Implement X11 TransierForHint for LV2 embed UIs

source/backend/CarlaHost.h

@@ -1079,6 +1079,7 @@ CARLA_EXPORT const char* carla_get_host_osc_url_udp();
 /*!
  * Implemented in standalone.
  */
+extern ulong carla_standalone_get_transient_win_id();
 extern const char* carla_standalone_file_callback(FileCallbackOpcode action, bool isDir, const char* title, const char* filter);
 
 #endif /* CARLA_HOST_H_INCLUDED */

source/backend/plugin/CarlaPluginUi.cpp

@@ -149,6 +149,14 @@ public:
         XStoreName(fDisplay, fWindow, title);
     }
 
+    void setTransientWinId(const uintptr_t winId) override
+    {
+        CARLA_SAFE_ASSERT_RETURN(fDisplay != nullptr,);
+        CARLA_SAFE_ASSERT_RETURN(fWindow != 0,);
+
+        XSetTransientForHint(fDisplay, fWindow, (Window)winId);
+    }
+
     void* getPtr() const noexcept
     {
         return (void*)fWindow;

source/backend/plugin/CarlaPluginUi.hpp

@@ -38,6 +38,7 @@ public:
     virtual void idle() = 0;
     virtual void setSize(const uint with, const uint height, const bool forceUpdate) = 0;
     virtual void setTitle(const char* const title) = 0;
+    virtual void setTransientWinId(const uintptr_t winId) = 0;
     virtual void* getPtr() const noexcept = 0;
 
 #ifdef CARLA_OS_MAC

source/backend/plugin/Lv2Plugin.cpp

@@ -24,6 +24,8 @@
 #include "CarlaMathUtils.hpp"
 
 #include "CarlaLv2Utils.hpp"
+
+#include "CarlaHost.h"
 #include "CarlaPluginUi.hpp"
 #include "Lv2AtomQueue.hpp"
 
@@ -1158,6 +1160,9 @@ public:
                 if (fUi.window == nullptr)
                     return pData->engine->callback(ENGINE_CALLBACK_UI_STATE_CHANGED, pData->id, -1, 0, 0.0f, msg);
 
+                if (const uintptr_t transientId = carla_standalone_get_transient_win_id())
+                    fUi.window->setTransientWinId(transientId);
+
                 fUi.window->setTitle(fUi.title);
 
 #if 0

source/backend/plugin/Makefile

@@ -78,7 +78,7 @@ LadspaPlugin.cpp.o: LadspaPlugin.cpp $(CARLA_PLUGIN_INTERNAL_HPP) $(CARLA_ENGINE
 DssiPlugin.cpp.o: DssiPlugin.cpp $(CARLA_PLUGIN_INTERNAL_HPP) $(CARLA_ENGINE_HPP) $(CARLA_DSSI_UTILS_HPP) $(CARLA_MATH_UTILS_HPP)
 	$(CXX) $< $(BUILD_CXX_FLAGS) $(QTCORE_FLAGS) -c -o $@
 
-Lv2Plugin.cpp.o: Lv2Plugin.cpp $(CARLA_PLUGIN_INTERNAL_HPP) $(CARLA_ENGINE_HPP) $(CARLA_MATH_UTILS_HPP) $(CARLA_LV2_UTILS_HPP) $(CARLA_PLUGIN_UI_HPP) $(LV2_ATOM_QUEUE_HPP) $(CARLA_ENGINE_OSC_HPP)
+Lv2Plugin.cpp.o: Lv2Plugin.cpp $(CARLA_PLUGIN_INTERNAL_HPP) $(CARLA_ENGINE_HPP) $(CARLA_MATH_UTILS_HPP) $(CARLA_LV2_UTILS_HPP) $(CARLA_HOST_H) $(CARLA_PLUGIN_UI_HPP) $(LV2_ATOM_QUEUE_HPP) $(CARLA_ENGINE_OSC_HPP)
 	$(CXX) $< $(BUILD_CXX_FLAGS) $(QTCORE_FLAGS) -c -o $@
 
 VstPlugin.cpp.o: VstPlugin.cpp $(CARLA_PLUGIN_INTERNAL_HPP) $(CARLA_ENGINE_HPP) $(CARLA_VST_UTILS_HPP) $(CARLA_MATH_UTILS_HPP)

source/backend/standalone/CarlaStandalone.cpp

@@ -113,6 +113,15 @@ struct CarlaBackendStandalone {
 
 static CarlaBackendStandalone gStandalone;
 
+// -------------------------------------------------------------------------------------------------------------------
+
+static ulong gTransientWinId = 0;
+
+ulong carla_standalone_get_transient_win_id()
+{
+    return gTransientWinId;
+}
+
 // -------------------------------------------------------------------------------------------------------------------
 // API
 
@@ -571,6 +580,13 @@ void carla_set_engine_option(EngineOption option, int value, const char* valueSt
     switch (option)
     {
     case CB::ENGINE_OPTION_DEBUG:
+        if (value == -1729)
+        {
+            CARLA_SAFE_ASSERT_BREAK(valueStr != nullptr && valueStr[0] != '\0');
+            const long winId(std::atol(valueStr));
+            CARLA_SAFE_ASSERT_BREAK(winId != 0);
+            gTransientWinId = static_cast<ulong>(winId);
+        }
         break;
 
     case CB::ENGINE_OPTION_PROCESS_MODE:

source/carla

@@ -303,11 +303,8 @@ if __name__ == '__main__':
 
     Carla.gui = CarlaHostW()
 
-    # test
-    win = Carla.gui.winId()
-
-    if win:
-        os.environ["CARLA_TRANSIENT_WINDOW"] = str(win)
+    # set our gui as transient for all plugins UIs
+    Carla.host.set_engine_option(ENGINE_OPTION_DEBUG, -1729, str(Carla.gui.winId()))
 
     # -------------------------------------------------------------
     # Load project file if set

source/carla-patchbay

@@ -87,6 +87,9 @@ if __name__ == '__main__':
 
     Carla.gui = CarlaHostW()
 
+    # set our gui as transient for all plugins UIs
+    Carla.host.set_engine_option(ENGINE_OPTION_DEBUG, -1729, str(Carla.gui.winId()))
+
     # -------------------------------------------------------------
     # Load project file if set
 

source/carla-rack

@@ -87,6 +87,9 @@ if __name__ == '__main__':
 
     Carla.gui = CarlaHostW()
 
+    # set our gui as transient for all plugins UIs
+    Carla.host.set_engine_option(ENGINE_OPTION_DEBUG, -1729, str(Carla.gui.winId()))
+
     # -------------------------------------------------------------
     # Load project file if set
 

source/plugin/carla-native-base.cpp

@@ -29,7 +29,12 @@
 
 // -----------------------------------------------------------------------
 
-const char* carla_file_callback(FileCallbackOpcode action, bool isDir, const char* title, const char* filter)
+ulong carla_standalone_get_transient_win_id()
+{
+    return 0;
+}
+
+const char* carla_standalone_file_callback(FileCallbackOpcode action, bool isDir, const char* title, const char* filter)
 {
     CARLA_SAFE_ASSERT_RETURN(title != nullptr && title[0] != '\0', nullptr);
     CARLA_SAFE_ASSERT_RETURN(filter != nullptr && filter[0] != '\0', nullptr);