[devicelock] Ensure settings are refreshed when changed. Fixes JB#37567

QSettings maintains an internal static cache of files it has read and
this can sometimes get out of sync with the source file.  Use an
alternative API to read the settings and avoid this.

And don't emit device lock state changes before the state has been
fully resolved.

rpm/nemo-qml-plugin-devicelock.spec

@@ -10,6 +10,7 @@ BuildRequires:  pkgconfig(Qt5DBus)
 BuildRequires:  pkgconfig(Qt5Core)
 BuildRequires:  pkgconfig(Qt5Network)
 BuildRequires:  pkgconfig(Qt5Qml)
+BuildRequires:  pkgconfig(glib-2.0)
 BuildRequires:  pkgconfig(keepalive)
 BuildRequires:  pkgconfig(libsystemd-daemon)
 BuildRequires:  pkgconfig(mce)

src/nemo-devicelock/host/mcedevicelock.cpp

@@ -293,7 +293,6 @@ void MceDeviceLock::lock()
 
         m_hbTimer.stop();
     }
-
 }
 
 bool MceDeviceLock::isLocked() const
@@ -318,10 +317,10 @@ void MceDeviceLock::setLocked(bool locked)
 
 void MceDeviceLock::stateChanged()
 {
-    emit m_adaptor.stateChanged(state());
-    emit HostDeviceLock::stateChanged();
-
     setStateAndSetupLockTimer();
+
+    emit HostDeviceLock::stateChanged();
+    emit m_adaptor.stateChanged(state());
 }
 
 void MceDeviceLock::automaticLockingChanged()

src/nemo-devicelock/lib.pro

@@ -12,7 +12,9 @@ CONFIG += \
 QT -= gui
 QT += dbus
 
-PKGCONFIG += nemodbus
+PKGCONFIG += \
+        glib-2.0 \
+        nemodbus
 
 INCLUDEPATH += ..
 

src/nemo-devicelock/private/settingswatcher.cpp

@@ -37,6 +37,7 @@
 #include <QFile>
 #include <QSettings>
 
+#include <glib.h>
 #include <sys/inotify.h>
 #include <sys/ioctl.h>
 #include <unistd.h>
@@ -130,16 +131,59 @@ bool SettingsWatcher::event(QEvent *event)
     }
 }
 
+
+template <typename T> T readConfigValue(GKeyFile *config, const char *group, const char *key, T defaultValue);
+
+template <> int readConfigValue<int>(GKeyFile *config, const char *group, const char *key, int defaultValue)
+{
+    GError *error = nullptr;
+    const int value = g_key_file_get_integer(config, group, key, &error);
+    if (error ) {
+        if (error->code != G_KEY_FILE_ERROR_KEY_NOT_FOUND
+                && error->code != G_KEY_FILE_ERROR_GROUP_NOT_FOUND) {
+            qCWarning(devicelock) << "Error reading" << group << key << error->message;
+        }
+        g_error_free(error);
+
+        return defaultValue;
+    } else {
+        return value;
+    }
+}
+
+template <> bool readConfigValue<bool>(
+        GKeyFile *config, const char *group, const char *key, bool defaultValue)
+{
+    GError *error = nullptr;
+    const gboolean value = g_key_file_get_boolean(config, group, key, &error);
+    if (error) {
+        if (error->code != G_KEY_FILE_ERROR_KEY_NOT_FOUND
+                && error->code != G_KEY_FILE_ERROR_GROUP_NOT_FOUND) {
+            qCWarning(devicelock) << "Error reading" << group << key << error->message;
+        }
+        g_error_free(error);
+
+        return defaultValue;
+    } else {
+        return value;
+    }
+}
+
+
 template <typename T>
 static void read(
-        const QSettings &settings,
+        GKeyFile *settings,
         SettingsWatcher *watcher,
         const char *key,
         T defaultValue,
         T (SettingsWatcher::*member),
         void (SettingsWatcher::*changed)() = nullptr)
 {
-    T value = settings.value(QString::fromUtf8(key), QVariant(defaultValue)).value<T>();
+    const T value = readConfigValue<T>(
+                settings,
+                "desktop",
+                QByteArray(key + 9 /* /desktop/ */).replace('/',  '\\').constData(),
+                defaultValue);
 
     if (watcher->*member != value) {
         watcher->*member = value;
@@ -151,11 +195,8 @@ static void read(
 
 void SettingsWatcher::reloadSettings()
 {
-    QSettings settings(m_settingsPath, QSettings::IniFormat);
-    // QSettings appears to be caching queried data between instances and that cache isn't
-    // being invalidated when the file is replaced but not deleted.  Forcing a sync makes it
-    // read the new file.
-    settings.sync();
+    GKeyFile * const settings = g_key_file_new();
+    g_key_file_load_from_file(settings, m_settingsPath.toUtf8().constData(), G_KEY_FILE_NONE, 0);
 
     read(settings, this, automaticLockingKey, 10, &SettingsWatcher::automaticLocking, &SettingsWatcher::automaticLockingChanged);
     read(settings, this, minimumLengthKey, 5, &SettingsWatcher::minimumLength, &SettingsWatcher::minimumLengthChanged);
@@ -168,6 +209,8 @@ void SettingsWatcher::reloadSettings()
     read(settings, this, inputIsKeyboardKey, false, &SettingsWatcher::inputIsKeyboard, &SettingsWatcher::inputIsKeyboardChanged);
     read(settings, this, currentIsDigitOnlyKey, true, &SettingsWatcher::currentCodeIsDigitOnly, &SettingsWatcher::currentCodeIsDigitOnlyChanged);
     read(settings, this, isHomeEncryptedKey, false, &SettingsWatcher::isHomeEncrypted);
+
+    g_key_file_free(settings);
 }
 
 }