native: Add a set_tooltip method

This lets us associate a tooltip window with the
native, so we can allocate it when necessary, without
having to rely on the ::size-allocate signal.

gtk/gtknative.c

@@ -60,12 +60,19 @@ gtk_native_default_check_resize (GtkNative *self)
 {
 }
 
+static void
+gtk_native_default_set_tooltip (GtkNative *self,
+                                GtkNative *tooltip)
+{
+}
+
 static void
 gtk_native_default_init (GtkNativeInterface *iface)
 {
   iface->get_renderer = gtk_native_default_get_renderer;
   iface->get_surface_transform = gtk_native_default_get_surface_transform;
   iface->check_resize = gtk_native_default_check_resize;
+  iface->set_tooltip = gtk_native_default_set_tooltip;
 }
 
 /**
@@ -149,3 +156,14 @@ gtk_native_get_for_surface (GdkSurface *surface)
 
   return NULL;
 }
+
+void
+gtk_native_set_tooltip (GtkNative *self,
+                        GtkNative *tooltip)
+{
+  g_return_if_fail (GTK_IS_NATIVE (self));
+  g_return_if_fail (tooltip == NULL || GTK_IS_NATIVE (tooltip));
+
+  GTK_NATIVE_GET_IFACE (self)->set_tooltip (self, tooltip);
+
+}

gtk/gtknative.h

@@ -53,6 +53,9 @@ struct _GtkNativeInterface
                                            int          *y);
 
   void          (* check_resize)          (GtkNative    *self);
+
+  void          (* set_tooltip)           (GtkNative    *self,
+                                           GtkNative    *tooltip);
 };
 
 GDK_AVAILABLE_IN_ALL
@@ -67,6 +70,10 @@ GdkSurface *gtk_native_get_surface     (GtkNative *self);
 GDK_AVAILABLE_IN_ALL
 GskRenderer *gtk_native_get_renderer   (GtkNative *self);
 
+GDK_AVAILABLE_IN_ALL
+void         gtk_native_set_tooltip (GtkNative *self,
+                                     GtkNative *tooltip);
+
 G_END_DECLS
 
 #endif /* __GTK_NATIVE_H__ */