feat(layer type): added property type to layer class that returns the GeoJSON layer type

In order to get more information about the type of a layer (e.g. obtained by calling `getLayers`), the GeoJSON layer type was added as property to the layer class. This is for example helpful to find the first symbol layer to add a polyline layer under all map annotations.

Author: benedictstrube

src/ui-mapbox/common.ts

@@ -263,11 +263,19 @@ export interface AddGeoJsonClusteredOptions {
     clusters?: MapboxCluster[];
 }
 
+// ------------------------------------------------------------
+
+export type LayerType = "fill" | "line" | "symbol" | "circle" | "heatmap" | "fill-extrusion" | "raster" | "hillshade" | "background" | "sky"
+
+export type SupportedLayerType = LayerType & ("line" | "circle" | "fill" | "symbol" | "raster")
+
+// ------------------------------------------------------------
+
 export interface AddLayerOptions {
     id: string;
     source: string;
     sourceLayer: string;
-    type: string;
+    type: SupportedLayerType;
 
     /**
      * 'circle' paint properties
@@ -553,6 +561,7 @@ export interface LayerCommon {
     getNativeInstance(): any;
     setFilter(filter: any[]): void;
     getFilter(): any[];
+    type(): LayerType;
 }
 
 // ------------------------------------------------------------

src/ui-mapbox/layers/layer-factory.android.ts

@@ -1,4 +1,4 @@
-import { LayerCommon } from '../common';
+import { LayerCommon, LayerType } from "../common"
 import { ExpressionParser } from '../expression/expression-parser';
 import { PropertyParser } from './parser/property-parser';
 
@@ -43,6 +43,40 @@ export class Layer implements LayerCommon {
     public getProperty(name: string): any {
         return PropertyParser.propertyValueFromLayer(this.instance, name);
     }
+
+    public type(): LayerType {
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.FillLayer) {
+            return "fill"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.LineLayer) {
+            return "line"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.SymbolLayer) {
+            return "symbol"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.CircleLayer) {
+            return "circle"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.HeatmapLayer) {
+            return "heatmap"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.FillExtrusionLayer) {
+            return "fill-extrusion"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.RasterLayer) {
+            return "raster"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.HillshadeLayer) {
+            return "hillshade"
+        }
+        if (this.instance instanceof com.mapbox.mapboxsdk.style.layers.BackgroundLayer) {
+            return "background"
+        }
+
+        // there is no sky layer in the Android Mapbox SDK
+
+        return null;
+    }
 }
 
 export class LayerFactory {

src/ui-mapbox/layers/layer-factory.d.ts

@@ -1,4 +1,4 @@
-import { LayerCommon } from '../common';
+import { LayerCommon, LayerType } from "../common"
 
 declare class LayerFactory {
     static createLayer(style, source): Promise<LayerCommon>;
@@ -16,4 +16,5 @@ export declare class Layer implements LayerCommon {
     getFilter(): any[];
     setProperty(name: string, value: any): void;
     getProperty(name: string): any;
-}
+    type(): LayerType;
+}

src/ui-mapbox/layers/layer-factory.ios.ts

@@ -1,4 +1,4 @@
-import { LayerCommon } from '../common';
+import { LayerCommon, LayerType } from "../common"
 import { ExpressionParser } from '../expression/expression-parser';
 import { PropertyParser } from './parser/property-parser';
 
@@ -53,13 +53,47 @@ export class LayerFactory {
 
 export class Layer implements LayerCommon {
     public id: string;
-    private instance;
+    private instance: MGLStyleLayer;
 
-    constructor(instance) {
+    constructor(instance: MGLStyleLayer) {
         this.instance = instance;
         this.id = instance.identifier;
     }
 
+    type(): LayerType {
+        if (this.instance instanceof MGLFillStyleLayer) {
+            return "fill"
+        }
+        if (this.instance instanceof MGLLineStyleLayer) {
+            return "line"
+        }
+        if (this.instance instanceof MGLSymbolStyleLayer) {
+            return "symbol"
+        }
+        if (this.instance instanceof MGLCircleStyleLayer) {
+            return "circle"
+        }
+        if (this.instance instanceof MGLHeatmapStyleLayer) {
+            return "heatmap"
+        }
+        if (this.instance instanceof MGLFillExtrusionStyleLayer) {
+            return "fill-extrusion"
+        }
+        if (this.instance instanceof MGLRasterStyleLayer) {
+            return "raster"
+        }
+        if (this.instance instanceof MGLHillshadeStyleLayer) {
+            return "hillshade"
+        }
+        if (this.instance instanceof MGLBackgroundStyleLayer) {
+            return "background"
+        }
+
+        // there is no sky layer in the Mapbox iOS SDK
+
+        return null;
+    }
+
     visibility(): boolean {
         return this.instance.visible;
     }