pair<Number, Number>) =
+internal fun FeatureGroup<Gmc>.coordinatesOf(pair: Pair<Number, Number>) =
     GeodeticMapCoordinates.ofDegrees(pair.first.toDouble(), pair.second.toDouble())
 
 public typealias MapFeature = Feature<Gmc>
 
-public fun FeatureBuilder<Gmc>.circle(
+public fun FeatureGroup<Gmc>.circle(
     centerCoordinates: Pair<Number, Number>,
-    zoomRange: FloatRange = defaultZoomRange,
     size: Dp = 5.dp,
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<CircleFeature<Gmc>> = feature(
-    id, CircleFeature(space, coordinatesOf(centerCoordinates), zoomRange, size, color)
+    id, CircleFeature(space, coordinatesOf(centerCoordinates), size)
 )
 
-public fun FeatureBuilder<Gmc>.rectangle(
+public fun FeatureGroup<Gmc>.rectangle(
     centerCoordinates: Pair<Number, Number>,
-    zoomRange: FloatRange = defaultZoomRange,
     size: DpSize = DpSize(5.dp, 5.dp),
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<RectangleFeature<Gmc>> = feature(
-    id, RectangleFeature(space, coordinatesOf(centerCoordinates), zoomRange, size, color)
+    id, RectangleFeature(space, coordinatesOf(centerCoordinates),  size)
 )
 
 
-public fun FeatureBuilder<Gmc>.draw(
+public fun FeatureGroup<Gmc>.draw(
     position: Pair<Number, Number>,
-    zoomRange: FloatRange = defaultZoomRange,
     id: String? = null,
     draw: DrawScope.() -> Unit,
 ): FeatureId<DrawFeature<Gmc>> = feature(
     id,
-    DrawFeature(space, coordinatesOf(position), zoomRange, drawFeature = draw)
+    DrawFeature(space, coordinatesOf(position), drawFeature = draw)
 )
 
 
-public fun FeatureBuilder<Gmc>.line(
+public fun FeatureGroup<Gmc>.line(
     curve: GmcCurve,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<LineFeature<Gmc>> = feature(
     id,
-    LineFeature(space, curve.forward.coordinates, curve.backward.coordinates, zoomRange, color)
+    LineFeature(space, curve.forward.coordinates, curve.backward.coordinates)
 )
 
 
-public fun FeatureBuilder<Gmc>.line(
+public fun FeatureGroup<Gmc>.line(
     aCoordinates: Pair<Double, Double>,
     bCoordinates: Pair<Double, Double>,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<LineFeature<Gmc>> = feature(
     id,
-    LineFeature(space, coordinatesOf(aCoordinates), coordinatesOf(bCoordinates), zoomRange, color)
+    LineFeature(space, coordinatesOf(aCoordinates), coordinatesOf(bCoordinates))
 )
 
 
-public fun FeatureBuilder<Gmc>.arc(
+public fun FeatureGroup<Gmc>.arc(
     center: Pair<Double, Double>,
     radius: Distance,
     startAngle: Angle,
     arcLength: Angle,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<ArcFeature<Gmc>> = feature(
     id,
@@ -86,26 +74,21 @@ public fun FeatureBuilder<Gmc>.arc(
         oval = space.Rectangle(coordinatesOf(center), radius, radius),
         startAngle = startAngle.radians.toFloat(),
         arcLength = arcLength.radians.toFloat(),
-        zoomRange = zoomRange,
-        color = color
     )
 )
 
-public fun FeatureBuilder<Gmc>.points(
+public fun FeatureGroup<Gmc>.points(
     points: List<Pair<Double, Double>>,
-    zoomRange: FloatRange = defaultZoomRange,
     stroke: Float = 2f,
-    color: Color = defaultColor,
     pointMode: PointMode = PointMode.Points,
     id: String? = null,
 ): FeatureId<PointsFeature<Gmc>> =
-    feature(id, PointsFeature(space, points.map(::coordinatesOf), zoomRange, stroke, color, pointMode))
+    feature(id, PointsFeature(space, points.map(::coordinatesOf),  stroke,  pointMode))
 
-public fun FeatureBuilder<Gmc>.image(
+public fun FeatureGroup<Gmc>.image(
     position: Pair<Double, Double>,
     image: ImageVector,
     size: DpSize = DpSize(20.dp, 20.dp),
-    zoomRange: FloatRange = defaultZoomRange,
     id: String? = null,
 ): FeatureId<VectorImageFeature<Gmc>> = feature(
     id,
@@ -114,18 +97,15 @@ public fun FeatureBuilder<Gmc>.image(
         coordinatesOf(position),
         size,
         image,
-        zoomRange
     )
 )
 
-public fun FeatureBuilder<Gmc>.text(
+public fun FeatureGroup<Gmc>.text(
     position: Pair<Double, Double>,
     text: String,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
     font: FeatureFont.() -> Unit = { size = 16f },
     id: String? = null,
 ): FeatureId<TextFeature<Gmc>> = feature(
     id,
-    TextFeature(space, coordinatesOf(position), text, zoomRange, color, fontConfig = font)
+    TextFeature(space, coordinatesOf(position), text, fontConfig = font)
 )

maps-kt-compose/src/jvmMain/kotlin/center/sciprog/maps/compose/MapViewJvm.kt

@@ -15,10 +15,10 @@ import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.dp
 import center.sciprog.maps.coordinates.Gmc
-import center.sciprog.maps.features.FeatureCollection
+import center.sciprog.maps.features.FeatureGroup
 import center.sciprog.maps.features.PainterFeature
 import center.sciprog.maps.features.drawFeature
-import center.sciprog.maps.features.z
+import center.sciprog.maps.features.zoomRange
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.supervisorScope
 import mu.KotlinLogging
@@ -44,7 +44,7 @@ private val logger = KotlinLogging.logger("MapView")
 @Composable
 public actual fun MapView(
     mapState: MapViewScope,
-    featuresState: FeatureCollection<Gmc>,
+    featuresState: FeatureGroup<Gmc>,
     modifier: Modifier,
 ): Unit = with(mapState) {
 
@@ -90,9 +90,10 @@ public actual fun MapView(
     }
 
     val painterCache: Map<PainterFeature<Gmc>, Painter> = key(featuresState) {
-        featuresState.features.values.filterIsInstance<PainterFeature<Gmc>>().associateWith { it.getPainter() }
+        featuresState.features.filterIsInstance<PainterFeature<Gmc>>().associateWith { it.getPainter() }
     }
 
+
     Canvas(modifier = modifier.mapControls(mapState, featuresState.features).fillMaxSize()) {
 
         if (canvasSize != size.toDpSize()) {
@@ -119,7 +120,7 @@ public actual fun MapView(
                 )
             }
 
-            featuresState.features.values.filter { viewPoint.zoom in it.zoomRange }.sortedBy { it.z }
+            featuresState.features.filter { viewPoint.zoom in it.zoomRange }
                 .forEach { feature ->
                     drawFeature(mapState, painterCache, feature)
                 }

maps-kt-features/src/commonMain/kotlin/center/sciprog/maps/features/Attribute.kt

@@ -18,4 +18,6 @@ public object VisibleAttribute : Attribute<Boolean>
 
 public object ColorAttribute : Attribute<Color>
 
+public object ZoomRangeAttribute : Attribute<FloatRange>
+
 public object AlphaAttribute : Attribute<Float>

maps-kt-features/src/commonMain/kotlin/center/sciprog/maps/features/Feature.kt

@@ -21,8 +21,6 @@ public interface Feature<T : Any> {
 
     public val space: CoordinateSpace<T>
 
-    public val zoomRange: FloatRange
-
     public val attributes: Attributes
 
     public fun getBoundingBox(zoom: Float): Rectangle<T>?
@@ -30,6 +28,11 @@ public interface Feature<T : Any> {
     public fun withAttributes(modify: Attributes.() -> Attributes): Feature<T>
 }
 
+public val Feature<*>.color: Color? get() = attributes[ColorAttribute]
+
+public val Feature<*>.zoomRange: FloatRange
+    get() = attributes[ZoomRangeAttribute] ?: Float.NEGATIVE_INFINITY..Float.POSITIVE_INFINITY
+
 public interface PainterFeature<T : Any> : Feature<T> {
     @Composable
     public fun getPainter(): Painter
@@ -65,7 +68,6 @@ public fun <T : Any> Iterable<Feature<T>>.computeBoundingBox(
 @Stable
 public data class FeatureSelector<T : Any>(
     override val space: CoordinateSpace<T>,
-    override val zoomRange: FloatRange,
     override val attributes: Attributes = Attributes.EMPTY,
     public val selector: (zoom: Float) -> Feature<T>,
 ) : Feature<T> {
@@ -81,7 +83,6 @@ public data class PathFeature<T : Any>(
     public val rectangle: Rectangle<T>,
     public val path: Path,
     public val brush: Brush,
-    override val zoomRange: FloatRange,
     public val style: DrawStyle = Fill,
     public val targetRect: Rect = path.getBounds(),
     override val attributes: Attributes = Attributes.EMPTY,
@@ -94,7 +95,6 @@ public data class PathFeature<T : Any>(
             brush = brush,
             style = style,
             targetRect = targetRect,
-            zoomRange = zoomRange
         )
     }
 
@@ -106,9 +106,7 @@ public data class PathFeature<T : Any>(
 public data class PointsFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     public val points: List<T>,
-    override val zoomRange: FloatRange,
     public val stroke: Float = 2f,
-    public val color: Color = Color.Red,
     public val pointMode: PointMode = PointMode.Points,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : Feature<T> {
@@ -125,8 +123,6 @@ public data class PointsFeature<T : Any>(
 public data class PolygonFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     public val points: List<T>,
-    override val zoomRange: FloatRange,
-    public val color: Color = Color.Red,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : DomainFeature<T> {
 
@@ -136,7 +132,8 @@ public data class PolygonFeature<T : Any>(
 
     override fun getBoundingBox(zoom: Float): Rectangle<T>? = boundingBox
 
-    override fun contains(viewPoint: ViewPoint<T>): Boolean =  viewPoint.focus in boundingBox!!//with(space) { viewPoint.focus.isInsidePolygon(points) }
+    override fun contains(viewPoint: ViewPoint<T>): Boolean =
+        viewPoint.focus in boundingBox!!//with(space) { viewPoint.focus.isInsidePolygon(points) }
 
     override fun withAttributes(modify: (Attributes) -> Attributes): Feature<T> = copy(attributes = modify(attributes))
 }
@@ -145,9 +142,7 @@ public data class PolygonFeature<T : Any>(
 public data class CircleFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     override val center: T,
-    override val zoomRange: FloatRange,
     public val size: Dp = 5.dp,
-    public val color: Color = Color.Red,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : MarkerFeature<T> {
     override fun getBoundingBox(zoom: Float): Rectangle<T> =
@@ -162,9 +157,7 @@ public data class CircleFeature<T : Any>(
 public data class RectangleFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     override val center: T,
-    override val zoomRange: FloatRange,
     public val size: DpSize = DpSize(5.dp, 5.dp),
-    public val color: Color = Color.Red,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : MarkerFeature<T> {
     override fun getBoundingBox(zoom: Float): Rectangle<T> =
@@ -180,8 +173,6 @@ public data class LineFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     public val a: T,
     public val b: T,
-    override val zoomRange: FloatRange,
-    public val color: Color = Color.Red,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : DomainFeature<T> {
     override fun getBoundingBox(zoom: Float): Rectangle<T> =
@@ -208,8 +199,6 @@ public data class ArcFeature<T : Any>(
     public val oval: Rectangle<T>,
     public val startAngle: Float,
     public val arcLength: Float,
-    override val zoomRange: FloatRange,
-    public val color: Color = Color.Red,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : DraggableFeature<T> {
     override fun getBoundingBox(zoom: Float): Rectangle<T> = oval
@@ -223,7 +212,6 @@ public data class ArcFeature<T : Any>(
 public data class DrawFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     public val position: T,
-    override val zoomRange: FloatRange,
     override val attributes: Attributes = Attributes.EMPTY,
     public val drawFeature: DrawScope.() -> Unit,
 ) : DraggableFeature<T> {
@@ -240,7 +228,6 @@ public data class BitmapImageFeature<T : Any>(
     override val center: T,
     public val size: DpSize,
     public val image: ImageBitmap,
-    override val zoomRange: FloatRange,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : MarkerFeature<T> {
     override fun getBoundingBox(zoom: Float): Rectangle<T> = space.Rectangle(center, zoom, size)
@@ -256,7 +243,6 @@ public data class VectorImageFeature<T : Any>(
     override val center: T,
     public val size: DpSize,
     public val image: ImageVector,
-    override val zoomRange: FloatRange,
     override val attributes: Attributes = Attributes.EMPTY,
 ) : MarkerFeature<T>, PainterFeature<T> {
     override fun getBoundingBox(zoom: Float): Rectangle<T> = space.Rectangle(center, zoom, size)
@@ -277,7 +263,6 @@ public data class VectorImageFeature<T : Any>(
 public data class ScalableImageFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     public val rectangle: Rectangle<T>,
-    override val zoomRange: FloatRange,
     override val attributes: Attributes = Attributes.EMPTY,
     public val painter: @Composable () -> Painter,
 ) : Feature<T>, PainterFeature<T> {
@@ -290,28 +275,10 @@ public data class ScalableImageFeature<T : Any>(
 }
 
 
-/**
- * A group of other features
- */
-public data class FeatureGroup<T : Any>(
-    override val space: CoordinateSpace<T>,
-    public val children: Map<FeatureId<*>, Feature<T>>,
-    override val zoomRange: FloatRange,
-    override val attributes: Attributes = Attributes.EMPTY,
-) : Feature<T> {
-    override fun getBoundingBox(zoom: Float): Rectangle<T>? = with(space) {
-        children.values.mapNotNull { it.getBoundingBox(zoom) }.wrapRectangles()
-    }
-
-    override fun withAttributes(modify: Attributes.() -> Attributes): Feature<T> = copy(attributes = attributes)
-}
-
 public data class TextFeature<T : Any>(
     override val space: CoordinateSpace<T>,
     public val position: T,
     public val text: String,
-    override val zoomRange: FloatRange,
-    public val color: Color = Color.Black,
     override val attributes: Attributes = Attributes.EMPTY,
     public val fontConfig: FeatureFont.() -> Unit,
 ) : DraggableFeature<T> {

maps-kt-features/src/commonMain/kotlin/center/sciprog/maps/features/FeatureCollection.kt

@@ -1,335 +0,0 @@
-package center.sciprog.maps.features
-
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.mutableStateMapOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.snapshots.SnapshotStateMap
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.PointMode
-import androidx.compose.ui.graphics.drawscope.DrawScope
-import androidx.compose.ui.graphics.painter.Painter
-import androidx.compose.ui.graphics.vector.ImageVector
-import androidx.compose.ui.input.pointer.PointerEvent
-import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.DpSize
-import androidx.compose.ui.unit.dp
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.isActive
-import kotlinx.coroutines.launch
-import kotlin.jvm.JvmInline
-
-@JvmInline
-public value class FeatureId<out F : Feature<*>>(public val id: String)
-
-public interface FeatureBuilder<T : Any> {
-
-    public val space: CoordinateSpace<T>
-
-    public fun generateUID(feature: Feature<T>?): String
-
-    public fun <F : Feature<T>> feature(id: String?, feature: F): FeatureId<F>
-
-    public fun <F : Feature<T>, V> FeatureId<F>.withAttribute(key: Attribute<V>, value: V?): FeatureId<F>
-
-    public val defaultColor: Color get() = Color.Red
-
-    public val defaultZoomRange: FloatRange get() = 0f..Float.POSITIVE_INFINITY
-}
-
-public fun <T : Any, F : Feature<T>> FeatureBuilder<T>.feature(id: FeatureId<F>, feature: F): FeatureId<F> =
-    feature(id.id, feature)
-
-public class FeatureCollection<T : Any>(
-    override val space: CoordinateSpace<T>,
-) : CoordinateSpace<T> by space, FeatureBuilder<T> {
-
-    @PublishedApi
-    internal val featureMap: SnapshotStateMap<String, Feature<T>> = mutableStateMapOf()
-
-    public val features: Map<FeatureId<*>, Feature<T>>
-        get() = featureMap.mapKeys { FeatureId<Feature<T>>(it.key) }
-
-    @Suppress("UNCHECKED_CAST")
-    public operator fun <F : Feature<T>> get(id: FeatureId<F>): F =
-        featureMap[id.id]?.let { it as F } ?: error("Feature with id=$id not found")
-
-    private var uidCounter = 0
-
-    override fun generateUID(feature: Feature<T>?): String = if(feature == null){
-        "@group[${uidCounter++}]"
-    } else {
-        "@${feature::class.simpleName}[${uidCounter++}]"
-    }
-
-    override fun <F : Feature<T>> feature(id: String?, feature: F): FeatureId<F> {
-        val safeId = id ?: generateUID(feature)
-        featureMap[safeId] = feature
-        return FeatureId(safeId)
-    }
-
-    public fun <F : Feature<T>> feature(id: FeatureId<F>, feature: F): FeatureId<F> = feature(id.id, feature)
-
-    @Suppress("UNCHECKED_CAST")
-    public fun <A> getAttribute(id: FeatureId<Feature<T>>, key: Attribute<A>): A? =
-        get(id).attributes[key]
-
-    /**
-     * Process all features with a given attribute from the one with highest [z] to lowest
-     */
-    public inline fun <A> forEachWithAttribute(
-        key: Attribute<A>,
-        block: (id: FeatureId<*>, feature: Feature<T>, attributeValue: A) -> Unit,
-    ) {
-        featureMap.entries.sortedByDescending { it.value.z }.forEach { (id, feature) ->
-            feature.attributes[key]?.let {
-                block(FeatureId<Feature<T>>(id), feature, it)
-            }
-        }
-    }
-
-    public fun <F : Feature<T>, V> FeatureId<F>.modifyAttributes(modify: Attributes.() -> Attributes) {
-        feature(this, get(this).withAttributes(modify))
-    }
-
-    override fun <F : Feature<T>, V> FeatureId<F>.withAttribute(key: Attribute<V>, value: V?): FeatureId<F> {
-        feature(this, get(this).withAttributes { withAttribute(key, value) })
-        return this
-    }
-
-
-    /**
-     * Add drag to this feature
-     *
-     * @param constraint optional drag constraint
-     *
-     * TODO use context receiver for that
-     */
-    @Suppress("UNCHECKED_CAST")
-    public fun FeatureId<DraggableFeature<T>>.draggable(
-        constraint: ((T) -> T)? = null,
-        listener: (PointerEvent.(from: ViewPoint<T>, to: ViewPoint<T>) -> Unit)? = null,
-    ) {
-        if (getAttribute(this, DraggableAttribute) == null) {
-            val handle = DragHandle.withPrimaryButton<Any> { event, start, end ->
-                val feature = featureMap[id] as? DraggableFeature<T> ?: return@withPrimaryButton DragResult(end)
-                start as ViewPoint<T>
-                end as ViewPoint<T>
-                if (start in feature) {
-                    val finalPosition = constraint?.invoke(end.focus) ?: end.focus
-                    feature(id, feature.withCoordinates(finalPosition))
-                    feature.attributes[DragListenerAttribute]?.forEach {
-                        it.handle(event, start, ViewPoint(finalPosition, end.zoom))
-                    }
-                    DragResult(ViewPoint(finalPosition, end.zoom), false)
-                } else {
-                    DragResult(end, true)
-                }
-            }
-            this.withAttribute(DraggableAttribute, handle)
-        }
-
-        //Apply callback
-        if (listener != null) {
-            onDrag(listener)
-        }
-    }
-
-
-    @Suppress("UNCHECKED_CAST")
-    public fun FeatureId<DraggableFeature<T>>.onDrag(
-        listener: PointerEvent.(from: ViewPoint<T>, to: ViewPoint<T>) -> Unit,
-    ) {
-        withAttribute(
-            DragListenerAttribute,
-            (getAttribute(this, DragListenerAttribute) ?: emptySet()) +
-                    DragListener { event, from, to ->
-                        event.listener(from as ViewPoint<T>, to as ViewPoint<T>)
-                    }
-        )
-    }
-
-    @Suppress("UNCHECKED_CAST")
-    public fun <F : DomainFeature<T>> FeatureId<F>.onClick(
-        onClick: PointerEvent.(click: ViewPoint<T>) -> Unit,
-    ) {
-        withAttribute(
-            ClickListenerAttribute,
-            (getAttribute(this, ClickListenerAttribute) ?: emptySet()) +
-                    MouseListener { event, point -> event.onClick(point as ViewPoint<T>) }
-        )
-    }
-
-    @Suppress("UNCHECKED_CAST")
-    public fun <F : DomainFeature<T>> FeatureId<F>.onHover(
-        onClick: PointerEvent.(move: ViewPoint<T>) -> Unit,
-    ) {
-        withAttribute(
-            HoverListenerAttribute,
-            (getAttribute(this, HoverListenerAttribute) ?: emptySet()) +
-                    MouseListener { event, point -> event.onClick(point as ViewPoint<T>) }
-        )
-    }
-
-    /**
-     * Cyclic update of a feature. Called infinitely until canceled.
-     */
-    public fun <F : Feature<T>> FeatureId<F>.updated(
-        scope: CoroutineScope,
-        update: suspend (F) -> F,
-    ): Job = scope.launch {
-        while (isActive) {
-            feature(this@updated, update(get(this@updated)))
-        }
-    }
-
-
-    public companion object {
-
-        /**
-         * Build, but do not remember map feature state
-         */
-        public fun <T : Any> build(
-            coordinateSpace: CoordinateSpace<T>,
-            builder: FeatureCollection<T>.() -> Unit = {},
-        ): FeatureCollection<T> = FeatureCollection(coordinateSpace).apply(builder)
-
-        /**
-         * Build and remember map feature state
-         */
-        @Composable
-        public fun <T : Any> remember(
-            coordinateSpace: CoordinateSpace<T>,
-            builder: FeatureCollection<T>.() -> Unit = {},
-        ): FeatureCollection<T> = remember(builder) {
-            build(coordinateSpace, builder)
-        }
-
-    }
-}
-
-public fun <T : Any> FeatureBuilder<T>.circle(
-    center: T,
-    zoomRange: FloatRange = defaultZoomRange,
-    size: Dp = 5.dp,
-    color: Color = defaultColor,
-    id: String? = null,
-): FeatureId<CircleFeature<T>> = feature(
-    id, CircleFeature(space, center, zoomRange, size, color)
-)
-
-public fun <T : Any> FeatureBuilder<T>.rectangle(
-    centerCoordinates: T,
-    zoomRange: FloatRange = defaultZoomRange,
-    size: DpSize = DpSize(5.dp, 5.dp),
-    color: Color = defaultColor,
-    id: String? = null,
-): FeatureId<RectangleFeature<T>> = feature(
-    id, RectangleFeature(space, centerCoordinates, zoomRange, size, color)
-)
-
-public fun <T : Any> FeatureBuilder<T>.draw(
-    position: T,
-    zoomRange: FloatRange = defaultZoomRange,
-    id: String? = null,
-    draw: DrawScope.() -> Unit,
-): FeatureId<DrawFeature<T>> = feature(
-    id,
-    DrawFeature(space, position, zoomRange, drawFeature = draw)
-)
-
-public fun <T : Any> FeatureBuilder<T>.line(
-    aCoordinates: T,
-    bCoordinates: T,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
-    id: String? = null,
-): FeatureId<LineFeature<T>> = feature(
-    id,
-    LineFeature(space, aCoordinates, bCoordinates, zoomRange, color)
-)
-
-public fun <T : Any> FeatureBuilder<T>.arc(
-    oval: Rectangle<T>,
-    startAngle: Float,
-    arcLength: Float,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
-    id: String? = null,
-): FeatureId<ArcFeature<T>> = feature(
-    id,
-    ArcFeature(space, oval, startAngle, arcLength, zoomRange, color)
-)
-
-public fun <T : Any> FeatureBuilder<T>.points(
-    points: List<T>,
-    zoomRange: FloatRange = defaultZoomRange,
-    stroke: Float = 2f,
-    color: Color = defaultColor,
-    pointMode: PointMode = PointMode.Points,
-    attributes: Attributes = Attributes.EMPTY,
-    id: String? = null,
-): FeatureId<PointsFeature<T>> = feature(
-    id,
-    PointsFeature(space, points, zoomRange, stroke, color, pointMode, attributes)
-)
-
-public fun <T : Any> FeatureBuilder<T>.polygon(
-    points: List<T>,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
-    id: String? = null,
-): FeatureId<PolygonFeature<T>> = feature(
-    id,
-    PolygonFeature(space, points, zoomRange, color)
-)
-
-public fun <T : Any> FeatureBuilder<T>.image(
-    position: T,
-    image: ImageVector,
-    zoomRange: FloatRange = defaultZoomRange,
-    size: DpSize = DpSize(image.defaultWidth, image.defaultHeight),
-    id: String? = null,
-): FeatureId<VectorImageFeature<T>> =
-    feature(
-        id,
-        VectorImageFeature(
-            space,
-            position,
-            size,
-            image,
-            zoomRange
-        )
-    )
-
-public fun <T : Any> FeatureBuilder<T>.group(
-    zoomRange: FloatRange = defaultZoomRange,
-    id: String? = null,
-    builder: FeatureCollection<T>.() -> Unit,
-): FeatureId<FeatureGroup<T>> {
-    val map = FeatureCollection(space).apply(builder).features
-    val feature = FeatureGroup(space, map, zoomRange)
-    return feature(id, feature)
-}
-
-public fun <T : Any> FeatureBuilder<T>.scalableImage(
-    box: Rectangle<T>,
-    zoomRange: FloatRange = defaultZoomRange,
-    id: String? = null,
-    painter: @Composable () -> Painter,
-): FeatureId<ScalableImageFeature<T>> = feature(
-    id,
-    ScalableImageFeature<T>(space, box, zoomRange, painter = painter)
-)
-
-public fun <T : Any> FeatureBuilder<T>.text(
-    position: T,
-    text: String,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = defaultColor,
-    font: FeatureFont.() -> Unit = { size = 16f },
-    id: String? = null,
-): FeatureId<TextFeature<T>> = feature(
-    id,
-    TextFeature(space, position, text, zoomRange, color, fontConfig = font)
-)

maps-kt-features/src/commonMain/kotlin/center/sciprog/maps/features/FeatureGroup.kt

@@ -1,37 +1,315 @@
 package center.sciprog.maps.features
 
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateMapOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.snapshots.SnapshotStateMap
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.PointMode
+import androidx.compose.ui.graphics.drawscope.DrawScope
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.input.pointer.PointerEvent
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.DpSize
+import androidx.compose.ui.unit.dp
+import kotlin.jvm.JvmInline
+
+@JvmInline
+public value class FeatureId<out F : Feature<*>>(public val id: String)
+
+/**
+ * A group of other features
+ */
+public data class FeatureGroup<T : Any>(
+    override val space: CoordinateSpace<T>,
+    public val featureMap: SnapshotStateMap<String, Feature<T>> = mutableStateMapOf(),
+    override val attributes: Attributes = Attributes.EMPTY,
+) : CoordinateSpace<T> by space, Feature<T> {
+
+    @Suppress("UNCHECKED_CAST")
+    public operator fun <F : Feature<T>> get(id: FeatureId<F>): F =
+        featureMap[id.id]?.let { it as F } ?: error("Feature with id=$id not found")
+
+    private var uidCounter = 0
+
+    private fun generateUID(feature: Feature<T>?): String = if (feature == null) {
+        "@group[${uidCounter++}]"
+    } else {
+        "@${feature::class.simpleName}[${uidCounter++}]"
+    }
+
+    public fun <F : Feature<T>> feature(id: String?, feature: F): FeatureId<F> {
+        val safeId = id ?: generateUID(feature)
+        featureMap[safeId] = feature
+        return FeatureId(safeId)
+    }
+
+    public fun <F : Feature<T>> feature(id: FeatureId<F>, feature: F): FeatureId<F> = feature(id.id, feature)
+
+    public val features: Collection<Feature<T>> get() = featureMap.values.sortedByDescending { it.z }
+
+    public fun visit(visitor: FeatureGroup<T>.(id: FeatureId<Feature<T>>, feature: Feature<T>) -> Unit) {
+        featureMap.forEach { (key, feature) ->
+            if (feature is FeatureGroup<T>) {
+                feature.visit(visitor)
+            } else {
+                visitor(this, FeatureId(key), feature)
+            }
+        }
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    public fun <A> getAttribute(id: FeatureId<Feature<T>>, key: Attribute<A>): A? =
+        get(id).attributes[key]
+
+    /**
+     * Process all features with a given attribute from the one with highest [z] to lowest
+     */
+    public inline fun <A> forEachWithAttribute(
+        key: Attribute<A>,
+        block: (id: FeatureId<*>, feature: Feature<T>, attributeValue: A) -> Unit,
+    ) {
+        featureMap.entries.sortedByDescending { it.value.z }.forEach { (id, feature) ->
+            feature.attributes[key]?.let {
+                block(FeatureId<Feature<T>>(id), feature, it)
+            }
+        }
+    }
+
+    public fun <F : Feature<T>, V> FeatureId<F>.modifyAttributes(modify: Attributes.() -> Attributes) {
+        feature(this, get(this).withAttributes(modify))
+    }
+
+    public fun <F : Feature<T>, V> FeatureId<F>.withAttribute(key: Attribute<V>, value: V?): FeatureId<F> {
+        feature(this, get(this).withAttributes { withAttribute(key, value) })
+        return this
+    }
+
+
+    /**
+     * Add drag to this feature
+     *
+     * @param constraint optional drag constraint
+     *
+     * TODO use context receiver for that
+     */
+    @Suppress("UNCHECKED_CAST")
+    public fun FeatureId<DraggableFeature<T>>.draggable(
+        constraint: ((T) -> T)? = null,
+        listener: (PointerEvent.(from: ViewPoint<T>, to: ViewPoint<T>) -> Unit)? = null,
+    ) {
+        if (getAttribute(this, DraggableAttribute) == null) {
+            val handle = DragHandle.withPrimaryButton<Any> { event, start, end ->
+                val feature = featureMap[id] as? DraggableFeature<T> ?: return@withPrimaryButton DragResult(end)
+                start as ViewPoint<T>
+                end as ViewPoint<T>
+                if (start in feature) {
+                    val finalPosition = constraint?.invoke(end.focus) ?: end.focus
+                    feature(id, feature.withCoordinates(finalPosition))
+                    feature.attributes[DragListenerAttribute]?.forEach {
+                        it.handle(event, start, ViewPoint(finalPosition, end.zoom))
+                    }
+                    DragResult(ViewPoint(finalPosition, end.zoom), false)
+                } else {
+                    DragResult(end, true)
+                }
+            }
+            this.withAttribute(DraggableAttribute, handle)
+        }
+
+        //Apply callback
+        if (listener != null) {
+            onDrag(listener)
+        }
+    }
+
+
+    @Suppress("UNCHECKED_CAST")
+    public fun FeatureId<DraggableFeature<T>>.onDrag(
+        listener: PointerEvent.(from: ViewPoint<T>, to: ViewPoint<T>) -> Unit,
+    ) {
+        withAttribute(
+            DragListenerAttribute,
+            (getAttribute(this, DragListenerAttribute) ?: emptySet()) +
+                    DragListener { event, from, to ->
+                        event.listener(from as ViewPoint<T>, to as ViewPoint<T>)
+                    }
+        )
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    public fun <F : DomainFeature<T>> FeatureId<F>.onClick(
+        onClick: PointerEvent.(click: ViewPoint<T>) -> Unit,
+    ) {
+        withAttribute(
+            ClickListenerAttribute,
+            (getAttribute(this, ClickListenerAttribute) ?: emptySet()) +
+                    MouseListener { event, point -> event.onClick(point as ViewPoint<T>) }
+        )
+    }
+
+    @Suppress("UNCHECKED_CAST")
+    public fun <F : DomainFeature<T>> FeatureId<F>.onHover(
+        onClick: PointerEvent.(move: ViewPoint<T>) -> Unit,
+    ) {
+        withAttribute(
+            HoverListenerAttribute,
+            (getAttribute(this, HoverListenerAttribute) ?: emptySet()) +
+                    MouseListener { event, point -> event.onClick(point as ViewPoint<T>) }
+        )
+    }
+
 //    /**
-// * A group of other features
+//     * Cyclic update of a feature. Called infinitely until canceled.
 //     */
-//public data class FeatureGroup<T : Any>(
+//    public fun <F : Feature<T>> FeatureId<F>.updated(
-//    val parentBuilder: FeatureBuilder<T>,
+//        scope: CoroutineScope,
-//    private val groupId: String,
+//        update: suspend (F) -> F,
-//    public override val zoomRange: FloatRange,
+//    ): Job = scope.launch {
-//    override val attributes: Attributes = Attributes.EMPTY,
+//        while (isActive) {
-//) : FeatureBuilder<T>, Feature<T> {
+//            feature(this@updated, update(get(this@updated)))
-//
-//    override val space: CoordinateSpace<T> get() = parentBuilder.space
-//
-//    override fun generateUID(feature: Feature<T>?): String = parentBuilder.generateUID(feature)
-//
-//    override fun <F : Feature<T>> feature(id: String?, feature: F): FeatureId<F> =
-//        parentBuilder.feature("${groupId}.${id ?: parentBuilder.generateUID(feature)}", feature)
-//
-//    override fun <F : Feature<T>, V> FeatureId<F>.withAttribute(key: Attribute<V>, value: V?): FeatureId<F> =
-//        with(parentBuilder) {
-//            FeatureId<F>("${groupId}.${this@withAttribute.id}").withAttribute(key, value)
 //        }
-//
-//    override fun getBoundingBox(zoom: Float): Rectangle<T>? {
-//        TODO("Not yet implemented")
 //    }
-//
+
-//    override fun withAttributes(modify: Attributes.() -> Attributes): Feature<T> =
+    public fun <F : Feature<T>> FeatureId<F>.color(color: Color): FeatureId<F> =
-//        copy(attributes = attributes.modify())
+        withAttribute(ColorAttribute, color)
-//}
+    public fun <F : Feature<T>> FeatureId<F>.zoomRange(range: FloatRange): FeatureId<F> =
-//
+        withAttribute(ZoomRangeAttribute, range)
-//public fun <T : Any> FeatureBuilder<T>.group(
+
-//    zoomRange: FloatRange = defaultZoomRange,
+    override fun getBoundingBox(zoom: Float): Rectangle<T>? = with(space) {
-//    id: String? = null,
+        featureMap.values.mapNotNull { it.getBoundingBox(zoom) }.wrapRectangles()
-//    builder: FeatureBuilder<T>.() -> Unit,
+    }
-//): FeatureId<FeatureGroup<T>> = feature(id, FeatureGroup(this, id ?: generateUID(null), zoomRange).apply(builder))
+
+    override fun withAttributes(modify: Attributes.() -> Attributes): Feature<T> = copy(attributes = attributes)
+
+    public companion object {
+
+        /**
+         * Build, but do not remember map feature state
+         */
+        public fun <T : Any> build(
+            coordinateSpace: CoordinateSpace<T>,
+            builder: FeatureGroup<T>.() -> Unit = {},
+        ): FeatureGroup<T> = FeatureGroup(coordinateSpace).apply(builder)
+
+        /**
+         * Build and remember map feature state
+         */
+        @Composable
+        public fun <T : Any> remember(
+            coordinateSpace: CoordinateSpace<T>,
+            builder: FeatureGroup<T>.() -> Unit = {},
+        ): FeatureGroup<T> = remember(builder) {
+            build(coordinateSpace, builder)
+        }
+
+    }
+}
+
+public fun <T : Any> FeatureGroup<T>.circle(
+    center: T,
+    size: Dp = 5.dp,
+    id: String? = null,
+): FeatureId<CircleFeature<T>> = feature(
+    id, CircleFeature(space, center, size)
+)
+
+public fun <T : Any> FeatureGroup<T>.rectangle(
+    centerCoordinates: T,
+    size: DpSize = DpSize(5.dp, 5.dp),
+    id: String? = null,
+): FeatureId<RectangleFeature<T>> = feature(
+    id, RectangleFeature(space, centerCoordinates, size)
+)
+
+public fun <T : Any> FeatureGroup<T>.draw(
+    position: T,
+    id: String? = null,
+    draw: DrawScope.() -> Unit,
+): FeatureId<DrawFeature<T>> = feature(
+    id,
+    DrawFeature(space, position, drawFeature = draw)
+)
+
+public fun <T : Any> FeatureGroup<T>.line(
+    aCoordinates: T,
+    bCoordinates: T,
+    id: String? = null,
+): FeatureId<LineFeature<T>> = feature(
+    id,
+    LineFeature(space, aCoordinates, bCoordinates)
+)
+
+public fun <T : Any> FeatureGroup<T>.arc(
+    oval: Rectangle<T>,
+    startAngle: Float,
+    arcLength: Float,
+    id: String? = null,
+): FeatureId<ArcFeature<T>> = feature(
+    id,
+    ArcFeature(space, oval, startAngle, arcLength)
+)
+
+public fun <T : Any> FeatureGroup<T>.points(
+    points: List<T>,
+    stroke: Float = 2f,
+    pointMode: PointMode = PointMode.Points,
+    attributes: Attributes = Attributes.EMPTY,
+    id: String? = null,
+): FeatureId<PointsFeature<T>> = feature(
+    id,
+    PointsFeature(space, points, stroke, pointMode, attributes)
+)
+
+public fun <T : Any> FeatureGroup<T>.polygon(
+    points: List<T>,
+    id: String? = null,
+): FeatureId<PolygonFeature<T>> = feature(
+    id,
+    PolygonFeature(space, points)
+)
+
+public fun <T : Any> FeatureGroup<T>.image(
+    position: T,
+    image: ImageVector,
+    size: DpSize = DpSize(image.defaultWidth, image.defaultHeight),
+    id: String? = null,
+): FeatureId<VectorImageFeature<T>> =
+    feature(
+        id,
+        VectorImageFeature(
+            space,
+            position,
+            size,
+            image,
+        )
+    )
+
+public fun <T : Any> FeatureGroup<T>.group(
+    id: String? = null,
+    builder: FeatureGroup<T>.() -> Unit,
+): FeatureId<FeatureGroup<T>> {
+    val collection = FeatureGroup(space).apply(builder)
+    val feature = FeatureGroup(space, collection.featureMap)
+    return feature(id, feature)
+}
+
+public fun <T : Any> FeatureGroup<T>.scalableImage(
+    box: Rectangle<T>,
+    id: String? = null,
+    painter: @Composable () -> Painter,
+): FeatureId<ScalableImageFeature<T>> = feature(
+    id,
+    ScalableImageFeature<T>(space, box, painter = painter)
+)
+
+public fun <T : Any> FeatureGroup<T>.text(
+    position: T,
+    text: String,
+    font: FeatureFont.() -> Unit = { size = 16f },
+    id: String? = null,
+): FeatureId<TextFeature<T>> = feature(
+    id,
+    TextFeature(space, position, text, fontConfig = font)
+)

maps-kt-features/src/commonMain/kotlin/center/sciprog/maps/features/compositeFeatures.kt

@@ -1,13 +1,9 @@
 package center.sciprog.maps.features
 
-import androidx.compose.ui.graphics.Color
 
-
+public fun <T : Any> FeatureGroup<T>.draggableLine(
-public fun <T : Any> FeatureCollection<T>.draggableLine(
     aId: FeatureId<MarkerFeature<T>>,
     bId: FeatureId<MarkerFeature<T>>,
-    zoomRange: FloatRange = defaultZoomRange,
-    color: Color = Color.Red,
     id: String? = null,
 ): FeatureId<LineFeature<T>> {
     var lineId: FeatureId<LineFeature<T>>? = null
@@ -15,8 +11,6 @@ public fun <T : Any> FeatureCollection<T>.draggableLine(
     fun drawLine(): FeatureId<LineFeature<T>> = line(
         get(aId).center,
         get(bId).center,
-        zoomRange,
-        color,
         lineId?.id ?: id
     ).also {
         lineId = it

maps-kt-features/src/jvmMain/kotlin/center/sciprog/maps/compose/mapControls.kt

@@ -14,10 +14,11 @@ import kotlin.math.min
 
 /**
  * Create a modifier for Map/Scheme canvas controls on desktop
+ * @param features a collection of features to be rendered in descending [ZAttribute] order
  */
 public fun <T : Any> Modifier.mapControls(
     state: CoordinateViewScope<T>,
-    features: Map<FeatureId<*>, Feature<T>>,
+    features: Collection<Feature<T>>,
 ): Modifier = with(state) {
     pointerInput(Unit) {
         fun Offset.toDpOffset() = DpOffset(x.toDp(), y.toDp())
@@ -27,10 +28,8 @@ public fun <T : Any> Modifier.mapControls(
                 val coordinates = event.changes.first().position.toDpOffset().toCoordinates()
                 val point = space.ViewPoint(coordinates, zoom)
 
-                val sortedFeatures =features.values.sortedByDescending { it.z }
-
                 if (event.type == PointerEventType.Move) {
-                    for (feature in sortedFeatures) {
+                    for (feature in features) {
                         val listeners = (feature as? DomainFeature)?.attributes?.get(HoverListenerAttribute)
                         if (listeners != null && point in feature) {
                             listeners.forEach { it.handle(event, point) }
@@ -43,7 +42,7 @@ public fun <T : Any> Modifier.mapControls(
                         event,
                         point
                     )
-                    for (feature in sortedFeatures) {
+                    for (feature in features) {
                         val listeners = (feature as? DomainFeature)?.attributes?.get(ClickListenerAttribute)
                         if (listeners != null && point in feature) {
                             listeners.forEach { it.handle(event, point) }
@@ -97,9 +96,8 @@ public fun <T : Any> Modifier.mapControls(
                             val dragResult = config.dragHandle?.handle(event, dragStart, dragEnd)
                             if (dragResult?.handleNext == false) return@drag
 
-                            features.values.asSequence()
+                            features.asSequence()
                                 .filterIsInstance<DraggableFeature<T>>()
-                                .sortedByDescending { it.z }
                                 .mapNotNull {
                                     it.attributes[DraggableAttribute]
                                 }.forEach { handler ->

maps-kt-features/src/jvmMain/kotlin/center/sciprog/maps/features/drawFeature.kt

@@ -25,21 +25,21 @@ public fun <T : Any> DrawScope.drawFeature(
     state: CoordinateViewScope<T>,
     painterCache: Map<PainterFeature<T>, Painter>,
     feature: Feature<T>,
-
 ): Unit = with(state) {
+    val color = feature.color ?: Color.Red
     val alpha = feature.attributes[AlphaAttribute]?:1f
     fun T.toOffset(): Offset = toOffset(this@drawFeature)
 
     when (feature) {
         is FeatureSelector -> drawFeature(state, painterCache, feature.selector(state.zoom))
         is CircleFeature -> drawCircle(
-            feature.color,
+            color,
             feature.size.toPx(),
             center = feature.center.toOffset()
         )
 
         is RectangleFeature -> drawRect(
-            feature.color,
+            color,
             topLeft = feature.center.toOffset() - Offset(
                 feature.size.width.toPx() / 2,
                 feature.size.height.toPx() / 2
@@ -47,14 +47,14 @@ public fun <T : Any> DrawScope.drawFeature(
             size = feature.size.toSize()
         )
 
-        is LineFeature -> drawLine(feature.color, feature.a.toOffset(), feature.b.toOffset())
+        is LineFeature -> drawLine(color, feature.a.toOffset(), feature.b.toOffset())
         is ArcFeature -> {
             val dpRect = feature.oval.toDpRect().toRect()
 
             val size = Size(dpRect.width, dpRect.height)
 
             drawArc(
-                color = feature.color,
+                color = color,
                 startAngle = feature.startAngle / PI.toFloat() * 180f,
                 sweepAngle = feature.arcLength / PI.toFloat() * 180f,
                 useCenter = false,
@@ -85,7 +85,7 @@ public fun <T : Any> DrawScope.drawFeature(
                 offset.x + 5,
                 offset.y - 5,
                 Font().apply(feature.fontConfig),
-                feature.color.toPaint()
+                (feature.color ?: Color.Black).toPaint()
             )
         }
 
@@ -97,8 +97,7 @@ public fun <T : Any> DrawScope.drawFeature(
         }
 
         is FeatureGroup -> {
-            //do nothing
+            feature.featureMap.values.forEach {
-            feature.children.values.forEach {
                 drawFeature(state, painterCache, it)
             }
         }
@@ -116,7 +115,7 @@ public fun <T : Any> DrawScope.drawFeature(
             val points = feature.points.map { it.toOffset() }
             drawPoints(
                 points = points,
-                color = feature.color,
+                color = color,
                 strokeWidth = feature.stroke,
                 pointMode = feature.pointMode,
                 alpha = alpha
@@ -133,7 +132,7 @@ public fun <T : Any> DrawScope.drawFeature(
             }
             drawPath(
                 path = polygonPath,
-                color = feature.color,
+                color = color,
                 alpha = alpha
             )
         }

maps-kt-geojson/src/commonMain/kotlin/center/sciprog/maps/geojson/geoJsonFeature.kt

@@ -12,14 +12,12 @@ import kotlinx.serialization.json.jsonPrimitive
 /**
  * Add a single Json geometry to a feature builder
  */
-public fun FeatureBuilder<Gmc>.geoJsonGeometry(
+public fun FeatureGroup<Gmc>.geoJsonGeometry(
     geometry: GeoJsonGeometry,
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<Feature<Gmc>> = when (geometry) {
     is GeoJsonLineString -> points(
         geometry.coordinates,
-        color = color,
         pointMode = PointMode.Lines
     )
 
@@ -27,7 +25,6 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
         geometry.coordinates.forEach {
             points(
                 it,
-                color = color,
                 pointMode = PointMode.Lines
             )
         }
@@ -35,7 +32,6 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
 
     is GeoJsonMultiPoint -> points(
         geometry.coordinates,
-        color = color,
         pointMode = PointMode.Points
     )
 
@@ -43,15 +39,13 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
         geometry.coordinates.forEach {
             polygon(
                 it.first(),
-                color = color,
             )
         }
     }
 
-    is GeoJsonPoint -> circle(geometry.coordinates, color = color, id = id)
+    is GeoJsonPoint -> circle(geometry.coordinates, id = id)
     is GeoJsonPolygon -> polygon(
         geometry.coordinates.first(),
-        color = color,
     )
 
     is GeoJsonGeometryCollection -> group(id = id) {
@@ -63,18 +57,22 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
     withAttribute(AlphaAttribute, 0.5f)
 }
 
-public fun FeatureBuilder<Gmc>.geoJsonFeature(
+public fun FeatureGroup<Gmc>.geoJsonFeature(
     geoJson: GeoJsonFeature,
-    color: Color = defaultColor,
     id: String? = null,
 ): FeatureId<Feature<Gmc>>? {
     val geometry = geoJson.geometry ?: return null
     val idOverride = geoJson.properties?.get("id")?.jsonPrimitive?.contentOrNull ?: id
-    val colorOverride = geoJson.properties?.get("color")?.jsonPrimitive?.intOrNull?.let { Color(it) } ?: color
+    val colorOverride = geoJson.properties?.get("color")?.jsonPrimitive?.intOrNull?.let { Color(it) }
-    return geoJsonGeometry(geometry, colorOverride, idOverride)
+    val jsonGeometry =  geoJsonGeometry(geometry, idOverride)
+    return if( colorOverride!= null){
+        jsonGeometry.color(colorOverride)
+    } else{
+        jsonGeometry
+    }
 }
 
-public fun FeatureBuilder<Gmc>.geoJson(
+public fun FeatureGroup<Gmc>.geoJson(
     geoJson: GeoJson,
     id: String? = null,
 ): FeatureId<Feature<Gmc>>? = when (geoJson) {

maps-kt-geojson/src/jvmMain/kotlin/center/sciprog/maps/geojson/geoJsonFeatureJvm.kt

@@ -1,7 +1,7 @@
 package center.sciprog.maps.geojson
 
 import center.sciprog.maps.coordinates.Gmc
-import center.sciprog.maps.features.FeatureBuilder
+import center.sciprog.maps.features.FeatureGroup
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.jsonObject
 import java.net.URL
@@ -9,7 +9,7 @@ import java.net.URL
 /**
  * Add geojson features from url
  */
-public fun FeatureBuilder<Gmc>.geoJson(
+public fun FeatureGroup<Gmc>.geoJson(
     geoJsonUrl: URL,
     id: String? = null,
 ) {

maps-kt-scheme/src/commonMain/kotlin/center/sciprog/maps/scheme/schemeFeatures.kt

@@ -12,7 +12,7 @@ import center.sciprog.maps.features.*
 
 internal fun Pair<Number, Number>.toCoordinates(): XY = XY(first.toFloat(), second.toFloat())
 
-fun FeatureBuilder<XY>.background(
+fun FeatureGroup<XY>.background(
     width: Float,
     height: Float,
     offset: XY = XY(0f, 0f),
@@ -35,7 +35,7 @@ fun FeatureBuilder<XY>.background(
     )
 }
 
-fun FeatureBuilder<XY>.circle(
+fun FeatureGroup<XY>.circle(
     centerCoordinates: Pair<Number, Number>,
     zoomRange: FloatRange = defaultZoomRange,
     size: Dp = 5.dp,
@@ -43,14 +43,14 @@ fun FeatureBuilder<XY>.circle(
     id: String? = null,
 ): FeatureId<CircleFeature<XY>> = circle(centerCoordinates.toCoordinates(), zoomRange, size, color, id = id)
 
-fun FeatureBuilder<XY>.draw(
+fun FeatureGroup<XY>.draw(
     position: Pair<Number, Number>,
     zoomRange: FloatRange = defaultZoomRange,
     id: String? = null,
     draw: DrawScope.() -> Unit,
 ): FeatureId<DrawFeature<XY>> = draw(position.toCoordinates(), zoomRange = zoomRange, id = id, draw = draw)
 
-fun FeatureBuilder<XY>.line(
+fun FeatureGroup<XY>.line(
     aCoordinates: Pair<Number, Number>,
     bCoordinates: Pair<Number, Number>,
     scaleRange: FloatRange = defaultZoomRange,
@@ -59,7 +59,7 @@ fun FeatureBuilder<XY>.line(
 ): FeatureId<LineFeature<XY>> = line(aCoordinates.toCoordinates(), bCoordinates.toCoordinates(), scaleRange, color, id)
 
 
-public fun FeatureBuilder<XY>.arc(
+public fun FeatureGroup<XY>.arc(
     center: Pair<Double, Double>,
     radius: Float,
     startAngle: Float,
@@ -76,7 +76,7 @@ public fun FeatureBuilder<XY>.arc(
     id = id
 )
 
-fun FeatureBuilder<XY>.image(
+fun FeatureGroup<XY>.image(
     position: Pair<Number, Number>,
     image: ImageVector,
     size: DpSize = DpSize(image.defaultWidth, image.defaultHeight),
@@ -85,7 +85,7 @@ fun FeatureBuilder<XY>.image(
 ): FeatureId<VectorImageFeature<XY>> =
     image(position.toCoordinates(), image, size = size, zoomRange = zoomRange, id = id)
 
-fun FeatureBuilder<XY>.text(
+fun FeatureGroup<XY>.text(
     position: Pair<Number, Number>,
     text: String,
     zoomRange: FloatRange = defaultZoomRange,

maps-kt-scheme/src/jvmMain/kotlin/center/sciprog/maps/scheme/SchemeView.kt

@@ -22,12 +22,12 @@ private val logger = KotlinLogging.logger("SchemeView")
 @Composable
 public fun SchemeView(
     state: XYViewScope,
-    featuresState: FeatureCollection<XY>,
+    featuresState: FeatureGroup<XY>,
     modifier: Modifier = Modifier.fillMaxSize(),
 ) {
     with(state) {
         val painterCache: Map<PainterFeature<XY>, Painter> = key(featuresState) {
-            featuresState.features.values.filterIsInstance<PainterFeature<XY>>().associateWith { it.getPainter() }
+            featuresState.features.filterIsInstance<PainterFeature<XY>>().associateWith { it.getPainter() }
         }
 
         Canvas(modifier = modifier.mapControls(state, featuresState.features).fillMaxSize()) {
@@ -38,9 +38,8 @@ public fun SchemeView(
             }
 
             clipRect {
-                featuresState.features.values
+                featuresState.features
                     .filter { viewPoint.zoom in it.zoomRange }
-                    .sortedBy { it.z }
                     .forEach { background ->
                         drawFeature(state, painterCache, background)
                     }
@@ -88,7 +87,7 @@ public fun SchemeView(
 
 
     val featureState = key(featureMap) {
-        FeatureCollection.build(XYCoordinateSpace) {
+        FeatureGroup.build(XYCoordinateSpace) {
             featureMap.forEach { feature(it.key.id, it.value) }
         }
     }
@@ -96,7 +95,7 @@ public fun SchemeView(
     val state = rememberMapState(
         config,
         initialViewPoint = initialViewPoint,
-        initialRectangle = initialRectangle ?: featureState.features.values.computeBoundingBox(XYCoordinateSpace, Float.MAX_VALUE),
+        initialRectangle = initialRectangle ?: featureState.features.computeBoundingBox(XYCoordinateSpace, Float.MAX_VALUE),
     )
 
     SchemeView(state, featureState, modifier)
@@ -115,13 +114,13 @@ public fun SchemeView(
     initialRectangle: Rectangle<XY>? = null,
     config: ViewConfig<XY> = ViewConfig(),
     modifier: Modifier = Modifier.fillMaxSize(),
-    buildFeatures: FeatureCollection<XY>.() -> Unit = {},
+    buildFeatures: FeatureGroup<XY>.() -> Unit = {},
 ) {
-    val featureState = FeatureCollection.remember(XYCoordinateSpace, buildFeatures)
+    val featureState = FeatureGroup.remember(XYCoordinateSpace, buildFeatures)
     val mapState: XYViewScope = rememberMapState(
         config,
         initialViewPoint = initialViewPoint,
-        initialRectangle = initialRectangle ?: featureState.features.values.computeBoundingBox(XYCoordinateSpace, Float.MAX_VALUE),
+        initialRectangle = initialRectangle ?: featureState.features.computeBoundingBox(XYCoordinateSpace, Float.MAX_VALUE),
     )
 
     SchemeView(mapState, featureState, modifier)

maps-kt-scheme/src/jvmMain/kotlin/center/sciprog/maps/svg/exportToSvg.kt

@@ -17,14 +17,14 @@ import kotlin.math.abs
 
 
 class FeatureStateSnapshot<T : Any>(
-    val features: Map<FeatureId<*>, Feature<T>>,
+    val features: Map<String, Feature<T>>,
     val painterCache: Map<PainterFeature<T>, Painter>,
 )
 
 @Composable
-fun <T: Any> FeatureCollection<T>.snapshot(): FeatureStateSnapshot<T> = FeatureStateSnapshot(
+fun <T: Any> FeatureGroup<T>.snapshot(): FeatureStateSnapshot<T> = FeatureStateSnapshot(
-    features,
+    featureMap,
-    features.values.filterIsInstance<PainterFeature<T>>().associateWith { it.getPainter() }
+    features.filterIsInstance<PainterFeature<T>>().associateWith { it.getPainter() }
 )
 
 fun FeatureStateSnapshot<XY>.generateSvg(
@@ -114,7 +114,7 @@ fun FeatureStateSnapshot<XY>.generateSvg(
             }
 
             is FeatureGroup -> {
-                feature.children.values.forEach {
+                feature.featureMap.values.forEach {
                     drawFeature(scale, it)
                 }
             }