Add geojson demo

demo/maps/build.gradle.kts

@@ -1,4 +1,3 @@
-import org.jetbrains.compose.compose
 import org.jetbrains.compose.desktop.application.dsl.TargetFormat
 
 plugins {
@@ -19,6 +18,7 @@ kotlin {
         val jvmMain by getting {
             dependencies {
                 implementation(projects.mapsKtCompose)
+                implementation(projects.mapsKtGeojson)
                 implementation(compose.desktop.currentOs)
                 implementation("io.ktor:ktor-client-cio")
                 implementation("ch.qos.logback:logback-classic:1.2.11")

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

@@ -13,9 +13,11 @@ import androidx.compose.ui.window.application
 import center.sciprog.maps.compose.*
 import center.sciprog.maps.coordinates.*
 import center.sciprog.maps.features.*
+import center.sciprog.maps.geojson.geoJson
 import io.ktor.client.HttpClient
 import io.ktor.client.engine.cio.CIO
 import kotlinx.coroutines.delay
+import java.net.URL
 import java.nio.file.Path
 import kotlin.math.PI
 import kotlin.random.Random
@@ -44,8 +46,6 @@ fun App() {
         val pointTwo = 55.929444 to 37.518434
         val pointThree = 60.929444 to 37.518434
 
-        val dragPoint = 55.744 to 37.614
-
         MapView(
             mapTileProvider = mapTileProvider,
 //            initialViewPoint = MapViewPoint(
@@ -62,6 +62,8 @@ fun App() {
             )
         ) {
 
+            geoJson(URL("https://raw.githubusercontent.com/ggolikov/cities-comparison/master/src/moscow.geo.json"))
+
             image(pointOne, Icons.Filled.Home)
 
             val marker1 = rectangle(55.744 to 37.614, size = DpSize(10.dp, 10.dp), color = Color.Magenta)

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

@@ -29,10 +29,6 @@ public value class GeoJsonFeature(override val json: JsonObject) : GeoJson {
 
     public val geometry: GeoJsonGeometry? get() = json[GEOMETRY_KEY]?.jsonObject?.let { GeoJsonGeometry(it) }
 
-    public fun getProperty(propertyName: String): JsonElement? = properties?.get(propertyName)
-
-    public fun getString(propertyName: String): String? = getProperty(propertyName)?.jsonPrimitive?.contentOrNull
-
     public companion object {
         public const val GEOMETRY_KEY: String = "geometry"
     }
@@ -62,6 +58,13 @@ public value class GeoJsonFeatureCollection(override val json: JsonObject) : Geo
     }
 }
 
+public fun GeoJson(json: JsonObject): GeoJson =
+    when (json[TYPE_KEY]?.jsonPrimitive?.contentOrNull ?: error("Not a GeoJson")) {
+        "Feature" -> GeoJsonFeature(json)
+        "FeatureCollection" -> GeoJsonFeatureCollection(json)
+        else -> GeoJsonGeometry(json)
+    }
+
 /**
  * Combine a collection of features to a new [GeoJsonFeatureCollection]
  */

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

@@ -83,10 +83,12 @@ public value class GeoJsonPolygon(override val json: JsonObject) : GeoJsonGeomet
         require(type == "Polygon") { "Not a GeoJson Polygon geometry" }
     }
 
-    public val coordinates: List<Gmc>
+    public val coordinates: List<List<Gmc>>
-        get() = json[COORDINATES_KEY]?.jsonArray
+        get() = json[COORDINATES_KEY]?.jsonArray?.map { polygon ->
-            ?.map { it.toGmc() }
+            polygon.jsonArray.map { point ->
-            ?: error("Coordinates are not provided")
+                point.toGmc()
+            }
+        } ?: error("Coordinates are not provided")
 }
 
 @JvmInline
@@ -95,10 +97,12 @@ public value class GeoJsonMultiPolygon(override val json: JsonObject) : GeoJsonG
         require(type == "MultiPolygon") { "Not a GeoJson MultiPolygon geometry" }
     }
 
-    public val coordinates: List<List<Gmc>>
+    public val coordinates: List<List<List<Gmc>>>
-        get() = json[COORDINATES_KEY]?.jsonArray?.map { lineJson ->
+        get() = json[COORDINATES_KEY]?.jsonArray?.map { allPolygons ->
-            lineJson.jsonArray.map {
+            allPolygons.jsonArray.map { polygon ->
-                it.toGmc()
+                polygon.jsonArray.map { point ->
+                    point.toGmc()
+                }
             }
         } ?: error("Coordinates are not provided")
 }

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

@@ -16,7 +16,7 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
     geometry: GeoJsonGeometry,
     color: Color = defaultColor,
     id: String? = null,
-): FeatureId<*> = when (geometry) {
+): FeatureId<Feature<Gmc>> = when (geometry) {
     is GeoJsonLineString -> points(
         geometry.coordinates,
         color = color,
@@ -42,7 +42,7 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
     is GeoJsonMultiPolygon -> group(id = id) {
         geometry.coordinates.forEach {
             points(
-                it,
+                it.first(),
                 color = color,
                 pointMode = PointMode.Polygon
             )
@@ -51,7 +51,7 @@ public fun FeatureBuilder<Gmc>.geoJsonGeometry(
 
     is GeoJsonPoint -> circle(geometry.coordinates, color = color, id = id)
     is GeoJsonPolygon -> points(
-        geometry.coordinates,
+        geometry.coordinates.first(),
         color = color,
         pointMode = PointMode.Polygon
     )
@@ -67,18 +67,23 @@ public fun FeatureBuilder<Gmc>.geoJsonFeature(
     geoJson: GeoJsonFeature,
     color: Color = defaultColor,
     id: String? = null,
-) {
+): FeatureId<Feature<Gmc>>? {
-    val geometry = geoJson.geometry ?: return
+    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
-    geoJsonGeometry(geometry, colorOverride, idOverride)
+    return geoJsonGeometry(geometry, colorOverride, idOverride)
 }
 
 public fun FeatureBuilder<Gmc>.geoJson(
-    geoJson: GeoJsonFeatureCollection,
+    geoJson: GeoJson,
     id: String? = null,
-): FeatureId<FeatureGroup<Gmc>> = group(id = id) {
+): FeatureId<Feature<Gmc>>? = when (geoJson) {
+    is GeoJsonFeature -> geoJsonFeature(geoJson, id = id)
+    is GeoJsonFeatureCollection -> group(id = id) {
         geoJson.features.forEach {
             geoJsonFeature(it)
         }
     }
+
+    is GeoJsonGeometry -> geoJsonGeometry(geoJson, id = id)
+}

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

@@ -0,0 +1,21 @@
+package center.sciprog.maps.geojson
+
+import center.sciprog.maps.coordinates.Gmc
+import center.sciprog.maps.features.FeatureBuilder
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.jsonObject
+import java.net.URL
+
+/**
+ * Add geojson features from url
+ */
+public fun FeatureBuilder<Gmc>.geoJson(
+    geoJsonUrl: URL,
+    id: String? = null,
+) {
+    val jsonString = geoJsonUrl.readText()
+    val json = Json.parseToJsonElement(jsonString).jsonObject
+    val geoJson = GeoJson(json)
+
+    geoJson(geoJson, id)
+}