[feat] add force relay connection option to settings

apps/desktop/src/config_center/config_center.cpp

@@ -296,14 +296,16 @@ int ConfigCenter::SetTurnMode(TURN_MODE turn_mode) {
   return 0;
 }
 
-int ConfigCenter::SetTurn(bool enable_turn) {
+int ConfigCenter::SetTurn(bool enable_turn, bool force_relay) {
   if (!enable_turn) {
     return SetTurnMode(TURN_MODE::DISABLED);
   }
-  if (turn_mode_ == TURN_MODE::DISABLED) {
+  if (!force_relay) {
     return SetTurnMode(TURN_MODE::AUTO_UDP_TCP);
   }
-  return SetTurnMode(turn_mode_);
+  // Use TURN/UDP by default, preserving an explicitly configured TCP relay.
+  return SetTurnMode(turn_mode_ == TURN_MODE::FORCE_TCP ? TURN_MODE::FORCE_TCP
+                                                     : TURN_MODE::FORCE_UDP);
 }
 
 int ConfigCenter::SetServerHost(const std::string& signal_server_host) {
@@ -467,6 +469,10 @@ bool ConfigCenter::IsEnableTurn() const {
   return turn_mode_ != TURN_MODE::DISABLED;
 }
 
+bool ConfigCenter::IsForceRelay() const {
+  return turn_mode_ == TURN_MODE::FORCE_UDP || turn_mode_ == TURN_MODE::FORCE_TCP;
+}
+
 bool ConfigCenter::IsEnableSrtp() const { return true; }
 
 std::string ConfigCenter::GetSignalServerHost() const {

apps/desktop/src/config_center/config_center.h

@@ -46,7 +46,7 @@ class ConfigCenter {
   int SetVideoEncodeFormat(VIDEO_ENCODE_FORMAT video_encode_format);
   int SetHardwareVideoCodec(bool hardware_video_codec);
   int SetTurnMode(TURN_MODE turn_mode);
-  int SetTurn(bool enable_turn);
+  int SetTurn(bool enable_turn, bool force_relay);
   int SetServerHost(const std::string& signal_server_host);
   int SetServerPort(int signal_server_port);
   int SetSelfHosted(bool enable_self_hosted);
@@ -69,6 +69,7 @@ class ConfigCenter {
   bool IsHardwareVideoCodec() const;
   TURN_MODE GetTurnMode() const;
   bool IsEnableTurn() const;
+  bool IsForceRelay() const;
   bool IsEnableSrtp() const;
   std::string GetSignalServerHost() const;
   int GetSignalServerPort() const;

apps/desktop/src/gui/application/gui_application.cpp

@@ -1261,6 +1261,7 @@ void GuiApplication::ResetSettingsUi() {
   ui_->main->set_hardware_codec_enabled(hardware_codec_available &&
                                        enable_hardware_video_codec_);
   ui_->main->set_turn_enabled(enable_turn_);
+  ui_->main->set_force_relay_enabled(config_center_->IsForceRelay());
   ui_->main->set_self_hosted_enabled(enable_self_hosted_);
   ui_->main->set_autostart_enabled(enable_autostart_);
   ui_->main->set_daemon_enabled(enable_daemon_);
@@ -3092,7 +3093,8 @@ void GuiApplication::SaveSettingsFromUi() {
       static_cast<ConfigCenter::VIDEO_ENCODE_FORMAT>(
           video_encode_format_button_value_));
   config_center_->SetHardwareVideoCodec(enable_hardware_video_codec_);
-  config_center_->SetTurn(enable_turn_);
+  config_center_->SetTurn(enable_turn_, main->get_force_relay_enabled());
+  main->set_force_relay_enabled(config_center_->IsForceRelay());
   config_center_->SetSelfHosted(enable_self_hosted_);
   config_center_->SetAutostart(enable_autostart_);
   config_center_->SetDaemon(enable_daemon_);

apps/desktop/src/gui/assets/localization/localization_data.h

@@ -151,6 +151,7 @@ struct TranslationRow {
     "Enable Hardware Video Codec:", u8"Использовать аппаратный кодек:")        \
   X(enable_turn, u8"启用中继服务:",                                            \
     "Enable TURN Service:", u8"Включить TURN-сервис:")                         \
+  X(force_relay, u8"强制中继连接:", "Force Relay:", u8"Только через реле:")   \
   X(self_hosted_server_config, u8"自托管配置", "Self-Hosted Config",           \
     u8"Конфигурация self-hosted")                                              \
   X(self_hosted_server_settings, u8"自托管设置", "Self-Hosted Settings",       \

apps/desktop/src/gui/ui/main_window.slint

@@ -49,6 +49,7 @@ export global UiStrings {
     in-out property <string> codec: "Video codec";
     in-out property <string> hardware-codec: "Hardware video codec";
     in-out property <string> turn-relay: "TURN relay";
+    in-out property <string> force-relay: "Force relay";
     in-out property <string> self-hosted: "Self-hosted server";
     in-out property <string> autostart: "Start with system";
     in-out property <string> daemon: "Run in background";
@@ -299,6 +300,10 @@ export component MainWindow inherits Window {
     in-out property <int> codec-index: 0;
     in-out property <bool> hardware-codec-enabled: true;
     in-out property <bool> turn-enabled: true;
+    in-out property <bool> force-relay-enabled: false;
+    changed turn-enabled => {
+        if !root.turn-enabled { root.force-relay-enabled = false; }
+    }
     in-out property <bool> self-hosted-enabled: false;
     in-out property <bool> autostart-enabled: false;
     in-out property <bool> daemon-enabled: false;
@@ -1518,6 +1523,11 @@ export component MainWindow inherits Window {
                         Text { x: 8px; y: 3px; width: root.compact-language ? 145px : 212px; height: 24px; text: UiStrings.turn-relay; font-size: ImGuiFontStyle.body; overflow: elide; vertical-alignment: center; }
                         ImGuiCheckBox { x: root.compact-language ? 157px : 224px; y: 3px; checked <=> root.turn-enabled; enabled: !root.settings-session-active; }
                     }
+                    Rectangle {
+                        height: 30px;
+                        Text { x: 8px; y: 3px; width: root.compact-language ? 145px : 212px; height: 24px; text: UiStrings.force-relay; color: root.turn-enabled ? #202124 : #8b8f95; font-size: ImGuiFontStyle.body; overflow: elide; vertical-alignment: center; }
+                        ImGuiCheckBox { x: root.compact-language ? 157px : 224px; y: 3px; checked <=> root.force-relay-enabled; enabled: root.turn-enabled && !root.settings-session-active; }
+                    }
                     Rectangle {
                         height: 30px;
                         Text { x: 8px; y: 3px; width: root.compact-language ? 145px : 212px; height: 24px; text: UiStrings.privacy-on-connect; color: root.privacy-setting-available ? #202124 : #8b8f95; font-size: ImGuiFontStyle.body; overflow: elide; vertical-alignment: center; }

apps/desktop/src/gui/ui/ui_localization.h

@@ -70,6 +70,7 @@ inline int ApplyMainWindowStrings(
   strings.set_hardware_codec(
       Text(localization::enable_hardware_video_codec[language]));
   strings.set_turn_relay(Text(localization::enable_turn[language]));
+  strings.set_force_relay(Text(localization::force_relay[language]));
   strings.set_self_hosted(
       Text(localization::self_hosted_server_config[language]));
   strings.set_autostart(Text(localization::enable_autostart[language]));