Make the local coordinate fix more robust

Without this fix and when using plugin groups, hovering over an opened
window that has not yet been interacted with shows some weird behavior.

src/wine-host/editor.cpp

@@ -92,15 +92,20 @@ Editor::Editor(const std::string& window_class_name,
     // TODO: Add a `KillTimer()` now that we are hosting multiple plugins
     SetTimer(win32_handle.get(), idle_timer_id, 100, nullptr);
 
-    // We need to tell the Wine window it has been moved whenever the window
+    // Because we're not using XEmbed Wine will interpret any local coordinates
-    // it's been embedded in gets moved around. In most cases this is
+    // as global coordinates. To work around this we'll tell the Wine window
-    // `parent_window`, but for instance REAPER reparents `parent_window` in
+    // it's located at its actual coordinates on screen rather than somewhere
-    // another window so we'll have to find the correct window first.
+    // within. For robustness's sake this should be done both when the actual
+    // window the Wine window is embedded in (which may not be the parent
+    // window) is moved or resized, and when the user moves his mouse over the
+    // window. We also want to set keyboard focus when the user clicks on the
+    // Windows since Bitwig 3.2 now explicitely requires this.
     const uint32_t topmost_event_mask = XCB_EVENT_MASK_STRUCTURE_NOTIFY;
     xcb_change_window_attributes(x11_connection.get(), topmost_window,
                                  XCB_CW_EVENT_MASK, &topmost_event_mask);
     xcb_flush(x11_connection.get());
-    const uint32_t parent_event_mask = XCB_EVENT_MASK_FOCUS_CHANGE;
+    const uint32_t parent_event_mask =
+        XCB_EVENT_MASK_FOCUS_CHANGE | XCB_EVENT_MASK_ENTER_WINDOW;
     xcb_change_window_attributes(x11_connection.get(), parent_window,
                                  XCB_CW_EVENT_MASK, &parent_event_mask);
     xcb_flush(x11_connection.get());
@@ -172,18 +177,20 @@ void Editor::handle_x11_events() {
     while ((generic_event = xcb_poll_for_event(x11_connection.get())) !=
            nullptr) {
         switch (generic_event->response_type & event_type_mask) {
-            // We're listening for ConfigureNotify events on the topmost window
+            // We're listening for `ConfigureNotify` events on the topmost
-            // before the root window, i.e. the window that's actually going to
+            // window before the root window, i.e. the window that's actually
-            // get dragged around the by the user. In most cases this is the
+            // going to get dragged around the by the user. In most cases this
-            // same as `parent_window`.
+            // is the same as `parent_window`. When either this window gets
+            // moved, or when the user moves his mouse over our window, the
+            // local coordinates should be updated. The additional `EnterWindow`
+            // check is sometimes necessary for using multiple editor windows
+            // within a single plugin group.
             case XCB_CONFIGURE_NOTIFY:
-                fox_local_coordinates();
+            case XCB_ENTER_NOTIFY:
+                fix_local_coordinates();
                 break;
-            // The coordinates should also be reset when the user clicks on the
-            // window. This is sometimes necessary when opening multiple editors
-            // in a single plugin group.
             case XCB_FOCUS_IN:
-                fox_local_coordinates();
+                fix_local_coordinates();
 
                 // Explicitely request input focus when the user clicks on the
                 // window. This is needed for Bitwig Studio 3.2, as the parent
@@ -194,7 +201,6 @@ void Editor::handle_x11_events() {
                                     XCB_INPUT_FOCUS_PARENT, child_window,
                                     XCB_CURRENT_TIME);
                 xcb_flush(x11_connection.get());
-
                 break;
         }
 
@@ -202,7 +208,7 @@ void Editor::handle_x11_events() {
     }
 }
 
-void Editor::fox_local_coordinates() {
+void Editor::fix_local_coordinates() {
     // We're purposely not using XEmbed. This has the consequence that wine
     // still thinks that any X and Y coordinates are relative to the x11 window
     // root instead of the parent window provided by the DAW, causing all sorts

src/wine-host/editor.h

@@ -118,7 +118,7 @@ class Editor {
      * reparenting without using XEmbed. See the comment at the top of the
      * implementation on why this is needed.
      */
-    void fox_local_coordinates();
+    void fix_local_coordinates();
 
     /**
      * A pointer to the currently active window. Will be a null pointer if no