From 472a539133578fdb14af3f47cde0b4f226a7970e Mon Sep 17 00:00:00 2001
From: Hans Dijkema <hans@dijkewijk.nl>
Date: Sat, 18 Apr 2026 15:26:49 +0200
Subject: [PATCH] trying to stop cleanly

---
 racket-webview-qt.rkt | 59 +++++++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 24 deletions(-)

diff --git a/racket-webview-qt.rkt b/racket-webview-qt.rkt
index 996e307..c4b961e 100644
--- a/racket-webview-qt.rkt
+++ b/racket-webview-qt.rkt
@@ -577,38 +577,47 @@
                     )  ; close without closing windows
   )
 
+(define evt-guard-stop -93273)
+
 (define (start-event-processing)
    (thread (λ ()
      (letrec
          ((f
            (λ ()
              (let ((waiting (sync events-channel)))
-               (set! waiting (rkt_webview_events_waiting))
-               ;(displayln (format "Events waiting: ~a" waiting))
-               (while (> waiting 0)
-                      (let* ((rkt-evt (rkt_webview_get_event)))
-                        (if (eq? rkt-evt #f)
-                            (displayln (format "Unexpected: event = nullptr"))
-                            (let* ((data (rkt_data_t-data rkt-evt))
-                                   (e (union-ref data 1))
-                                   (wv (rkt_evt_t-w e))
-                                   (evt (cast (rkt_evt_t-evt e)
-                                                             _pointer
-                                                             _string*/utf-8))
-                                   )
-                              (rkt_webview_free_data rkt-evt)
-                              ;(displayln (format "~a ~a" wv evt))
-                              (if (= wv alive-error-event)
-                                  (close-down-on-alive-error)
-                                  (let ((cb (hash-ref evt-cb-hash wv #f)))
-                                    (unless (eq? cb #f)
-                                      (cb evt)))))))
-                      (set! waiting (- waiting 1))
-                      )
+               (if (= waiting evt-guard-stop)
+                   (begin
+                     (displayln "got evt-guard-stop, exiting event processing")
+                     evt-guard-stop)
+                   (begin
+                     (set! waiting (rkt_webview_events_waiting))
+                     (while (> waiting 0)
+                            (let* ((rkt-evt (rkt_webview_get_event)))
+                              (if (eq? rkt-evt #f)
+                                  (displayln (format "Unexpected: event = nullptr"))
+                                  (let* ((data (rkt_data_t-data rkt-evt))
+                                         (e (union-ref data 1))
+                                         (wv (rkt_evt_t-w e))
+                                         (evt (cast (rkt_evt_t-evt e)
+                                                    _pointer
+                                                    _string*/utf-8))
+                                         )
+                                    (rkt_webview_free_data rkt-evt)
+                                    ;(displayln (format "~a ~a" wv evt))
+                                    (if (= wv alive-error-event)
+                                        (close-down-on-alive-error)
+                                        (let ((cb (hash-ref evt-cb-hash wv #f)))
+                                          (unless (eq? cb #f)
+                                            (cb evt)))))))
+                            (set! waiting (- waiting 1))
+                            )
+                     (f))
+                   )
                )
-             (f))
+             )
            ))
-       (f)))))
+       (f))))
+  )
 
 (define evt-processing-thread (start-event-processing))
 
@@ -813,6 +822,7 @@
 
 
 (define (rkt-webview-finalizer rkt-wv-store close-windows message)
+  (displayln "rkt-webview-finalizer active")
   (when close-windows
     (let ((open-windows (hash->list rkt-wv-store)))
       (for-each (λ (kv)
@@ -820,6 +830,7 @@
                         (handle (cdr kv)))
                     (rkt-webview-close handle)))
                 open-windows)))
+  (event-callback evt-guard-stop)
   (rkt_webview_cleanup)
   (unless (eq? message #f) (error message))
   (stop-event-processing)