Add a configuration option for double embedding

Only plugin that needs this so far is PSPaudioware's E27 (and likely
other PSP plugins with expandable GUIs).

src/common/configuration.cpp

@@ -49,6 +49,8 @@ Configuration::Configuration(const fs::path& config_path,
         // If the table is missing some fields then they will simply be left at
         // their defaults
         if (toml::table* config = value.as_table()) {
+            editor_double_embed =
+                (*config)["editor_double_embed"].value<bool>().value_or(false);
             group = (*config)["group"].value<std::string>();
         }
 

src/common/configuration.h

@@ -73,6 +73,20 @@ class Configuration {
     Configuration(const boost::filesystem::path& config_path,
                   const boost::filesystem::path& yabridge_path);
 
+    /**
+     * If this is set to true, then the plugin editor should be embedded in yet
+     * another window. This would result in an embedding sequence of
+     * `<window_provided_by_host> <-> <wine_parent_window> <->
+     * <wine_child_window> <-> <window_created_by_plugin>`, where
+     * `<wine_child_window>` is the new addition. The only plugin I've
+     * encountered where this was necessary was PSPaudioware E27 (and it likely
+     * also applies to other PSPaudioware plugins with expandable GUIs). I also
+     * haven't noticed any issues caused from having this enabled, but having it
+     * behind a flag reduces the amount of moving parts so that's probably a
+     * better idea.
+     */
+    bool editor_double_embed = false;
+
     /**
      * The name of the plugin group that should be used for the plugin this
      * configuration object was created for. If not set, then the plugin should
@@ -92,6 +106,7 @@ class Configuration {
 
     template <typename S>
     void serialize(S& s) {
+        s.value1b(editor_double_embed);
         s.ext(group, bitsery::ext::StdOptional(),
               [](S& s, auto& v) { s.text1b(v, 4096); });
         s.ext(matched_file, bitsery::ext::StdOptional(),

src/plugin/plugin-bridge.cpp

@@ -633,6 +633,13 @@ void PluginBridge::log_init_message() {
         init_msg << ", 64-bit";
     }
     init_msg << "'" << std::endl;
+    init_msg << "other options: '";
+    if (config.editor_double_embed) {
+        init_msg << "editor: double embed";
+    } else {
+        init_msg << "<none>";
+    }
+    init_msg << "'" << std::endl;
     init_msg << std::endl;
 
     // Include a list of enabled compile-tiem features, mostly to make debug