From cf67c54f87e7ae035a6bf0f19fd37e1751af41d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marco=20Trevisan=20=28Trevi=C3=B1o=29?= <mail@3v1n0.net>
Date: Fri, 17 Jul 2020 17:40:12 +0200
Subject: [PATCH] clutter-seat: Handle device events and emit signals

Clutter device events are special events coming from the backend when an
input device is added or removed.

When such events are processed, we should make the seat to handle them by
calling vfunc that can be implemented by each backend and eventually
emitting the appropriate signal.

If a device is removed, we can also safely dispose it, as it can be
considered stale at this point.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1371
---
 clutter/clutter/clutter-main.c | 11 ++++++++++
 clutter/clutter/clutter-seat.c | 40 ++++++++++++++++++++++++++++++++++
 clutter/clutter/clutter-seat.h |  6 +++++
 3 files changed, 57 insertions(+)

diff --git a/clutter/clutter/clutter-main.c b/clutter/clutter/clutter-main.c
index 2fa3d39ce..a2adc0d0f 100644
--- a/clutter/clutter/clutter-main.c
+++ b/clutter/clutter/clutter-main.c
@@ -1954,6 +1954,17 @@ _clutter_process_event_details (ClutterActor        *stage,
       case CLUTTER_CLIENT_MESSAGE:
         break;
 
+      case CLUTTER_DEVICE_ADDED:
+      case CLUTTER_DEVICE_REMOVED:
+        if (!_clutter_event_process_filters (event))
+          {
+            ClutterSeat *seat;
+
+            seat = clutter_backend_get_default_seat (context->backend);
+            clutter_seat_handle_device_event (seat, event);
+          }
+        break;
+
       case CLUTTER_EVENT_LAST:
         break;
     }
diff --git a/clutter/clutter/clutter-seat.c b/clutter/clutter/clutter-seat.c
index 73672bd36..ba9f2f55a 100644
--- a/clutter/clutter/clutter-seat.c
+++ b/clutter/clutter/clutter-seat.c
@@ -674,6 +674,46 @@ clutter_seat_compress_motion (ClutterSeat        *seat,
     seat_class->compress_motion (seat, event, to_discard);
 }
 
+gboolean
+clutter_seat_handle_device_event (ClutterSeat  *seat,
+                                  ClutterEvent *event)
+{
+  ClutterSeatClass *seat_class;
+  ClutterInputDevice *device;
+
+  g_return_val_if_fail (CLUTTER_IS_SEAT (seat), FALSE);
+  g_return_val_if_fail (event, FALSE);
+
+  g_assert (event->type == CLUTTER_DEVICE_ADDED ||
+            event->type == CLUTTER_DEVICE_REMOVED);
+
+  seat_class = CLUTTER_SEAT_GET_CLASS (seat);
+
+  if (seat_class->handle_device_event)
+    {
+      if (!seat_class->handle_device_event (seat, event))
+        return FALSE;
+    }
+
+  device = clutter_event_get_source_device (event);
+  g_assert_true (CLUTTER_IS_INPUT_DEVICE (device));
+
+  switch (event->type)
+    {
+      case CLUTTER_DEVICE_ADDED:
+        g_signal_emit (seat, signals[DEVICE_ADDED], 0, device);
+        break;
+      case CLUTTER_DEVICE_REMOVED:
+        g_signal_emit (seat, signals[DEVICE_REMOVED], 0, device);
+        g_object_run_dispose (G_OBJECT (device));
+        break;
+      default:
+        break;
+    }
+
+  return TRUE;
+}
+
 void
 clutter_seat_warp_pointer (ClutterSeat *seat,
                            int          x,
diff --git a/clutter/clutter/clutter-seat.h b/clutter/clutter/clutter-seat.h
index 7818647af..aa88d7300 100644
--- a/clutter/clutter/clutter-seat.h
+++ b/clutter/clutter/clutter-seat.h
@@ -106,6 +106,9 @@ struct _ClutterSeatClass
                             ClutterEvent       *event,
                             const ClutterEvent *to_discard);
 
+  gboolean (* handle_device_event) (ClutterSeat  *seat,
+                                    ClutterEvent *event);
+
   void (* warp_pointer) (ClutterSeat *seat,
                          int          x,
                          int          y);
@@ -181,6 +184,9 @@ void clutter_seat_compress_motion (ClutterSeat        *seat,
                                    ClutterEvent       *event,
                                    const ClutterEvent *to_discard);
 
+gboolean clutter_seat_handle_device_event (ClutterSeat  *seat,
+                                           ClutterEvent *event);
+
 CLUTTER_EXPORT
 void clutter_seat_warp_pointer (ClutterSeat *seat,
                                 int          x,