clutter: Pass events to pointer a11y before going through filters

We want all pointer events to be passed through the pointer a11y
processing before going through event filters: Once we go through event
filters, events might be dispatched to Wayland and get filtered out.

With the changes to immediately dispatch events to wayland, this changed
and the pointer a11y is now no longer seeing any events going to wayland
clients. Fix it by shuffling things around a bit and letting pointer
a11y take a peek at events earlier.

Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/5192
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2332>

3 files changed, 42 insertions, 28 deletions

diff --git a/clutter/clutter/clutter-input-pointer-a11y-private.h b/clutter/clutter/clutter-input-pointer-a11y-private.h
index fbbe04101..a66ddeac9 100644
--- a/clutter/clutter/clutter-input-pointer-a11y-private.h
+++ b/clutter/clutter/clutter-input-pointer-a11y-private.h
@@ -42,6 +42,9 @@ void _clutter_input_pointer_a11y_on_button_event (ClutterInputDevice   *device,
 CLUTTER_EXPORT
 gboolean _clutter_is_input_pointer_a11y_enabled  (ClutterInputDevice     *device);
 
+CLUTTER_EXPORT
+void _clutter_input_pointer_a11y_maybe_handle_event (ClutterEvent *event);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_INPUT_POINTER_A11Y_H__ */
diff --git a/clutter/clutter/clutter-input-pointer-a11y.c b/clutter/clutter/clutter-input-pointer-a11y.c
index 365b85fd6..cfee58e55 100644
--- a/clutter/clutter/clutter-input-pointer-a11y.c
+++ b/clutter/clutter/clutter-input-pointer-a11y.c
@@ -25,11 +25,13 @@
 
 #include "clutter-build-config.h"
 
+#include "clutter-backend-private.h"
 #include "clutter-enum-types.h"
 #include "clutter-input-device.h"
 #include "clutter-input-device-private.h"
 #include "clutter-input-pointer-a11y-private.h"
 #include "clutter-main.h"
+#include "clutter-private.h"
 #include "clutter-virtual-input-device.h"
 
 static gboolean
@@ -726,3 +728,39 @@ _clutter_is_input_pointer_a11y_enabled (ClutterInputDevice *device)
 
   return (is_secondary_click_enabled (device) || is_dwell_click_enabled (device));
 }
+
+void
+_clutter_input_pointer_a11y_maybe_handle_event (ClutterEvent *event)
+{
+
+  ClutterInputDevice *device = clutter_event_get_device (event);
+  ClutterMainContext *clutter_context;
+  ClutterBackend *backend;
+
+  if (!_clutter_is_input_pointer_a11y_enabled (device))
+    return;
+
+  if ((event->any.flags & CLUTTER_EVENT_FLAG_SYNTHETIC) != 0)
+    return;
+
+  clutter_context = _clutter_context_get_default ();
+  backend = clutter_context->backend;
+
+  if (!clutter_backend_is_display_server (backend))
+    return;
+
+  if (event->type == CLUTTER_MOTION)
+    {
+      float x, y;
+
+      clutter_event_get_coords (event, &x, &y);
+      _clutter_input_pointer_a11y_on_motion_event (device, x, y);
+    }
+  else if (event->type == CLUTTER_BUTTON_PRESS ||
+           event->type == CLUTTER_BUTTON_RELEASE)
+    {
+      _clutter_input_pointer_a11y_on_button_event (device,
+                                                   event->button.button,
+                                                   event->type == CLUTTER_BUTTON_PRESS);
+    }
+}
diff --git a/clutter/clutter/clutter-main.c b/clutter/clutter/clutter-main.c
index df872bd42..239d36838 100644
--- a/clutter/clutter/clutter-main.c
+++ b/clutter/clutter/clutter-main.c
@@ -778,6 +778,7 @@ clutter_do_event (ClutterEvent *event)
 
   context->current_event = g_slist_prepend (context->current_event, event);
 
+  _clutter_input_pointer_a11y_maybe_handle_event (event);
   if (_clutter_event_process_filters (event, event_actor))
     {
       context->current_event =
@@ -830,13 +831,8 @@ _clutter_process_event_details (ClutterActor        *stage,
 {
   ClutterInputDevice *device = clutter_event_get_device (event);
   ClutterEventSequence *sequence = clutter_event_get_event_sequence (event);
-  ClutterMainContext *clutter_context;
-  ClutterBackend *backend;
   ClutterActor *target;
 
-  clutter_context = _clutter_context_get_default ();
-  backend = clutter_context->backend;
-
   switch (event->type)
     {
       case CLUTTER_NOTHING:
@@ -878,31 +874,8 @@ _clutter_process_event_details (ClutterActor        *stage,
         break;
 
       case CLUTTER_MOTION:
-        if (clutter_backend_is_display_server (backend) &&
-            !(event->any.flags & CLUTTER_EVENT_FLAG_SYNTHETIC))
-          {
-            if (_clutter_is_input_pointer_a11y_enabled (device))
-              {
-                gfloat x, y;
-
-                clutter_event_get_coords (event, &x, &y);
-                _clutter_input_pointer_a11y_on_motion_event (device, x, y);
-              }
-          }
-        G_GNUC_FALLTHROUGH;
       case CLUTTER_BUTTON_PRESS:
       case CLUTTER_BUTTON_RELEASE:
-        if (clutter_backend_is_display_server (backend))
-          {
-            if (_clutter_is_input_pointer_a11y_enabled (device) && (event->type != CLUTTER_MOTION))
-              {
-                _clutter_input_pointer_a11y_on_button_event (device,
-                                                             event->button.button,
-                                                             event->type == CLUTTER_BUTTON_PRESS);
-              }
-          }
-
-        G_GNUC_FALLTHROUGH;
       case CLUTTER_SCROLL:
       case CLUTTER_TOUCHPAD_PINCH:
       case CLUTTER_TOUCHPAD_SWIPE: