Qt: Clear OSD messages on system stop

src/duckstation-qt/qthostinterface.cpp

@@ -641,6 +641,7 @@ void QtHostInterface::OnSystemDestroyed()
 {
   CommonHostInterface::OnSystemDestroyed();
 
+  ClearOSDMessages();
   startBackgroundControllerPollTimer();
   emit emulationStopped();
 }

src/frontend-common/common_host_interface.cpp

@@ -830,6 +830,12 @@ void CommonHostInterface::AddOSDMessage(std::string message, float duration /*=
   m_osd_messages.push_back(std::move(msg));
 }
 
+void CommonHostInterface::ClearOSDMessages()
+{
+  std::unique_lock<std::mutex> lock(m_osd_messages_lock);
+  m_osd_messages.clear();
+}
+
 void CommonHostInterface::DrawOSDMessages()
 {
   constexpr ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoInputs |

src/frontend-common/common_host_interface.h

@@ -128,6 +128,7 @@ public:
 
   /// Adds OSD messages, duration is in seconds.
   void AddOSDMessage(std::string message, float duration = 2.0f) override;
+  void ClearOSDMessages();
 
   /// Displays a loading screen with the logo, rendered with ImGui. Use when executing possibly-time-consuming tasks
   /// such as compiling shaders when starting up.