Make debug UI background layers configurable with new file debug-ui-config.json

application/src/main/java/org/opentripplanner/apis/vectortiles/DebugStyleSpec.java

@@ -4,7 +4,6 @@
 
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.opentripplanner.apis.vectortiles.model.StyleBuilder;
 import org.opentripplanner.apis.vectortiles.model.StyleSpec;
@@ -14,6 +13,7 @@
 import org.opentripplanner.apis.vectortiles.model.ZoomDependentNumber;
 import org.opentripplanner.apis.vectortiles.model.ZoomDependentNumber.ZoomStop;
 import org.opentripplanner.service.vehiclerental.street.StreetVehicleRentalLink;
+import org.opentripplanner.standalone.config.debuguiconfig.BackgroundTileLayer;
 import org.opentripplanner.street.model.StreetTraversalPermission;
 import org.opentripplanner.street.model.edge.AreaEdge;
 import org.opentripplanner.street.model.edge.BoardingLocationToStopLink;
@@ -37,13 +37,25 @@
  */
 public class DebugStyleSpec {
 
-  private static final TileSource BACKGROUND_SOURCE = new RasterSource(
-    "background",
+  private static final TileSource OSM_BACKGROUND = new RasterSource(
+    "OSM Carto",
     List.of("https://a.tile.openstreetmap.org/{z}/{x}/{y}.png"),
     19,
     256,
     "© OpenStreetMap Contributors"
   );
+  private static final TileSource POSITRON_BACKGROUND = new RasterSource(
+    "Positron",
+    List.of("https://cartodb-basemaps-a.global.ssl.fastly.net/light_all/{z}/{x}/{y}{ratio}.png"),
+    19,
+    256,
+    "© <a href=\"http://www.openstreetmap.org/copyright\">OpenStreetMap</a>, &copy; <a href=\"https://carto.com/attributions\">CARTO</a>"
+  );
+
+  private static final List<TileSource> BACKGROUND_LAYERS = List.of(
+    OSM_BACKGROUND,
+    POSITRON_BACKGROUND
+  );
   private static final String MAGENTA = "#f21d52";
   private static final String BRIGHT_GREEN = "#22DD9E";
   private static final String DARK_GREEN = "#136b04";
@@ -92,19 +104,33 @@ static StyleSpec build(
     VectorSourceLayer areaStops,
     VectorSourceLayer groupStops,
     VectorSourceLayer edges,
-    VectorSourceLayer vertices
+    VectorSourceLayer vertices,
+    List<BackgroundTileLayer> extraLayers
   ) {
-    var vectorSources = Stream
+    List<TileSource> vectorSources = Stream
       .of(regularStops, edges, vertices)
-      .map(VectorSourceLayer::vectorSource);
-    var allSources = Stream
-      .concat(Stream.of(BACKGROUND_SOURCE), vectorSources)
-      .collect(Collectors.toSet());
+      .map(VectorSourceLayer::vectorSource)
+      .map(TileSource.class::cast)
+      .toList();
+
+    List<TileSource> extraRasterSources = extraLayers
+      .stream()
+      .map(l ->
+        (TileSource) new RasterSource(
+          l.name(),
+          List.of(l.templateUrl()),
+          19,
+          l.tileSize(),
+          l.attribution()
+        )
+      )
+      .toList();
+    var allSources = ListUtils.combine(BACKGROUND_LAYERS, extraRasterSources, vectorSources);
     return new StyleSpec(
       "OTP Debug Tiles",
       allSources,
       ListUtils.combine(
-        List.of(StyleBuilder.ofId("background").typeRaster().source(BACKGROUND_SOURCE).minZoom(0)),
+        backgroundLayers(extraRasterSources),
         wheelchair(edges),
         noThruTraffic(edges),
         traversalPermissions(edges),
@@ -115,6 +141,25 @@ static StyleSpec build(
     );
   }
 
+  private static List<StyleBuilder> backgroundLayers(List<TileSource> extraLayers) {
+    return ListUtils
+      .combine(BACKGROUND_LAYERS, extraLayers)
+      .stream()
+      .map(layer -> {
+        var builder = StyleBuilder
+          .ofId(layer.id())
+          .displayName(layer.name())
+          .typeRaster()
+          .source(layer)
+          .minZoom(0);
+        if (!layer.equals(OSM_BACKGROUND)) {
+          builder.intiallyHidden();
+        }
+        return builder;
+      })
+      .toList();
+  }
+
   private static List<StyleBuilder> stops(
     VectorSourceLayer regularStops,
     VectorSourceLayer areaStops,

application/src/main/java/org/opentripplanner/apis/vectortiles/GraphInspectorVectorTileResource.java

@@ -147,7 +147,8 @@ public StyleSpec getTileJson(@Context UriInfo uri, @Context HttpHeaders headers)
       AREA_STOPS.toVectorSourceLayer(stopsSource),
       GROUP_STOPS.toVectorSourceLayer(stopsSource),
       EDGES.toVectorSourceLayer(streetSource),
-      VERTICES.toVectorSourceLayer(streetSource)
+      VERTICES.toVectorSourceLayer(streetSource),
+      serverContext.debugUiConfig().additionalBackgroundLayers()
     );
   }
 

application/src/main/java/org/opentripplanner/apis/vectortiles/model/StyleBuilder.java

@@ -30,7 +30,7 @@ public class StyleBuilder {
   private final Map<String, Object> layout = new LinkedHashMap<>();
   private final Map<String, Object> metadata = new LinkedHashMap<>();
   private final Map<String, Object> line = new LinkedHashMap<>();
-  private List<? extends Object> filter = List.of();
+  private List<?> filter = List.of();
 
   public static StyleBuilder ofId(String id) {
     return new StyleBuilder(id);
@@ -120,6 +120,14 @@ public StyleBuilder group(String group) {
     return this;
   }
 
+  /**
+   * A nice human-readable name for the layer.
+   */
+  public StyleBuilder displayName(String name) {
+    metadata.put("name", name);
+    return this;
+  }
+
   public StyleBuilder lineText(String name) {
     layout.put("symbol-placement", "line-center");
     layout.put("symbol-spacing", 1000);

application/src/main/java/org/opentripplanner/apis/vectortiles/model/TileSource.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import java.util.List;
+import org.opentripplanner.utils.lang.StringUtils;
 
 /**
  * Represent a data source where Maplibre can fetch data for rendering directly in the browser.
@@ -12,6 +13,8 @@ public sealed interface TileSource {
 
   String id();
 
+  String name();
+
   /**
    * Represents a vector tile source which is rendered into a map in the browser.
    */
@@ -20,17 +23,32 @@ record VectorSource(String id, String url) implements TileSource {
     public String type() {
       return "vector";
     }
+
+    @Override
+    public String name() {
+      return id;
+    }
   }
 
   /**
    * Represents a raster-based source for map tiles. These are used mainly for background
    * map layers with vector data being rendered on top of it.
    */
-  record RasterSource(String id, List<String> tiles, int maxzoom, int tileSize, String attribution)
+  record RasterSource(
+    String name,
+    List<String> tiles,
+    int maxzoom,
+    int tileSize,
+    String attribution
+  )
     implements TileSource {
     @Override
     public String type() {
       return "raster";
     }
+
+    public String id() {
+      return StringUtils.slugify(name);
+    }
   }
 }

application/src/main/java/org/opentripplanner/framework/application/OtpFileNames.java

@@ -9,16 +9,18 @@ public class OtpFileNames {
   public static final String OTP_CONFIG_FILENAME = "otp-config.json";
   public static final String BUILD_CONFIG_FILENAME = "build-config.json";
   public static final String ROUTER_CONFIG_FILENAME = "router-config.json";
+  public static final String DEBUG_UI_CONFIG_FILENAME = "debug-ui-config.json";
 
   /**
    * Check if a file is a config file using the configuration file name. This method returns {@code
-   * true} if the file match {@code (otp|build|router)-config.json}.
+   * true} if the file match {@code (otp|build|router|debug-ui)-config.json}.
    */
   public static boolean isConfigFile(String filename) {
     return (
       OTP_CONFIG_FILENAME.equals(filename) ||
       BUILD_CONFIG_FILENAME.equals(filename) ||
-      ROUTER_CONFIG_FILENAME.equals(filename)
+      ROUTER_CONFIG_FILENAME.equals(filename) ||
+      DEBUG_UI_CONFIG_FILENAME.equals(filename)
     );
   }
 }

application/src/main/java/org/opentripplanner/standalone/api/OtpServerRequestContext.java

@@ -26,6 +26,7 @@
 import org.opentripplanner.service.vehicleparking.VehicleParkingService;
 import org.opentripplanner.service.vehiclerental.VehicleRentalService;
 import org.opentripplanner.service.worldenvelope.WorldEnvelopeService;
+import org.opentripplanner.standalone.config.DebugUiConfig;
 import org.opentripplanner.standalone.config.routerconfig.VectorTileConfig;
 import org.opentripplanner.street.model.edge.Edge;
 import org.opentripplanner.street.search.state.State;
@@ -127,6 +128,8 @@ default GraphFinder graphFinder() {
 
   VectorTileConfig vectorTileConfig();
 
+  DebugUiConfig debugUiConfig();
+
   /* Sandbox modules */
 
   @Nullable

application/src/main/java/org/opentripplanner/standalone/config/ConfigModel.java

@@ -49,16 +49,29 @@ public class ConfigModel {
    */
   private RouterConfig routerConfig;
 
-  public ConfigModel(OtpConfig otpConfig, BuildConfig buildConfig, RouterConfig routerConfig) {
+  private final DebugUiConfig debugUiConfig;
+
+  public ConfigModel(
+    OtpConfig otpConfig,
+    BuildConfig buildConfig,
+    RouterConfig routerConfig,
+    DebugUiConfig debugUiConfig
+  ) {
     this.otpConfig = otpConfig;
     this.buildConfig = buildConfig;
     this.routerConfig = routerConfig;
+    this.debugUiConfig = debugUiConfig;
 
     initializeOtpFeatures(otpConfig);
   }
 
   public ConfigModel(OtpConfigLoader loader) {
-    this(loader.loadOtpConfig(), loader.loadBuildConfig(), loader.loadRouterConfig());
+    this(
+      loader.loadOtpConfig(),
+      loader.loadBuildConfig(),
+      loader.loadRouterConfig(),
+      loader.loadDebugUiConfig()
+    );
   }
 
   public void updateConfigFromSerializedGraph(BuildConfig buildConfig, RouterConfig routerConfig) {
@@ -102,6 +115,10 @@ public RouterConfig routerConfig() {
     return routerConfig;
   }
 
+  public DebugUiConfig debugUiConfig() {
+    return debugUiConfig;
+  }
+
   public static void initializeOtpFeatures(OtpConfig otpConfig) {
     OTPFeature.enableFeatures(otpConfig.otpFeatures);
     OTPFeature.logFeatureSetup();
@@ -117,7 +134,8 @@ public void abortOnUnknownParameters() {
       (
         otpConfig.hasUnknownParameters() ||
         buildConfig.hasUnknownParameters() ||
-        routerConfig.hasUnknownParameters()
+        routerConfig.hasUnknownParameters() ||
+        debugUiConfig.hasUnknownParameters()
       )
     ) {
       throw new OtpAppException(

application/src/main/java/org/opentripplanner/standalone/config/DebugUiConfig.java

@@ -0,0 +1,106 @@
+package org.opentripplanner.standalone.config;
+
+import static org.opentripplanner.standalone.config.framework.json.OtpVersion.V2_7;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.MissingNode;
+import java.util.List;
+import org.opentripplanner.standalone.config.debuguiconfig.BackgroundTileLayer;
+import org.opentripplanner.standalone.config.framework.json.NodeAdapter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class is an object representation of the 'debug-ui-config.json'.
+ */
+public class DebugUiConfig {
+
+  private static final Logger LOG = LoggerFactory.getLogger(DebugUiConfig.class);
+
+  public static final DebugUiConfig DEFAULT = new DebugUiConfig(
+    MissingNode.getInstance(),
+    "DEFAULT",
+    false
+  );
+
+  /**
+   * The node adaptor kept for reference and (de)serialization.
+   */
+  private final NodeAdapter root;
+  private final List<BackgroundTileLayer> additionalBackgroundLayers;
+
+  public DebugUiConfig(JsonNode node, String source, boolean logUnusedParams) {
+    this(new NodeAdapter(node, source), logUnusedParams);
+  }
+
+  /** protected to give unit-test access */
+  DebugUiConfig(NodeAdapter root, boolean logUnusedParams) {
+    this.root = root;
+
+    this.additionalBackgroundLayers =
+      root
+        .of("additionalBackgroundLayers")
+        .since(V2_7)
+        .summary("Additional background raster map layers.")
+        .description(
+          """
+          Add additional background layers that will appear in the Debug UI as one of the choices.
+
+          Currently only raster tile layers are supported.
+          """
+        )
+        .asObjects(
+          List.of(),
+          node ->
+            new BackgroundTileLayer(
+              node
+                .of("name")
+                .since(V2_7)
+                .summary("Name to appear in the layer selector.")
+                .asString(),
+              node
+                .of("templateUrl")
+                .since(V2_7)
+                .summary(
+                  """
+                The [Maplibre-compatible template URL](https://maplibre.org/maplibre-native/ios/api/tile-url-templates.html) 
+                for the raster layer, for example `https://examples.com/tiles/{z}/{x}/{y}.png`.
+                """
+                )
+                .asString(),
+              node.of("tileSize").since(V2_7).summary("Size of the tile in pixels.").asInt(256),
+              node
+                .of("attribution")
+                .since(V2_7)
+                .summary("Attribution for the map data.")
+                .asString("© OpenTripPlanner")
+            )
+        );
+
+    if (logUnusedParams) {
+      root.logAllWarnings(LOG::warn);
+    }
+  }
+
+  public NodeAdapter asNodeAdapter() {
+    return root;
+  }
+
+  public List<BackgroundTileLayer> additionalBackgroundLayers() {
+    return additionalBackgroundLayers;
+  }
+
+  /**
+   * If {@code true} the config is loaded from file, in not the DEFAULT config is used.
+   */
+  public boolean isDefault() {
+    return root.isEmpty();
+  }
+
+  /**
+   * Checks if any unknown or invalid parameters were encountered while loading the configuration.
+   */
+  public boolean hasUnknownParameters() {
+    return root.hasUnknownParameters();
+  }
+}