[mutter/wip/carlosg/grabs-pt1: 6/9] clutter: Add ClutterSeat private API to grab devices

[Carlos Garnacho <carlosg src gnome org>]

commit d78566454034ec57c8c73d580de69b7f0925c8a4
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Oct 28 17:04:49 2021 +0200

    clutter: Add ClutterSeat private API to grab devices
    
    This will be necessary to string along ClutterGrab with backend
    behavior, and mostly for the X11 backend so implement this pair
    of vfuncs there.

 clutter/clutter/clutter-enums.h        |  9 ++++++
 clutter/clutter/clutter-seat-private.h |  5 ++++
 clutter/clutter/clutter-seat.c         | 24 +++++++++++++++
 clutter/clutter/clutter-seat.h         |  5 ++++
 src/backends/x11/meta-seat-x11.c       | 53 ++++++++++++++++++++++++++++++++++
 5 files changed, 96 insertions(+)
---
diff --git a/clutter/clutter/clutter-enums.h b/clutter/clutter/clutter-enums.h
index 8165bcf5d0..9177f1095e 100644
--- a/clutter/clutter/clutter-enums.h
+++ b/clutter/clutter/clutter-enums.h
@@ -1628,6 +1628,15 @@ typedef enum
   CLUTTER_PHASE_BUBBLE,
 } ClutterEventPhase;
 
+typedef enum
+{
+  CLUTTER_GRAB_STATE_NONE = 0,
+  CLUTTER_GRAB_STATE_POINTER = 1 << 0,
+  CLUTTER_GRAB_STATE_KEYBOARD = 1 << 1,
+  CLUTTER_GRAB_STATE_ALL = (CLUTTER_GRAB_STATE_POINTER |
+                            CLUTTER_GRAB_STATE_KEYBOARD),
+} ClutterGrabState;
+
 G_END_DECLS
 
 #endif /* __CLUTTER_ENUMS_H__ */
diff --git a/clutter/clutter/clutter-seat-private.h b/clutter/clutter/clutter-seat-private.h
index 2adb7bcd6e..da6349e664 100644
--- a/clutter/clutter/clutter-seat-private.h
+++ b/clutter/clutter/clutter-seat-private.h
@@ -28,4 +28,9 @@
 CLUTTER_EXPORT
 void clutter_seat_destroy (ClutterSeat *seat);
 
+ClutterGrabState clutter_seat_grab (ClutterSeat *seat,
+                                    uint32_t     time);
+void clutter_seat_ungrab (ClutterSeat *seat,
+                          uint32_t     time);
+
 #endif /* CLUTTER_SEAT_PRIVATE_H */
diff --git a/clutter/clutter/clutter-seat.c b/clutter/clutter/clutter-seat.c
index 3e7435fd93..1213042971 100644
--- a/clutter/clutter/clutter-seat.c
+++ b/clutter/clutter/clutter-seat.c
@@ -705,3 +705,27 @@ clutter_seat_destroy (ClutterSeat *seat)
   g_object_run_dispose (G_OBJECT (seat));
   g_object_unref (seat);
 }
+
+ClutterGrabState
+clutter_seat_grab (ClutterSeat *seat,
+                   uint32_t     time)
+{
+  ClutterSeatClass *seat_class;
+
+  seat_class = CLUTTER_SEAT_GET_CLASS (seat);
+  if (seat_class->grab)
+    return seat_class->grab (seat, time);
+  else
+    return CLUTTER_GRAB_STATE_ALL;
+}
+
+void
+clutter_seat_ungrab (ClutterSeat *seat,
+                     uint32_t     time)
+{
+  ClutterSeatClass *seat_class;
+
+  seat_class = CLUTTER_SEAT_GET_CLASS (seat);
+  if (seat_class->ungrab)
+    return seat_class->ungrab (seat, time);
+}
diff --git a/clutter/clutter/clutter-seat.h b/clutter/clutter/clutter-seat.h
index 5c5dfe6eb5..5195b6c8bf 100644
--- a/clutter/clutter/clutter-seat.h
+++ b/clutter/clutter/clutter-seat.h
@@ -97,6 +97,11 @@ struct _ClutterSeatClass
                             graphene_point_t     *coords,
                             ClutterModifierType  *modifiers);
 
+  ClutterGrabState (* grab) (ClutterSeat *seat,
+                             uint32_t     time);
+  void (* ungrab) (ClutterSeat *seat,
+                   uint32_t     time);
+
   /* Virtual devices */
   ClutterVirtualInputDevice * (* create_virtual_device) (ClutterSeat            *seat,
                                                          ClutterInputDeviceType  device_type);
diff --git a/src/backends/x11/meta-seat-x11.c b/src/backends/x11/meta-seat-x11.c
index 0cfa2e510d..5cab92e4b1 100644
--- a/src/backends/x11/meta-seat-x11.c
+++ b/src/backends/x11/meta-seat-x11.c
@@ -71,6 +71,7 @@ struct _MetaSeatX11
   int pointer_id;
   int keyboard_id;
   int opcode;
+  ClutterGrabState grab_state;
   guint has_touchscreens : 1;
   guint touch_mode : 1;
   guint has_pointer_focus : 1;
@@ -1652,6 +1653,56 @@ meta_touch_info_free (MetaTouchInfo *touch_info)
   g_free (touch_info);
 }
 
+static ClutterGrabState
+meta_seat_x11_grab (ClutterSeat *seat,
+                    uint32_t     time)
+{
+  MetaSeatX11 *seat_x11 = META_SEAT_X11 (seat);
+  MetaBackend *backend = meta_get_backend ();
+  ClutterGrabState state = CLUTTER_GRAB_STATE_NONE;
+
+  g_return_val_if_fail (seat_x11->grab_state == CLUTTER_GRAB_STATE_NONE,
+                        seat_x11->grab_state);
+
+  if (meta_backend_grab_device (backend,
+                                META_VIRTUAL_CORE_POINTER_ID,
+                                time))
+    state |= CLUTTER_GRAB_STATE_POINTER;
+
+  if (meta_backend_grab_device (backend,
+                                META_VIRTUAL_CORE_KEYBOARD_ID,
+                                time))
+    state |= CLUTTER_GRAB_STATE_KEYBOARD;
+
+  seat_x11->grab_state = state;
+
+  return state;
+}
+
+static void
+meta_seat_x11_ungrab (ClutterSeat *seat,
+                      uint32_t     time)
+{
+  MetaSeatX11 *seat_x11 = META_SEAT_X11 (seat);
+  MetaBackend *backend = meta_get_backend ();
+
+  if ((seat_x11->grab_state & CLUTTER_GRAB_STATE_POINTER) != 0)
+    {
+      meta_backend_ungrab_device (backend,
+                                  META_VIRTUAL_CORE_POINTER_ID,
+                                  time);
+    }
+
+  if ((seat_x11->grab_state & CLUTTER_GRAB_STATE_KEYBOARD) != 0)
+    {
+      meta_backend_ungrab_device (backend,
+                                  META_VIRTUAL_CORE_KEYBOARD_ID,
+                                  time);
+    }
+
+  seat_x11->grab_state = CLUTTER_GRAB_STATE_NONE;
+}
+
 static void
 meta_seat_x11_class_init (MetaSeatX11Class *klass)
 {
@@ -1673,6 +1724,8 @@ meta_seat_x11_class_init (MetaSeatX11Class *klass)
   seat_class->warp_pointer = meta_seat_x11_warp_pointer;
   seat_class->handle_event_post = meta_seat_x11_handle_event_post;
   seat_class->query_state = meta_seat_x11_query_state;
+  seat_class->grab = meta_seat_x11_grab;
+  seat_class->ungrab = meta_seat_x11_ungrab;
 
   props[PROP_OPCODE] =
     g_param_spec_int ("opcode",