WIP

src/Logic/State/LayerState.ts

@@ -7,7 +7,13 @@ import { Tag } from "../Tags/Tag"
 import Translations from "../../UI/i18n/Translations"
 import { RegexTag } from "../Tags/RegexTag"
 import { Or } from "../Tags/Or"
+import FilterConfig from "../../Models/ThemeConfig/FilterConfig"
 
+export type ActiveFilter = {
+    layer: LayerConfig,
+    filter: FilterConfig,
+    control: UIEventSource<string | number | undefined>
+}
 /**
  * The layer state keeps track of:
  * - Which layers are enabled
@@ -26,6 +32,9 @@ export default class LayerState {
      * Which layers are enabled in the current theme and what filters are applied onto them
      */
     public readonly filteredLayers: ReadonlyMap<string, FilteredLayer>
+    private readonly _activeFilters: UIEventSource<ActiveFilter[]> = new UIEventSource([])
+
+    public readonly activeFilters: Store<ActiveFilter[]> = this._activeFilters
     private readonly osmConnection: OsmConnection
 
     /**
@@ -56,6 +65,41 @@ export default class LayerState {
         }
         this.filteredLayers = filteredLayers
         layers.forEach((l) => LayerState.linkFilterStates(l, filteredLayers))
+
+        this.filteredLayers.forEach(fl => {
+            fl.isDisplayed.addCallback(() => this.updateActiveFilters())
+            for (const [_, appliedFilter] of fl.appliedFilters) {
+                appliedFilter.addCallback(() => this.updateActiveFilters())
+            }
+        })
+        this.updateActiveFilters()
+    }
+
+    private updateActiveFilters(){
+        const filters: ActiveFilter[] = []
+        this.filteredLayers.forEach(fl => {
+            if(!fl.isDisplayed.data){
+                return
+            }
+            for (const [filtername, appliedFilter] of fl.appliedFilters) {
+                if (appliedFilter.data === undefined) {
+                    continue
+                }
+                const filter = fl.layerDef.filters.find(f => f.id === filtername)
+                if(typeof appliedFilter.data === "number"){
+                    if(filter.options[appliedFilter.data].osmTags === undefined){
+                        // This is probably the first, generic option which doesn't _actually_ filter
+                        continue
+                    }
+                }
+                filters.push({
+                    layer: fl.layerDef,
+                    control: appliedFilter,
+                    filter,
+                })
+            }
+        })
+        this._activeFilters.set(filters)
     }
 
     /**