From 8160a8d9c8553294068bf6d814b04e701ad2a659 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 13 Dec 2020 14:19:37 +0530
Subject: [PATCH] E-book viewer: Fix clock in header/footer not using system
 time format.  Fixes #1907907 [Feature request: 24h clock format in
 reader](https://bugs.launchpad.net/calibre/+bug/1907907)

---
 src/calibre/gui2/viewer/web_view.py   | 3 ++-
 src/pyj/read_book/prefs/head_foot.pyj | 5 +++++
 src/pyj/viewer-main.pyj               | 5 +++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/calibre/gui2/viewer/web_view.py b/src/calibre/gui2/viewer/web_view.py
index 694001d703..aaed12d86c 100644
--- a/src/calibre/gui2/viewer/web_view.py
+++ b/src/calibre/gui2/viewer/web_view.py
@@ -9,7 +9,7 @@ import sys
 from itertools import count
 from PyQt5.Qt import (
     QT_VERSION, QApplication, QBuffer, QByteArray, QFontDatabase, QFontInfo, QPalette,
-    QHBoxLayout, QMimeData, QSize, Qt, QTimer, QUrl, QWidget, pyqtSignal, QIODevice
+    QHBoxLayout, QMimeData, QSize, Qt, QTimer, QUrl, QWidget, pyqtSignal, QIODevice, QLocale
 )
 from PyQt5.QtWebEngineCore import QWebEngineUrlSchemeHandler
 from PyQt5.QtWebEngineWidgets import (
@@ -602,6 +602,7 @@ class WebView(RestartingWebEngineView):
             'show_home_page_on_ready': self.show_home_page_on_ready,
             'system_colors': system_colors(),
             'QT_VERSION': QT_VERSION,
+            'short_time_fmt': QLocale.system().timeFormat(QLocale.FormatType.ShortFormat),
         }
         self.bridge.create_view(
             vprefs['session_data'], vprefs['local_storage'], field_metadata.all_metadata(), ui_data)
diff --git a/src/pyj/read_book/prefs/head_foot.pyj b/src/pyj/read_book/prefs/head_foot.pyj
index 95c4bfaa37..d40e52783b 100644
--- a/src/pyj/read_book/prefs/head_foot.pyj
+++ b/src/pyj/read_book/prefs/head_foot.pyj
@@ -140,6 +140,11 @@ else:
     }
 
 
+def set_time_formatter(func):
+    nonlocal time_formatter
+    time_formatter = {'format': func}
+
+
 def format_time_left(seconds):
     hours, minutes = divmod(int(seconds / 60), 60)
     if hours <= 0:
diff --git a/src/pyj/viewer-main.pyj b/src/pyj/viewer-main.pyj
index 6bf71ed2b8..5c59dc24a9 100644
--- a/src/pyj/viewer-main.pyj
+++ b/src/pyj/viewer-main.pyj
@@ -5,6 +5,7 @@ from __python__ import bound_methods, hash_literals
 import traceback
 from elementmaker import E
 from gettext import gettext as _, install
+from date import format_date
 
 import initialize  # noqa: unused-import
 from ajax import ajax, workaround_qt_bug
@@ -20,6 +21,7 @@ from read_book.globals import runtime, set_system_colors, ui_operations, default
 from read_book.iframe import main as iframe_main
 from read_book.shortcuts import add_standalone_viewer_shortcuts
 from read_book.view import View
+from read_book.prefs.head_foot import set_time_formatter
 from session import local_storage, session_defaults
 from utils import debounce, encode_query_with_path, parse_url_params
 from viewer.constants import FAKE_HOST, FAKE_PROTOCOL, READER_BACKGROUND_URL
@@ -177,6 +179,9 @@ def create_view(prefs, local_storage, field_metadata, ui_data):
     document.documentElement.style.fontFamily = f'"{ui_data.ui_font_family}", sans-serif'
     document.documentElement.style.fontSize = ui_data.ui_font_sz
     runtime.QT_VERSION = ui_data.QT_VERSION
+    set_time_formatter(def (d):
+        return format_date(d, ui_data.short_time_fmt)
+    )
     if view is None:
         create_session_data(prefs, local_storage)
         view = View(document.getElementById('view'))