docs: Mention custom tooltip windows in the migration guide

These no longer exist.

diff --git a/docs/reference/gtk/migrating-3to4.xml b/docs/reference/gtk/migrating-3to4.xml
index c7fa65e83509140013dcaacb0ccf1ae94138972b..d64261eee7ad3ab2f743fc6ba4837203a35d959c 100644 (file)
--- a/docs/reference/gtk/migrating-3to4.xml
+++ b/docs/reference/gtk/migrating-3to4.xml
@@ -893,6 +893,16 @@
         radioitem as proxy.
       </para>
     </section>
+
+    <section>
+      <title>Stop using custom tooltip windows</title>
+      <para>
+        Tooltips no longer use GtkWindows in GTK 4, and it is no longer
+        possible to provide a custom window for tooltips. Replacing the content
+        of the tooltip with a custom widget is still possible, with
+        gtk_tooltip_set_custom().
+      </para>
+    </section>
   </section>
 
 </chapter>