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.

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`).
      */