Fix panel clock from not respecting 12/24 hour settings

containments/panel/package/contents/ui/main.qml

@@ -205,7 +205,7 @@ Item {
 
         PlasmaComponents.Label {
             id: clock
-            property bool is24HourTime: Qt.locale().timeFormat(Locale.ShortFormat).toLowerCase().indexOf("ap") === -1
+            property bool is24HourTime: plasmoid.nativeInterface.isSystem24HourFormat
             
             anchors.fill: parent
             text: Qt.formatTime(timeSource.data.Local.DateTime, is24HourTime ? "h:mm" : "h:mm ap")

containments/panel/phonepanel.cpp

@@ -13,6 +13,7 @@
 
 #include <KNotification>
 #include <KLocalizedString>
+#include <KConfigGroup>
 
 #include <QDateTime>
 #include <QDBusPendingReply>
@@ -23,6 +24,8 @@
 #include <QtConcurrent/QtConcurrent>
 #include <QScreen>
 
+#define FORMAT24H "HH:mm:ss"
+
 constexpr int SCREENSHOT_DELAY = 200;
 
 /* -- Static Helpers --------------------------------------------------------------------------- */
@@ -73,6 +76,19 @@ PhonePanel::PhonePanel(QObject *parent, const QVariantList &args)
     //setHasConfigurationInterface(true);
     m_kscreenInterface = new org::kde::KScreen(QStringLiteral("org.kde.kded5"), QStringLiteral("/modules/kscreen"), QDBusConnection::sessionBus(), this);
     m_screenshotInterface = new org::kde::kwin::Screenshot(QStringLiteral("org.kde.KWin"), QStringLiteral("/Screenshot"), QDBusConnection::sessionBus(), this);
+    
+    m_localeConfig = KSharedConfig::openConfig(QStringLiteral("kdeglobals"), KConfig::SimpleConfig);
+    m_localeConfigWatcher = KConfigWatcher::create(m_localeConfig);
+    
+    // watch for changes to locale config, to update 12/24 hour time
+    connect(m_localeConfigWatcher.data(), &KConfigWatcher::configChanged, 
+            this, [this](const KConfigGroup &group, const QByteArrayList &names) -> void {
+                if (group.name() == "Locale") {
+                    // we have to reparse for new changes (from system settings)
+                    m_localeConfig->reparseConfiguration();
+                    Q_EMIT isSystem24HourFormatChanged();
+                }
+            });
 }
 
 PhonePanel::~PhonePanel() = default;
@@ -183,6 +199,14 @@ void PhonePanel::takeScreenshot()
     });
 }
 
+bool PhonePanel::isSystem24HourFormat()
+{
+    KConfigGroup localeSettings = KConfigGroup(m_localeConfig, "Locale");
+    
+    QString timeFormat = localeSettings.readEntry("TimeFormat", QStringLiteral(FORMAT24H));
+    return timeFormat == QStringLiteral(FORMAT24H);
+}
+
 K_EXPORT_PLASMA_APPLET_WITH_JSON(quicksettings, PhonePanel, "metadata.json")
 
 #include "phonepanel.moc"

containments/panel/phonepanel.h

@@ -10,6 +10,9 @@
 
 #include <Plasma/Containment>
 
+#include <KSharedConfig>
+#include <KConfigWatcher>
+
 #include "kscreeninterface.h"
 #include "screenshotinterface.h"
 
@@ -18,6 +21,7 @@ class PhonePanel : public Plasma::Containment
     Q_OBJECT
     Q_PROPERTY(bool autoRotateEnabled READ autoRotate WRITE setAutoRotate NOTIFY autoRotateChanged);
     Q_PROPERTY(bool torchEnabled READ torchEnabled NOTIFY torchChanged);
+    Q_PROPERTY(bool isSystem24HourFormat READ isSystem24HourFormat NOTIFY isSystem24HourFormatChanged);
 public:
     PhonePanel( QObject *parent, const QVariantList &args );
     ~PhonePanel() override;
@@ -32,13 +36,19 @@ public Q_SLOTS:
     
     bool torchEnabled() const;
     
+    bool isSystem24HourFormat();
+
 signals:
     void autoRotateChanged(bool value);
     void torchChanged(bool value);
+    void isSystem24HourFormatChanged();
 
 private:
     bool m_running = false;
     
+    KConfigWatcher::Ptr m_localeConfigWatcher;
+    KSharedConfig::Ptr m_localeConfig;
+
     org::kde::KScreen *m_kscreenInterface;
     org::kde::kwin::Screenshot *m_screenshotInterface;
 };