Make sure we run the gui callback on the main thread

plugins/core-plugin.cc

@@ -151,10 +151,14 @@ namespace clap {
 
    bool CorePlugin::guiCreate(const char *api, bool isFloating) noexcept {
       _guiFactory = LocalGuiFactory::getInstance();
-      if (!_guiFactory)
+      if (_guiFactory) {
+         _guiHandle = _guiFactory->createGui(*this);
+      } else {
          _guiFactory = ThreadedGuiFactory::getInstance();
-
-      _guiHandle = _guiFactory->createGui(*this);
+         if (!_threadedGuiListenerProxy)
+            _threadedGuiListenerProxy = std::make_unique<ThreadedGuiListenerProxy>(*this);
+         _guiHandle = _guiFactory->createGui(*_threadedGuiListenerProxy);
+      }
 
       if (!_guiHandle)
          return false;
@@ -282,6 +286,10 @@ namespace clap {
    //---------------------//
    // AbstractGuiListener //
    //---------------------//
+   void CorePlugin::onGuiRunOnMainThread(std::function<void()> callback) {
+      runOnMainThread(std::move(callback));
+   }
+
    void CorePlugin::onGuiPoll() {
       _pluginToGuiQueue.consume([this](clap_id paramId, const CorePlugin::PluginToGuiValue &value) {
          _guiHandle->gui().updateParameter(paramId, value.value, value.mod);

plugins/core-plugin.hh

@@ -10,6 +10,7 @@
 #include "context.hh"
 #include "gui/abstract-gui-factory.hh"
 #include "gui/abstract-gui-listener.hh"
+#include "gui/threaded-gui-listener-proxy.hh"
 #include "intrusive-list.hh"
 #include "parameters.hh"
 #include "path-provider.hh"
@@ -171,6 +172,7 @@ namespace clap {
       //---------------------//
       // AbstractGuiListener //
       //---------------------//
+      void onGuiRunOnMainThread(std::function<void()> callback) override;
       void onGuiPoll() override;
       void pollVoiceInfo();
       void onGuiParamBeginAdjust(clap_id paramId) override;
@@ -314,5 +316,7 @@ namespace clap {
       bool _canRedo{false};
       std::optional<std::string> _undoName;
       std::optional<std::string> _redoName;
+
+      std::unique_ptr<ThreadedGuiListenerProxy> _threadedGuiListenerProxy;
    };
 } // namespace clap

plugins/gui/CMakeLists.txt

@@ -47,6 +47,8 @@ add_library(
   threaded-gui-factory.cc
   threaded-gui-proxy.hh
   threaded-gui-proxy.cc
+  threaded-gui-listener-proxy.hh
+  threaded-gui-listener-proxy.cc
   timer.hh
   timer.cc
   cf-timer.hh

plugins/gui/abstract-gui-listener.hh

@@ -3,6 +3,7 @@
 #include <string>
 #include <variant>
 #include <vector>
+#include <functional>
 
 #include <clap/clap.h>
 
@@ -17,6 +18,8 @@ namespace clap {
    public:
       virtual ~AbstractGuiListener();
 
+      virtual void onGuiRunOnMainThread(std::function<void()> callback) = 0;
+
       // timer based polling of new parameter changes, transport value, ...
       // the plugin shall transmit them via
       virtual void onGuiPoll() = 0;

plugins/gui/threaded-gui-listener-proxy.cc

@@ -0,0 +1,48 @@
+#include "threaded-gui-listener-proxy.hh"
+
+namespace clap {
+   ThreadedGuiListenerProxy::ThreadedGuiListenerProxy(AbstractGuiListener &guiListener)
+      : _guiListener(guiListener) {}
+
+   void ThreadedGuiListenerProxy::onGuiRunOnMainThread(std::function<void()> callback) {
+      _guiListener.onGuiRunOnMainThread(std::move(callback));
+   }
+
+   void ThreadedGuiListenerProxy::onGuiPoll() {
+      onGuiRunOnMainThread([this] { _guiListener.onGuiPoll(); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiParamBeginAdjust(clap_id paramId) {
+      onGuiRunOnMainThread([this, paramId] { _guiListener.onGuiParamBeginAdjust(paramId); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiParamAdjust(clap_id paramId, double value) {
+      onGuiRunOnMainThread([this, paramId, value] { _guiListener.onGuiParamAdjust(paramId, value); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiParamEndAdjust(clap_id paramId) {
+      onGuiRunOnMainThread([this, paramId] { _guiListener.onGuiParamEndAdjust(paramId); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiSetTransportIsSubscribed(bool isSubscribed) {
+      onGuiRunOnMainThread(
+         [this, isSubscribed] { _guiListener.onGuiSetTransportIsSubscribed(isSubscribed); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiWindowClosed(bool wasDestroyed) {
+      onGuiRunOnMainThread([this, wasDestroyed] { _guiListener.onGuiWindowClosed(wasDestroyed); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiUndo() {
+      onGuiRunOnMainThread([this] { _guiListener.onGuiUndo(); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiRedo() {
+      onGuiRunOnMainThread([this] { _guiListener.onGuiRedo(); });
+   }
+
+   void ThreadedGuiListenerProxy::onGuiInvoke(const std::string &method,
+                                              const InvocationArgumentsType &args) {
+      onGuiRunOnMainThread([this, method, args] { _guiListener.onGuiInvoke(method, args); });
+   }
+} // namespace clap

plugins/gui/threaded-gui-listener-proxy.hh

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "abstract-gui-listener.hh"
+
+namespace clap {
+   class ThreadedGuiListenerProxy final : public AbstractGuiListener {
+   public:
+      ThreadedGuiListenerProxy(AbstractGuiListener &guiListener);
+
+      void onGuiRunOnMainThread(std::function<void()> callback) override;
+
+      void onGuiPoll() override;
+
+      void onGuiParamBeginAdjust(clap_id paramId) override;
+      void onGuiParamAdjust(clap_id paramId, double value) override;
+      void onGuiParamEndAdjust(clap_id paramId) override;
+
+      void onGuiSetTransportIsSubscribed(bool isSubscribed) override;
+
+      void onGuiWindowClosed(bool wasDestroyed) override;
+
+      void onGuiUndo() override;
+      void onGuiRedo() override;
+
+      void onGuiInvoke(const std::string &method, const InvocationArgumentsType &args) override;
+
+   private:
+      AbstractGuiListener &_guiListener;
+   };
+} // namespace clap