Allow a layer to be hidden by default; add some validation and behaviour tweaks

Logic/State/MapState.ts

@@ -301,7 +301,7 @@ export default class MapState extends UserRelatedState {
             } else {
                 isDisplayed = QueryParameters.GetBooleanQueryParameter(
                     "layer-" + layer.id,
-                    "true",
+                     ""+layer.shownByDefault,
                     "Wether or not layer " + layer.id + " is shown"
                 )
             }

Logic/Tags/TagUtils.ts

@@ -255,6 +255,9 @@ export class TagUtils {
             }
             if (tag.indexOf("~") >= 0) {
                 const split = Utils.SplitFirst(tag, "~");
+                if(split[1] === "") {
+                    throw "Detected a regextag with an empty regex; this is not allowed. Use '"+split[0]+"='instead (at "+context+")"
+                }
                 if (split[1] === "*") {
                     split[1] = "..*"
                 }

Models/ThemeConfig/Json/LayerConfigJson.ts

@@ -109,6 +109,13 @@ export interface LayerConfigJson {
      */
     minzoom?: number;
 
+
+    /**
+     * Indicates if this layer is shown by default;
+     * can be used to hide a layer from start, or to load the layer but only to show it where appropriate (e.g. for snapping to it)
+     */
+    shownByDefault?: true | boolean;
+    
     /**
      * The zoom level at which point the data is hidden again
      * Default: 100 (thus: always visible

Models/ThemeConfig/LayerConfig.ts

@@ -47,6 +47,7 @@ export default class LayerConfig extends WithContextLoader {
     public readonly deletion: DeleteConfig | null;
     public readonly allowMove: MoveConfig | null
     public readonly allowSplit: boolean
+    public readonly shownByDefault: boolean;
     /**
      * In seconds
      */
@@ -147,6 +148,7 @@ export default class LayerConfig extends WithContextLoader {
         this.passAllFeatures = json.passAllFeatures ?? false;
         this.minzoom = json.minzoom ?? 0;
         this.minzoomVisible = json.minzoomVisible ?? this.minzoom;
+        this.shownByDefault = json.shownByDefault ?? true;
         if (json.presets !== undefined && json.presets?.map === undefined) {
             throw "Presets should be a list of items (at " + context + ")"
         }

Models/ThemeConfig/LayoutConfig.ts

@@ -221,6 +221,8 @@ export default class LayoutConfig {
             result.push(AllKnownLayers.sharedLayers.get(defaultLayer))
         }
 
+      
+        
         return {layers: result, extractAllNodes: exportAllNodes}
     }
 

Models/ThemeConfig/LegacyJsonConvert.ts

@@ -77,6 +77,7 @@ export default class LegacyJsonConvert {
         delete config["iconSize"]
         delete config["rotation"]
         delete config["wayHandling"]
+        delete config["hideUnderlayingFeaturesMinPercentage"]
         
         for (const mapRenderingElement of config.mapRendering) {
             if (mapRenderingElement["iconOverlays"] !== undefined) {

UI/Input/LocationInput.ts

@@ -227,7 +227,7 @@ export default class LocationInput extends InputElement<Loc> implements MinimapO
 
                 leaflet.setMaxZoom(layer.max_zoom)
                 leaflet.setMinZoom(self._minZoom ?? layer.max_zoom - 2)
-                leaflet.setZoom(layer.max_zoom - 1)
+                leaflet.setZoom(layer.max_zoom)
 
             }, [this.map.leafletMap])