Add boilerplate for Vst3ComponentHandlerProxy

src/common/serialization/vst3/README.md

@@ -19,11 +19,14 @@ VST3 plugin interfaces are implemented as follows:
 
 VST3 host interfaces are implemented as follows:
 
-| yabridge class      | Interfaces         |
-| ------------------- | ------------------ |
-| `YaHostApplication` | `IHostApplication` |
+| yabridge class              | Included in                 | Interfaces          |
+| --------------------------- | --------------------------- | ------------------- |
+| `YaHostApplication`         |                             | `IHostApplication`  |
+| `Vst3ComponentHandlerProxy` |                             | All of the below:   |
+| `YaComponentHandler`        | `Vst3ComponentHandlerProxy` | `IComponentHandler` |
 
-The following (host) interfaces are also implemented for serialization purposes:
+The following host interfaces are passed as function arguments and are thus also
+implemented for serialization purposes:
 
 | yabridge class       | Interfaces          | Notes                                                                  |
 | -------------------- | ------------------- | ---------------------------------------------------------------------- |

src/common/serialization/vst3/component-handler-proxy.h

@@ -0,0 +1,115 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include "../common.h"
+#include "base.h"
+#include "host-application.h"
+#include "plugin/audio-processor.h"
+#include "plugin/component.h"
+#include "plugin/connection-point.h"
+#include "plugin/edit-controller.h"
+#include "plugin/plugin-base.h"
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+
+/**
+ * An abstract class that implements `IComponentHandler`, and optionally also
+ * all other VST3 interfaces an object passed to
+ * `IEditController::setComponentHandler()`. This works exactly the same as
+ * `Vst3PluginProxy`, but instead of proxying for an object provided by the
+ * plugin we are proxying for the `IComponentHandler*` argument passed to plugin
+ * by the host.
+ */
+class Vst3ComponentHandlerProxy {
+   public:
+    /**
+     * These are the arguments for constructing a
+     * `Vst3ComponentHandlerProxyImpl`.
+     */
+    struct ConstructArgs {
+        ConstructArgs();
+
+        /**
+         * Read from an existing object. We will try to mimic this object, so
+         * we'll support any interfaces this object also supports.
+         */
+        ConstructArgs(Steinberg::IPtr<FUnknown> object,
+                      size_t owner_instance_id);
+
+        /**
+         * The unique instance identifier of the proxy object instance this
+         * component handler has been passed to and thus belongs to. This way we
+         * can refer to the correct 'actual' `IComponentHandler` instance when
+         * the plugin does a callback.
+         */
+        native_size_t owner_instance_id;
+
+        // TODO:
+        // YaAudioProcessor::ConstructArgs audio_processor_args;
+        // YaComponent::ConstructArgs component_args;
+        // YaConnectionPoint::ConstructArgs connection_point_args;
+        // YaEditController::ConstructArgs edit_controller_2_args;
+        // YaPluginBase::ConstructArgs plugin_base_args;
+
+        template <typename S>
+        void serialize(S& s) {
+            s.value8b(owner_instance_id);
+            // TODO:
+            // s.object(audio_processor_args);
+            // s.object(component_args);
+            // s.object(connection_point_args);
+            // s.object(edit_controller_2_args);
+            // s.object(plugin_base_args);
+        }
+    };
+
+    /**
+     * Instantiate this instance with arguments read from an actual component
+     * handler.
+     *
+     * @note Since this is passed as part of
+     *   `IEditController::setComponentHandler()`, there are no direct
+     *   `Construct` or `Destruct` messages. This object's lifetime is bound to
+     *   that of the objects they are passed to. If those objects get dropped,
+     *   then the host contexts should also be dropped.
+     */
+    Vst3ComponentHandlerProxy(const ConstructArgs&& args);
+
+    /**
+     * The lifetime of this object should be bound to the object we created it
+     * for. When for instance the `Vst3PluginProxy` instance with id `n` gets
+     * dropped a corresponding `Vst3ComponentHandlerProxyImpl` should also be
+     * dropped.
+     */
+    virtual ~Vst3ComponentHandlerProxy() = 0;
+
+    DECLARE_FUNKNOWN_METHODS
+
+    /**
+     * Get the instance ID of the owner of this object.
+     */
+    inline size_t owner_instance_id() const {
+        return arguments.owner_instance_id;
+    }
+
+   private:
+    ConstructArgs arguments;
+};
+
+#pragma GCC diagnostic pop

src/common/serialization/vst3/host-application.h

@@ -90,8 +90,8 @@ class YaHostApplication : public Steinberg::Vst::IHostApplication {
     /**
      * The lifetime of this object should be bound to the object we created it
      * for. When for instance the `Vst3PluginProxy` instance with id `n` gets
-     * dropped and we also track a `YaHostApplicationImpl` for the component
-     * with instance id `n`, then that should also be dropped.
+     * dropped, the corresponding `YaHostApplicationImpl` then that should also
+     * be dropped.
      */
     virtual ~YaHostApplication();
 

src/common/serialization/vst3/plugin-proxy.h

@@ -17,11 +17,8 @@
 #pragma once
 
 #include <bitsery/ext/std_variant.h>
-#include <pluginterfaces/vst/ivstcomponent.h>
 
 #include "../common.h"
-#include "base.h"
-#include "host-application.h"
 #include "plugin/audio-processor.h"
 #include "plugin/component.h"
 #include "plugin/connection-point.h"