Create Vst3HostContextProxy from YaHostApplication

This is quite a huge refactor, but note everything is consistent (and
we're going to need one or two more of these `Vst3*Proxy` objects).
Right now nothing extends `IHostApplication`, but this way it will be
trivial to add support for more host context interfaces.

src/plugin/bridges/vst3-impls/plugin-factory.cpp

@@ -100,24 +100,21 @@ YaPluginFactoryImpl::createInstance(Steinberg::FIDString cid,
 
 tresult PLUGIN_API
 YaPluginFactoryImpl::setHostContext(Steinberg::FUnknown* context) {
-    // This `context` will likely be an `IHostApplication`. If it is, we will
-    // store it for future calls, create a proxy object on the Wine side, and
-    // then pass it to the Windows VST3 plugin's plugin factory using the same
-    // function. If we get passed anything else we'll just return instead since
-    // there's nothing we can do with it.
-    host_application_context = context;
+    // We will create a proxy object that that supports all the same interfaces
+    // as `context`, and then we'll store `context` in this object. We can then
+    // use it to handle callbacks made by the Windows VST3 plugin to this
+    // context.
+    host_context = context;
 
-    if (host_application_context) {
-        YaHostApplication::ConstructArgs host_application_context_args(
-            host_application_context, std::nullopt);
-
-        return bridge.send_message(YaPluginFactory::SetHostContext{
-            .host_application_context_args =
-                std::move(host_application_context_args)});
+    std::optional<Vst3HostContextProxy::ConstructArgs> host_context_args{};
+    if (host_context) {
+        host_context_args =
+            Vst3HostContextProxy::ConstructArgs(host_context, std::nullopt);
     } else {
-        bridge.logger.log_unknown_interface(
-            "In IPluginFactory3::setHostContext(), ignoring",
-            context ? std::optional(context->iid) : std::nullopt);
-        return Steinberg::kNotImplemented;
+        bridge.logger.log(
+            "Null pointer passed to 'IPluginFactory3::setHostContext()'");
     }
+
+    return bridge.send_message(YaPluginFactory::SetHostContext{
+        .host_context_args = std::move(host_context_args)});
 }

src/plugin/bridges/vst3-impls/plugin-factory.h

@@ -32,9 +32,8 @@ class YaPluginFactoryImpl : public YaPluginFactory {
     Vst3PluginBridge& bridge;
 
     /**
-     * An `IHostApplication` instance if we get one through
+     * An host context if we get passed one through
      * `IPluginFactory3::setHostContext()`.
      */
-    Steinberg::FUnknownPtr<Steinberg::Vst::IHostApplication>
-        host_application_context;
+    Steinberg::IPtr<Steinberg::FUnknown> host_context;
 };

src/plugin/bridges/vst3-impls/plugin-proxy.cpp

@@ -315,18 +315,18 @@ Vst3PluginProxyImpl::setParamNormalized(Steinberg::Vst::ParamID id,
 
 tresult PLUGIN_API Vst3PluginProxyImpl::setComponentHandler(
     Steinberg::Vst::IComponentHandler* handler) {
+    // We'll store the pointer for when the plugin later makes a callback to
+    // this component handler
+    component_handler = handler;
+
     std::optional<Vst3ComponentHandlerProxy::ConstructArgs>
         component_handler_proxy_args = std::nullopt;
     if (handler) {
-        // We'll store the pointer for when the plugin later makes a callback to
-        // this component handler
-        component_handler = handler;
-
         component_handler_proxy_args = Vst3ComponentHandlerProxy::ConstructArgs(
             component_handler, instance_id());
     } else {
         bridge.logger.log(
-            "Null pointer passed to 'IEditController::setComponentHandler'");
+            "Null pointer passed to 'IEditController::setComponentHandler()'");
     }
 
     return bridge.send_message(YaEditController::SetComponentHandler{
@@ -362,27 +362,23 @@ tresult PLUGIN_API Vst3PluginProxyImpl::openAboutBox(TBool onlyCheck) {
 }
 
 tresult PLUGIN_API Vst3PluginProxyImpl::initialize(FUnknown* context) {
-    // This `context` will likely be an `IHostApplication`. If it is, we
-    // will store it here, and we'll proxy through all calls to it made from
-    // the Wine side. Otherwise we'll still call `IPluginBase::initialize()`
-    // but with a null pointer instead.
-    host_application_context = context;
+    // We will create a proxy object that that supports all the same interfaces
+    // as `context`, and then we'll store `context` in this object. We can then
+    // use it to handle callbacks made by the Windows VST3 plugin to this
+    // context.
+    host_context = context;
 
-    std::optional<YaHostApplication::ConstructArgs>
-        host_application_context_args = std::nullopt;
-    if (host_application_context) {
-        host_application_context_args = YaHostApplication::ConstructArgs(
-            host_application_context, instance_id());
+    std::optional<Vst3HostContextProxy::ConstructArgs> host_context_args{};
+    if (host_context) {
+        host_context_args =
+            Vst3HostContextProxy::ConstructArgs(host_context, instance_id());
     } else {
-        bridge.logger.log_unknown_interface(
-            "In IPluginBase::initialize()",
-            context ? std::optional(context->iid) : std::nullopt);
+        bridge.logger.log("Null pointer passed to 'IPluginBase::initialize()'");
     }
 
-    return bridge.send_message(
-        YaPluginBase::Initialize{.instance_id = instance_id(),
-                                 .host_application_context_args =
-                                     std::move(host_application_context_args)});
+    return bridge.send_message(YaPluginBase::Initialize{
+        .instance_id = instance_id(),
+        .host_context_args = std::move(host_context_args)});
 }
 
 tresult PLUGIN_API Vst3PluginProxyImpl::terminate() {

src/plugin/bridges/vst3-impls/plugin-proxy.h

@@ -122,15 +122,6 @@ class Vst3PluginProxyImpl : public Vst3PluginProxy {
     tresult PLUGIN_API initialize(FUnknown* context) override;
     tresult PLUGIN_API terminate() override;
 
-    /**
-     * An `IHostApplication` instance if we get one through
-     * `IPluginBase::initialize()`. This should be the same for all plugin
-     * instances so we should not have to store it here separately, but for the
-     * sake of correctness we will.
-     */
-    Steinberg::FUnknownPtr<Steinberg::Vst::IHostApplication>
-        host_application_context;
-
     /**
      * The component handler the host passed to us during
      * `IEditController::setComponentHandler()`. When the plugin makes a
@@ -141,4 +132,13 @@ class Vst3PluginProxyImpl : public Vst3PluginProxy {
 
    private:
     Vst3PluginBridge& bridge;
+
+    /**
+     * An host context if we get passed one through `IPluginBase::initialize()`.
+     * We'll read which interfaces it supports and we'll then create a proxy
+     * object that supports those same interfaces. This should be the same for
+     * all plugin instances so we should not have to store it here separately,
+     * but for the sake of correctness we will.
+     */
+    Steinberg::IPtr<Steinberg::FUnknown> host_context;
 };