Refactoring: simplify working with 'DoesImageExist'

src/Models/ThemeConfig/Conversion/Validation.ts

@@ -22,6 +22,7 @@ import PointRenderingConfigJson from "../Json/PointRenderingConfigJson"
 import { PrevalidateLayer } from "./PrevalidateLayer"
 import { AvailableRasterLayers } from "../../RasterLayers"
 import { eliCategory } from "../../RasterLayerProperties"
+import licenses from "../../../assets/generated/license_info.json"
 
 export class ValidateLanguageCompleteness extends DesugaringStep<ThemeConfig> {
     private readonly _languages: string[]
@@ -126,6 +127,21 @@ export class DoesImageExist extends DesugaringStep<string> {
         }
         return image
     }
+
+    private static licensePaths: Set<string>
+
+    public static constructWithLicenses(checkExistsSync?: (path: string) => boolean, ignore?: Set<string>) {
+        if (!DoesImageExist.licensePaths) {
+
+            const licensePaths = new Set<string>()
+            for (const i in licenses) {
+                licensePaths.add(licenses[i].path)
+            }
+            DoesImageExist.licensePaths = licensePaths
+        }
+        return new DoesImageExist(DoesImageExist.licensePaths, checkExistsSync, ignore)
+    }
+
 }
 
 class OverrideShadowingCheck extends DesugaringStep<ThemeConfigJson> {