wayland: Refactor grab checks for tablets

Do not jump at MetaWaylandSeat across the MetaWaylandTabletSeat to
poke at the tablet tools, and chain up the checks through a
MetaWaylandTabletSeat method instead.

While at it, use g_autoptr to manage the tool list, and fix a leak.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3420>

src/wayland/meta-wayland-seat.c

@@ -489,10 +489,6 @@ meta_wayland_seat_get_grab_info (MetaWaylandSeat       *seat,
                                  float                 *x,
                                  float                 *y)
 {
-  GList *tools, *l;
-
-  tools = g_hash_table_get_values (seat->tablet_seat->tools);
-
   if (meta_wayland_seat_has_touch (seat))
     {
       ClutterEventSequence *sequence;
@@ -534,25 +530,16 @@ meta_wayland_seat_get_grab_info (MetaWaylandSeat       *seat,
         }
     }
 
-  for (l = tools; l; l = l->next)
+  if (meta_wayland_tablet_seat_get_grab_info (seat->tablet_seat,
+                                              surface,
+                                              serial,
+                                              require_pressed,
+                                              device_out,
+                                              x, y))
     {
-      MetaWaylandTabletTool *tool = l->data;
+      if (sequence_out)
-
+        *sequence_out = NULL;
-      if ((!require_pressed || tool->button_count > 0) &&
+      return TRUE;
-          meta_wayland_tablet_tool_can_grab_surface (tool, surface, serial))
-        {
-          if (device_out)
-            *device_out = tool->device;
-          if (sequence_out)
-            *sequence_out = NULL;
-
-          if (x)
-            *x = tool->grab_x;
-          if (y)
-            *y = tool->grab_y;
-
-          return TRUE;
-        }
     }
 
   return FALSE;

src/wayland/meta-wayland-tablet-seat.c

@@ -567,3 +567,39 @@ meta_wayland_tablet_seat_can_popup (MetaWaylandTabletSeat *tablet_seat,
 
   return FALSE;
 }
+
+gboolean
+meta_wayland_tablet_seat_get_grab_info (MetaWaylandTabletSeat *tablet_seat,
+                                        MetaWaylandSurface    *surface,
+                                        uint32_t               serial,
+                                        gboolean               require_pressed,
+                                        ClutterInputDevice   **device_out,
+                                        float                 *x,
+                                        float                 *y)
+{
+  g_autoptr (GList) tools = NULL;
+  GList *l;
+
+  tools = g_hash_table_get_values (tablet_seat->tools);
+
+  for (l = tools; l; l = l->next)
+    {
+      MetaWaylandTabletTool *tool = l->data;
+
+      if ((!require_pressed || tool->button_count > 0) &&
+          meta_wayland_tablet_tool_can_grab_surface (tool, surface, serial))
+        {
+          if (device_out)
+            *device_out = tool->device;
+
+          if (x)
+            *x = tool->grab_x;
+          if (y)
+            *y = tool->grab_y;
+
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}

src/wayland/meta-wayland-tablet-seat.h

@@ -76,3 +76,11 @@ GList                 *meta_wayland_tablet_seat_lookup_paired_pads   (MetaWaylan
                                                                       MetaWaylandTablet     *tablet);
 gboolean               meta_wayland_tablet_seat_can_popup            (MetaWaylandTabletSeat *tablet_seat,
                                                                       uint32_t               serial);
+
+gboolean meta_wayland_tablet_seat_get_grab_info (MetaWaylandTabletSeat *tablet_seat,
+                                                 MetaWaylandSurface    *surface,
+                                                 uint32_t               serial,
+                                                 gboolean               require_pressed,
+                                                 ClutterInputDevice   **device_out,
+                                                 float                 *x,
+                                                 float                 *y);