FIx several compiler warnings (#1025)

* Do not use deprecated QAbstractSocket::SocketError

* Do not use deprecated ::location

* Do not discard translation load return value

* Use static function calls where applicable

* Remove unused include

* Remove qt6 check

* Remove deprecated type()

* Remove qt6 check

* Use typeId instead of deprecated type

* clang-format fix

4 files changed, 26 insertions, 22 deletions

diff --git a/src/main.cpp b/src/main.cpp
index cb9e138a..41215f33 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,7 +4,6 @@
 #include "courtroom.h"
 #include "datatypes.h"
 #include "lobby.h"
-#include "networkmanager.h"
 
 #include <QDebug>
 #include <QDirIterator>
@@ -29,24 +28,23 @@ int main(int argc, char *argv[])
 #endif
 
   AOApplication main_app;
-  app.setApplicationVersion(AOApplication::get_version_string());
-  app.setApplicationDisplayName(QObject::tr("Attorney Online %1").arg(app.applicationVersion()));
+  QApplication::setApplicationVersion(AOApplication::get_version_string());
+  QApplication::setApplicationDisplayName(QObject::tr("Attorney Online %1").arg(QApplication::applicationVersion()));
 
   QResource::registerResource(main_app.get_asset("themes/" + Options::getInstance().theme() + ".rcc"));
 
-  QFont main_font = app.font();
+  QFont main_font = QApplication::font();
   main_app.default_font = main_font;
 
   QFont new_font = main_font;
   int new_font_size = main_app.default_font.pointSize() * Options::getInstance().themeScalingFactor();
   new_font.setPointSize(new_font_size);
-  app.setFont(new_font);
+  QApplication::setFont(new_font);
 
-  QFontDatabase fontDatabase;
   QDirIterator it(get_base_path() + "fonts", QDirIterator::Subdirectories);
   while (it.hasNext())
   {
-    fontDatabase.addApplicationFont(it.next());
+    QFontDatabase::addApplicationFont(it.next());
   }
 
   QStringList expected_formats{"webp", "apng", "gif"};
@@ -70,18 +68,30 @@ int main(int argc, char *argv[])
   }
 
   QTranslator qtTranslator;
-  qtTranslator.load("qt_" + p_language, QLibraryInfo::location(QLibraryInfo::TranslationsPath));
-  app.installTranslator(&qtTranslator);
+  if (!qtTranslator.load("qt_" + p_language, QLibraryInfo::path(QLibraryInfo::TranslationsPath)))
+  {
+    qDebug() << "Failed to load translation qt_" + p_language;
+  }
+  else
+  {
+    QApplication::installTranslator(&qtTranslator);
+  }
 
   QTranslator appTranslator;
-  qDebug() << ":/data/translations/ao_" + p_language;
-  appTranslator.load("ao_" + p_language, ":/data/translations/");
-  app.installTranslator(&appTranslator);
+  if (!appTranslator.load("ao_" + p_language, ":/data/translations/"))
+  {
+    qDebug() << "Failed to load translation ao_" + p_language;
+  }
+  else
+  {
+    QApplication::installTranslator(&appTranslator);
+    qDebug() << ":/data/translations/ao_" + p_language;
+  }
 
   main_app.construct_lobby();
   main_app.net_manager->get_server_list();
   main_app.net_manager->send_heartbeat();
   main_app.w_lobby->show();
 
-  return app.exec();
+  return QApplication::exec();
 }
diff --git a/src/network/websocketconnection.cpp b/src/network/websocketconnection.cpp
index 133eae1d..9d9183ca 100644
--- a/src/network/websocketconnection.cpp
+++ b/src/network/websocketconnection.cpp
@@ -11,7 +11,7 @@ WebSocketConnection::WebSocketConnection(AOApplication *ao_app, QObject *parent)
     , m_socket(new QWebSocket(QString(), QWebSocketProtocol::VersionLatest, this))
     , m_last_state(QAbstractSocket::UnconnectedState)
 {
-  connect(m_socket, QOverload<QAbstractSocket::SocketError>::of(&QWebSocket::error), this, &WebSocketConnection::onError);
+  connect(m_socket, &QWebSocket::errorOccurred, this, &WebSocketConnection::onError);
   connect(m_socket, &QWebSocket::stateChanged, this, &WebSocketConnection::onStateChanged);
   connect(m_socket, &QWebSocket::textMessageReceived, this, &WebSocketConnection::onTextMessageReceived);
 }
diff --git a/src/path_functions.cpp b/src/path_functions.cpp
index 8de2904b..9b969c48 100644
--- a/src/path_functions.cpp
+++ b/src/path_functions.cpp
@@ -273,11 +273,8 @@ QString AOApplication::get_config_value(QString p_identifier, QString p_config,
     if (!path.isEmpty())
     {
       QSettings settings(path, QSettings::IniFormat);
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-      settings.setIniCodec("UTF-8");
-#endif
       QVariant value = settings.value(p_identifier);
-      if (value.type() == QVariant::StringList)
+      if (value.typeId() == QMetaType::QStringList)
       {
         return value.toStringList().join(",");
       }
diff --git a/src/text_file_functions.cpp b/src/text_file_functions.cpp
index 97e632e3..0b077b6c 100644
--- a/src/text_file_functions.cpp
+++ b/src/text_file_functions.cpp
@@ -160,11 +160,8 @@ QString AOApplication::read_design_ini(QString p_identifier, VPath p_design_path
 QString AOApplication::read_design_ini(QString p_identifier, QString p_design_path)
 {
   QSettings settings(p_design_path, QSettings::IniFormat);
-#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-  settings.setIniCodec("UTF-8");
-#endif
   QVariant value = settings.value(p_identifier);
-  if (value.type() == QVariant::StringList)
+  if (value.typeId() == QMetaType::QStringList)
   {
     return value.toStringList().join(",");
   }