Start experimenting with embed-ui API, for use in external tools

Signed-off-by: falkTX <falktx@falktx.com>

source/backend/CarlaBackend.h

@@ -188,6 +188,13 @@ static const uint PLUGIN_USES_MULTI_PROGS = 0x400;
  */
 static const uint PLUGIN_HAS_INLINE_DISPLAY = 0x800;
 
+/*!
+ * Plugin has its own custom UI which can be embed into another Window.
+ * @see CarlaPlugin::embedCustomUI() and carla_embed_custom_ui()
+ * @note This is very experimental and subject to change at this point
+ */
+static const uint PLUGIN_HAS_CUSTOM_EMBED_UI = 0x1000;
+
 /** @} */
 
 /* ------------------------------------------------------------------------------------------------------------
@@ -1153,6 +1160,14 @@ typedef enum {
      */
     ENGINE_CALLBACK_PATCHBAY_CLIENT_POSITION_CHANGED = 47,
 
+    /*!
+     * A plugin embed UI has been resized.
+     * @a pluginId Plugin Id to resize
+     * @a value1   New width
+     * @a value2   New height
+     */
+    ENGINE_CALLBACK_EMBED_UI_RESIZED = 48,
+
 } EngineCallbackOpcode;
 
 /* ------------------------------------------------------------------------------------------------------------

source/backend/CarlaHost.h

@@ -1121,6 +1121,13 @@ CARLA_EXPORT void carla_set_custom_ui_title(CarlaHostHandle handle, uint pluginI
  */
 CARLA_EXPORT void carla_show_custom_ui(CarlaHostHandle handle, uint pluginId, bool yesNo);
 
+/*!
+  * Embed the plugin's custom UI to the system pointer @a ptr.
+  * This function is always called from the main thread.
+  * @note This is very experimental and subject to change at this point
+  */
+CARLA_EXPORT void* carla_embed_custom_ui(CarlaHostHandle handle, uint pluginId, void* ptr);
+
 /*!
  * Get the current engine buffer size.
  */

source/backend/CarlaPlugin.hpp

@@ -802,6 +802,13 @@ public:
      */
     virtual void showCustomUI(bool yesNo);
 
+    /*!
+     * Embed the plugin's custom UI to the system pointer @a ptr.
+     * This function is always called from the main thread.
+     * @note This is very experimental and subject to change at this point
+     */
+    virtual void* embedCustomUI(void* ptr);
+
     /*!
      * UI idle function, called at regular intervals.
      * This function is only called from the main thread if PLUGIN_NEEDS_UI_MAIN_THREAD is set.

source/backend/CarlaStandalone.cpp

@@ -2167,6 +2167,16 @@ void carla_show_custom_ui(CarlaHostHandle handle, uint pluginId, bool yesNo)
         plugin->showCustomUI(yesNo);
 }
 
+void* carla_embed_custom_ui(CarlaHostHandle handle, uint pluginId, void* ptr)
+{
+    CARLA_SAFE_ASSERT_RETURN(handle->engine != nullptr, nullptr);
+
+    if (const CarlaPluginPtr plugin = handle->engine->getPlugin(pluginId))
+        return plugin->embedCustomUI(ptr);
+
+    return nullptr;
+}
+
 // --------------------------------------------------------------------------------------------------------------------
 
 uint32_t carla_get_buffer_size(CarlaHostHandle handle)

source/backend/plugin/CarlaPlugin.cpp

@@ -2375,6 +2375,11 @@ void CarlaPlugin::showCustomUI(const bool yesNo)
     }
 }
 
+void* CarlaPlugin::embedCustomUI(void*)
+{
+    return nullptr;
+}
+
 void CarlaPlugin::uiIdle()
 {
     if (pData->hints & PLUGIN_NEEDS_UI_MAIN_THREAD)

source/backend/plugin/CarlaPluginLV2.cpp

@@ -1561,7 +1561,7 @@ public:
             return;
         }
 
-        const uintptr_t frontendWinId(pData->engine->getOptions().frontendWinId);
+        const uintptr_t frontendWinId = pData->engine->getOptions().frontendWinId;
 
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
         if (! yesNo)
@@ -1845,6 +1845,27 @@ public:
         }
     }
 
+#ifndef LV2_UIS_ONLY_BRIDGES
+    void* embedCustomUI(void* const ptr) override
+    {
+        CARLA_SAFE_ASSERT_RETURN(fUI.type == UI::TYPE_EMBED, nullptr);
+        CARLA_SAFE_ASSERT_RETURN(fUI.descriptor != nullptr, nullptr);
+        CARLA_SAFE_ASSERT_RETURN(fUI.descriptor->instantiate != nullptr, nullptr);
+        CARLA_SAFE_ASSERT_RETURN(fUI.descriptor->cleanup != nullptr, nullptr);
+        CARLA_SAFE_ASSERT_RETURN(fUI.rdfDescriptor->Type != LV2_UI_NONE, nullptr);
+        CARLA_SAFE_ASSERT_RETURN(fUI.window == nullptr, nullptr);
+
+        fFeatures[kFeatureIdUiParent]->data = ptr;
+
+        fUI.embedded = true;
+        fUI.widget = nullptr;
+        fUI.handle = fUI.descriptor->instantiate(fUI.descriptor, fRdfDescriptor->URI, fUI.rdfDescriptor->Bundle,
+                                                 carla_lv2_ui_write_function, this, &fUI.widget, fFeatures);
+
+        return fUI.widget;
+    }
+#endif
+
     void idle() override
     {
         if (fAtomBufferWorkerIn.isDataAvailableForReading())
@@ -5457,12 +5478,24 @@ public:
 
     int handleUIResize(const int width, const int height)
     {
-        CARLA_SAFE_ASSERT_RETURN(fUI.window != nullptr, 1);
         CARLA_SAFE_ASSERT_RETURN(width > 0, 1);
         CARLA_SAFE_ASSERT_RETURN(height > 0, 1);
         carla_debug("CarlaPluginLV2::handleUIResize(%i, %i)", width, height);
 
-        fUI.window->setSize(static_cast<uint>(width), static_cast<uint>(height), true);
+
+        if (fUI.embedded)
+        {
+            pData->engine->callback(true, true,
+                                    ENGINE_CALLBACK_EMBED_UI_RESIZED,
+                                    pData->id, width, height,
+                                    0, 0.0f, nullptr);
+        }
+        else
+        {
+            CARLA_SAFE_ASSERT_RETURN(fUI.window != nullptr, 1);
+            fUI.window->setSize(static_cast<uint>(width), static_cast<uint>(height), true);
+        }
+
         return 0;
     }
 
@@ -6712,6 +6745,7 @@ private:
         const LV2UI_Descriptor* descriptor;
         const LV2_RDF_UI*       rdfDescriptor;
 
+        bool embedded;
         bool fileBrowserOpen;
         const char* fileNeededForURI;
         CarlaPluginUI* window;
@@ -6722,6 +6756,7 @@ private:
               widget(nullptr),
               descriptor(nullptr),
               rdfDescriptor(nullptr),
+              embedded(false),
               fileBrowserOpen(false),
               fileNeededForURI(nullptr),
               window(nullptr) {}

source/utils/CarlaBackendUtils.hpp

@@ -317,6 +317,8 @@ const char* EngineCallbackOpcode2Str(const EngineCallbackOpcode opcode) noexcept
         return "ENGINE_CALLBACK_PARAMETER_MAPPED_RANGE_CHANGED";
     case ENGINE_CALLBACK_PATCHBAY_CLIENT_POSITION_CHANGED:
         return "ENGINE_CALLBACK_PATCHBAY_CLIENT_POSITION_CHANGED";
+    case ENGINE_CALLBACK_EMBED_UI_RESIZED:
+        return "ENGINE_CALLBACK_EMBED_UI_RESIZED";
     }
 
     carla_stderr("CarlaBackend::EngineCallbackOpcode2Str(%i) - invalid opcode", opcode);