diff --git a/ChangeLog b/ChangeLog
index fbb9d62f7..a1c6edc39 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -71,6 +71,7 @@ Enhancements:
 - #7425 Refactored core process management and IPC client
 - #7426 Fixed warnings and enable errors as warnings
 - #7427 More reliable button click detection for add client dialog
+- #7428 Refactor settings dialog to simplify enable/disable logic
 
 # 1.14.6
 
diff --git a/cspell.json b/cspell.json
index a9b1eaa99..fe1cac8fd 100644
--- a/cspell.json
+++ b/cspell.json
@@ -33,6 +33,7 @@
     "Olena",
     "outputdir",
     "Petroules",
+    "Pixmap",
     "Poschta",
     "Priddy",
     "runas",
diff --git a/src/gui/src/MainWindow.cpp b/src/gui/src/MainWindow.cpp
index 0f5640808..15eef033c 100644
--- a/src/gui/src/MainWindow.cpp
+++ b/src/gui/src/MainWindow.cpp
@@ -94,8 +94,8 @@ MainWindow::MainWindow(ConfigScopes &configScopes, AppConfig &appConfig)
       m_AppConfig(appConfig),
       m_ServerConfig(appConfig, *this),
       m_CoreProcess(appConfig, m_ServerConfig),
-      m_ServerConnection(*this, appConfig, m_ServerConfig),
-      m_ClientConnection(*this, appConfig),
+      m_ServerConnection(this, appConfig, m_ServerConfig),
+      m_ClientConnection(this, appConfig),
       m_TlsUtility(appConfig, m_LicenseHandler.license()),
       m_WindowSaveTimer(this) {
 
@@ -251,7 +251,9 @@ void MainWindow::connectSlots() {
 
   connect(m_pActionMinimize, &QAction::triggered, this, &MainWindow::hide);
 
-  connect(m_pActionRestore, &QAction::triggered, this, &MainWindow::showNormal);
+  connect(
+      m_pActionRestore, &QAction::triggered, //
+      [this]() { showAndActivate(); });
 
   connect(
       m_pActionStartCore, &QAction::triggered, this,
@@ -278,6 +280,14 @@ void MainWindow::connectSlots() {
   connect(
       &m_ServerConnection, &ServerConnection::configureClient, this,
       &MainWindow::onServerConnectionConfigureClient);
+
+  connect(
+      &m_ServerConnection, &ServerConnection::messageShowing, this,
+      [this]() { showAndActivate(); });
+
+  connect(
+      &m_ClientConnection, &ClientConnection::messageShowing, this,
+      [this]() { showAndActivate(); });
 }
 
 void MainWindow::onAppAboutToQuit() { m_ConfigScopes.save(); }
@@ -339,8 +349,7 @@ void MainWindow::onTrayIconActivated(QSystemTrayIcon::ActivationReason reason) {
     if (isVisible()) {
       hide();
     } else {
-      showNormal();
-      activateWindow();
+      showAndActivate();
     }
   }
 }
@@ -355,7 +364,7 @@ void MainWindow::onVersionCheckerUpdateFound(const QString &version) {
 }
 
 void MainWindow::onActionStartCoreTriggered() {
-  m_ClientConnection.setCheckConnection(true);
+  m_ClientConnection.setShowMessage();
   m_CoreProcess.start();
 }
 
@@ -408,9 +417,11 @@ void MainWindow::on_m_pActionHelp_triggered() {
 }
 
 void MainWindow::on_m_pActionSettings_triggered() {
-  auto result =
-      SettingsDialog(this, m_AppConfig, m_LicenseHandler.license()).exec();
-  if (result == QDialog::Accepted) {
+  auto dialog = SettingsDialog(
+      this, m_AppConfig, m_ServerConfig, m_LicenseHandler.license(),
+      m_CoreProcess);
+
+  if (dialog.exec() == QDialog::Accepted) {
     m_ConfigScopes.save();
 
     applyConfig();
@@ -445,7 +456,7 @@ void MainWindow::on_m_pLineEditClientIp_textChanged(const QString &text) {
 }
 
 void MainWindow::on_m_pButtonApply_clicked() {
-  m_ClientConnection.setCheckConnection(true);
+  m_ClientConnection.setShowMessage();
   m_CoreProcess.restart();
 }
 
@@ -516,7 +527,7 @@ void MainWindow::open() {
   if (m_AppConfig.autoHide()) {
     hide();
   } else {
-    showNormal();
+    showAndActivate();
   }
 
   m_VersionChecker.checkLatest();
@@ -651,10 +662,10 @@ void MainWindow::updateFromLogLine(const QString &line) {
 
 void MainWindow::checkConnected(const QString &line) {
   if (m_pRadioGroupServer->isChecked()) {
-    m_ServerConnection.update(line);
+    m_ServerConnection.handleLogLine(line);
     m_pLabelServerState->updateServerState(line);
   } else {
-    m_ClientConnection.update(line);
+    m_ClientConnection.handleLogLine(line);
     m_pLabelClientState->updateClientState(line);
   }
 }
@@ -1071,3 +1082,13 @@ void MainWindow::enableClient(bool enable) {
     m_CoreProcess.setMode(CoreProcess::Mode::Client);
   }
 }
+
+void MainWindow::showAndActivate() {
+  if (!isMinimized() && !isHidden()) {
+    qDebug("window already visible");
+    return;
+  }
+
+  showNormal();
+  activateWindow();
+}
diff --git a/src/gui/src/MainWindow.h b/src/gui/src/MainWindow.h
index de9edd72d..2087f4dd1 100644
--- a/src/gui/src/MainWindow.h
+++ b/src/gui/src/MainWindow.h
@@ -171,6 +171,7 @@ private:
   void showDevThanksMessage();
   QString productName() const;
   void updateStatus();
+  void showAndActivate();
 
   VersionChecker m_VersionChecker;
   synergy::gui::TrayIcon m_TrayIcon;
diff --git a/src/gui/src/ScreenSettingsDialog.cpp b/src/gui/src/ScreenSettingsDialog.cpp
index bc0807485..4e58f601e 100644
--- a/src/gui/src/ScreenSettingsDialog.cpp
+++ b/src/gui/src/ScreenSettingsDialog.cpp
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -17,7 +17,8 @@
  */
 
 #include "ScreenSettingsDialog.h"
-#include "Screen.h"
+
+#include "gui/config/Screen.h"
 #include "gui/styles.h"
 #include "validators/AliasValidator.h"
 #include "validators/ScreenNameValidator.h"
@@ -28,6 +29,9 @@
 #include <QtGui>
 
 using namespace synergy::gui;
+using enum ScreenConfig::Modifier;
+using enum ScreenConfig::SwitchCorner;
+using enum ScreenConfig::Fix;
 
 ScreenSettingsDialog::ScreenSettingsDialog(
     QWidget *parent, Screen *pScreen, const ScreenList *pScreens)
@@ -53,26 +57,28 @@ ScreenSettingsDialog::ScreenSettingsDialog(
   for (int i = 0; i < m_pScreen->aliases().count(); i++)
     new QListWidgetItem(m_pScreen->aliases()[i], m_pListAliases);
 
-  m_pComboBoxShift->setCurrentIndex(m_pScreen->modifier(Screen::Shift));
-  m_pComboBoxCtrl->setCurrentIndex(m_pScreen->modifier(Screen::Ctrl));
-  m_pComboBoxAlt->setCurrentIndex(m_pScreen->modifier(Screen::Alt));
-  m_pComboBoxMeta->setCurrentIndex(m_pScreen->modifier(Screen::Meta));
-  m_pComboBoxSuper->setCurrentIndex(m_pScreen->modifier(Screen::Super));
+  m_pComboBoxShift->setCurrentIndex(
+      m_pScreen->modifier(static_cast<int>(Shift)));
+  m_pComboBoxCtrl->setCurrentIndex(m_pScreen->modifier(static_cast<int>(Ctrl)));
+  m_pComboBoxAlt->setCurrentIndex(m_pScreen->modifier(static_cast<int>(Alt)));
+  m_pComboBoxMeta->setCurrentIndex(m_pScreen->modifier(static_cast<int>(Meta)));
+  m_pComboBoxSuper->setCurrentIndex(
+      m_pScreen->modifier(static_cast<int>(Super)));
 
   m_pCheckBoxCornerTopLeft->setChecked(
-      m_pScreen->switchCorner(Screen::TopLeft));
+      m_pScreen->switchCorner(static_cast<int>(TopLeft)));
   m_pCheckBoxCornerTopRight->setChecked(
-      m_pScreen->switchCorner(Screen::TopRight));
+      m_pScreen->switchCorner(static_cast<int>(TopRight)));
   m_pCheckBoxCornerBottomLeft->setChecked(
-      m_pScreen->switchCorner(Screen::BottomLeft));
+      m_pScreen->switchCorner(static_cast<int>(BottomLeft)));
   m_pCheckBoxCornerBottomRight->setChecked(
-      m_pScreen->switchCorner(Screen::BottomRight));
+      m_pScreen->switchCorner(static_cast<int>(BottomRight)));
   m_pSpinBoxSwitchCornerSize->setValue(m_pScreen->switchCornerSize());
 
-  m_pCheckBoxCapsLock->setChecked(m_pScreen->fix(Screen::CapsLock));
-  m_pCheckBoxNumLock->setChecked(m_pScreen->fix(Screen::NumLock));
-  m_pCheckBoxScrollLock->setChecked(m_pScreen->fix(Screen::ScrollLock));
-  m_pCheckBoxXTest->setChecked(m_pScreen->fix(Screen::XTest));
+  m_pCheckBoxCapsLock->setChecked(m_pScreen->fix(CapsLock));
+  m_pCheckBoxNumLock->setChecked(m_pScreen->fix(NumLock));
+  m_pCheckBoxScrollLock->setChecked(m_pScreen->fix(ScrollLock));
+  m_pCheckBoxXTest->setChecked(m_pScreen->fix(XTest));
 }
 
 void ScreenSettingsDialog::accept() {
@@ -102,26 +108,32 @@ void ScreenSettingsDialog::accept() {
     m_pScreen->addAlias(alias);
   }
 
-  m_pScreen->setModifier(Screen::Shift, m_pComboBoxShift->currentIndex());
-  m_pScreen->setModifier(Screen::Ctrl, m_pComboBoxCtrl->currentIndex());
-  m_pScreen->setModifier(Screen::Alt, m_pComboBoxAlt->currentIndex());
-  m_pScreen->setModifier(Screen::Meta, m_pComboBoxMeta->currentIndex());
-  m_pScreen->setModifier(Screen::Super, m_pComboBoxSuper->currentIndex());
+  m_pScreen->setModifier(
+      static_cast<int>(Shift), m_pComboBoxShift->currentIndex());
+  m_pScreen->setModifier(
+      static_cast<int>(Ctrl), m_pComboBoxCtrl->currentIndex());
+  m_pScreen->setModifier(static_cast<int>(Alt), m_pComboBoxAlt->currentIndex());
+  m_pScreen->setModifier(
+      static_cast<int>(Meta), m_pComboBoxMeta->currentIndex());
+  m_pScreen->setModifier(
+      static_cast<int>(Super), m_pComboBoxSuper->currentIndex());
 
   m_pScreen->setSwitchCorner(
-      Screen::TopLeft, m_pCheckBoxCornerTopLeft->isChecked());
+      static_cast<int>(TopLeft), m_pCheckBoxCornerTopLeft->isChecked());
   m_pScreen->setSwitchCorner(
-      Screen::TopRight, m_pCheckBoxCornerTopRight->isChecked());
+      static_cast<int>(TopRight), m_pCheckBoxCornerTopRight->isChecked());
   m_pScreen->setSwitchCorner(
-      Screen::BottomLeft, m_pCheckBoxCornerBottomLeft->isChecked());
+      static_cast<int>(BottomLeft), m_pCheckBoxCornerBottomLeft->isChecked());
   m_pScreen->setSwitchCorner(
-      Screen::BottomRight, m_pCheckBoxCornerBottomRight->isChecked());
+      static_cast<int>(BottomRight), m_pCheckBoxCornerBottomRight->isChecked());
   m_pScreen->setSwitchCornerSize(m_pSpinBoxSwitchCornerSize->value());
 
-  m_pScreen->setFix(Screen::CapsLock, m_pCheckBoxCapsLock->isChecked());
-  m_pScreen->setFix(Screen::NumLock, m_pCheckBoxNumLock->isChecked());
-  m_pScreen->setFix(Screen::ScrollLock, m_pCheckBoxScrollLock->isChecked());
-  m_pScreen->setFix(Screen::XTest, m_pCheckBoxXTest->isChecked());
+  m_pScreen->setFix(
+      static_cast<int>(CapsLock), m_pCheckBoxCapsLock->isChecked());
+  m_pScreen->setFix(static_cast<int>(NumLock), m_pCheckBoxNumLock->isChecked());
+  m_pScreen->setFix(
+      static_cast<int>(ScrollLock), m_pCheckBoxScrollLock->isChecked());
+  m_pScreen->setFix(static_cast<int>(XTest), m_pCheckBoxXTest->isChecked());
 
   QDialog::accept();
 }
diff --git a/src/gui/src/ScreenSetupModel.cpp b/src/gui/src/ScreenSetupModel.cpp
index b68021b1c..7d26da740 100644
--- a/src/gui/src/ScreenSetupModel.cpp
+++ b/src/gui/src/ScreenSetupModel.cpp
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -17,7 +17,8 @@
  */
 
 #include "ScreenSetupModel.h"
-#include "Screen.h"
+
+#include "gui/config/Screen.h"
 
 #include <QtCore>
 #include <QtGui>
@@ -137,7 +138,7 @@ bool ScreenSetupModel::dropMimeData(
   Screen droppedScreen;
   stream >> droppedScreen;
 
-  Screen oldScreen = screen(parent.column(), parent.row());
+  auto oldScreen = Screen(screen(parent.column(), parent.row()));
   if (!oldScreen.isNull() && sourceColumn != -1 && sourceRow != -1) {
     // mark the screen so it isn't deleted after the dragndrop succeeded
     // see ScreenSetupView::startDrag()
diff --git a/src/gui/src/ScreenSetupModel.h b/src/gui/src/ScreenSetupModel.h
index 1b54a4e98..24121df6d 100644
--- a/src/gui/src/ScreenSetupModel.h
+++ b/src/gui/src/ScreenSetupModel.h
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -16,16 +16,14 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#if !defined(SCREENSETUPMODEL__H)
-
-#define SCREENSETUPMODEL__H
+#pragma once
 
 #include <QAbstractTableModel>
 #include <QList>
 #include <QString>
 #include <QStringList>
 
-#include "ScreenList.h"
+#include "gui/config/ScreenList.h"
 
 class ScreenSetupView;
 class ServerConfigDialog;
@@ -80,5 +78,3 @@ private:
 
   static const QString m_MimeType;
 };
-
-#endif
diff --git a/src/gui/src/ScreenSetupView.cpp b/src/gui/src/ScreenSetupView.cpp
index 6821c826c..660e6a8f0 100644
--- a/src/gui/src/ScreenSetupView.cpp
+++ b/src/gui/src/ScreenSetupView.cpp
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -17,6 +17,7 @@
  */
 
 #include "ScreenSetupView.h"
+
 #include "ScreenSettingsDialog.h"
 #include "ScreenSetupModel.h"
 
diff --git a/src/gui/src/ScreenSetupView.h b/src/gui/src/ScreenSetupView.h
index bd77d4bec..b6b1e40ea 100644
--- a/src/gui/src/ScreenSetupView.h
+++ b/src/gui/src/ScreenSetupView.h
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -16,14 +16,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#if !defined(SCREENSETUPVIEW__H)
-
-#define SCREENSETUPVIEW__H
+#pragma once
 
 #include <QFlags>
 #include <QTableView>
 
-#include "Screen.h"
+#include "gui/config/Screen.h"
 
 class QWidget;
 class QMouseEvent;
@@ -51,5 +49,3 @@ protected:
   void initViewItemOption(QStyleOptionViewItem *option) const override;
   void scrollTo(const QModelIndex &, ScrollHint) override {}
 };
-
-#endif
diff --git a/src/gui/src/ServerConfig.cpp b/src/gui/src/ServerConfig.cpp
index f41b779e4..e6ced9e2a 100644
--- a/src/gui/src/ServerConfig.cpp
+++ b/src/gui/src/ServerConfig.cpp
@@ -27,6 +27,11 @@
 #include <QPushButton>
 #include <QtCore>
 
+using namespace synergy::gui::proxy;
+using enum ScreenConfig::Modifier;
+using enum ScreenConfig::SwitchCorner;
+using enum ScreenConfig::Fix;
+
 static const struct {
   int x;
   int y;
@@ -94,7 +99,7 @@ void ServerConfig::setupScreens() {
   hotkeys().clear();
 
   // m_NumSwitchCorners is used as a fixed size array. See Screen::init()
-  for (int i = 0; i < NumSwitchCorners; i++)
+  for (int i = 0; i < static_cast<int>(NumSwitchCorners); i++)
     switchCorners() << false;
 
   // There must always be screen objects for each cell in the screens QList.
@@ -147,7 +152,7 @@ void ServerConfig::commit() {
   settings().beginWriteArray("hotkeys");
   for (int i = 0; i < hotkeys().size(); i++) {
     settings().setArrayIndex(i);
-    hotkeys()[i].saveSettings(settings());
+    hotkeys()[i].saveSettings(settings().get());
   }
   settings().endArray();
 
@@ -189,7 +194,8 @@ void ServerConfig::recall() {
   setClientAddress(settings().value("clientAddress", "").toString());
 
   readSettings(
-      settings(), switchCorners(), "switchCorner", false, NumSwitchCorners);
+      settings(), switchCorners(), "switchCorner", 0,
+      static_cast<int>(NumSwitchCorners));
 
   int numScreens = settings().beginReadArray("screens");
   Q_ASSERT(numScreens <= screens().size());
@@ -206,7 +212,7 @@ void ServerConfig::recall() {
   for (int i = 0; i < numHotkeys; i++) {
     settings().setArrayIndex(i);
     Hotkey h;
-    h.loadSettings(settings());
+    h.loadSettings(settings().get());
     hotkeys().append(h);
   }
   settings().endArray();
@@ -449,7 +455,7 @@ void ServerConfig::addClient(const QString &clientName) {
     fixNoServer(m_pAppConfig->screenName(), serverIndex);
   }
 
-  m_Screens.addScreenByPriority(clientName);
+  m_Screens.addScreenByPriority(Screen(clientName));
 }
 
 void ServerConfig::setConfigFile(const QString &configFile) {
@@ -542,6 +548,6 @@ QString ServerConfig::getClientAddress() const {
   return clientAddress;
 }
 
-QSettings &ServerConfig::settings() {
-  return *m_pAppConfig->scopes().activeSettings();
+QSettingsProxy &ServerConfig::settings() {
+  return m_pAppConfig->scopes().activeSettings();
 }
diff --git a/src/gui/src/ServerConfig.h b/src/gui/src/ServerConfig.h
index f4764c567..741b954e0 100644
--- a/src/gui/src/ServerConfig.h
+++ b/src/gui/src/ServerConfig.h
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -19,9 +19,9 @@
 #pragma once
 
 #include "Hotkey.h"
-#include "ScreenConfig.h"
-#include "ScreenList.h"
 #include "gui/config/IServerConfig.h"
+#include "gui/config/ScreenConfig.h"
+#include "gui/config/ScreenList.h"
 
 #include <QList>
 
@@ -37,6 +37,8 @@ class MainWindow;
 class AppConfig;
 
 class ServerConfig : public ScreenConfig, public synergy::gui::IServerConfig {
+  using QSettingsProxy = synergy::gui::proxy::QSettingsProxy;
+
   friend class ServerConfigDialog;
   friend QTextStream &
   operator<<(QTextStream &outStream, const ServerConfig &config);
@@ -49,7 +51,15 @@ public:
 
   bool operator==(const ServerConfig &sc) const;
 
-  const ScreenList &screens() const { return m_Screens; }
+  //
+  // Overrides
+  //
+  const ScreenList &screens() const override { return m_Screens; }
+  bool enableDragAndDrop() const override { return m_EnableDragAndDrop; }
+
+  //
+  // New methods
+  //
   int numColumns() const { return m_Columns; }
   int numRows() const { return m_Rows; }
   bool hasHeartbeat() const { return m_HasHeartbeat; }
@@ -64,23 +74,29 @@ public:
   int switchCornerSize() const { return m_SwitchCornerSize; }
   const QList<bool> &switchCorners() const { return m_SwitchCorners; }
   const HotkeyList &hotkeys() const { return m_Hotkeys; }
-  bool enableDragAndDrop() const override { return m_EnableDragAndDrop; }
   bool disableLockToScreen() const { return m_DisableLockToScreen; }
   bool clipboardSharing() const { return m_ClipboardSharing; }
   size_t clipboardSharingSize() const { return m_ClipboardSharingSize; }
   static size_t defaultClipboardSharingSize();
 
-  void commit();
+  //
+  // Overrides
+  //
   bool save(const QString &fileName) const override;
+  bool screenExists(const QString &screenName) const override;
   void save(QFile &file) const override;
+  bool isFull() const override;
+
+  //
+  // New methods
+  //
+  void commit();
   int numScreens() const;
   int autoAddScreen(const QString name);
   const QString &getServerName() const;
   void updateServerName();
   const QString &configFile() const;
   bool useExternalConfig() const;
-  bool isFull() const override;
-  bool screenExists(const QString &screenName) const override;
   void addClient(const QString &clientName);
   QString getClientAddress() const;
   void setClientAddress(const QString &address);
@@ -88,7 +104,7 @@ public:
 private:
   void recall();
   void setupScreens();
-  QSettings &settings();
+  QSettingsProxy &settings();
   ScreenList &screens() { return m_Screens; }
   void setScreens(const ScreenList &screens) { m_Screens = screens; }
   void addScreen(const Screen &screen) { m_Screens.append(screen); }
diff --git a/src/gui/src/ServerConfigDialog.cpp b/src/gui/src/ServerConfigDialog.cpp
index e82ae9a3f..f1649227f 100644
--- a/src/gui/src/ServerConfigDialog.cpp
+++ b/src/gui/src/ServerConfigDialog.cpp
@@ -28,6 +28,8 @@
 #include <QtCore>
 #include <QtGui>
 
+using enum ScreenConfig::SwitchCorner;
+
 ServerConfigDialog::ServerConfigDialog(
     QWidget *parent, ServerConfig &config, AppConfig &appConfig)
     : QDialog(parent, Qt::WindowTitleHint | Qt::WindowSystemMenuHint),
@@ -65,13 +67,13 @@ ServerConfigDialog::ServerConfigDialog(
   m_pSpinBoxSwitchDoubleTap->setValue(serverConfig().switchDoubleTap());
 
   m_pCheckBoxCornerTopLeft->setChecked(
-      serverConfig().switchCorner(ScreenConfig::TopLeft));
+      serverConfig().switchCorner(static_cast<int>(TopLeft)));
   m_pCheckBoxCornerTopRight->setChecked(
-      serverConfig().switchCorner(ScreenConfig::TopRight));
+      serverConfig().switchCorner(static_cast<int>(TopRight)));
   m_pCheckBoxCornerBottomLeft->setChecked(
-      serverConfig().switchCorner(ScreenConfig::BottomLeft));
+      serverConfig().switchCorner(static_cast<int>(BottomLeft)));
   m_pCheckBoxCornerBottomRight->setChecked(
-      serverConfig().switchCorner(ScreenConfig::BottomRight));
+      serverConfig().switchCorner(static_cast<int>(BottomRight)));
   m_pSpinBoxSwitchCornerSize->setValue(serverConfig().switchCornerSize());
   m_pCheckBoxDisableLockToScreen->setChecked(
       serverConfig().disableLockToScreen());
@@ -189,25 +191,25 @@ ServerConfigDialog::ServerConfigDialog(
   connect(
       m_pCheckBoxCornerTopLeft, &QCheckBox::stateChanged, this,
       [this](const int &v) {
-        serverConfig().setSwitchCorner(ScreenConfig::TopLeft, v);
+        serverConfig().setSwitchCorner(static_cast<int>(TopLeft), v);
         onChange();
       });
   connect(
       m_pCheckBoxCornerTopRight, &QCheckBox::stateChanged, this,
       [this](const int &v) {
-        serverConfig().setSwitchCorner(ScreenConfig::TopRight, v);
+        serverConfig().setSwitchCorner(static_cast<int>(TopRight), v);
         onChange();
       });
   connect(
       m_pCheckBoxCornerBottomLeft, &QCheckBox::stateChanged, this,
       [this](const int &v) {
-        serverConfig().setSwitchCorner(ScreenConfig::BottomLeft, v);
+        serverConfig().setSwitchCorner(static_cast<int>(BottomLeft), v);
         onChange();
       });
   connect(
       m_pCheckBoxCornerBottomRight, &QCheckBox::stateChanged, this,
       [this](const int &v) {
-        serverConfig().setSwitchCorner(ScreenConfig::BottomRight, v);
+        serverConfig().setSwitchCorner(static_cast<int>(BottomRight), v);
         onChange();
       });
   connect(
diff --git a/src/gui/src/SettingsDialog.cpp b/src/gui/src/SettingsDialog.cpp
index 637031c86..7b1b2622f 100644
--- a/src/gui/src/SettingsDialog.cpp
+++ b/src/gui/src/SettingsDialog.cpp
@@ -40,12 +40,15 @@ using namespace synergy::gui;
 const char *const kProProductName = "Synergy 1 Pro";
 
 SettingsDialog::SettingsDialog(
-    QWidget *parent, AppConfig &config, const License &license)
+    MainWindow *parent, AppConfig &appConfig, const IServerConfig &serverConfig,
+    const License &license, const CoreProcess &coreProcess)
     : QDialog(parent, Qt::WindowTitleHint | Qt::WindowSystemMenuHint),
       Ui::SettingsDialogBase(),
-      m_appConfig(config),
+      m_appConfig(appConfig),
+      m_serverConfig(serverConfig),
       m_license(license),
-      m_tlsUtility(config, license) {
+      m_coreProcess(coreProcess),
+      m_tlsUtility(appConfig, license) {
 
   setupUi(this);
 
@@ -53,124 +56,18 @@ SettingsDialog::SettingsDialog(
   // the developer was looking at, and it's easy to accidentally save that.
   m_pTabWidget->setCurrentIndex(0);
 
-  m_pMainWindow = dynamic_cast<MainWindow *>(parent);
-
   loadFromConfig();
-  m_wasOriginallySystemScope = appConfig().isActiveScopeSystem();
-  updateControlsEnabled();
-
-  const auto &serveConfig = m_pMainWindow->serverConfig();
+  m_wasOriginallySystemScope = m_appConfig.isActiveScopeSystem();
+  updateControls();
 
   m_pScreenNameError = new validators::ValidationError(this);
   m_pLineEditScreenName->setValidator(new validators::ScreenNameValidator(
-      m_pLineEditScreenName, m_pScreenNameError, &serveConfig.screens()));
+      m_pLineEditScreenName, m_pScreenNameError, &serverConfig.screens()));
 }
 
-void SettingsDialog::accept() {
-  if (!m_pLineEditScreenName->hasAcceptableInput()) {
-    QMessageBox::warning(
-        this, tr("Invalid screen name"), m_pScreenNameError->message());
-    return;
-  }
-
-  appConfig().setLoadFromSystemScope(m_pRadioSystemScope->isChecked());
-  appConfig().setScreenName(m_pLineEditScreenName->text());
-  appConfig().setPort(m_pSpinBoxPort->value());
-  appConfig().setNetworkInterface(m_pLineEditInterface->text());
-  appConfig().setLogLevel(m_pComboLogLevel->currentIndex());
-  appConfig().setLogToFile(m_pCheckBoxLogToFile->isChecked());
-  appConfig().setLogFilename(m_pLineEditLogFilename->text());
-  appConfig().setElevateMode(
-      static_cast<ElevateMode>(m_pComboElevate->currentIndex()));
-  appConfig().setAutoHide(m_pCheckBoxAutoHide->isChecked());
-  appConfig().setPreventSleep(m_pCheckBoxPreventSleep->isChecked());
-  appConfig().setTlsCertPath(m_pLineEditCertificatePath->text());
-  appConfig().setTlsKeyLength(m_pComboBoxKeyLength->currentText().toInt());
-  appConfig().setTlsEnabled(m_pCheckBoxEnableCrypto->isChecked());
-  appConfig().setLanguageSync(m_pCheckBoxLanguageSync->isChecked());
-  appConfig().setInvertScrollDirection(m_pCheckBoxScrollDirection->isChecked());
-  appConfig().setEnableService(m_pCheckBoxServiceEnabled->isChecked());
-  appConfig().setCloseToTray(m_pCheckBoxCloseToTray->isChecked());
-  appConfig().setInvertConnection(m_pInvertConnection->isChecked());
-
-  QDialog::accept();
-}
-
-void SettingsDialog::reject() {
-  // restore original system scope value on reject.
-  if (appConfig().isActiveScopeSystem() != m_wasOriginallySystemScope) {
-    appConfig().setLoadFromSystemScope(m_wasOriginallySystemScope);
-  }
-
-  QDialog::reject();
-}
-
-void SettingsDialog::loadFromConfig() {
-
-  m_pLineEditScreenName->setText(appConfig().screenName());
-  m_pSpinBoxPort->setValue(appConfig().port());
-  m_pLineEditInterface->setText(appConfig().networkInterface());
-  m_pComboLogLevel->setCurrentIndex(appConfig().logLevel());
-  m_pCheckBoxLogToFile->setChecked(appConfig().logToFile());
-  m_pLineEditLogFilename->setText(appConfig().logFilename());
-  m_pCheckBoxAutoHide->setChecked(appConfig().autoHide());
-  m_pCheckBoxPreventSleep->setChecked(appConfig().preventSleep());
-  m_pLineEditCertificatePath->setText(appConfig().tlsCertPath());
-  m_pCheckBoxEnableCrypto->setChecked(m_appConfig.tlsEnabled());
-  m_pCheckBoxLanguageSync->setChecked(m_appConfig.languageSync());
-  m_pCheckBoxScrollDirection->setChecked(m_appConfig.invertScrollDirection());
-  m_pCheckBoxServiceEnabled->setChecked(m_appConfig.enableService());
-  m_pCheckBoxCloseToTray->setChecked(m_appConfig.closeToTray());
-
-  if (m_appConfig.isActiveScopeSystem()) {
-    m_pRadioSystemScope->setChecked(true);
-  } else {
-    m_pRadioUserScope->setChecked(true);
-  }
-
-  m_pInvertConnection->setChecked(m_appConfig.invertConnection());
-  m_pInvertConnection->setEnabled(
-      m_license.productEdition() == Edition::kBusiness);
-
-  updateTlsControls();
-}
-
-void SettingsDialog::updateTlsControls() {
-  if (QFile(appConfig().tlsCertPath()).exists()) {
-    updateKeyLengthOnFile(appConfig().tlsCertPath());
-  } else {
-    const auto keyLengthText = QString::number(appConfig().tlsKeyLength());
-    m_pComboBoxKeyLength->setCurrentIndex(
-        m_pComboBoxKeyLength->findText(keyLengthText));
-  }
-
-  m_pCheckBoxEnableCrypto->setChecked(m_appConfig.tlsEnabled());
-
-  updateTlsControlsEnabled();
-}
-
-void SettingsDialog::updateTlsControlsEnabled() {
-  bool writable = appConfig().isActiveScopeWritable();
-  auto clientMode = appConfig().clientGroupChecked();
-  auto tlsAvailable = m_tlsUtility.isAvailableAndEnabled();
-  auto tlsChecked = m_pCheckBoxEnableCrypto->isChecked();
-  auto enabled = writable && !clientMode && tlsAvailable && tlsChecked;
-
-  qDebug(
-      "tls enabled=%d, writable=%d, client=%d, available=%d, checked=%d",
-      enabled, writable, clientMode, tlsAvailable, tlsChecked);
-
-  m_pLabelKeyLength->setEnabled(enabled);
-  m_pComboBoxKeyLength->setEnabled(enabled);
-  m_pLabelCertificate->setEnabled(enabled);
-  m_pLineEditCertificatePath->setEnabled(enabled);
-  m_pPushButtonBrowseCert->setEnabled(enabled);
-  m_pPushButtonRegenCert->setEnabled(enabled);
-}
-
-bool SettingsDialog::isClientMode() const {
-  return m_pMainWindow->coreMode() == MainWindow::CoreMode::Client;
-}
+//
+// Auto-connect slots
+//
 
 void SettingsDialog::on_m_pCheckBoxLogToFile_stateChanged(int i) {
   bool checked = i == 2;
@@ -206,9 +103,9 @@ void SettingsDialog::on_m_pCheckBoxEnableCrypto_clicked(bool) {
 
 void SettingsDialog::on_m_pRadioSystemScope_toggled(bool checked) {
   // We only need to test the System scoped Radio as they are connected
-  appConfig().setLoadFromSystemScope(checked);
+  m_appConfig.setLoadFromSystemScope(checked);
   loadFromConfig();
-  updateControlsEnabled();
+  updateControls();
 }
 
 void SettingsDialog::on_m_pPushButtonBrowseCert_clicked() {
@@ -233,18 +130,6 @@ void SettingsDialog::on_m_pComboBoxKeyLength_currentIndexChanged(int index) {
   updateTlsRegenerateButton();
 }
 
-void SettingsDialog::updateTlsRegenerateButton() {
-  const auto keyLength = m_pComboBoxKeyLength->currentText().toInt();
-  auto keyChanged = appConfig().tlsKeyLength() != keyLength;
-  auto pathChanged =
-      appConfig().tlsCertPath() != m_pLineEditCertificatePath->text();
-  // NOR the above bools, if any have changed regen should be disabled as it
-  // will be done on save
-  auto nor = !(keyChanged || pathChanged);
-  m_pPushButtonRegenCert->setEnabled(
-      nor && m_pCheckBoxEnableCrypto->isChecked());
-}
-
 void SettingsDialog::on_m_pPushButtonRegenCert_clicked() {
   if (m_tlsUtility.generateCertificate()) {
     QMessageBox::information(
@@ -253,6 +138,134 @@ void SettingsDialog::on_m_pPushButtonRegenCert_clicked() {
   }
 }
 
+void SettingsDialog::on_m_pCheckBoxServiceEnabled_toggled(bool) {
+  updateControls();
+}
+
+//
+// End of auto-connect slots
+//
+
+void SettingsDialog::accept() {
+  if (!m_pLineEditScreenName->hasAcceptableInput()) {
+    QMessageBox::warning(
+        this, tr("Invalid screen name"), m_pScreenNameError->message());
+    return;
+  }
+
+  m_appConfig.setLoadFromSystemScope(m_pRadioSystemScope->isChecked());
+  m_appConfig.setScreenName(m_pLineEditScreenName->text());
+  m_appConfig.setPort(m_pSpinBoxPort->value());
+  m_appConfig.setNetworkInterface(m_pLineEditInterface->text());
+  m_appConfig.setLogLevel(m_pComboLogLevel->currentIndex());
+  m_appConfig.setLogToFile(m_pCheckBoxLogToFile->isChecked());
+  m_appConfig.setLogFilename(m_pLineEditLogFilename->text());
+  m_appConfig.setElevateMode(
+      static_cast<ElevateMode>(m_pComboElevate->currentIndex()));
+  m_appConfig.setAutoHide(m_pCheckBoxAutoHide->isChecked());
+  m_appConfig.setPreventSleep(m_pCheckBoxPreventSleep->isChecked());
+  m_appConfig.setTlsCertPath(m_pLineEditCertificatePath->text());
+  m_appConfig.setTlsKeyLength(m_pComboBoxKeyLength->currentText().toInt());
+  m_appConfig.setTlsEnabled(m_pCheckBoxEnableCrypto->isChecked());
+  m_appConfig.setLanguageSync(m_pCheckBoxLanguageSync->isChecked());
+  m_appConfig.setInvertScrollDirection(m_pCheckBoxScrollDirection->isChecked());
+  m_appConfig.setEnableService(m_pCheckBoxServiceEnabled->isChecked());
+  m_appConfig.setCloseToTray(m_pCheckBoxCloseToTray->isChecked());
+  m_appConfig.setInvertConnection(m_pInvertConnection->isChecked());
+
+  QDialog::accept();
+}
+
+void SettingsDialog::reject() {
+  // restore original system scope value on reject.
+  if (m_appConfig.isActiveScopeSystem() != m_wasOriginallySystemScope) {
+    m_appConfig.setLoadFromSystemScope(m_wasOriginallySystemScope);
+  }
+
+  QDialog::reject();
+}
+
+void SettingsDialog::loadFromConfig() {
+
+  m_pLineEditScreenName->setText(m_appConfig.screenName());
+  m_pSpinBoxPort->setValue(m_appConfig.port());
+  m_pLineEditInterface->setText(m_appConfig.networkInterface());
+  m_pComboLogLevel->setCurrentIndex(m_appConfig.logLevel());
+  m_pCheckBoxLogToFile->setChecked(m_appConfig.logToFile());
+  m_pLineEditLogFilename->setText(m_appConfig.logFilename());
+  m_pCheckBoxAutoHide->setChecked(m_appConfig.autoHide());
+  m_pCheckBoxPreventSleep->setChecked(m_appConfig.preventSleep());
+  m_pLineEditCertificatePath->setText(m_appConfig.tlsCertPath());
+  m_pCheckBoxEnableCrypto->setChecked(m_appConfig.tlsEnabled());
+  m_pCheckBoxLanguageSync->setChecked(m_appConfig.languageSync());
+  m_pCheckBoxScrollDirection->setChecked(m_appConfig.invertScrollDirection());
+  m_pCheckBoxServiceEnabled->setChecked(m_appConfig.enableService());
+  m_pCheckBoxCloseToTray->setChecked(m_appConfig.closeToTray());
+  m_pComboElevate->setCurrentIndex(static_cast<int>(m_appConfig.elevateMode()));
+
+  if (m_appConfig.isActiveScopeSystem()) {
+    m_pRadioSystemScope->setChecked(true);
+  } else {
+    m_pRadioUserScope->setChecked(true);
+  }
+
+  m_pInvertConnection->setChecked(m_appConfig.invertConnection());
+  m_pInvertConnection->setEnabled(
+      m_license.productEdition() == Edition::kBusiness);
+
+  updateTlsControls();
+}
+
+void SettingsDialog::updateTlsControls() {
+  if (QFile(m_appConfig.tlsCertPath()).exists()) {
+    updateKeyLengthOnFile(m_appConfig.tlsCertPath());
+  } else {
+    const auto keyLengthText = QString::number(m_appConfig.tlsKeyLength());
+    m_pComboBoxKeyLength->setCurrentIndex(
+        m_pComboBoxKeyLength->findText(keyLengthText));
+  }
+
+  m_pCheckBoxEnableCrypto->setChecked(m_appConfig.tlsEnabled());
+
+  updateTlsControlsEnabled();
+}
+
+void SettingsDialog::updateTlsControlsEnabled() {
+  const auto writable = m_appConfig.isActiveScopeWritable();
+  const auto clientMode = m_appConfig.clientGroupChecked();
+  const auto tlsAvailable = m_tlsUtility.isAvailableAndEnabled();
+  const auto tlsChecked = m_pCheckBoxEnableCrypto->isChecked();
+
+  auto enabled = writable && !clientMode && tlsAvailable && tlsChecked;
+
+  qDebug(
+      "tls enabled=%d, writable=%d, client=%d, available=%d, checked=%d",
+      enabled, writable, clientMode, tlsAvailable, tlsChecked);
+
+  m_pLabelKeyLength->setEnabled(enabled);
+  m_pComboBoxKeyLength->setEnabled(enabled);
+  m_pLabelCertificate->setEnabled(enabled);
+  m_pLineEditCertificatePath->setEnabled(enabled);
+  m_pPushButtonBrowseCert->setEnabled(enabled);
+  m_pPushButtonRegenCert->setEnabled(enabled);
+}
+
+bool SettingsDialog::isClientMode() const {
+  return m_coreProcess.mode() == MainWindow::CoreMode::Client;
+}
+
+void SettingsDialog::updateTlsRegenerateButton() {
+  const auto writable = m_appConfig.isActiveScopeWritable();
+  const auto keyLength = m_pComboBoxKeyLength->currentText().toInt();
+  const auto path = m_pLineEditCertificatePath->text();
+  const auto keyChanged = m_appConfig.tlsKeyLength() != keyLength;
+  const auto pathChanged = m_appConfig.tlsCertPath() != path;
+  const auto tlsEnabled = m_pCheckBoxEnableCrypto->isChecked();
+
+  m_pPushButtonRegenCert->setEnabled(
+      writable && tlsEnabled && (keyChanged || pathChanged));
+}
+
 void SettingsDialog::updateKeyLengthOnFile(const QString &path) {
   TlsCertificate ssl;
   if (!QFile(path).exists()) {
@@ -262,52 +275,48 @@ void SettingsDialog::updateKeyLengthOnFile(const QString &path) {
   auto length = ssl.getCertKeyLength(path);
   auto index = m_pComboBoxKeyLength->findText(QString::number(length));
   m_pComboBoxKeyLength->setCurrentIndex(index);
-  appConfig().setTlsKeyLength(length);
+  m_appConfig.setTlsKeyLength(length);
 }
 
-void SettingsDialog::updateControlsEnabled() {
-  bool writable = appConfig().isActiveScopeWritable();
+void SettingsDialog::updateControls() {
+
+#if defined(Q_OS_WIN)
+  const auto serviceAvailable = true;
+#else
+  // service not supported on unix yet, so always disable.
+  const auto serviceAvailable = false;
+  m_pGroupService->setTitle("Service (Windows only)");
+#endif
+
+  const bool writable = m_appConfig.isActiveScopeWritable();
+  const bool serviceChecked = m_pCheckBoxServiceEnabled->isChecked();
+  const bool logToFile = m_pCheckBoxLogToFile->isChecked();
 
   m_pLineEditScreenName->setEnabled(writable);
   m_pSpinBoxPort->setEnabled(writable);
   m_pLineEditInterface->setEnabled(writable);
   m_pComboLogLevel->setEnabled(writable);
   m_pCheckBoxLogToFile->setEnabled(writable);
-  m_pComboElevate->setEnabled(writable);
   m_pCheckBoxAutoHide->setEnabled(writable);
   m_pCheckBoxPreventSleep->setEnabled(writable);
   m_pLineEditCertificatePath->setEnabled(writable);
   m_pComboBoxKeyLength->setEnabled(writable);
   m_pPushButtonBrowseCert->setEnabled(writable);
   m_pCheckBoxEnableCrypto->setEnabled(writable);
-  m_pCheckBoxServiceEnabled->setEnabled(writable);
   m_pCheckBoxCloseToTray->setEnabled(writable);
 
+  m_pCheckBoxServiceEnabled->setEnabled(writable && serviceAvailable);
+  m_pLabelElevate->setEnabled(writable && serviceChecked && serviceAvailable);
+  m_pComboElevate->setEnabled(writable && serviceChecked && serviceAvailable);
+
   m_pCheckBoxLanguageSync->setEnabled(writable && isClientMode());
   m_pCheckBoxScrollDirection->setEnabled(writable && isClientMode());
 
-#if !defined(Q_OS_WIN)
-  m_pCheckBoxServiceEnabled->setEnabled(false);
-#endif
-
-  m_pLabelLogPath->setEnabled(writable && m_pCheckBoxLogToFile->isChecked());
-  m_pLineEditLogFilename->setEnabled(
-      writable && m_pCheckBoxLogToFile->isChecked());
-  m_pButtonBrowseLog->setEnabled(writable && m_pCheckBoxLogToFile->isChecked());
+  m_pLabelLogPath->setEnabled(writable && logToFile);
+  m_pLineEditLogFilename->setEnabled(writable && logToFile);
+  m_pButtonBrowseLog->setEnabled(writable && logToFile);
 
   updateTlsControlsEnabled();
-
-  if (writable) {
-    updateTlsRegenerateButton();
-  }
-
-#if defined(Q_OS_WIN)
-  m_pComboElevate->setCurrentIndex(static_cast<int>(appConfig().elevateMode()));
-#else
-  // elevate checkbox is only usable on ms windows.
-  m_pLabelElevate->setEnabled(false);
-  m_pComboElevate->setEnabled(false);
-#endif
-
+  updateTlsRegenerateButton();
   updateTlsControls();
 }
diff --git a/src/gui/src/SettingsDialog.h b/src/gui/src/SettingsDialog.h
index aa0e060aa..0f6a3d51b 100644
--- a/src/gui/src/SettingsDialog.h
+++ b/src/gui/src/SettingsDialog.h
@@ -20,6 +20,9 @@
 
 #include "ui_SettingsDialogBase.h"
 
+#include "gui/config/AppConfig.h"
+#include "gui/config/IServerConfig.h"
+#include "gui/core/CoreProcess.h"
 #include "gui/core/CoreTool.h"
 #include "gui/tls/TlsUtility.h"
 #include "license/License.h"
@@ -28,15 +31,19 @@
 #include <QDialog>
 
 class MainWindow;
-class AppConfig;
 
 class SettingsDialog : public QDialog, public Ui::SettingsDialogBase {
+  using IServerConfig = synergy::gui::IServerConfig;
+  using CoreProcess = synergy::gui::CoreProcess;
+  using License = synergy::license::License;
+
   Q_OBJECT
 
 public:
   SettingsDialog(
-      QWidget *parent, AppConfig &config,
-      const synergy::license::License &license);
+      MainWindow *parent, AppConfig &appConfig,
+      const IServerConfig &serverConfig, const License &license,
+      const CoreProcess &coreProcess);
   static QString browseForSynergyc(
       QWidget *parent, const QString &programDir,
       const QString &coreClientName);
@@ -44,10 +51,19 @@ public:
       QWidget *parent, const QString &programDir,
       const QString &coreServerName);
 
-protected:
+private slots:
+  void on_m_pCheckBoxEnableCrypto_clicked(bool checked);
+  void on_m_pCheckBoxLogToFile_stateChanged(int);
+  void on_m_pButtonBrowseLog_clicked();
+  void on_m_pRadioSystemScope_toggled(bool checked);
+  void on_m_pPushButtonBrowseCert_clicked();
+  void on_m_pComboBoxKeyLength_currentIndexChanged(int index);
+  void on_m_pPushButtonRegenCert_clicked();
+  void on_m_pCheckBoxServiceEnabled_toggled(bool checked);
+
+private:
   void accept() override;
   void reject() override;
-  AppConfig &appConfig() { return m_appConfig; }
 
   /// @brief Load all settings.
   void loadFromConfig();
@@ -59,31 +75,23 @@ protected:
   void updateKeyLengthOnFile(const QString &path);
 
   /// @brief Enables controls when they should be.
-  void updateControlsEnabled();
+  void updateControls();
 
   bool isClientMode() const;
   void updateTlsControls();
   void updateTlsControlsEnabled();
 
-private:
-  MainWindow *m_pMainWindow;
-  AppConfig &m_appConfig;
   [[no_unique_address]] CoreTool m_coreTool;
-  const synergy::license::License &m_license;
-  synergy::gui::TlsUtility m_tlsUtility;
   validators::ValidationError *m_pScreenNameError;
 
   /// @brief Stores settings scope at start of settings dialog
-  /// This is neccessary to restore state if user changes
+  /// This is necessary to restore state if user changes
   /// the scope and doesn't save changes
   bool m_wasOriginallySystemScope = false;
 
-private slots:
-  void on_m_pCheckBoxEnableCrypto_clicked(bool checked);
-  void on_m_pCheckBoxLogToFile_stateChanged(int);
-  void on_m_pButtonBrowseLog_clicked();
-  void on_m_pRadioSystemScope_toggled(bool checked);
-  void on_m_pPushButtonBrowseCert_clicked();
-  void on_m_pComboBoxKeyLength_currentIndexChanged(int index);
-  void on_m_pPushButtonRegenCert_clicked();
+  AppConfig &m_appConfig;
+  const IServerConfig &m_serverConfig;
+  const License &m_license;
+  const CoreProcess &m_coreProcess;
+  synergy::gui::TlsUtility m_tlsUtility;
 };
diff --git a/src/gui/src/validators/ScreenDuplicationsValidator.cpp b/src/gui/src/validators/ScreenDuplicationsValidator.cpp
index 7e9545c1b..168b33518 100644
--- a/src/gui/src/validators/ScreenDuplicationsValidator.cpp
+++ b/src/gui/src/validators/ScreenDuplicationsValidator.cpp
@@ -1,7 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2021 Symless Ltd.
- * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
+ * Copyright (C) 2021 Symless Ltd.
  *
  * This package is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -15,6 +14,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+
 #include "ScreenDuplicationsValidator.h"
 
 namespace validators {
diff --git a/src/gui/src/validators/ScreenDuplicationsValidator.h b/src/gui/src/validators/ScreenDuplicationsValidator.h
index 075048977..d54ce635d 100644
--- a/src/gui/src/validators/ScreenDuplicationsValidator.h
+++ b/src/gui/src/validators/ScreenDuplicationsValidator.h
@@ -1,7 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2021 Symless Ltd.
- * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
+ * Copyright (C) 2021 Symless Ltd.
  *
  * This package is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -15,11 +14,12 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef SCREENDUPLICATIONSVALIDATOR_H
-#define SCREENDUPLICATIONSVALIDATOR_H
+
+#pragma once
 
 #include "IStringValidator.h"
-#include "ScreenList.h"
+
+#include "gui/config/ScreenList.h"
 
 namespace validators {
 
@@ -35,5 +35,3 @@ public:
 };
 
 } // namespace validators
-
-#endif // SCREENDUPLICATIONSVALIDATOR_H
diff --git a/src/gui/src/validators/ScreenNameValidator.cpp b/src/gui/src/validators/ScreenNameValidator.cpp
index 74edf74df..faec86e56 100644
--- a/src/gui/src/validators/ScreenNameValidator.cpp
+++ b/src/gui/src/validators/ScreenNameValidator.cpp
@@ -1,7 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2021 Symless Ltd.
- * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
+ * Copyright (C) 2021 Symless Ltd.
  *
  * This package is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
diff --git a/src/gui/src/validators/ScreenNameValidator.h b/src/gui/src/validators/ScreenNameValidator.h
index 872848106..3afdc0b4d 100644
--- a/src/gui/src/validators/ScreenNameValidator.h
+++ b/src/gui/src/validators/ScreenNameValidator.h
@@ -18,7 +18,7 @@
 #pragma once
 
 #include "LineEditValidator.h"
-#include "ScreenList.h"
+#include "gui/config/ScreenList.h"
 #include "validators/ValidationError.h"
 
 namespace validators {
diff --git a/src/lib/gui/config/AppConfig.cpp b/src/lib/gui/config/AppConfig.cpp
index cede9cce0..7130ba5d4 100644
--- a/src/lib/gui/config/AppConfig.cpp
+++ b/src/lib/gui/config/AppConfig.cpp
@@ -520,7 +520,7 @@ bool AppConfig::useInternalConfig() const { return m_UseInternalConfig; }
 
 bool AppConfig::clientGroupChecked() const { return m_ClientGroupChecked; }
 
-QString AppConfig::serverHostname() const { return m_ServerHostname; }
+const QString &AppConfig::serverHostname() const { return m_ServerHostname; }
 
 void AppConfig::setActivationHasRun(bool value) { m_ActivationHasRun = value; }
 
diff --git a/src/lib/gui/config/AppConfig.h b/src/lib/gui/config/AppConfig.h
index 0e5b158ea..ebe7e9506 100644
--- a/src/lib/gui/config/AppConfig.h
+++ b/src/lib/gui/config/AppConfig.h
@@ -136,10 +136,9 @@ public:
    */
   void commit();
 
-  /**
-   * Getters
-   */
-
+  //
+  // Getters (overrides)
+  //
   ProcessMode processMode() const override;
   ElevateMode elevateMode() const override;
   bool tlsEnabled() const override;
@@ -161,6 +160,12 @@ public:
   bool useExternalConfig() const override;
   const QString &configFile() const override;
   const QString &networkInterface() const override;
+  const QString &serverHostname() const override;
+
+  //
+  // Getters (new methods)
+  //
+
   bool isActiveScopeWritable() const;
   bool isActiveScopeSystem() const;
   int logLevel() const;
@@ -172,7 +177,6 @@ public:
   bool serverGroupChecked() const;
   bool useInternalConfig() const;
   bool clientGroupChecked() const;
-  QString serverHostname() const;
   QString lastVersion() const;
   bool enableService() const;
   bool closeToTray() const;
@@ -182,9 +186,9 @@ public:
   bool showDevThanks() const;
   bool showCloseReminder() const;
 
-  /**
-   * Setters
-   */
+  //
+  // Setters
+  //
 
   void setActivationHasRun(bool value);
   void setScreenName(const QString &s);
diff --git a/src/lib/gui/config/ConfigScopes.cpp b/src/lib/gui/config/ConfigScopes.cpp
index 121d5ea9b..facfb06cd 100644
--- a/src/lib/gui/config/ConfigScopes.cpp
+++ b/src/lib/gui/config/ConfigScopes.cpp
@@ -30,6 +30,8 @@ const auto kUnixSystemConfigPath = "/usr/local/etc/symless/";
 
 namespace synergy::gui {
 
+using namespace proxy;
+
 QString getSystemSettingPath() {
   const QString settingFilename(kSystemConfigFilename);
 #if defined(Q_OS_WIN)
@@ -92,6 +94,7 @@ ConfigScopes::ConfigScopes() {
   // if we set the scope specifically then we also have to set the application
   // name and the organisation name which breaks backwards compatibility.
   m_pUserSettings = std::make_unique<QSettings>();
+  m_userSettingsProxy.set(*m_pUserSettings);
 
   qDebug() << "user settings path:" << m_pUserSettings->fileName();
 
@@ -104,6 +107,7 @@ ConfigScopes::ConfigScopes() {
   m_pSystemSettings = std::make_unique<QSettings>(
       QSettings::Format::IniFormat, QSettings::Scope::SystemScope, orgName,
       appName);
+  m_systemSettingsProxy.set(*m_pSystemSettings);
 
   qDebug() << "system settings path:" << m_pSystemSettings->fileName();
 
@@ -124,7 +128,7 @@ void ConfigScopes::save() {
 }
 
 bool ConfigScopes::isActiveScopeWritable() const {
-  return activeSettings()->isWritable();
+  return activeSettings().isWritable();
 }
 
 void ConfigScopes::setActiveScope(ConfigScopes::Scope scope) {
@@ -140,15 +144,23 @@ bool ConfigScopes::scopeContains(const QString &name, Scope scope) const {
   case Scope::System:
     return m_pSystemSettings->contains(name);
   default:
-    return activeSettings()->contains(name);
+    return activeSettings().contains(name);
   }
 }
 
-QSettings *ConfigScopes::activeSettings() const {
+QSettingsProxy &ConfigScopes::activeSettings() {
   if (m_currentScope == Scope::User) {
-    return m_pUserSettings.get();
+    return m_userSettingsProxy;
   } else {
-    return m_pSystemSettings.get();
+    return m_systemSettingsProxy;
+  }
+}
+
+const QSettingsProxy &ConfigScopes::activeSettings() const {
+  if (m_currentScope == Scope::User) {
+    return m_userSettingsProxy;
+  } else {
+    return m_systemSettingsProxy;
   }
 }
 
@@ -160,7 +172,7 @@ QVariant ConfigScopes::getFromScope(
   case Scope::System:
     return m_pSystemSettings->value(name, defaultValue);
   default:
-    return activeSettings()->value(name, defaultValue);
+    return activeSettings().value(name, defaultValue);
   }
 }
 
@@ -174,7 +186,7 @@ void ConfigScopes::setInScope(
     m_pSystemSettings->setValue(name, value);
     break;
   default:
-    activeSettings()->setValue(name, value);
+    activeSettings().setValue(name, value);
     break;
   }
 }
diff --git a/src/lib/gui/config/ConfigScopes.h b/src/lib/gui/config/ConfigScopes.h
index 00c5db925..85668a0b2 100644
--- a/src/lib/gui/config/ConfigScopes.h
+++ b/src/lib/gui/config/ConfigScopes.h
@@ -28,6 +28,8 @@ namespace synergy::gui {
 
 /// @brief Encapsulates Qt config for both user and global scopes.
 class ConfigScopes : public QObject, public IConfigScopes {
+  using QSettingsProxy = synergy::gui::proxy::QSettingsProxy;
+
   Q_OBJECT
 
 public:
@@ -47,7 +49,8 @@ public:
       Scope scope = Scope::Current) const override;
   void setActiveScope(Scope scope = Scope::User) override;
   Scope activeScope() const override;
-  QSettings *activeSettings() const override;
+  QSettingsProxy &activeSettings() override;
+  const QSettingsProxy &activeSettings() const override;
 
 signals:
   void ready();
@@ -57,6 +60,8 @@ private:
   Scope m_currentScope = Scope::User;
   std::unique_ptr<QSettings> m_pUserSettings;
   std::unique_ptr<QSettings> m_pSystemSettings;
+  QSettingsProxy m_userSettingsProxy;
+  QSettingsProxy m_systemSettingsProxy;
 };
 
 } // namespace synergy::gui
diff --git a/src/lib/gui/config/IAppConfig.h b/src/lib/gui/config/IAppConfig.h
index bd958da20..460c25b9a 100644
--- a/src/lib/gui/config/IAppConfig.h
+++ b/src/lib/gui/config/IAppConfig.h
@@ -49,6 +49,7 @@ public:
   virtual bool useExternalConfig() const = 0;
   virtual const QString &configFile() const = 0;
   virtual const QString &networkInterface() const = 0;
+  virtual const QString &serverHostname() const = 0;
 };
 
 } // namespace synergy::gui
diff --git a/src/lib/gui/config/IConfigScopes.h b/src/lib/gui/config/IConfigScopes.h
index 4d78bf941..a6b9e409b 100644
--- a/src/lib/gui/config/IConfigScopes.h
+++ b/src/lib/gui/config/IConfigScopes.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#include "gui/proxy/QSettingsProxy.h"
+
 #include <QSettings>
 #include <QString>
 #include <QVariant>
@@ -24,6 +26,8 @@
 namespace synergy::gui {
 
 class IConfigScopes {
+  using QSettingsProxy = synergy::gui::proxy::QSettingsProxy;
+
 public:
   enum class Scope { Current, System, User };
 
@@ -32,7 +36,8 @@ public:
   virtual Scope activeScope() const = 0;
   virtual void setActiveScope(Scope scope = Scope::User) = 0;
   virtual bool isActiveScopeWritable() const = 0;
-  virtual QSettings *activeSettings() const = 0;
+  virtual QSettingsProxy &activeSettings() = 0;
+  virtual const QSettingsProxy &activeSettings() const = 0;
 
   /**
    * @brief Signals to listeners that the settings that they should read.
@@ -40,7 +45,7 @@ public:
   virtual void signalReady() = 0;
 
   /**
-   * @brief Signalls to listeners to save and calls `sync` on underlying Qt
+   * @brief Signals to listeners to save and calls `sync` on underlying Qt
    * config.
    *
    */
diff --git a/src/lib/gui/config/IServerConfig.h b/src/lib/gui/config/IServerConfig.h
index 313dda7f9..1114c97d3 100644
--- a/src/lib/gui/config/IServerConfig.h
+++ b/src/lib/gui/config/IServerConfig.h
@@ -20,6 +20,8 @@
 #include <QFile>
 #include <QString>
 
+#include "ScreenList.h"
+
 namespace synergy::gui {
 
 class IServerConfig {
@@ -30,6 +32,7 @@ public:
   virtual bool save(const QString &fileName) const = 0;
   virtual void save(QFile &file) const = 0;
   virtual bool enableDragAndDrop() const = 0;
+  virtual const ScreenList &screens() const = 0;
 };
 
 } // namespace synergy::gui
diff --git a/src/gui/src/Screen.cpp b/src/lib/gui/config/Screen.cpp
similarity index 73%
rename from src/gui/src/Screen.cpp
rename to src/lib/gui/config/Screen.cpp
index bb5f0c688..1ebde0ad3 100644
--- a/src/gui/src/Screen.cpp
+++ b/src/lib/gui/config/Screen.cpp
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -17,19 +17,19 @@
  */
 
 #include "Screen.h"
+#include "config/ScreenConfig.h"
 
 #include <QtCore>
 #include <QtGui>
 
-Screen::Screen()
-    : m_Pixmap(QPixmap(":res/icons/64x64/video-display.png")),
-      m_Swapped(false) {
-  init();
-}
+using namespace synergy::gui::proxy;
+using enum ScreenConfig::Modifier;
+using enum ScreenConfig::SwitchCorner;
+using enum ScreenConfig::Fix;
 
-Screen::Screen(const QString &name)
-    : m_Pixmap(QPixmap(":res/icons/64x64/video-display.png")),
-      m_Swapped(false) {
+Screen::Screen() { init(); }
+
+Screen::Screen(const QString &name) {
   init();
   setName(name);
 }
@@ -45,17 +45,17 @@ void Screen::init() {
   // m_Modifiers, m_SwitchCorners and m_Fixes are QLists we use like fixed-size
   // arrays, thus we need to make sure to fill them with the required number of
   // elements.
-  for (int i = 0; i < NumModifiers; i++)
+  for (int i = 0; i < static_cast<int>(NumModifiers); i++)
     modifiers() << i;
 
-  for (int i = 0; i < NumSwitchCorners; i++)
+  for (int i = 0; i < static_cast<int>(NumSwitchCorners); i++)
     switchCorners() << false;
 
-  for (int i = 0; i < NumFixes; i++)
+  for (int i = 0; i < static_cast<int>(NumFixes); i++)
     fixes() << false;
 }
 
-void Screen::loadSettings(QSettings &settings) {
+void Screen::loadSettings(QSettingsProxy &settings) {
   setName(settings.value("name").toString());
 
   if (name().isEmpty())
@@ -66,13 +66,14 @@ void Screen::loadSettings(QSettings &settings) {
   readSettings(settings, aliases(), "alias", QString(""));
   readSettings(
       settings, modifiers(), "modifier", static_cast<int>(DefaultMod),
-      NumModifiers);
+      static_cast<int>(NumModifiers));
   readSettings(
-      settings, switchCorners(), "switchCorner", false, NumSwitchCorners);
-  readSettings(settings, fixes(), "fix", false, NumFixes);
+      settings, switchCorners(), "switchCorner", 0,
+      static_cast<int>(NumSwitchCorners));
+  readSettings(settings, fixes(), "fix", 0, static_cast<int>(NumFixes));
 }
 
-void Screen::saveSettings(QSettings &settings) const {
+void Screen::saveSettings(QSettingsProxy &settings) const {
   settings.setValue("name", name());
 
   if (name().isEmpty())
@@ -130,16 +131,3 @@ bool Screen::operator==(const Screen &screen) const {
          m_Fixes == screen.m_Fixes && m_Swapped == screen.m_Swapped &&
          m_isServer == screen.m_isServer;
 }
-
-QDataStream &operator<<(QDataStream &outStream, const Screen &screen) {
-  return outStream << screen.name() << screen.switchCornerSize()
-                   << screen.aliases() << screen.modifiers()
-                   << screen.switchCorners() << screen.fixes()
-                   << screen.isServer();
-}
-
-QDataStream &operator>>(QDataStream &inStream, Screen &screen) {
-  return inStream >> screen.m_Name >> screen.m_SwitchCornerSize >>
-         screen.m_Aliases >> screen.m_Modifiers >> screen.m_SwitchCorners >>
-         screen.m_Fixes >> screen.m_isServer;
-}
diff --git a/src/gui/src/Screen.h b/src/lib/gui/config/Screen.h
similarity index 72%
rename from src/gui/src/Screen.h
rename to src/lib/gui/config/Screen.h
index 4b2253506..eee8e7fda 100644
--- a/src/gui/src/Screen.h
+++ b/src/lib/gui/config/Screen.h
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
@@ -20,6 +20,8 @@
 
 #include "ScreenConfig.h"
 
+#include "gui/proxy/QSettingsProxy.h"
+
 #include <QList>
 #include <QPixmap>
 #include <QString>
@@ -30,34 +32,49 @@ class QTextStream;
 class ScreenSettingsDialog;
 
 class Screen : public ScreenConfig {
-  friend QDataStream &operator<<(QDataStream &outStream, const Screen &screen);
-  friend QDataStream &operator>>(QDataStream &inStream, Screen &screen);
+  using QSettingsProxy = synergy::gui::proxy::QSettingsProxy;
+
   friend class ScreenSettingsDialog;
   friend class ScreenSetupModel;
   friend class ScreenSetupView;
 
-public:
-  Screen();
-  Screen(const QString &name);
+  friend QDataStream &operator<<(QDataStream &outStream, const Screen &screen) {
+    return outStream << screen.name() << screen.switchCornerSize()
+                     << screen.aliases() << screen.modifiers()
+                     << screen.switchCorners() << screen.fixes()
+                     << screen.isServer();
+  }
+
+  friend QDataStream &operator>>(QDataStream &inStream, Screen &screen) {
+    return inStream >> screen.m_Name >> screen.m_SwitchCornerSize >>
+           screen.m_Aliases >> screen.m_Modifiers >> screen.m_SwitchCorners >>
+           screen.m_Fixes >> screen.m_isServer;
+  }
 
 public:
+  explicit Screen();
+  explicit Screen(const QString &name);
+
   const QPixmap &pixmap() const { return m_Pixmap; }
   const QString &name() const { return m_Name; }
   const QStringList &aliases() const { return m_Aliases; }
 
   bool isNull() const { return m_Name.isEmpty(); }
   int modifier(int m) const {
-    return m_Modifiers[m] == DefaultMod ? m : m_Modifiers[m];
+    return m_Modifiers[m] ==
+                   static_cast<int>(ScreenConfig::Modifier::DefaultMod)
+               ? m
+               : m_Modifiers[m];
   }
   const QList<int> &modifiers() const { return m_Modifiers; }
   bool switchCorner(int c) const { return m_SwitchCorners[c]; }
   const QList<bool> &switchCorners() const { return m_SwitchCorners; }
   int switchCornerSize() const { return m_SwitchCornerSize; }
-  bool fix(Fix f) const { return m_Fixes[f]; }
+  bool fix(Fix f) const { return m_Fixes[static_cast<int>(f)]; }
   const QList<bool> &fixes() const { return m_Fixes; }
 
-  void loadSettings(QSettings &settings);
-  void saveSettings(QSettings &settings) const;
+  void loadSettings(QSettingsProxy &settings);
+  void saveSettings(QSettingsProxy &settings) const;
   QTextStream &writeScreensSection(QTextStream &outStream) const;
   QTextStream &writeAliasesSection(QTextStream &outStream) const;
 
@@ -84,18 +101,13 @@ protected:
   void setSwapped(bool on) { m_Swapped = on; }
 
 private:
-  QPixmap m_Pixmap;
+  QPixmap m_Pixmap = QPixmap(":res/icons/64x64/video-display.png");
   QString m_Name;
-
   QStringList m_Aliases;
   QList<int> m_Modifiers;
   QList<bool> m_SwitchCorners;
   int m_SwitchCornerSize;
   QList<bool> m_Fixes;
-
-  bool m_Swapped;
+  bool m_Swapped = false;
   bool m_isServer = false;
 };
-
-QDataStream &operator<<(QDataStream &outStream, const Screen &screen);
-QDataStream &operator>>(QDataStream &inStream, Screen &screen);
diff --git a/src/gui/src/ScreenConfig.cpp b/src/lib/gui/config/ScreenConfig.cpp
similarity index 96%
rename from src/gui/src/ScreenConfig.cpp
rename to src/lib/gui/config/ScreenConfig.cpp
index 55042a76f..697b70ba7 100644
--- a/src/gui/src/ScreenConfig.cpp
+++ b/src/lib/gui/config/ScreenConfig.cpp
@@ -1,6 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2012 Symless Ltd.
  * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
  *
  * This package is free software; you can redistribute it and/or
diff --git a/src/gui/src/ScreenConfig.h b/src/lib/gui/config/ScreenConfig.h
similarity index 78%
rename from src/gui/src/ScreenConfig.h
rename to src/lib/gui/config/ScreenConfig.h
index 61e78b037..c4e5aa5f8 100644
--- a/src/gui/src/ScreenConfig.h
+++ b/src/lib/gui/config/ScreenConfig.h
@@ -18,14 +18,17 @@
 
 #pragma once
 
-#include <QSettings>
 #include <QString>
 #include <QVariant>
 
+#include "gui/proxy/QSettingsProxy.h"
+
 /// @brief Screen configuration base class
 class ScreenConfig {
+  using QSettingsProxy = synergy::gui::proxy::QSettingsProxy;
+
 public:
-  enum Modifier {
+  enum class Modifier {
     DefaultMod = -1,
     Shift,
     Ctrl,
@@ -35,29 +38,28 @@ public:
     None,
     NumModifiers
   };
-  enum SwitchCorner {
+  enum class SwitchCorner {
     TopLeft,
     TopRight,
     BottomLeft,
     BottomRight,
     NumSwitchCorners
   };
-  enum Fix { CapsLock, NumLock, ScrollLock, XTest, NumFixes };
+  enum class Fix { CapsLock, NumLock, ScrollLock, XTest, NumFixes };
 
 protected:
   explicit ScreenConfig() = default;
   ~ScreenConfig() = default;
 
-protected:
   template <typename T1, typename T2>
   void readSettings(
-      QSettings &settings, T1 &array, const QString &arrayName,
-      const T2 &deflt) {
+      QSettingsProxy &settings, T1 &array, const QString &arrayName,
+      const T2 &defaultValue) {
     int entries = settings.beginReadArray(arrayName + "Array");
     array.clear();
     for (int i = 0; i < entries; i++) {
       settings.setArrayIndex(i);
-      QVariant v = settings.value(arrayName, deflt);
+      QVariant v = settings.value(arrayName, defaultValue);
       array.append(v.value<T2>());
     }
     settings.endArray();
@@ -65,13 +67,13 @@ protected:
 
   template <typename T1, typename T2>
   void readSettings(
-      QSettings &settings, T1 &array, const QString &arrayName, const T2 &deflt,
-      int entries) {
+      QSettingsProxy &settings, T1 &array, const QString &arrayName,
+      const T2 &defaultValue, int entries) {
     Q_ASSERT(array.size() >= entries);
     settings.beginReadArray(arrayName + "Array");
     for (int i = 0; i < entries; i++) {
       settings.setArrayIndex(i);
-      QVariant v = settings.value(arrayName, deflt);
+      QVariant v = settings.value(arrayName, defaultValue);
       array[i] = v.value<T2>();
     }
     settings.endArray();
@@ -79,7 +81,8 @@ protected:
 
   template <typename T>
   void writeSettings(
-      QSettings &settings, const T &array, const QString &arrayName) const {
+      QSettingsProxy &settings, const T &array,
+      const QString &arrayName) const {
     settings.beginWriteArray(arrayName + "Array");
     for (int i = 0; i < array.size(); i++) {
       settings.setArrayIndex(i);
diff --git a/src/gui/src/ScreenList.cpp b/src/lib/gui/config/ScreenList.cpp
similarity index 97%
rename from src/gui/src/ScreenList.cpp
rename to src/lib/gui/config/ScreenList.cpp
index e269c03a6..c06624ebb 100644
--- a/src/gui/src/ScreenList.cpp
+++ b/src/lib/gui/config/ScreenList.cpp
@@ -90,7 +90,8 @@ ScreenList::ScreenList(int width) : QList<Screen>(), m_width(width) {}
 
 void ScreenList::addScreenByPriority(const Screen &newScreen) {
   int serverIndex = getServerIndex(*this);
-  auto indexes = getNeighborsIndexes(serverIndex, m_width, size());
+  auto indexes =
+      getNeighborsIndexes(serverIndex, m_width, static_cast<int>(size()));
 
   bool isAdded = false;
   for (const auto &index : indexes) {
diff --git a/src/gui/src/ScreenList.h b/src/lib/gui/config/ScreenList.h
similarity index 90%
rename from src/gui/src/ScreenList.h
rename to src/lib/gui/config/ScreenList.h
index f2c247b56..c8bd89fcc 100644
--- a/src/gui/src/ScreenList.h
+++ b/src/lib/gui/config/ScreenList.h
@@ -1,7 +1,6 @@
 /*
  * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2012-2021 Symless Ltd.
- * Copyright (C) 2008 Volker Lanz (vl@fidra.de)
+ * Copyright (C) 2021 Symless Ltd.
  *
  * This package is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -15,8 +14,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef SCREENLIST_H
-#define SCREENLIST_H
+
+#pragma once
 
 #include "Screen.h"
 
@@ -51,5 +50,3 @@ public:
    */
   bool operator==(const ScreenList &sc) const;
 };
-
-#endif // SCREENLIST_H
diff --git a/src/lib/gui/core/ClientConnection.cpp b/src/lib/gui/core/ClientConnection.cpp
index 43fb09d5b..050227297 100644
--- a/src/lib/gui/core/ClientConnection.cpp
+++ b/src/lib/gui/core/ClientConnection.cpp
@@ -17,71 +17,67 @@
 
 #include "ClientConnection.h"
 
+#include "messages.h"
+
 #include <QHostAddress>
 #include <QMessageBox>
 
 namespace synergy::gui {
 
-ClientConnection::ClientConnection(QWidget &parent, AppConfig &appConfig)
-    : m_parent(parent),
-      m_appConfig(appConfig) {}
+//
+// ClientConnection::Deps
+//
 
-void ClientConnection::update(const QString &line) {
-  if (m_checkConnection && checkMainWindow()) {
-    if (line.contains("failed to connect to server")) {
-      m_checkConnection = false;
-      if (!line.contains("server refused client with our name") &&
-          !line.contains("Trying next address")) {
-        showMessage(getMessage(line));
-      }
-    } else if (line.contains("connected to server")) {
-      m_checkConnection = false;
+void ClientConnection::Deps::showError(
+    QWidget *parent, messages::ClientError error,
+    const QString &address) const {
+  messages::showClientConnectError(parent, error, address);
+}
+
+//
+// ClientConnection
+//
+
+void ClientConnection::handleLogLine(const QString &logLine) {
+  if (!m_showMessage) {
+    qDebug("message already shown, skipping");
+    return;
+  }
+
+  if (logLine.contains("failed to connect to server")) {
+    m_showMessage = false;
+
+    // ignore the message if it's about the server refusing by name as
+    // this will trigger the server to show an 'add client' dialog.
+    if (logLine.contains("server refused client with our name")) {
+      qDebug("ignoring client name refused message");
+      return;
     }
+
+    showMessage(logLine);
+  } else if (logLine.contains("connected to server")) {
+    m_showMessage = false;
   }
 }
 
-bool ClientConnection::checkMainWindow() {
-  bool result = m_parent.isActiveWindow();
+void ClientConnection::showMessage(const QString &logLine) {
+  using enum messages::ClientError;
 
-  if (m_parent.isMinimized() || m_parent.isHidden()) {
-    m_parent.showNormal();
-    m_parent.activateWindow();
-    result = true;
-  }
+  emit messageShowing();
 
-  return result;
-}
+  const auto address = m_appConfig.serverHostname();
+  auto message =
+      QString("<p>The connection to server '%1' didn't work.</p>").arg(address);
 
-QString ClientConnection::getMessage(const QString &line) const {
-  QString message(QObject::tr("Connection failed.\nCheck the IP address on the "
-                              "server, your TLS and firewall settings."));
-
-  if (line.contains("server already has a connected client with our name")) {
-    message =
-        QObject::tr("Connection failed.\nYou can’t name 2 computers the same.");
+  if (logLine.contains("server already has a connected client with our name")) {
+    m_deps->showError(m_pParent, AlreadyConnected, address);
+  } else if (QHostAddress a(address); a.isNull()) {
+    qDebug("ip not detected, showing hostname error");
+    m_deps->showError(m_pParent, HostnameError, address);
   } else {
-    QHostAddress address(m_appConfig.serverHostname());
-    if (address.isNull()) {
-      message =
-          QObject::tr(
-              "We can’t connect to the server \"%1\" try to connect using the "
-              "server IP address and check your firewall settings.")
-              .arg(m_appConfig.serverHostname());
-    }
+    qDebug("ip detected, showing generic error");
+    m_deps->showError(m_pParent, GenericError, address);
   }
-
-  return message;
-}
-
-void ClientConnection::showMessage(const QString &message) const {
-  QMessageBox dialog(&m_parent);
-  dialog.addButton(QObject::tr("Close"), QMessageBox::RejectRole);
-  dialog.setText(message);
-  dialog.exec();
-}
-
-void ClientConnection::setCheckConnection(bool checkConnection) {
-  m_checkConnection = checkConnection;
 }
 
 } // namespace synergy::gui
diff --git a/src/lib/gui/core/ClientConnection.h b/src/lib/gui/core/ClientConnection.h
index 5c64ce6f3..8b7d31946 100644
--- a/src/lib/gui/core/ClientConnection.h
+++ b/src/lib/gui/core/ClientConnection.h
@@ -17,27 +17,50 @@
 
 #pragma once
 
-#include "gui/config/AppConfig.h"
+#include "gui/config/IAppConfig.h"
 
+#include "gui/messages.h"
+
+#include <QObject>
 #include <QString>
 #include <QWidget>
+#include <memory>
+
+class QWidget;
 
 namespace synergy::gui {
 
-class ClientConnection {
+class ClientConnection : public QObject {
+  Q_OBJECT
+
 public:
-  explicit ClientConnection(QWidget &parent, AppConfig &appConfig);
-  void update(const QString &line);
-  void setCheckConnection(bool checkConnection);
+  struct Deps {
+    virtual ~Deps() = default;
+    virtual void showError(
+        QWidget *parent, messages::ClientError error,
+        const QString &address) const;
+  };
+
+  explicit ClientConnection(
+      QWidget *parent, IAppConfig &appConfig,
+      std::shared_ptr<Deps> deps = std::make_shared<Deps>())
+      : m_pParent(parent),
+        m_appConfig(appConfig),
+        m_deps(deps) {}
+
+  void handleLogLine(const QString &line);
+  void setShowMessage() { m_showMessage = true; }
+
+signals:
+  void messageShowing();
 
 private:
-  QString getMessage(const QString &line) const;
-  bool checkMainWindow();
-  void showMessage(const QString &message) const;
+  void showMessage(const QString &logLine);
 
-  QWidget &m_parent;
-  AppConfig &m_appConfig;
-  bool m_checkConnection = false;
+  QWidget *m_pParent;
+  IAppConfig &m_appConfig;
+  std::shared_ptr<Deps> m_deps;
+  bool m_showMessage = true;
 };
 
 } // namespace synergy::gui
diff --git a/src/lib/gui/core/ServerConnection.cpp b/src/lib/gui/core/ServerConnection.cpp
index 3f23e1b61..bc489f17a 100644
--- a/src/lib/gui/core/ServerConnection.cpp
+++ b/src/lib/gui/core/ServerConnection.cpp
@@ -18,42 +18,46 @@
 #include "ServerConnection.h"
 
 #include "ServerMessage.h"
-#include "gui/config/AppConfig.h"
+#include "messages.h"
 
 #include <QMessageBox>
 #include <QPushButton>
 
 namespace synergy::gui {
 
-ServerConnection::ServerConnection(
-    QWidget &parent, AppConfig &appConfig, IServerConfig &serverConfig)
-    : m_parent(parent),
-      m_appConfig(appConfig),
-      m_serverConfig(serverConfig) {}
+//
+// ServerConnection::Deps
+//
 
-void ServerConnection::update(const QString &line) {
-  ServerMessage message(line);
+messages::NewClientPromptResult ServerConnection::Deps::showNewClientPrompt(
+    QWidget *parent, const QString &clientName) const {
+  return messages::showNewClientPrompt(parent, clientName);
+}
+
+//
+// ServerConnection
+//
+
+ServerConnection::ServerConnection(
+    QWidget *parent, IAppConfig &appConfig, IServerConfig &serverConfig,
+    std::shared_ptr<Deps> deps)
+    : m_pParent(parent),
+      m_appConfig(appConfig),
+      m_serverConfig(serverConfig),
+      m_pDeps(deps) {}
+
+void ServerConnection::handleLogLine(const QString &logLine) {
+  ServerMessage message(logLine);
 
   if (!m_appConfig.useExternalConfig() && message.isNewClientMessage() &&
       !m_ignoredClients.contains(message.getClientName())) {
-    addClient(message.getClientName());
+    handleNewClient(message.getClientName());
   }
 }
 
-// TOOD: merge duplicated code between client and server connection
-bool ServerConnection::checkMainWindow() {
-  bool result = m_parent.isActiveWindow();
+void ServerConnection::handleNewClient(const QString &clientName) {
+  using enum messages::NewClientPromptResult;
 
-  if (m_parent.isMinimized() || m_parent.isHidden()) {
-    m_parent.showNormal();
-    m_parent.activateWindow();
-    result = true;
-  }
-
-  return result;
-}
-
-void ServerConnection::addClient(const QString &clientName) {
   if (m_serverConfig.isFull()) {
     qDebug(
         "server config full, skipping add client prompt for: %s",
@@ -68,30 +72,17 @@ void ServerConnection::addClient(const QString &clientName) {
     return;
   }
 
-  if (!checkMainWindow()) {
-    qDebug(
-        "main window not active, skipping add client prompt for: %s",
-        qPrintable(clientName));
-    return;
-  }
+  emit messageShowing();
 
-  QMessageBox message(&m_parent);
-  const QPushButton *ignore =
-      message.addButton("Ignore", QMessageBox::RejectRole);
-  const QPushButton *add =
-      message.addButton("Add client", QMessageBox::AcceptRole);
-  message.setText(
-      QString("A new client called '%1' wants to connect").arg(clientName));
-  message.exec();
-
-  if (message.clickedButton() == add) {
+  const auto result = m_pDeps->showNewClientPrompt(m_pParent, clientName);
+  if (result == Add) {
     qDebug("accepted dialog, adding client: %s", qPrintable(clientName));
     emit configureClient(clientName);
-  } else if (message.clickedButton() == ignore) {
+  } else if (result == Ignore) {
     qDebug("declined dialog, ignoring client: %s", qPrintable(clientName));
     m_ignoredClients.append(clientName);
   } else {
-    qFatal("no expected dialog button was clicked");
+    qFatal("unexpected add client result");
   }
 }
 
diff --git a/src/lib/gui/core/ServerConnection.h b/src/lib/gui/core/ServerConnection.h
index 312acab5e..5351b7e6d 100644
--- a/src/lib/gui/core/ServerConnection.h
+++ b/src/lib/gui/core/ServerConnection.h
@@ -20,8 +20,9 @@
 #include <QString>
 #include <QStringList>
 
-#include "gui/config/AppConfig.h"
+#include "gui/config/IAppConfig.h"
 #include "gui/config/IServerConfig.h"
+#include "gui/messages.h"
 
 namespace synergy::gui {
 
@@ -30,20 +31,28 @@ class ServerConnection : public QObject {
   using IServerConfig = synergy::gui::IServerConfig;
 
 public:
+  struct Deps {
+    virtual ~Deps() = default;
+    virtual messages::NewClientPromptResult
+    showNewClientPrompt(QWidget *parent, const QString &clientName) const;
+  };
+
   explicit ServerConnection(
-      QWidget &parent, AppConfig &appConfig, IServerConfig &serverConfig);
-  void update(const QString &line);
+      QWidget *parent, IAppConfig &appConfig, IServerConfig &serverConfig,
+      std::shared_ptr<Deps> deps = std::make_shared<Deps>());
+  void handleLogLine(const QString &logLine);
 
 signals:
+  void messageShowing();
   void configureClient(const QString &clientName);
 
 private:
-  void addClient(const QString &clientName);
-  bool checkMainWindow();
+  void handleNewClient(const QString &clientName);
 
-  QWidget &m_parent;
-  AppConfig &m_appConfig;
+  QWidget *m_pParent;
+  IAppConfig &m_appConfig;
   IServerConfig &m_serverConfig;
+  std::shared_ptr<Deps> m_pDeps;
   QStringList m_ignoredClients;
 };
 
diff --git a/src/lib/gui/core/ServerMessage.cpp b/src/lib/gui/core/ServerMessage.cpp
index c8124534f..48e930121 100644
--- a/src/lib/gui/core/ServerMessage.cpp
+++ b/src/lib/gui/core/ServerMessage.cpp
@@ -21,7 +21,7 @@ namespace synergy::gui {
 
 ServerMessage::ServerMessage(const QString &message)
     : m_message(message),
-      m_clienName(parseClientName(message)) {}
+      m_clientName(parseClientName(message)) {}
 
 bool ServerMessage::isNewClientMessage() const {
   return m_message.contains("unrecognised client name");
@@ -39,7 +39,7 @@ bool ServerMessage::isDisconnectedMessage() const {
   return m_message.contains("has disconnected");
 }
 
-const QString &ServerMessage::getClientName() const { return m_clienName; }
+const QString &ServerMessage::getClientName() const { return m_clientName; }
 
 QString ServerMessage::parseClientName(const QString &line) const {
   QString clientName("Unknown");
diff --git a/src/lib/gui/core/ServerMessage.h b/src/lib/gui/core/ServerMessage.h
index 557179161..5ced6a079 100644
--- a/src/lib/gui/core/ServerMessage.h
+++ b/src/lib/gui/core/ServerMessage.h
@@ -23,7 +23,7 @@ namespace synergy::gui {
 
 class ServerMessage {
   QString m_message;
-  QString m_clienName;
+  QString m_clientName;
 
 public:
   explicit ServerMessage(const QString &message);
diff --git a/src/lib/gui/messages.cpp b/src/lib/gui/messages.cpp
index 0afe54487..e97d87890 100644
--- a/src/lib/gui/messages.cpp
+++ b/src/lib/gui/messages.cpp
@@ -25,6 +25,7 @@
 #include <QDateTime>
 #include <QDir>
 #include <QMessageBox>
+#include <QPushButton>
 #include <QTime>
 #include <memory>
 
@@ -181,4 +182,59 @@ void showDevThanks(QWidget *parent, const QString &productName) {
               kColorSecondary));
 }
 
+void showClientConnectError(
+    QWidget *parent, ClientError error, const QString &address) {
+  using enum ClientError;
+
+  auto message =
+      QString("<p>The connection to server '%1' didn't work.</p>").arg(address);
+
+  if (error == AlreadyConnected) {
+    message += //
+        "<p>Two of your client computers have the same name or there are "
+        "two instances of the client process running.</p>"
+        "<p>Please ensure that you're using a unique name and that only a "
+        "single client process is running.</p>";
+  } else if (error == HostnameError) {
+    message += //
+        "<p>Please try to connect to the server using the server IP address "
+        "instead of the hostname. </p>"
+        "<p>If that doesn't work, please check your TLS and "
+        "firewall settings.</p>";
+  } else if (error == GenericError) {
+    message += //
+        "<p>Please check your TLS and firewall settings.</p>";
+  } else {
+    qFatal("unknown client error");
+  }
+
+  QMessageBox dialog(parent);
+  dialog.addButton(QObject::tr("Close"), QMessageBox::RejectRole);
+  dialog.setText(message);
+  dialog.exec();
+}
+
+NewClientPromptResult
+showNewClientPrompt(QWidget *parent, const QString &clientName) {
+  using enum NewClientPromptResult;
+
+  QMessageBox message(parent);
+  const QPushButton *ignore =
+      message.addButton("Ignore", QMessageBox::RejectRole);
+  const QPushButton *add =
+      message.addButton("Add client", QMessageBox::AcceptRole);
+  message.setText(
+      QString("A new client called '%1' wants to connect").arg(clientName));
+  message.exec();
+
+  if (message.clickedButton() == add) {
+    return Add;
+  } else if (message.clickedButton() == ignore) {
+    return Ignore;
+  } else {
+    qFatal("no expected dialog button was clicked");
+    abort();
+  }
+}
+
 } // namespace synergy::gui::messages
diff --git a/src/lib/gui/messages.h b/src/lib/gui/messages.h
index 5926a9c37..239f8c197 100644
--- a/src/lib/gui/messages.h
+++ b/src/lib/gui/messages.h
@@ -19,10 +19,15 @@
 
 #include <QMessageLogContext>
 #include <QString>
-#include <QWidget>
+
+class QWidget;
 
 namespace synergy::gui::messages {
 
+enum class ClientError { AlreadyConnected, HostnameError, GenericError };
+
+enum class NewClientPromptResult { Add, Ignore };
+
 void messageHandler(
     QtMsgType type, const QMessageLogContext &context, const QString &msg);
 
@@ -33,4 +38,10 @@ void showCloseReminder(QWidget *parent);
 
 void showDevThanks(QWidget *parent, const QString &productName);
 
+void showClientConnectError(
+    QWidget *parent, ClientError error, const QString &address);
+
+NewClientPromptResult
+showNewClientPrompt(QWidget *parent, const QString &clientName);
+
 } // namespace synergy::gui::messages
diff --git a/src/lib/gui/proxy/QSettingsProxy.cpp b/src/lib/gui/proxy/QSettingsProxy.cpp
new file mode 100644
index 000000000..7e4fdeebd
--- /dev/null
+++ b/src/lib/gui/proxy/QSettingsProxy.cpp
@@ -0,0 +1,61 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2024 Symless Ltd.
+ *
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ *
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "QSettingsProxy.h"
+
+namespace synergy::gui::proxy {
+
+int QSettingsProxy::beginReadArray(const QString &prefix) {
+  return m_pSettings->beginReadArray(prefix);
+}
+
+void QSettingsProxy::setArrayIndex(int i) { m_pSettings->setArrayIndex(i); }
+
+QVariant QSettingsProxy::value(const QString &key) const {
+  return m_pSettings->value(key);
+}
+
+QVariant
+QSettingsProxy::value(const QString &key, const QVariant &defaultValue) const {
+  return m_pSettings->value(key, defaultValue);
+}
+
+void QSettingsProxy::endArray() { m_pSettings->endArray(); }
+
+void QSettingsProxy::beginWriteArray(const QString &prefix) {
+  m_pSettings->beginWriteArray(prefix);
+}
+
+void QSettingsProxy::setValue(const QString &key, const QVariant &value) {
+  m_pSettings->setValue(key, value);
+}
+
+void QSettingsProxy::beginGroup(const QString &prefix) {
+  m_pSettings->beginGroup(prefix);
+}
+
+void QSettingsProxy::remove(const QString &key) { m_pSettings->remove(key); }
+
+void QSettingsProxy::endGroup() { m_pSettings->endGroup(); }
+
+bool QSettingsProxy::isWritable() const { return m_pSettings->isWritable(); }
+
+bool QSettingsProxy::contains(const QString &key) const {
+  return m_pSettings->contains(key);
+}
+
+} // namespace synergy::gui::proxy
diff --git a/src/lib/gui/proxy/QSettingsProxy.h b/src/lib/gui/proxy/QSettingsProxy.h
new file mode 100644
index 000000000..398025f05
--- /dev/null
+++ b/src/lib/gui/proxy/QSettingsProxy.h
@@ -0,0 +1,48 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2024 Symless Ltd.
+ *
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ *
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <QSettings>
+
+namespace synergy::gui::proxy {
+
+class QSettingsProxy {
+public:
+  virtual ~QSettingsProxy() = default;
+  virtual int beginReadArray(const QString &prefix);
+  virtual void beginWriteArray(const QString &prefix);
+  virtual void setArrayIndex(int i);
+  virtual QVariant value(const QString &key) const;
+  virtual QVariant
+  value(const QString &key, const QVariant &defaultValue) const;
+  virtual void endArray();
+  virtual void setValue(const QString &key, const QVariant &value);
+  virtual void beginGroup(const QString &prefix);
+  virtual void endGroup();
+  virtual void remove(const QString &key);
+  virtual bool isWritable() const;
+  virtual bool contains(const QString &key) const;
+
+  void set(QSettings &settings) { m_pSettings = &settings; }
+  QSettings &get() const { return *m_pSettings; }
+
+private:
+  QSettings *m_pSettings;
+};
+
+} // namespace synergy::gui::proxy
diff --git a/src/test/integtests/gui/core/CoreToolTests.cpp b/src/test/integtests/gui/core/CoreToolTests.cpp
index 90e98b356..48daec5e3 100644
--- a/src/test/integtests/gui/core/CoreToolTests.cpp
+++ b/src/test/integtests/gui/core/CoreToolTests.cpp
@@ -16,13 +16,12 @@
  */
 
 #include "gui/core/CoreTool.h"
-#include "shared/gui/QtCoreTest.h"
+#include "shared/gui/TestQtCoreApp.h"
 
 #include <gtest/gtest.h>
 
-class CoreToolTests : public QtCoreTest {};
-
-TEST_F(CoreToolTests, getProfileDir_noMock_returnsNonEmpty) {
+TEST(CoreToolTests, getProfileDir_noMock_returnsNonEmpty) {
+  TestQtCoreApp app;
   CoreTool coreTool;
 
   QString profileDir = coreTool.getProfileDir();
@@ -30,7 +29,8 @@ TEST_F(CoreToolTests, getProfileDir_noMock_returnsNonEmpty) {
   EXPECT_FALSE(profileDir.isEmpty());
 }
 
-TEST_F(CoreToolTests, getInstalledDir_noMock_returnsNonEmpty) {
+TEST(CoreToolTests, getInstalledDir_noMock_returnsNonEmpty) {
+  TestQtCoreApp app;
   CoreTool coreTool;
 
   QString installedDir = coreTool.getInstalledDir();
@@ -38,7 +38,8 @@ TEST_F(CoreToolTests, getInstalledDir_noMock_returnsNonEmpty) {
   EXPECT_FALSE(installedDir.isEmpty());
 }
 
-TEST_F(CoreToolTests, getArch_noMock_returnsNonEmpty) {
+TEST(CoreToolTests, getArch_noMock_returnsNonEmpty) {
+  TestQtCoreApp app;
   CoreTool coreTool;
 
   QString arch = coreTool.getArch();
@@ -46,7 +47,8 @@ TEST_F(CoreToolTests, getArch_noMock_returnsNonEmpty) {
   EXPECT_FALSE(arch.isEmpty());
 }
 
-TEST_F(CoreToolTests, getSerialKeyFilePath_noMock_returnsNonEmpty) {
+TEST(CoreToolTests, getSerialKeyFilePath_noMock_returnsNonEmpty) {
+  TestQtCoreApp app;
   CoreTool coreTool;
 
   QString serialKeyFilePath = coreTool.getSerialKeyFilePath();
diff --git a/src/test/shared/gui/QtCoreTest.h b/src/test/shared/gui/QtCoreTest.h
deleted file mode 100644
index fb7d05b90..000000000
--- a/src/test/shared/gui/QtCoreTest.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * synergy -- mouse and keyboard sharing utility
- * Copyright (C) 2024 Symless Ltd.
- *
- * This package is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * found in the file LICENSE that should have accompanied this file.
- *
- * This package is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#pragma once
-
-#include "gui/messages.h"
-
-#include <QCoreApplication>
-#include <gtest/gtest.h>
-
-class QtCoreTest : public ::testing::Test {
-public:
-  static void SetUpTestSuite() {
-    char **argv = nullptr;
-    int argc = 0;
-    s_app = std::make_unique<QCoreApplication>(argc, argv);
-    qInstallMessageHandler(synergy::gui::messages::messageHandler);
-  }
-
-  static void TearDownTestSuite() { s_app.reset(); }
-
-  static std::unique_ptr<QCoreApplication> s_app;
-};
diff --git a/src/test/shared/gui/QtTest.cpp b/src/test/shared/gui/TestQtCoreApp.h
similarity index 75%
rename from src/test/shared/gui/QtTest.cpp
rename to src/test/shared/gui/TestQtCoreApp.h
index 984cb9416..c72e74468 100644
--- a/src/test/shared/gui/QtTest.cpp
+++ b/src/test/shared/gui/TestQtCoreApp.h
@@ -15,10 +15,14 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifdef QT_GUI_LIB
+#pragma once
 
-#include "QtTest.h"
+#include <QCoreApplication>
 
-std::unique_ptr<QApplication> QtTest::s_app;
+int argc = 0;          // NOLINT
+char **argv = nullptr; // NOLINT
 
-#endif
+class TestQtCoreApp : public QCoreApplication {
+public:
+  explicit TestQtCoreApp() : QCoreApplication(argc, argv) {}
+};
diff --git a/src/test/shared/gui/QtCoreTest.cpp b/src/test/shared/gui/TestQtFullApp.h
similarity index 72%
rename from src/test/shared/gui/QtCoreTest.cpp
rename to src/test/shared/gui/TestQtFullApp.h
index 8331e4694..810508d86 100644
--- a/src/test/shared/gui/QtCoreTest.cpp
+++ b/src/test/shared/gui/TestQtFullApp.h
@@ -15,10 +15,17 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifdef QT_GUI_LIB
+#pragma once
 
-#include "QtCoreTest.h"
+#include <QApplication>
 
-std::unique_ptr<QCoreApplication> QtCoreTest::s_app;
+int argc = 0;          // NOLINT
+char **argv = nullptr; // NOLINT
 
-#endif
+/**
+ * Prefer using `TestQtCoreApp` instead.
+ */
+class TestQtFullApp : public QApplication {
+public:
+  explicit TestQtFullApp() : QApplication(argc, argv) {}
+};
diff --git a/src/test/shared/gui/mocks/AppConfigMock.h b/src/test/shared/gui/mocks/AppConfigMock.h
new file mode 100644
index 000000000..966b44b46
--- /dev/null
+++ b/src/test/shared/gui/mocks/AppConfigMock.h
@@ -0,0 +1,65 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2024 Symless Ltd.
+ *
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ *
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "gui/config/IAppConfig.h"
+
+#include "gui/config/ElevateMode.h"
+
+#include <gmock/gmock.h>
+
+class AppConfigMock : public synergy::gui::IAppConfig {
+  using ProcessMode = synergy::gui::ProcessMode;
+
+public:
+  AppConfigMock() {
+    ON_CALL(*this, screenName()).WillByDefault(testing::ReturnRef(m_stubName));
+    ON_CALL(*this, networkInterface())
+        .WillByDefault(testing::ReturnRef(m_stubInterface));
+    ON_CALL(*this, logLevelText())
+        .WillByDefault(testing::Return("stub log level"));
+  }
+
+  MOCK_METHOD(QString, tlsCertPath, (), (const, override));
+  MOCK_METHOD(int, tlsKeyLength, (), (const, override));
+  MOCK_METHOD(bool, tlsEnabled, (), (const, override));
+  MOCK_METHOD(ProcessMode, processMode, (), (const, override));
+  MOCK_METHOD(ElevateMode, elevateMode, (), (const, override));
+  MOCK_METHOD(QString, logLevelText, (), (const, override));
+  MOCK_METHOD(const QString &, screenName, (), (const, override));
+  MOCK_METHOD(bool, preventSleep, (), (const, override));
+  MOCK_METHOD(bool, logToFile, (), (const, override));
+  MOCK_METHOD(const QString &, logFilename, (), (const, override));
+  MOCK_METHOD(QString, coreServerName, (), (const, override));
+  MOCK_METHOD(QString, coreClientName, (), (const, override));
+  MOCK_METHOD(bool, invertConnection, (), (const, override));
+  MOCK_METHOD(void, persistLogDir, (), (const, override));
+  MOCK_METHOD(QString, serialKey, (), (const, override));
+  MOCK_METHOD(bool, languageSync, (), (const, override));
+  MOCK_METHOD(bool, invertScrollDirection, (), (const, override));
+  MOCK_METHOD(int, port, (), (const, override));
+  MOCK_METHOD(bool, useExternalConfig, (), (const, override));
+  MOCK_METHOD(const QString &, configFile, (), (const, override));
+  MOCK_METHOD(const QString &, networkInterface, (), (const, override));
+  MOCK_METHOD(const QString &, serverHostname, (), (const, override));
+
+private:
+  const QString m_stubName = "stub name";
+  const QString m_stubInterface = "stub interface";
+  const QString m_stubAddress = "stub address";
+};
diff --git a/src/test/shared/gui/QtTest.h b/src/test/shared/gui/mocks/ServerConfigMock.h
similarity index 57%
rename from src/test/shared/gui/QtTest.h
rename to src/test/shared/gui/mocks/ServerConfigMock.h
index cd2186fff..d7c4942ab 100644
--- a/src/test/shared/gui/QtTest.h
+++ b/src/test/shared/gui/mocks/ServerConfigMock.h
@@ -17,21 +17,17 @@
 
 #pragma once
 
-#include "gui/messages.h"
+#include "gui/config/IServerConfig.h"
 
-#include <QApplication>
-#include <gtest/gtest.h>
+#include <gmock/gmock.h>
 
-class QtTest : public ::testing::Test {
+class ServerConfigMock : public synergy::gui::IServerConfig {
 public:
-  static void SetUpTestSuite() {
-    char **argv = nullptr;
-    int argc = 0;
-    s_app = std::make_unique<QApplication>(argc, argv);
-    qInstallMessageHandler(synergy::gui::messages::messageHandler);
-  }
-
-  static void TearDownTestSuite() { s_app.reset(); }
-
-  static std::unique_ptr<QApplication> s_app;
+  MOCK_METHOD(bool, isFull, (), (const, override));
+  MOCK_METHOD(
+      bool, screenExists, (const QString &screenName), (const, override));
+  MOCK_METHOD(bool, save, (const QString &fileName), (const, override));
+  MOCK_METHOD(void, save, (QFile & file), (const, override));
+  MOCK_METHOD(bool, enableDragAndDrop, (), (const, override));
+  MOCK_METHOD(const ScreenList &, screens, (), (const, override));
 };
diff --git a/src/test/unittests/gui/config/AppConfigTests.cpp b/src/test/unittests/gui/config/AppConfigTests.cpp
index ddad213e0..bd5a242c7 100644
--- a/src/test/unittests/gui/config/AppConfigTests.cpp
+++ b/src/test/unittests/gui/config/AppConfigTests.cpp
@@ -17,15 +17,20 @@
 
 #include "gui/config/AppConfig.h"
 
+#include "gui/proxy/QSettingsProxy.h"
+
 #include "gmock/gmock.h"
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 using namespace testing;
+using namespace synergy::gui::proxy;
 
 namespace {
 
-class MockScopes : public synergy::gui::IConfigScopes {
+class ConfigScopesMock : public synergy::gui::IConfigScopes {
+  using QSettingsProxy = synergy::gui::proxy::QSettingsProxy;
+
 public:
   MOCK_METHOD(void, signalReady, (), (override));
   MOCK_METHOD(
@@ -41,18 +46,19 @@ public:
   MOCK_METHOD(Scope, activeScope, (), (const, override));
   MOCK_METHOD(void, setActiveScope, (Scope scope), (override));
   MOCK_METHOD(bool, isActiveScopeWritable, (), (const, override));
-  MOCK_METHOD(QSettings *, activeSettings, (), (const, override));
+  MOCK_METHOD(const QSettingsProxy &, activeSettings, (), (const, override));
+  MOCK_METHOD(QSettingsProxy &, activeSettings, (), (override));
   MOCK_METHOD(void, save, (), (override));
 };
 
-struct MockDeps : public AppConfig::Deps {
-  MockDeps() {
+struct DepsMock : public AppConfig::Deps {
+  DepsMock() {
     ON_CALL(*this, profileDir()).WillByDefault(Return("stub"));
     ON_CALL(*this, hostname()).WillByDefault(Return("stub"));
   }
 
-  static std::shared_ptr<NiceMock<MockDeps>> makeNice() {
-    return std::make_shared<NiceMock<MockDeps>>();
+  static std::shared_ptr<NiceMock<DepsMock>> makeNice() {
+    return std::make_shared<NiceMock<DepsMock>>();
   }
 
   MOCK_METHOD(QString, profileDir, (), (const, override));
@@ -64,8 +70,8 @@ struct MockDeps : public AppConfig::Deps {
 class AppConfigTests : public Test {};
 
 TEST_F(AppConfigTests, ctor_byDefault_screenNameIsHostname) {
-  NiceMock<MockScopes> scopes;
-  auto deps = MockDeps::makeNice();
+  NiceMock<ConfigScopesMock> scopes;
+  auto deps = DepsMock::makeNice();
   ON_CALL(*deps, hostname()).WillByDefault(Return("test hostname"));
 
   AppConfig appConfig(scopes, deps);
@@ -74,8 +80,8 @@ TEST_F(AppConfigTests, ctor_byDefault_screenNameIsHostname) {
 }
 
 TEST_F(AppConfigTests, ctor_byDefault_getsFromScope) {
-  NiceMock<MockScopes> scopes;
-  auto deps = MockDeps::makeNice();
+  NiceMock<ConfigScopesMock> scopes;
+  auto deps = DepsMock::makeNice();
 
   ON_CALL(scopes, scopeContains(_, _)).WillByDefault(Return(true));
   ON_CALL(scopes, getFromScope(_, _, _))
@@ -88,8 +94,8 @@ TEST_F(AppConfigTests, ctor_byDefault_getsFromScope) {
 }
 
 TEST_F(AppConfigTests, commit_byDefault_setsToScope) {
-  NiceMock<MockScopes> scopes;
-  auto deps = MockDeps::makeNice();
+  NiceMock<ConfigScopesMock> scopes;
+  auto deps = DepsMock::makeNice();
   AppConfig appConfig(scopes, deps);
 
   ON_CALL(scopes, isActiveScopeWritable()).WillByDefault(Return(true));
diff --git a/src/test/unittests/gui/config/ScreenTests.cpp b/src/test/unittests/gui/config/ScreenTests.cpp
new file mode 100644
index 000000000..99e2ae25b
--- /dev/null
+++ b/src/test/unittests/gui/config/ScreenTests.cpp
@@ -0,0 +1,68 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2024 Symless Ltd.
+ *
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ *
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "gui/config/Screen.h"
+
+#include "gui/proxy/QSettingsProxy.h"
+#include "shared/gui/TestQtCoreApp.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+using namespace synergy::gui::proxy;
+using namespace testing;
+
+class QSettingsProxyMock : public QSettingsProxy {
+public:
+  MOCK_METHOD(int, beginReadArray, (const QString &prefix), (override));
+  MOCK_METHOD(void, beginWriteArray, (const QString &prefix), (override));
+  MOCK_METHOD(void, setArrayIndex, (int i), (override));
+  MOCK_METHOD(QVariant, value, (const QString &key), (const, override));
+  MOCK_METHOD(
+      QVariant, value, (const QString &key, const QVariant &defaultValue),
+      (const, override));
+  MOCK_METHOD(void, endArray, (), (override));
+  MOCK_METHOD(
+      void, setValue, (const QString &key, const QVariant &value), (override));
+  MOCK_METHOD(void, beginGroup, (const QString &prefix), (override));
+  MOCK_METHOD(void, endGroup, (), (override));
+  MOCK_METHOD(void, remove, (const QString &key), (override));
+  MOCK_METHOD(bool, isWritable, (), (const, override));
+  MOCK_METHOD(bool, contains, (const QString &key), (const, override));
+};
+
+TEST(ScreenTests, loadSettings_whenHasSetting_readsArray) {
+  TestQtCoreApp app;
+  NiceMock<QSettingsProxyMock> settings;
+  Screen screen;
+  ON_CALL(settings, value(_)).WillByDefault(Return("stub"));
+
+  EXPECT_CALL(settings, beginReadArray(_)).Times(4);
+
+  screen.loadSettings(settings);
+}
+
+TEST(ScreenTests, saveSettings_whenNameIsSet_writesArray) {
+  TestQtCoreApp app;
+  NiceMock<QSettingsProxyMock> settings;
+  Screen screen;
+  screen.setName("stub");
+
+  EXPECT_CALL(settings, beginWriteArray(_)).Times(4);
+
+  screen.saveSettings(settings);
+}
diff --git a/src/test/unittests/gui/core/ClientConnectionTests.cpp b/src/test/unittests/gui/core/ClientConnectionTests.cpp
new file mode 100644
index 000000000..00aaf4fb2
--- /dev/null
+++ b/src/test/unittests/gui/core/ClientConnectionTests.cpp
@@ -0,0 +1,129 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2024 Symless Ltd.
+ *
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ *
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "gui/core/ClientConnection.h"
+
+#include "shared/gui/mocks/AppConfigMock.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+class QWidget;
+
+using testing::_;
+using testing::NiceMock;
+using namespace synergy::gui;
+using enum messages::ClientError;
+
+namespace {
+
+struct DepsMock : public ClientConnection::Deps {
+  MOCK_METHOD(
+      void, showError,
+      (QWidget * parent, messages::ClientError error, const QString &address),
+      (const, override));
+};
+
+} // namespace
+
+class ClientConnectionTests : public testing::Test {
+public:
+  ClientConnectionTests() {
+    ON_CALL(m_appConfig, serverHostname())
+        .WillByDefault(testing::ReturnRef(stub));
+  }
+
+  std::shared_ptr<DepsMock> m_pDeps = std::make_shared<NiceMock<DepsMock>>();
+  NiceMock<AppConfigMock> m_appConfig;
+
+private:
+  const QString stub = "stub";
+};
+
+TEST_F(ClientConnectionTests, handleLogLine_alreadyConnected_showError) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+  const QString serverName = "test server";
+  ON_CALL(m_appConfig, serverHostname())
+      .WillByDefault(testing::ReturnRef(serverName));
+
+  EXPECT_CALL(*m_pDeps, showError(_, AlreadyConnected, serverName));
+
+  clientConnection.handleLogLine(
+      "failed to connect to server\n"
+      "server already has a connected client with our name");
+}
+
+TEST_F(ClientConnectionTests, handleLogLine_withHostname_showError) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+  const QString serverName = "test-hostname";
+  ON_CALL(m_appConfig, serverHostname())
+      .WillByDefault(testing::ReturnRef(serverName));
+
+  EXPECT_CALL(*m_pDeps, showError(_, HostnameError, serverName));
+
+  clientConnection.handleLogLine("failed to connect to server");
+}
+
+TEST_F(ClientConnectionTests, handleLogLine_withIpAddress_showError) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+  const QString serverName = "1.1.1.1";
+  ON_CALL(m_appConfig, serverHostname())
+      .WillByDefault(testing::ReturnRef(serverName));
+
+  EXPECT_CALL(*m_pDeps, showError(_, GenericError, serverName));
+
+  clientConnection.handleLogLine("failed to connect to server");
+}
+
+TEST_F(ClientConnectionTests, handleLogLine_messageShown_shouldNotShowAgain) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+
+  clientConnection.handleLogLine("failed to connect to server");
+
+  EXPECT_CALL(*m_pDeps, showError(_, _, _)).Times(0);
+
+  clientConnection.handleLogLine("failed to connect to server");
+}
+
+TEST_F(
+    ClientConnectionTests,
+    handleLogLine_serverRefusedClient_shouldNotShowError) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+
+  EXPECT_CALL(*m_pDeps, showError(_, _, _)).Times(0);
+
+  clientConnection.handleLogLine("failed to connect to server\n"
+                                 "server refused client with our name");
+}
+
+TEST_F(
+    ClientConnectionTests, handleLogLine_connected_shouldPreventFutureError) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+  clientConnection.handleLogLine("connected to server");
+
+  EXPECT_CALL(*m_pDeps, showError(_, _, _)).Times(0);
+
+  clientConnection.handleLogLine("failed to connect to server");
+}
+
+TEST_F(ClientConnectionTests, handleLogLine_otherMessage_shouldNotShowError) {
+  ClientConnection clientConnection(nullptr, m_appConfig, m_pDeps);
+
+  EXPECT_CALL(*m_pDeps, showError(_, _, _)).Times(0);
+
+  clientConnection.handleLogLine("hello world");
+}
diff --git a/src/test/unittests/gui/core/CoreProcessTests.cpp b/src/test/unittests/gui/core/CoreProcessTests.cpp
index 73ab3aa91..610e921fb 100644
--- a/src/test/unittests/gui/core/CoreProcessTests.cpp
+++ b/src/test/unittests/gui/core/CoreProcessTests.cpp
@@ -19,6 +19,8 @@
 #include "gui/core/CoreProcess.h"
 #include "gui/ipc/IQIpcClient.h"
 #include "gui/proxy/QProcessProxy.h"
+#include "shared/gui/mocks/AppConfigMock.h"
+#include "shared/gui/mocks/ServerConfigMock.h"
 
 #include "gmock/gmock.h"
 #include <gmock/gmock.h>
@@ -30,58 +32,13 @@ using ::testing::NiceMock;
 using ::testing::Return;
 using ::testing::ReturnRef;
 
-class MockAppConfig : public IAppConfig {
-public:
-  MockAppConfig() {
-    ON_CALL(*this, screenName()).WillByDefault(ReturnRef(m_stubName));
-    ON_CALL(*this, networkInterface())
-        .WillByDefault(ReturnRef(m_stubInterface));
-    ON_CALL(*this, logLevelText()).WillByDefault(Return("stub log level"));
-  }
+namespace {
 
-  MOCK_METHOD(QString, tlsCertPath, (), (const, override));
-  MOCK_METHOD(int, tlsKeyLength, (), (const, override));
-  MOCK_METHOD(bool, tlsEnabled, (), (const, override));
-  MOCK_METHOD(ProcessMode, processMode, (), (const, override));
-  MOCK_METHOD(ElevateMode, elevateMode, (), (const, override));
-  MOCK_METHOD(QString, logLevelText, (), (const, override));
-  MOCK_METHOD(const QString &, screenName, (), (const, override));
-  MOCK_METHOD(bool, preventSleep, (), (const, override));
-  MOCK_METHOD(bool, logToFile, (), (const, override));
-  MOCK_METHOD(const QString &, logFilename, (), (const, override));
-  MOCK_METHOD(QString, coreServerName, (), (const, override));
-  MOCK_METHOD(QString, coreClientName, (), (const, override));
-  MOCK_METHOD(bool, invertConnection, (), (const, override));
-  MOCK_METHOD(void, persistLogDir, (), (const, override));
-  MOCK_METHOD(QString, serialKey, (), (const, override));
-  MOCK_METHOD(bool, languageSync, (), (const, override));
-  MOCK_METHOD(bool, invertScrollDirection, (), (const, override));
-  MOCK_METHOD(int, port, (), (const, override));
-  MOCK_METHOD(bool, useExternalConfig, (), (const, override));
-  MOCK_METHOD(const QString &, configFile, (), (const, override));
-  MOCK_METHOD(const QString &, networkInterface, (), (const, override));
-
-private:
-  const QString m_stubName = "stub name";
-  const QString m_stubInterface = "stub interface";
-  const QString m_stubAddress = "stub address";
-};
-
-class MockServerConfig : public IServerConfig {
-public:
-  MOCK_METHOD(bool, isFull, (), (const, override));
-  MOCK_METHOD(
-      bool, screenExists, (const QString &screenName), (const, override));
-  MOCK_METHOD(bool, save, (const QString &fileName), (const, override));
-  MOCK_METHOD(void, save, (QFile & file), (const, override));
-  MOCK_METHOD(bool, enableDragAndDrop, (), (const, override));
-};
-
-class MockQProcessProxy : public proxy::QProcessProxy {
+class QProcessProxyMock : public proxy::QProcessProxy {
 public:
   operator bool() const override { return toBool(); }
 
-  MockQProcessProxy() {
+  QProcessProxyMock() {
     ON_CALL(*this, toBool()).WillByDefault(Return(true));
     ON_CALL(*this, state())
         .WillByDefault(Return(QProcess::ProcessState::Running));
@@ -100,9 +57,9 @@ public:
   MOCK_METHOD(QString, readAllStandardError, (), (override));
 };
 
-class MockQIpcClient : public ipc::IQIpcClient {
+class QIpcClientMock : public ipc::IQIpcClient {
 public:
-  MockQIpcClient() {
+  QIpcClientMock() {
     ON_CALL(*this, isConnected()).WillByDefault(Return(true));
   }
 
@@ -115,9 +72,9 @@ public:
   MOCK_METHOD(bool, isConnected, (), (const, override));
 };
 
-class MockDeps : public CoreProcess::Deps {
+class DepsMock : public CoreProcess::Deps {
 public:
-  MockDeps() {
+  DepsMock() {
     ON_CALL(*this, process()).WillByDefault(ReturnRef(m_process));
     ON_CALL(*this, ipcClient()).WillByDefault(ReturnRef(m_ipcClient));
     ON_CALL(*this, appPath(_)).WillByDefault(Return("stub app path"));
@@ -131,21 +88,23 @@ public:
   MOCK_METHOD(bool, fileExists, (const QString &path), (const, override));
   MOCK_METHOD(QString, getProfileRoot, (), (const, override));
 
-  NiceMock<MockQProcessProxy> m_process;
-  NiceMock<MockQIpcClient> m_ipcClient;
+  NiceMock<QProcessProxyMock> m_process;
+  NiceMock<QIpcClientMock> m_ipcClient;
 };
 
 class CoreProcessTests : public ::testing::Test {
 public:
   CoreProcessTests() : m_coreProcess(m_appConfig, m_serverConfig, m_pDeps) {}
 
-  NiceMock<MockAppConfig> m_appConfig;
-  NiceMock<MockServerConfig> m_serverConfig;
-  std::shared_ptr<NiceMock<MockDeps>> m_pDeps =
-      std::make_shared<NiceMock<MockDeps>>();
+  NiceMock<AppConfigMock> m_appConfig;
+  NiceMock<ServerConfigMock> m_serverConfig;
+  std::shared_ptr<NiceMock<DepsMock>> m_pDeps =
+      std::make_shared<NiceMock<DepsMock>>();
   CoreProcess m_coreProcess;
 };
 
+} // namespace
+
 TEST_F(CoreProcessTests, start_serverDesktop_callsProcessStart) {
   m_coreProcess.setMode(CoreProcess::Mode::Server);
 
diff --git a/src/test/unittests/gui/core/ServerConnectionTests.cpp b/src/test/unittests/gui/core/ServerConnectionTests.cpp
new file mode 100644
index 000000000..5a6d19569
--- /dev/null
+++ b/src/test/unittests/gui/core/ServerConnectionTests.cpp
@@ -0,0 +1,91 @@
+/*
+ * synergy -- mouse and keyboard sharing utility
+ * Copyright (C) 2024 Symless Ltd.
+ *
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ *
+ * This package is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "gui/core/ServerConnection.h"
+
+#include "shared/gui/mocks/AppConfigMock.h"
+#include "shared/gui/mocks/ServerConfigMock.h"
+
+#include "gmock/gmock.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+using testing::_;
+using testing::NiceMock;
+using namespace synergy::gui;
+
+class QWidget;
+
+namespace {
+
+struct DepsMock : public ServerConnection::Deps {
+  MOCK_METHOD(
+      messages::NewClientPromptResult, showNewClientPrompt,
+      (QWidget * parent, const QString &clientName), (const, override));
+};
+
+} // namespace
+
+class ServerConnectionTests : public testing::Test {
+public:
+  std::shared_ptr<DepsMock> m_pDeps = std::make_shared<NiceMock<DepsMock>>();
+  NiceMock<AppConfigMock> m_appConfig;
+  NiceMock<ServerConfigMock> m_serverConfig;
+};
+
+TEST_F(ServerConnectionTests, handleLogLine_newClient_shouldShowPrompt) {
+  ServerConnection serverConnection(
+      nullptr, m_appConfig, m_serverConfig, m_pDeps);
+
+  QString clientName = "test client";
+  EXPECT_CALL(*m_pDeps, showNewClientPrompt(_, clientName));
+
+  serverConnection.handleLogLine(R"(unrecognised client name "test client")");
+}
+
+TEST_F(ServerConnectionTests, handleLogLine_ignoredClient_shouldNotShowPrompt) {
+  ServerConnection serverConnection(
+      nullptr, m_appConfig, m_serverConfig, m_pDeps);
+  ON_CALL(*m_pDeps, showNewClientPrompt(_, _))
+      .WillByDefault(testing::Return(messages::NewClientPromptResult::Ignore));
+  serverConnection.handleLogLine(R"(unrecognised client name "stub")");
+
+  EXPECT_CALL(*m_pDeps, showNewClientPrompt(_, _)).Times(0);
+
+  serverConnection.handleLogLine(R"(unrecognised client name "stub")");
+}
+
+TEST_F(
+    ServerConnectionTests, handleLogLine_serverConfigFull_shouldNotShowPrompt) {
+  ServerConnection serverConnection(
+      nullptr, m_appConfig, m_serverConfig, m_pDeps);
+  ON_CALL(m_serverConfig, isFull()).WillByDefault(testing::Return(true));
+
+  EXPECT_CALL(*m_pDeps, showNewClientPrompt(_, _)).Times(0);
+
+  serverConnection.handleLogLine(R"(unrecognised client name "test client")");
+}
+
+TEST_F(ServerConnectionTests, handleLogLine_screenExists_shouldNotShowPrompt) {
+  ServerConnection serverConnection(
+      nullptr, m_appConfig, m_serverConfig, m_pDeps);
+  ON_CALL(m_serverConfig, screenExists(_)).WillByDefault(testing::Return(true));
+
+  EXPECT_CALL(*m_pDeps, showNewClientPrompt(_, _)).Times(0);
+
+  serverConnection.handleLogLine(R"(unrecognised client name "test client")");
+}