From 7e07428a811ea22a3d6dd53f8eb5b8aa9a3e6be6 Mon Sep 17 00:00:00 2001
From: Jos Rothman <jos@rothman.nl>
Date: Wed, 4 Nov 2026 22:44:42 +0100
Subject: [PATCH] Do not delay a browser restart without a screen; clearer
 reload error

Without a connected monitor every Chromium start waited 30 s for one, so
DevTools was unreachable for ~35 s after a restart. Only wait right after
boot. The reload error now says Chromium may still be starting.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/voxip_kiosk/browser.py   | 14 ++++++++++----
 src/voxip_kiosk/web/views.py |  7 ++++++-
 tests/test_browser.py        | 14 ++++++++++++++
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/voxip_kiosk/browser.py b/src/voxip_kiosk/browser.py
index 1790c0b..6a7d680 100644
--- a/src/voxip_kiosk/browser.py
+++ b/src/voxip_kiosk/browser.py
@@ -19,7 +19,7 @@ from pathlib import Path
 from typing import Any
 from urllib.parse import urlencode
 
-from . import logutil
+from . import logutil, sysinfo
 from .config import load_config
 from .paths import Paths, load_paths
 from .validation import parse_resolution
@@ -153,15 +153,21 @@ def wait_for_x(timeout: float = 60) -> bool:
     return False
 
 
+BOOT_GRACE_SECONDS = 180
+
+
 def prepare_display(paths: Paths, config: dict[str, Any]) -> tuple[int, int] | None:
     outputs: list[dict[str, Any]] = []
-    # A monitor that powers up after the Pi may need a moment to report itself.
-    for _ in range(15):
+    # A monitor that powers up together with the Pi may need a moment to report
+    # itself. Later starts (a browser restart without a screen) should not wait.
+    attempts = 15 if (sysinfo.uptime_seconds() or 0) < BOOT_GRACE_SECONDS else 1
+    for attempt in range(attempts):
+        if attempt:
+            time.sleep(2)
         proc = _run(["xrandr", "--query"])
         outputs = parse_xrandr(proc.stdout) if proc and proc.returncode == 0 else []
         if outputs:
             break
-        time.sleep(2)
     size = None
     if outputs:
         output = outputs[0]
diff --git a/src/voxip_kiosk/web/views.py b/src/voxip_kiosk/web/views.py
index 3d66449..5bf67c5 100644
--- a/src/voxip_kiosk/web/views.py
+++ b/src/voxip_kiosk/web/views.py
@@ -357,7 +357,12 @@ def kiosk_reload():
         audit("page_reload")
         return _action_response(True, "De pagina wordt herladen.", request.referrer or url_for("ui.dashboard"))
     except CDPError as exc:
-        return _action_response(False, f"Herladen mislukt: {exc}", request.referrer or url_for("ui.dashboard"))
+        current_app.logger.warning("Herladen mislukt: %s", exc)
+        return _action_response(
+            False,
+            "Herladen mislukt: Chromium reageert niet. Als hij net (her)start, probeer het over een halve minuut opnieuw.",
+            request.referrer or url_for("ui.dashboard"),
+        )
 
 
 def _helper_action(event: str, verb: str, *args: str, back: str):
diff --git a/tests/test_browser.py b/tests/test_browser.py
index fb302ec..93b27e3 100644
--- a/tests/test_browser.py
+++ b/tests/test_browser.py
@@ -78,3 +78,17 @@ def test_local_pages_exist():
     www = Path(__file__).resolve().parents[1] / "www"
     for page in ("start.html", "offline.html", "setup.html", "kiosk.css", "logo.svg"):
         assert (www / page).exists()
+
+
+def test_prepare_display_waits_for_a_screen_only_after_boot(paths, monkeypatch):
+    calls = []
+    monkeypatch.setattr(b, "_run", lambda args: calls.append(args) or None)
+    monkeypatch.setattr(b.time, "sleep", lambda s: None)
+    monkeypatch.setattr(b.sysinfo, "uptime_seconds", lambda: 3600.0)
+    assert b.prepare_display(paths, dict(DEFAULTS)) is None
+    assert sum(c == ["xrandr", "--query"] for c in calls) == 1
+
+    calls.clear()
+    monkeypatch.setattr(b.sysinfo, "uptime_seconds", lambda: 40.0)
+    b.prepare_display(paths, dict(DEFAULTS))
+    assert sum(c == ["xrandr", "--query"] for c in calls) == 15