Make legacy fileOpen API accept configurable cleanup and rejection

index.d.ts

@@ -10,6 +10,15 @@ export function fileOpen<M extends boolean | undefined = false>(options?: {
   description?: string;
   /** Allow multiple files to be selected. Defaults to false. */
   multiple?: M;
+  /**
+   * Configurable cleanup and `Promise` rejector usable with legacy API for determining when (and reacting when) a user cancels the operation.
+   * The method will be called a reference to the internal `rejectionHandler` that can, e.g., be attached to/removed from the window or called after a timeout.
+   * The method should return a function that will be called when either the user chooses to open a file or the `rejectionHandler` is called.
+   * In the latter case, the returned function will also be passed a reference to the `reject` callback for the `Promise` returned by `fileOpen`, so that developers may reject the `Promise` when desired at that time.
+   */
+  setupLegacyCleanupAndRejection?: (
+    rejectionHandler?: () => void
+  ) => (reject: (reason?: any) => void) => void;
 }): M extends false | undefined
   ? Promise<FileWithHandle>
   : Promise<FileWithHandle[]>;

src/legacy/file-open.mjs

@@ -33,21 +33,30 @@ export default async (options = {}) => {
 
     // ToDo: Remove this workaround once
     // https://github.com/whatwg/html/issues/6376 is specified and supported.
-    const rejectOnPageInteraction = () => {
-      window.removeEventListener('pointermove', rejectOnPageInteraction);
-      window.removeEventListener('pointerdown', rejectOnPageInteraction);
-      window.removeEventListener('keydown', rejectOnPageInteraction);
-      reject(new DOMException('The user aborted a request.', 'AbortError'));
-    };
+    let cleanupListenersAndMaybeReject;
+    const rejectionHandler = () => cleanupListenersAndMaybeReject(reject);
+    if (options.setupLegacyCleanupAndRejection) {
+      cleanupListenersAndMaybeReject = options.setupLegacyCleanupAndRejection(
+        rejectionHandler
+      );
+    } else {
+      // Default rejection behavior; works in most cases, but not in Chrome in non-secure contexts.
+      cleanupListenersAndMaybeReject = (reject) => {
+        window.removeEventListener('pointermove', rejectionHandler);
+        window.removeEventListener('pointerdown', rejectionHandler);
+        window.removeEventListener('keydown', rejectionHandler);
+        if (reject) {
+          reject(new DOMException('The user aborted a request.', 'AbortError'));
+        }
+      };
 
-    window.addEventListener('pointermove', rejectOnPageInteraction);
-    window.addEventListener('pointerdown', rejectOnPageInteraction);
-    window.addEventListener('keydown', rejectOnPageInteraction);
+      window.addEventListener('pointermove', rejectionHandler);
+      window.addEventListener('pointerdown', rejectionHandler);
+      window.addEventListener('keydown', rejectionHandler);
+    }
 
     input.addEventListener('change', () => {
-      window.removeEventListener('pointermove', rejectOnPageInteraction);
-      window.removeEventListener('pointerdown', rejectOnPageInteraction);
-      window.removeEventListener('keydown', rejectOnPageInteraction);
+      cleanupListenersAndMaybeReject();
       resolve(input.multiple ? input.files : input.files[0]);
     });