From 0823f9b2ed6dc4161548e5eab152b355c3657588 Mon Sep 17 00:00:00 2001
From: jrtxio <jirentianxiang1024@gmail.com>
Date: Wed, 16 Sep 2026 09:08:48 +0800
Subject: [PATCH] webview (macOS): exempt the process from App Nap while a
 window is open
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macOS throttles/suspends 'idle' apps whose windows are fully occluded.
For monitoring-style Glaze UIs (live charts, streaming logs, dashboards)
that means the page's timers and rendering freeze as soon as another
window covers the app — the backend keeps serving, the UI goes stale.

ensure-app! now declares NSActivityUserInitiated via
[NSProcessInfo beginActivityWithOptions:] once per process. A Glaze app
with an open window is by definition user-initiated work, so the token
is intentionally never ended. Failure to acquire the activity is
non-fatal (best effort).

Note: this removes the process-level suspension component. WebKit may
still apply its own page-visibility throttling in some macOS versions;
that behavior, if observed, is a documented platform limitation rather
than an App Nap effect.

glaze-test: 216 passed (includes the macOS WebView e2e suite).

Fixes #2
---
 glaze/webview/webview-macos.rkt | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/glaze/webview/webview-macos.rkt b/glaze/webview/webview-macos.rkt
index 73b795e..2642e56 100644
--- a/glaze/webview/webview-macos.rkt
+++ b/glaze/webview/webview-macos.rkt
@@ -89,6 +89,7 @@
 
 (import-class NSString NSNull
               NSApplication
+              NSProcessInfo
               NSMenu
               NSMenuItem
               NSWindow
@@ -306,6 +307,27 @@
 ;; Standard menus install once; re-running install-standard-menus! would
 ;; replace the main menu and wipe any custom menus set-menu! appended.
 (define standard-menus-installed? #f)
+(define app-nap-disabled? #f)
+
+;; App Nap exemption. macOS throttles/suspends "idle" apps whose windows are
+;; fully occluded, which freezes monitoring-style Glaze UIs (live charts,
+;; log tails, streaming views) the moment another window covers them. Decla-
+;; ring user-initiated activity for the process lifetime keeps the WebView
+;; live in the background; a Glaze app with an open window IS user-initiated
+;; work, so the token is intentionally never ended. Options value:
+;; NSActivityUserInitiated = 0x00FFFFFF (mask includes the IdleSystemSleep
+;; bit; per NSProcessInfo.h).
+(define (disable-app-nap!)
+  (unless app-nap-disabled?
+    (set! app-nap-disabled? #t)
+    (with-handlers ([exn:fail? (lambda (_) (void))])
+      (define pi (tell NSProcessInfo processInfo))
+      (define token
+        (tell #:type _id pi beginActivityWithOptions: #:type _uint64 16777215
+              reason: #:type _id (->nsstring "Glaze UI running")))
+      ;; token kept forever; no endActivity counterpart by design
+      (void token))))
+
 (define (ensure-app!)
   (call-with-semaphore
    app-init-sema
@@ -315,6 +337,7 @@
      (unless standard-menus-installed?
        (install-standard-menus! app)
        (set! standard-menus-installed? #t))
+     (disable-app-nap!)
      ;; macOS 14+ deprecates activateIgnoringOtherApps: in favor of -activate.
      (if (tell app respondsToSelector: #:type _SEL (selector activate))
          (tellv app activate)