Directly focus wine_window while holding Shift

This lets you type spaces in Bitwig, and it also allows you to interact
with the settings/license popup dialogs in Voxengo plugins in a normal
way.

CHANGELOG.md

@@ -8,6 +8,19 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Added
+
+- Added the ability to directly focus the plugin's editor instead of allowing
+  the host to also process keyboard events by holding down the <kbd>Shift</kbd>
+  key while entering the plugin's GUI with your mouse. Certain hosts like
+  **Bitwig Studio** normally still respond to the common key presses like Space
+  for play/pause while interacting with a plugin. This does mean that it becomes
+  impossible to type a space character in those hosts, which can become a
+  problem when naming presets. With this feature you can temporarily override
+  this behaviour, and allow all keyboard input to go directly to Wine. This can
+  also be useful for _Voxengo_ plugins, which don't grab keyboard focus in their
+  settings and license dialogs.
+
 ### Changed
 
 - Added more tracing for input focus handling when using the `+editor`

README.md

@@ -24,6 +24,7 @@ while also staying easy to debug and maintain.
   - [Bitbridge](#bitbridge)
   - [Wine prefixes](#wine-prefixes)
   - [Drag-and-drop](#drag-and-drop)
+  - [Input focus grabbing](#input-focus-grabbing)
   - [Downgrading Wine](#downgrading-wine)
   - [Installing a development build](#installing-a-development-build)
 - [Configuration](#configuration)
@@ -200,6 +201,24 @@ X11 applications like your DAW. If you're using yabridge in _REAPER_ or _Carla_,
 then you may need to enable a [compatibility option](#compatibility-options) to
 prevent those hosts from stealing the drop.
 
+### Input focus grabbing
+
+Yabridge tries to be clever about the way grabbing input focus for a plugin and
+subsequently giving it back to the host works. One important detail here is that
+when grabbing input focus, yabridge will always focus the _parent window_ passed
+by the host for the plugin to embed itself into. This means that hosts like
+Bitwig Studio can still process common keys like Space for play/pause even while
+interacting with a plugin's GUI. The downside of this approach is that this also
+means that in those hosts you simply cannot type a space character, as the key
+will always go to the host.
+
+For the very specific situations where you may want to focus the plugin's editor
+directly so that all keyboard input goes to Wine, you can hold down the
+<kbd>Shift</kbd> key while entering the plugin's GUI with your mouse. This will
+let you type spaces in text fields in **Bitwig Studio**, type text into the
+settings and license dialogs in **Voxengo** plugins, and it will also allow you
+to navigate dropdowns with the keyboard.
+
 ### Downgrading Wine
 
 There have been a couple of small regressions in Wine after Wine 6.4. If you run

src/wine-host/editor.cpp

@@ -785,7 +785,17 @@ void Editor::fix_local_coordinates() const {
 }
 
 void Editor::set_input_focus(bool grab) const {
-    const xcb_window_t focus_target = grab ? parent_window : host_window;
+    // NOTE: When grabbing focus, you can hold down the shift key to focus the
+    //       Wine window directly. This allows you to use the space key in
+    //       plugin GUIs in Bitwig when necessary (e.g. for naming presets) but
+    //       still allow space to pause/resume the transport when it's not
+    //       needed. It's also needed for dialogs in Voxengo plugins to function
+    //       properly, as they don't grab input focus themselves.
+    const xcb_window_t focus_target =
+        grab ? (get_active_modifiers().value_or(0) & XCB_MOD_MASK_SHIFT
+                    ? wine_window
+                    : parent_window)
+             : host_window;
 
     xcb_generic_error_t* error = nullptr;
     const xcb_get_input_focus_cookie_t focus_cookie =
@@ -865,6 +875,11 @@ std::optional<uint16_t> Editor::get_active_modifiers() const noexcept {
         return std::nullopt;
     }
 
+    logger.log_editor_trace([&]() {
+        return "DEBUG: Active keyboard modifiers: " +
+               std::to_string(query_pointer_reply->mask);
+    });
+
     return query_pointer_reply->mask;
 }
 

src/wine-host/editor.h

@@ -242,6 +242,16 @@ class Editor {
      * is calling `SetFocus()`. See the comment inside of this function for more
      * details on when this is used.
      *
+     * NOTE: There's a little bit of special behaviour in here. When the shift
+     *       key is held while grabbing input focus, then we'll focus
+     *       `wine_window` directly instead of focussing `wrapper_window`. This
+     *       allows you to temporarily override the default focus grabbing
+     *       behaviour, allowing you to use the space key in plugins GUIs in
+     *       Bitwig and to enter text in Voxengo settings and license dialogs.
+     *       This can also help with plugins that use popups but still rely on
+     *       the parent window's keyboard events to come up to control those
+     *       popups.
+     *
      * @param grab Whether to grab input focus (if `true`) or to give back input
      *   focus to `host_window` (if `false`).
      */