[mutter/wip/carlosg/null-selection-events] wayland: Rely on MetaSelection::owner-changed for .selection event emission

[Carlos Garnacho <carlosg src gnome org>]

commit f541e784f39134df04b84ff6c6aba2ba8addd019
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Apr 16 23:45:31 2020 +0200

    wayland: Rely on MetaSelection::owner-changed for .selection event emission
    
    We already have a signal callback that translates selection ownership changes to
    data_device/primary .selection events. Given both will be run when a data source
    is being replaced, and this event emission being deleted is kinda short sighted
    in that in only knows about Wayland, rely entirely on MetaSelection::owner-changed
    emission.
    
    Fixes spurious .selection(null) events being sent when a compositor-local source
    takes over the selection without the focus changing (eg. screenshot to clipboard).
    
    Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1160
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1204

 src/wayland/meta-wayland-data-device.c | 53 ----------------------------------
 1 file changed, 53 deletions(-)
---
diff --git a/src/wayland/meta-wayland-data-device.c b/src/wayland/meta-wayland-data-device.c
index 3a7cfd4dc..c3f934d3f 100644
--- a/src/wayland/meta-wayland-data-device.c
+++ b/src/wayland/meta-wayland-data-device.c
@@ -1344,20 +1344,8 @@ static void
 selection_data_source_destroyed (gpointer data, GObject *object_was_here)
 {
   MetaWaylandDataDevice *data_device = data;
-  MetaWaylandSeat *seat = wl_container_of (data_device, seat, data_device);
-  struct wl_resource *data_device_resource;
-  struct wl_client *focus_client = NULL;
 
   data_device->selection_data_source = NULL;
-
-  focus_client = meta_wayland_keyboard_get_focus_client (seat->keyboard);
-  if (focus_client)
-    {
-      data_device_resource = wl_resource_find_for_client (&data_device->resource_list, focus_client);
-      if (data_device_resource)
-        wl_data_device_send_selection (data_device_resource, NULL);
-    }
-
   unset_selection_source (data_device, META_SELECTION_CLIPBOARD);
 }
 
@@ -1659,8 +1647,6 @@ meta_wayland_data_device_set_selection (MetaWaylandDataDevice *data_device,
                                         guint32 serial)
 {
   MetaWaylandSeat *seat = wl_container_of (data_device, seat, data_device);
-  struct wl_resource *data_device_resource;
-  struct wl_client *focus_client;
   MetaSelectionSource *selection_source;
 
   if (data_device->selection_data_source &&
@@ -1696,18 +1682,6 @@ meta_wayland_data_device_set_selection (MetaWaylandDataDevice *data_device,
   set_selection_source (data_device, META_SELECTION_CLIPBOARD,
                         selection_source);
   g_object_unref (selection_source);
-
-  focus_client = meta_wayland_keyboard_get_focus_client (seat->keyboard);
-  if (focus_client)
-    {
-      data_device_resource = wl_resource_find_for_client (&data_device->resource_list, focus_client);
-      if (data_device_resource)
-        {
-          struct wl_resource *offer;
-          offer = create_and_send_clipboard_offer (data_device, data_device_resource);
-          wl_data_device_send_selection (data_device_resource, offer);
-        }
-    }
 }
 
 static void
@@ -1758,21 +1732,8 @@ primary_source_destroyed (gpointer  data,
                           GObject  *object_was_here)
 {
   MetaWaylandDataDevice *data_device = data;
-  MetaWaylandSeat *seat = wl_container_of (data_device, seat, data_device);
-  struct wl_client *focus_client = NULL;
 
   data_device->primary_data_source = NULL;
-
-  focus_client = meta_wayland_keyboard_get_focus_client (seat->keyboard);
-  if (focus_client)
-    {
-      struct wl_resource *data_device_resource;
-
-      data_device_resource = wl_resource_find_for_client (&data_device->primary_resource_list, focus_client);
-      if (data_device_resource)
-        gtk_primary_selection_device_send_selection (data_device_resource, NULL);
-    }
-
   unset_selection_source (data_device, META_SELECTION_PRIMARY);
 }
 
@@ -1782,8 +1743,6 @@ meta_wayland_data_device_set_primary (MetaWaylandDataDevice *data_device,
                                       guint32                serial)
 {
   MetaWaylandSeat *seat = wl_container_of (data_device, seat, data_device);
-  struct wl_resource *data_device_resource;
-  struct wl_client *focus_client;
   MetaSelectionSource *selection_source;
 
   g_assert (!source || META_IS_WAYLAND_DATA_SOURCE_PRIMARY (source));
@@ -1820,18 +1779,6 @@ meta_wayland_data_device_set_primary (MetaWaylandDataDevice *data_device,
   set_selection_source (data_device, META_SELECTION_PRIMARY,
                         selection_source);
   g_object_unref (selection_source);
-
-  focus_client = meta_wayland_keyboard_get_focus_client (seat->keyboard);
-  if (focus_client)
-    {
-      data_device_resource = wl_resource_find_for_client (&data_device->primary_resource_list, focus_client);
-      if (data_device_resource)
-        {
-          struct wl_resource *offer;
-          offer = create_and_send_primary_offer (data_device, data_device_resource);
-          gtk_primary_selection_device_send_selection (data_device_resource, offer);
-        }
-    }
 }
 
 static void