seat/impl: Move out the GSource implementation to a helper object

This will help adding similar sources that work practically the same.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2628>

src/backends/meta-fd-source.c

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2010 Intel Corp.
+ * Copyright (C) 2014 Jonas Ådahl
+ * Copyright (C) 2016-2022 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include "backends/meta-fd-source.h"
+
+typedef struct _MetaFdtSource
+{
+  GSource source;
+
+  GSourceFunc prepare;
+  GSourceFunc dispatch;
+  gpointer user_data;
+
+  GPollFD poll_fd;
+} MetaFdSource;
+
+static gboolean
+meta_fd_source_prepare (GSource *source,
+                        int     *timeout_ms)
+{
+  MetaFdSource *fd_source = (MetaFdSource *) source;
+
+  *timeout_ms = -1;
+
+  return fd_source->prepare (fd_source->user_data);
+}
+
+static gboolean
+meta_fd_source_check (GSource *source)
+{
+  MetaFdSource *fd_source = (MetaFdSource *) source;
+
+  return !!(fd_source->poll_fd.revents & G_IO_IN);
+}
+
+static gboolean
+meta_fd_source_dispatch (GSource     *source,
+                         GSourceFunc  callback,
+                         gpointer     user_data)
+{
+  MetaFdSource *fd_source = (MetaFdSource *) source;
+
+  return fd_source->dispatch (fd_source->user_data);
+}
+
+static void
+meta_fd_source_finalize (GSource *source)
+{
+  MetaFdSource *fd_source = (MetaFdSource *) source;
+
+  close (fd_source->poll_fd.fd);
+}
+
+static GSourceFuncs fd_source_funcs = {
+  .prepare = meta_fd_source_prepare,
+  .check = meta_fd_source_check,
+  .dispatch = meta_fd_source_dispatch,
+  .finalize = meta_fd_source_finalize,
+};
+
+GSource *
+meta_create_fd_source (int             fd,
+                       const char     *name,
+                       GSourceFunc     prepare,
+                       GSourceFunc     dispatch,
+                       gpointer        user_data,
+                       GDestroyNotify  notify)
+{
+  GSource *source;
+  MetaFdSource *fd_source;
+
+  source = g_source_new (&fd_source_funcs, sizeof (MetaFdSource));
+  g_source_set_name (source, name);
+  fd_source = (MetaFdSource *) source;
+
+  fd_source->poll_fd.fd = fd;
+  fd_source->poll_fd.events = G_IO_IN;
+
+  fd_source->prepare = prepare;
+  fd_source->dispatch = dispatch;
+  fd_source->user_data = user_data;
+
+  g_source_set_callback (source, dispatch, user_data, notify);
+  g_source_set_priority (source, G_PRIORITY_DEFAULT);
+  g_source_add_poll (source, &fd_source->poll_fd);
+  g_source_set_can_recurse (source, TRUE);
+
+  return source;
+}

src/backends/meta-fd-source.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2016-2022 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#ifndef META_FD_SOURCE_H
+#define META_FD_SOURCE_H
+
+#include <glib.h>
+
+GSource * meta_create_fd_source (int             fd,
+                                 const char     *name,
+                                 GSourceFunc     prepare,
+                                 GSourceFunc     dispatch,
+                                 gpointer        user_data,
+                                 GDestroyNotify  notify);
+
+#endif /* META_FD_SOURCE_H */

src/backends/native/meta-seat-impl.c

@@ -34,6 +34,7 @@
 #include <math.h>
 
 #include "backends/meta-cursor-tracker-private.h"
+#include "backends/meta-fd-source.h"
 #include "backends/native/meta-backend-native-private.h"
 #include "backends/native/meta-barrier-native.h"
 #include "backends/native/meta-device-pool.h"
@@ -1337,39 +1338,6 @@ meta_seat_impl_notify_touch_event_in_impl (MetaSeatImpl       *seat_impl,
   queue_event (seat_impl, event);
 }
 
-/*
- * MetaEventSource for reading input devices
- */
-
-static gboolean
-meta_event_prepare (GSource *g_source,
-                    int     *timeout_ms)
-{
-  MetaEventSource *source = (MetaEventSource *) g_source;
-  MetaSeatImpl *seat_impl = source->seat_impl;
-
-  *timeout_ms = -1;
-
-  switch (libinput_next_event_type (seat_impl->libinput))
-    {
-    case LIBINPUT_EVENT_NONE:
-      return FALSE;
-    default:
-      return TRUE;
-    }
-}
-
-static gboolean
-meta_event_check (GSource *source)
-{
-  MetaEventSource *event_source = (MetaEventSource *) source;
-  gboolean retval;
-
-  retval = !!(event_source->event_poll_fd.revents & G_IO_IN);
-
-  return retval;
-}
-
 static void
 constrain_to_barriers (MetaSeatImpl       *seat_impl,
                        ClutterInputDevice *device,
@@ -1878,68 +1846,6 @@ notify_pad_ring (ClutterInputDevice *input_device,
   queue_event (seat_impl, event);
 }
 
-static gboolean
-meta_event_dispatch (GSource     *g_source,
-                     GSourceFunc  callback,
-                     gpointer     user_data)
-{
-  MetaEventSource *source = (MetaEventSource *) g_source;
-  MetaSeatImpl *seat_impl;
-
-  seat_impl = source->seat_impl;
-
-  dispatch_libinput (seat_impl);
-
-  return TRUE;
-}
-
-static GSourceFuncs event_funcs = {
-  meta_event_prepare,
-  meta_event_check,
-  meta_event_dispatch,
-  NULL
-};
-
-static MetaEventSource *
-meta_event_source_new (MetaSeatImpl *seat_impl)
-{
-  GSource *source;
-  MetaEventSource *event_source;
-  int fd;
-
-  source = g_source_new (&event_funcs, sizeof (MetaEventSource));
-  g_source_set_name (source, "[mutter] Events");
-  event_source = (MetaEventSource *) source;
-
-  /* setup the source */
-  event_source->seat_impl = seat_impl;
-
-  fd = libinput_get_fd (seat_impl->libinput);
-  event_source->event_poll_fd.fd = fd;
-  event_source->event_poll_fd.events = G_IO_IN;
-
-  /* and finally configure and attach the GSource */
-  g_source_set_priority (source, CLUTTER_PRIORITY_EVENTS);
-  g_source_add_poll (source, &event_source->event_poll_fd);
-  g_source_set_can_recurse (source, TRUE);
-  g_source_attach (source, seat_impl->input_context);
-
-  return event_source;
-}
-
-static void
-meta_event_source_free (MetaEventSource *source)
-{
-  GSource *g_source = (GSource *) source;
-
-  /* ignore the return value of close, it's not like we can do something
-   * about it */
-  close (source->event_poll_fd.fd);
-
-  g_source_destroy (g_source);
-  g_source_unref (g_source);
-}
-
 static gboolean
 has_touchscreen (MetaSeatImpl *seat_impl)
 {
@@ -3132,6 +3038,30 @@ meta_seat_impl_set_keyboard_numlock_in_impl (MetaSeatImpl *seat_impl,
                                      seat_impl->xkb);
 }
 
+static gboolean
+meta_libinput_source_prepare (gpointer user_data)
+{
+  MetaSeatImpl *seat_impl = META_SEAT_IMPL (user_data);
+
+  switch (libinput_next_event_type (seat_impl->libinput))
+    {
+    case LIBINPUT_EVENT_NONE:
+      return FALSE;
+    default:
+      return TRUE;
+    }
+}
+
+static gboolean
+meta_libinput_source_dispatch (gpointer user_data)
+{
+  MetaSeatImpl *seat_impl = META_SEAT_IMPL (user_data);
+
+  dispatch_libinput (seat_impl);
+
+  return G_SOURCE_CONTINUE;
+}
+
 static gboolean
 init_libinput (MetaSeatImpl  *seat_impl,
                GError       **error)
@@ -3176,10 +3106,19 @@ init_libinput (MetaSeatImpl  *seat_impl,
 static void
 init_libinput_source (MetaSeatImpl *seat_impl)
 {
-  MetaEventSource *source;
+  int fd;
+  GSource *source;
 
-  source = meta_event_source_new (seat_impl);
+  fd = libinput_get_fd (seat_impl->libinput);
-  seat_impl->event_source = source;
+  source = meta_create_fd_source (fd,
+                                  "[mutter] libinput",
+                                  meta_libinput_source_prepare,
+                                  meta_libinput_source_dispatch,
+                                  seat_impl,
+                                  NULL);
+  seat_impl->libinput_source = source;
+  g_source_attach (source, seat_impl->input_context);
+  g_source_unref (source);
 }
 
 static gpointer
@@ -3377,7 +3316,7 @@ destroy_in_impl (GTask *task)
   g_clear_pointer (&seat_impl->libinput, libinput_unref);
   g_clear_pointer (&seat_impl->tools, g_hash_table_unref);
   g_clear_pointer (&seat_impl->touch_states, g_hash_table_destroy);
-  g_clear_pointer (&seat_impl->event_source, meta_event_source_free);
+  g_clear_pointer (&seat_impl->libinput_source, g_source_destroy);
 
   numlock_active =
     xkb_state_mod_name_is_active (seat_impl->xkb, XKB_MOD_NAME_NUM,
@@ -3424,7 +3363,7 @@ meta_seat_impl_finalize (GObject *object)
 
   g_assert (!seat_impl->libinput);
   g_assert (!seat_impl->tools);
-  g_assert (!seat_impl->event_source);
+  g_assert (!seat_impl->libinput_source);
 
   g_free (seat_impl->seat_id);
 

src/backends/native/meta-seat-impl.h

@@ -68,7 +68,7 @@ struct _MetaSeatImpl
   MetaSeatNative *seat_native;
   char *seat_id;
   MetaSeatNativeFlag flags;
-  MetaEventSource *event_source;
+  GSource *libinput_source;
   struct libinput *libinput;
   GRWLock state_lock;
 

src/meson.build

@@ -220,6 +220,8 @@ mutter_sources = [
   'backends/meta-dbus-session-watcher.h',
   'backends/meta-display-config-shared.h',
   'backends/meta-dnd-private.h',
+  'backends/meta-fd-source.c',
+  'backends/meta-fd-source.h',
   'backends/meta-gpu.c',
   'backends/meta-gpu.h',
   'backends/meta-idle-monitor.c',