fix: apply polygon styling to GeoJSON MultiPolygon features

GeoJsonMapper matched MultiGeometry in the LineString branch, so a
MultiPolygon feature carrying simplestyle properties was given a
LineStyle. MapViewRenderer then casts the feature style with
'as? PolygonStyle' when rendering each member polygon, gets null, and
draws the polygons with SDK defaults — the feature's fill and stroke
colors were silently dropped.

Style a multi-geometry whose members are all (recursively) polygons —
i.e. a GeoJSON MultiPolygon — with PolygonStyle; mixed collections and
MultiLineStrings keep the previous line styling.

Author: jamesarich

data/src/main/java/com/google/maps/android/data/renderer/mapper/GeoJsonMapper.kt

@@ -91,8 +91,9 @@ object GeoJsonMapper {
         val finalProperties = if (id != null) featureProperties + ("id" to id) else featureProperties
 
         val style = properties?.let { props ->
-            when (geometry) {
-                is LineString, is MultiGeometry -> { // MultiGeometry could contain lines
+            when {
+                geometry is LineString || (geometry is MultiGeometry && !geometry.isPolygonal()) -> {
+                    // MultiGeometry could contain lines
                     val strokeColor = props["stroke"]?.let { parseColor(it) }
                     val strokeWidth = props["stroke-width"]?.toFloatOrNull()
                     if (strokeColor != null || strokeWidth != null) {
@@ -102,7 +103,7 @@ object GeoJsonMapper {
                         )
                     } else null
                 }
-                is ModelPolygon -> {
+                geometry is ModelPolygon || geometry is MultiGeometry -> {
                     val strokeColor = props["stroke"]?.let { parseColor(it) }
                     val strokeWidth = props["stroke-width"]?.toFloatOrNull()
                     val fillColor = props["fill"]?.let { parseColor(it) }
@@ -125,7 +126,7 @@ object GeoJsonMapper {
                         )
                     } else null
                 }
-                is PointGeometry -> {
+                geometry is PointGeometry -> {
                      // TODO: Marker styling (marker-color, marker-size, marker-symbol)
                      null
                 }
@@ -136,6 +137,14 @@ object GeoJsonMapper {
         return Feature(geometry, style = style, properties = finalProperties)
     }
 
+    /**
+     * True for a Polygon or a multi-geometry whose members are all (recursively) polygons — i.e. a
+     * GeoJSON MultiPolygon — which per the simplestyle-spec carries fill styling rather than line styling.
+     */
+    private fun Geometry.isPolygonal(): Boolean =
+        this is ModelPolygon ||
+            (this is MultiGeometry && geometries.isNotEmpty() && geometries.all { it.isPolygonal() })
+
     private fun parseColor(colorString: String): Int? {
         if (colorString.startsWith("#")) {
             // Handle hex color

data/src/test/java/com/google/maps/android/data/renderer/mapper/GeoJsonStylingTest.kt

@@ -113,4 +113,94 @@ class GeoJsonStylingTest {
         // Verify stroke width
         assertEquals(3.0f, style.width!!, 0.001f)
     }
+
+    @Test
+    fun `parse styled multipolygon applies polygon style`() {
+        val geoJson =
+            """
+            {
+              "type": "Feature",
+              "properties": {
+                "stroke": "#ff0000",
+                "stroke-width": 2.0,
+                "fill": "#00ff00",
+                "fill-opacity": 0.25
+              },
+              "geometry": {
+                "type": "MultiPolygon",
+                "coordinates": [
+                  [
+                    [
+                      [100.0, 0.0],
+                      [101.0, 0.0],
+                      [101.0, 1.0],
+                      [100.0, 0.0]
+                    ]
+                  ],
+                  [
+                    [
+                      [102.0, 2.0],
+                      [103.0, 2.0],
+                      [103.0, 3.0],
+                      [102.0, 2.0]
+                    ]
+                  ]
+                ]
+              }
+            }
+            """.trimIndent()
+
+        val parser = GeoJsonParser()
+        val geoJsonObject = parser.parse(ByteArrayInputStream(geoJson.toByteArray()))!!
+        val layer = GeoJsonMapper.toLayer(geoJsonObject)
+        val feature = layer.features.first()
+
+        // A MultiPolygon must carry polygon styling (fill), not line styling.
+        assertTrue(feature.style is PolygonStyle)
+        val style = feature.style as PolygonStyle
+
+        assertEquals(0xFFFF0000.toInt(), style.strokeColor)
+        assertEquals(2.0f, style.strokeWidth, 0.001f)
+
+        // Fill: green with 0.25 opacity (0.25 * 255 = 63 = 0x3F)
+        val expectedFillColor = (0x3F shl 24) or 0x00FF00
+        assertEquals(expectedFillColor, style.fillColor)
+    }
+
+    @Test
+    fun `parse styled multilinestring keeps line style`() {
+        val geoJson =
+            """
+            {
+              "type": "Feature",
+              "properties": {
+                "stroke": "#0000ff",
+                "stroke-width": 3.0
+              },
+              "geometry": {
+                "type": "MultiLineString",
+                "coordinates": [
+                  [
+                    [100.0, 0.0],
+                    [101.0, 1.0]
+                  ],
+                  [
+                    [102.0, 2.0],
+                    [103.0, 3.0]
+                  ]
+                ]
+              }
+            }
+            """.trimIndent()
+
+        val parser = GeoJsonParser()
+        val geoJsonObject = parser.parse(ByteArrayInputStream(geoJson.toByteArray()))!!
+        val layer = GeoJsonMapper.toLayer(geoJsonObject)
+        val feature = layer.features.first()
+
+        assertTrue(feature.style is LineStyle)
+        val style = feature.style as LineStyle
+        assertEquals(0xFF0000FF.toInt(), style.color)
+        assertEquals(3.0f, style.width!!, 0.001f)
+    }
 }