Remove FdoSecretsSettings::collectionAliasesChanged()

Remove the collectionAliasesChanged() signal from FdoSecretsSettings
to avoid making it a QObject.  Instead connect to Config::changed and
check which Config key changed.
This does break the abstraction layer that FdoSecretsSettings was
between Service and Config, and requires comparing the key each time any
config value is updated, but averts the QObject overhead for
FdoSecretsSettings.

Suggested-by: Jonathan White <droidmonkey@users.noreply.github.com>
(https://github.com/keepassxreboot/keepassxc/pull/12252#discussion_r2181100088)

src/fdosecrets/FdoSecretsSettings.cpp

@@ -112,7 +112,6 @@ namespace FdoSecrets
     void FdoSecretsSettings::setCollectionAliases(const QVariantMap& aliases)
     {
         config()->set(Config::FdoSecrets_CollectionAliasDatabaseUUIDs, aliases);
-        emit collectionAliasesChanged();
     }
 
     void FdoSecretsSettings::setCollectionAlias(QString alias, QUuid publicUuid)

src/fdosecrets/FdoSecretsSettings.h

@@ -27,10 +27,8 @@ class Database;
 namespace FdoSecrets
 {
 
-    class FdoSecretsSettings : public QObject
+    class FdoSecretsSettings
     {
-        Q_OBJECT
-
     public:
         FdoSecretsSettings() = default;
         static FdoSecretsSettings* instance();
@@ -62,9 +60,6 @@ namespace FdoSecrets
         QUuid exposedGroup(Database* db) const;
         void setExposedGroup(Database* db, const QUuid& group);
 
-    signals:
-        void collectionAliasesChanged() const;
-
     private:
         static FdoSecretsSettings* m_instance;
     };

src/fdosecrets/objects/Service.cpp

@@ -81,8 +81,7 @@ namespace FdoSecrets
         // when a new database is opened, apply it's aliases
         connect(m_databases.data(), &DatabaseTabWidget::databaseOpened, this, &Service::applyCollectionAliasSettings);
         // apply aliases from settings, when they change
-        connect(
-            settings(), &FdoSecretsSettings::collectionAliasesChanged, this, &Service::applyCollectionAliasSettings);
+        connect(config(), &Config::changed, this, &Service::handleSettingsChanged);
 
         // make default alias track current activated database
         connect(m_databases.data(), &DatabaseTabWidget::activeDatabaseChanged, this, &Service::ensureDefaultAlias);
@@ -469,6 +468,13 @@ namespace FdoSecrets
         return collection->addAlias(name);
     }
 
+    void Service::handleSettingsChanged(Config::ConfigKey key)
+    {
+        if (key == Config::FdoSecrets_CollectionAliasDatabaseUUIDs) {
+            applyCollectionAliasSettings();
+        }
+    }
+
     void Service::applyCollectionAliasSettings()
     {
         auto aliases = settings()->collectionAliases();

src/fdosecrets/objects/Service.h

@@ -18,6 +18,7 @@
 #ifndef KEEPASSXC_FDOSECRETS_SERVICE_H
 #define KEEPASSXC_FDOSECRETS_SERVICE_H
 
+#include "core/Config.h"
 #include "fdosecrets/dbus/DBusClient.h"
 #include "fdosecrets/dbus/DBusObject.h"
 
@@ -143,6 +144,7 @@ namespace FdoSecrets
 
         void onCollectionAliasRemoved(const QString& alias);
 
+        void handleSettingsChanged(Config::ConfigKey key);
         void applyCollectionAliasSettings();
 
     private: