[mutter/wip/carlosg/broadcast-offers: 1/2] wayland: Send clipboard offers to all data devices from the same client

[Carlos Garnacho <carlosg src gnome org>]

commit fc9a9eb7156b0288b45025a5680c8dda3ea17e42
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed May 13 16:36:13 2020 +0200

    wayland: Send clipboard offers to all data devices from the same client
    
    Make the data device track the keyboard focus, and use that list to
    forward the clipboard selection to all data devices from the same
    client.
    
    This is however not the case of DnD data offers, as the semantics
    of multiple in-flight offers is unclear.
    
    Fixes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1250
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1253

 src/wayland/meta-wayland-data-device.c | 46 +++++++++++++++++++++++++++++-----
 src/wayland/meta-wayland-data-device.h |  1 +
 2 files changed, 41 insertions(+), 6 deletions(-)
---
diff --git a/src/wayland/meta-wayland-data-device.c b/src/wayland/meta-wayland-data-device.c
index 98831e1c6..daf296853 100644
--- a/src/wayland/meta-wayland-data-device.c
+++ b/src/wayland/meta-wayland-data-device.c
@@ -53,6 +53,30 @@ drag_grab_data_source_destroyed (gpointer data, GObject *where_the_object_was);
 static struct wl_resource * create_and_send_clipboard_offer (MetaWaylandDataDevice *data_device,
                                                              struct wl_resource    *target);
 
+static void
+move_resources (struct wl_list *destination,
+                struct wl_list *source)
+{
+  wl_list_insert_list (destination, source);
+  wl_list_init (source);
+}
+
+static void
+move_resources_for_client (struct wl_list   *destination,
+                          struct wl_list   *source,
+                          struct wl_client *client)
+{
+  struct wl_resource *resource, *tmp;
+  wl_resource_for_each_safe (resource, tmp, source)
+    {
+      if (wl_resource_get_client (resource) == client)
+        {
+          wl_list_remove (wl_resource_get_link (resource));
+          wl_list_insert (destination, wl_resource_get_link (resource));
+        }
+    }
+}
+
 static void
 unbind_resource (struct wl_resource *resource)
 {
@@ -251,6 +275,12 @@ meta_wayland_drag_grab_set_focus (MetaWaylandDragGrab *drag_grab,
   client = wl_resource_get_client (surface->resource);
 
   data_device_resource = wl_resource_find_for_client (&seat->data_device.resource_list, client);
+  if (!data_device_resource)
+    {
+      data_device_resource =
+        wl_resource_find_for_client (&seat->data_device.focus_resource_list,
+                                     client);
+    }
 
   if (source && data_device_resource)
     offer = create_and_send_dnd_offer (source, data_device_resource);
@@ -948,10 +978,7 @@ owner_changed_cb (MetaSelection         *selection,
 
   if (selection_type == META_SELECTION_CLIPBOARD)
     {
-      data_device_resource =
-        wl_resource_find_for_client (&data_device->resource_list, focus_client);
-
-      if (data_device_resource)
+      wl_resource_for_each (data_device_resource, &data_device->focus_resource_list)
         {
           struct wl_resource *offer = NULL;
 
@@ -1021,6 +1048,7 @@ void
 meta_wayland_data_device_init (MetaWaylandDataDevice *data_device)
 {
   wl_list_init (&data_device->resource_list);
+  wl_list_init (&data_device->focus_resource_list);
 }
 
 static struct wl_resource *
@@ -1063,14 +1091,20 @@ meta_wayland_data_device_set_keyboard_focus (MetaWaylandDataDevice *data_device)
     return;
 
   data_device->focus_client = focus_client;
+  move_resources (&data_device->resource_list,
+                  &data_device->focus_resource_list);
 
   if (!focus_client)
     return;
 
-  data_device_resource = wl_resource_find_for_client (&data_device->resource_list, focus_client);
-  if (data_device_resource)
+  move_resources_for_client (&data_device->focus_resource_list,
+                             &data_device->resource_list,
+                             focus_client);
+
+  wl_resource_for_each (data_device_resource, &data_device->focus_resource_list)
     {
       struct wl_resource *offer;
+
       offer = create_and_send_clipboard_offer (data_device, data_device_resource);
       wl_data_device_send_selection (data_device_resource, offer);
     }
diff --git a/src/wayland/meta-wayland-data-device.h b/src/wayland/meta-wayland-data-device.h
index eb2ff6fd2..840893389 100644
--- a/src/wayland/meta-wayland-data-device.h
+++ b/src/wayland/meta-wayland-data-device.h
@@ -41,6 +41,7 @@ struct _MetaWaylandDataDevice
   MetaWaylandDataSource *selection_data_source;
   MetaWaylandDataSource *dnd_data_source;
   struct wl_list resource_list;
+  struct wl_list focus_resource_list;
   MetaWaylandDragGrab *current_grab;
   struct wl_client *focus_client;