Implement the host side of the GUI functions

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

@@ -21,6 +21,8 @@
 ClapHostExtensions::ClapHostExtensions(const clap_host& host) noexcept
     : audio_ports(static_cast<const clap_host_audio_ports_t*>(
           host.get_extension(&host, CLAP_EXT_AUDIO_PORTS))),
+      gui(static_cast<const clap_host_gui_t*>(
+          host.get_extension(&host, CLAP_EXT_GUI))),
       latency(static_cast<const clap_host_latency_t*>(
           host.get_extension(&host, CLAP_EXT_LATENCY))),
       note_ports(static_cast<const clap_host_note_ports_t*>(
@@ -38,6 +40,7 @@ clap::host::SupportedHostExtensions ClapHostExtensions::supported()
     const noexcept {
     return clap::host::SupportedHostExtensions{
         .supports_audio_ports = audio_ports != nullptr,
+        .supports_gui = gui != nullptr,
         .supports_latency = latency != nullptr,
         .supports_note_ports = note_ports != nullptr,
         .supports_params = params != nullptr,

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

@@ -21,6 +21,7 @@
 #include <vector>
 
 #include <clap/ext/audio-ports.h>
+#include <clap/ext/gui.h>
 #include <clap/ext/latency.h>
 #include <clap/ext/note-ports.h>
 #include <clap/ext/params.h>
@@ -62,6 +63,7 @@ struct ClapHostExtensions {
     clap::host::SupportedHostExtensions supported() const noexcept;
 
     const clap_host_audio_ports_t* audio_ports = nullptr;
+    const clap_host_gui_t* gui = nullptr;
     const clap_host_latency_t* latency = nullptr;
     const clap_host_note_ports_t* note_ports = nullptr;
     const clap_host_params_t* params = nullptr;

src/plugin/bridges/clap.cpp

@@ -115,6 +115,55 @@ ClapPluginBridge::ClapPluginBridge(const ghc::filesystem::path& plugin_path)
 
                     return Ack{};
                 },
+                [&](const clap::ext::gui::host::ResizeHintsChanged& request)
+                    -> clap::ext::gui::host::ResizeHintsChanged::Response {
+                    const auto& [plugin_proxy, _] =
+                        get_proxy(request.owner_instance_id);
+
+                    // This callback is thread-safe
+                    plugin_proxy.host_extensions_.gui->resize_hints_changed(
+                        plugin_proxy.host_);
+
+                    return Ack{};
+                },
+                [&](const clap::ext::gui::host::RequestResize& request)
+                    -> clap::ext::gui::host::RequestResize::Response {
+                    const auto& [plugin_proxy, _] =
+                        get_proxy(request.owner_instance_id);
+
+                    // This callback is thread-safe
+                    return plugin_proxy.host_extensions_.gui->request_resize(
+                        plugin_proxy.host_, request.width, request.height);
+                },
+                [&](const clap::ext::gui::host::RequestShow& request)
+                    -> clap::ext::gui::host::RequestShow::Response {
+                    const auto& [plugin_proxy, _] =
+                        get_proxy(request.owner_instance_id);
+
+                    // This callback is thread-safe
+                    return plugin_proxy.host_extensions_.gui->request_show(
+                        plugin_proxy.host_);
+                },
+                [&](const clap::ext::gui::host::RequestHide& request)
+                    -> clap::ext::gui::host::RequestHide::Response {
+                    const auto& [plugin_proxy, _] =
+                        get_proxy(request.owner_instance_id);
+
+                    // This callback is thread-safe
+                    return plugin_proxy.host_extensions_.gui->request_hide(
+                        plugin_proxy.host_);
+                },
+                [&](const clap::ext::gui::host::Closed& request)
+                    -> clap::ext::gui::host::Closed::Response {
+                    const auto& [plugin_proxy, _] =
+                        get_proxy(request.owner_instance_id);
+
+                    // This callback is thread-safe
+                    plugin_proxy.host_extensions_.gui->closed(
+                        plugin_proxy.host_, request.was_destroyed);
+
+                    return Ack{};
+                },
                 [&](const clap::ext::latency::host::Changed& request)
                     -> clap::ext::latency::host::Changed::Response {
                     const auto& [plugin_proxy, _] =