Add helper to invoke back onto the UI thread from the replay thread

qrenderdoc/Code/Interface/Extensions.h

@@ -338,6 +338,21 @@ struct IMiniQtHelper
 {
   typedef std::function<void(ICaptureContext *, QWidget *, rdcstr)> WidgetCallback;
 
+  DOCUMENT(R"(Invoke a callback on the UI thread. All widget accesses must come from the UI thread,
+so if work has been done on the render thread then this function can be used to asynchronously and
+safely go back to the UI thread.
+
+This function is safe to call on the UI thread, but it will synchronously call the callback
+immediately before returning.
+
+.. note::
+  No parameters are provided to the callback, it is assumed that the callback will maintain its own
+  context as needed.
+
+:param function callback: The callback to invoke on the UI thread.
+)");
+  virtual void InvokeOntoUIThread(std::function<void()> callback) = 0;
+
   // top level widgets
 
   DOCUMENT(R"(Creates and returns a top-level widget for creating layouts.

qrenderdoc/Code/MiniQtHelper.cpp

@@ -58,6 +58,11 @@ MiniQtHelper::~MiniQtHelper()
   });
 }
 
+void MiniQtHelper::InvokeOntoUIThread(std::function<void()> callback)
+{
+  GUIInvoke::call(m_Ctx.GetMainWindow()->Widget(), callback);
+}
+
 void MiniQtHelper::AddWidgetCallback(QWidget *widget, QMetaObject::Connection connection)
 {
   // remember the connection and delete it python-safely at shutdown if it's still there

qrenderdoc/Code/MiniQtHelper.h

@@ -35,6 +35,8 @@ public:
   MiniQtHelper(ICaptureContext &ctx);
   virtual ~MiniQtHelper();
 
+  void InvokeOntoUIThread(std::function<void()> callback) override;
+
   QWidget *CreateToplevelWidget(const rdcstr &windowTitle, WidgetCallback closed) override;
 
   // widget hierarchy

qrenderdoc/Windows/PythonShell.cpp

@@ -85,6 +85,12 @@ struct MiniQtInvoker : ObjectForwarder<IMiniQtHelper>
 {
   MiniQtInvoker(PythonShell *shell, IMiniQtHelper &obj) : ObjectForwarder(shell, obj) {}
   virtual ~MiniQtInvoker() {}
+  void InvokeOntoUIThread(std::function<void()> callback)
+  {
+    // this function is already thread safe since it's invoking, so just call it directly
+    m_Obj.InvokeOntoUIThread(callback);
+  }
+
   ///////////////////////////////////////////////////////////////////////
   // all functions invoke onto the UI thread since they deal with widgets!
   ///////////////////////////////////////////////////////////////////////