Work around resizing bug in Surge XT/CJE

src/wine-host/bridges/clap-impls/host-proxy.cpp

@@ -218,6 +218,19 @@ bool CLAP_ABI clap_host_proxy::ext_gui_request_resize(const clap_host_t* host,
     assert(host && host->host_data);
     auto self = static_cast<const clap_host_proxy*>(host->host_data);
 
+    // HACK: Surge XT/the CLAP JUCE Extensions get stuck in a resize loop when
+    //       the host tries to resize the window. It will send
+    //       `clap_host_gui::request_resize()` in response to
+    //       `clap_plugin_gui::set_size()` with the same size it has just set.
+    //       We'll need to filter these calls out to prevent this from causing
+    //       issues.
+    if (const std::optional<Size> current_size =
+            self->bridge_.editor_size(self->owner_instance_id());
+        current_size && current_size->width == width &&
+        current_size->height == height) {
+        return true;
+    }
+
     const bool result =
         self->bridge_.send_mutually_recursive_main_thread_message(
             clap::ext::gui::host::RequestResize{

src/wine-host/bridges/clap.cpp

@@ -508,15 +508,23 @@ void ClapBridge::run() {
                     [&, plugin = instance.plugin.get(),
                      gui = instance.extensions.gui,
                      &editor = instance.editor]() {
+                        assert(editor);
+
+                        // HACK: We need to resize the editor window before
+                        //       setting the size on the plugin. Surge XT and
+                        //       presumably other CLAP JUCE Extensions plugins
+                        //       will request a resize to the same size that was
+                        //       just set. This causes a resize loop, so we'll
+                        //       try to prevent resizes to the same size.
+                        const Size old_size = editor->size();
+                        editor->resize(request.width, request.height);
+
                         if (gui->set_size(plugin, request.width,
                                           request.height)) {
-                            // Also resize the editor window. We do the same
-                            // thing when the plugin requests a resize.
-                            assert(editor);
-                            editor->resize(request.width, request.height);
-
                             return true;
                         } else {
+                            editor->resize(old_size.width, old_size.height);
+
                             return false;
                         }
                     });
@@ -745,6 +753,16 @@ bool ClapBridge::maybe_resize_editor(size_t instance_id,
     }
 }
 
+std::optional<Size> ClapBridge::editor_size(size_t instance_id) {
+    const auto& [instance, _] = get_instance(instance_id);
+
+    if (instance.editor) {
+        return instance.editor->size();
+    } else {
+        return std::nullopt;
+    }
+}
+
 void ClapBridge::close_sockets() {
     sockets_.close();
 }

src/wine-host/bridges/clap.h

@@ -219,6 +219,12 @@ class ClapBridge : public HostBridge {
                              uint16_t width,
                              uint16_t height);
 
+    /**
+     * Get the plugin instance's current editor size, if it has an active
+     * editor.
+     */
+    std::optional<Size> editor_size(size_t instance_id);
+
    protected:
     void close_sockets() override;
 

src/wine-host/editor.cpp

@@ -270,6 +270,7 @@ Editor::Editor(MainContext& main_context,
       x11_connection_(xcb_connect(nullptr, nullptr), xcb_disconnect),
       dnd_proxy_handle_(WineXdndProxy::get_handle()),
       client_area_(get_maximum_screen_dimensions(*x11_connection_)),
+      wrapper_window_size_({128, 128}),
       // Create a window without any decoratiosn for easy embedding. The
       // combination of `WS_EX_TOOLWINDOW` and `WS_POPUP` causes the window to
       // be drawn without any decorations (making resizes behave as you'd
@@ -319,7 +320,8 @@ Editor::Editor(MainContext& main_context,
       parent_window_(parent_window_handle),
       wrapper_window_(
           x11_connection_,
-          [parent_window = parent_window_](
+          [parent_window = parent_window_,
+           wrapper_window_size = wrapper_window_size_](
               std::shared_ptr<xcb_connection_t> x11_connection,
               xcb_window_t window) {
               xcb_generic_error_t* error = nullptr;
@@ -330,10 +332,11 @@ Editor::Editor(MainContext& main_context,
                                        &error));
               THROW_X11_ERROR(error);
 
-              xcb_create_window(x11_connection.get(), XCB_COPY_FROM_PARENT,
-                                window, query_reply->root, 0, 0, 128, 128, 0,
-                                XCB_WINDOW_CLASS_INPUT_OUTPUT,
-                                XCB_COPY_FROM_PARENT, 0, nullptr);
+              xcb_create_window(
+                  x11_connection.get(), XCB_COPY_FROM_PARENT, window,
+                  query_reply->root, 0, 0, wrapper_window_size.width,
+                  wrapper_window_size.height, 0, XCB_WINDOW_CLASS_INPUT_OUTPUT,
+                  XCB_COPY_FROM_PARENT, 0, nullptr);
           }),
       wine_window_(get_x11_handle(win32_window_.handle_)),
       host_window_(find_host_window(*x11_connection_,
@@ -429,6 +432,12 @@ void Editor::resize(uint16_t width, uint16_t height) {
                          value_mask, values.data());
     xcb_flush(x11_connection_.get());
 
+    // NOTE: This lets us skip resize requests in CLAP plugins when the plugin
+    //       tries to resize to its current size. This fixes resize loops when
+    //       using the CLAP JUCE Extensions.
+    wrapper_window_size_.width = width;
+    wrapper_window_size_.height = height;
+
     // When the `editor_coordinate_hack` option is enabled, we will make sure
     // that the window is actually placed at (0, 0) coordinates. Otherwise some
     // plugins that rely on screen coordinates, like the Soundtoys plugins and

src/wine-host/editor.h

@@ -261,6 +261,11 @@ class Editor {
      */
     void run_timer_proc();
 
+    /**
+     * Get the editor's (or, the wrapper window's) current size.
+     */
+    inline Size size() const noexcept { return wrapper_window_size_; }
+
     /**
      * Whether to reposition `win32_window_` to (0, 0) every time the window
      * resizes. This can help with buggy plugins that use the (top level)
@@ -361,12 +366,17 @@ class Editor {
      * will be set to a size that's large enough to be able to enter full screen
      * on a single display. This is more of a theoretical maximum size, as the
      * plugin will only use a portion of this window to draw to. Because we're
-     * not changing the size of the Wine window and simply letting the user or
-     * the host resize the X11 parent window it's been embedded in instead,
-     * resizing will feel smooth and native.
+     * not changing the size of the Wine window and only resize the wrapper
+     * window it's been embedded in, resizing will feel smooth and native.
      */
     const Size client_area_;
 
+    /**
+     * The size of the wrapper window. We'll prevent CLAP resize requests when
+     * the wrapper window is already at the correct size.
+     */
+    Size wrapper_window_size_;
+
     /**
      * The handle for the window created through Wine that the plugin uses to
      * embed itself in.