[gtk/wip/matthiasc/listview-2: 141/174] widget: Add a hook for resizes

[Matthias Clasen <matthiasc src gnome org>]

commit ebac532757ae1c3fbfc5d1a1779e415196999f59
Author: Benjamin Otte <otte redhat com>
Date:   Tue Nov 5 00:40:17 2019 +0100

    widget: Add a hook for resizes
    
    It's private, no APIs, we don't talk about it. But we will start using
    it very soon, so we can do size request caching in columns and avoid
    sizegroups...

 gtk/gtkwidget.c        | 3 +++
 gtk/gtkwidgetprivate.h | 1 +
 2 files changed, 4 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 2a146c2e80..96f4656d4c 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -3555,6 +3555,9 @@ gtk_widget_queue_resize_internal (GtkWidget *widget)
   priv->resize_needed = TRUE;
   gtk_widget_set_alloc_needed (widget);
 
+  if (priv->resize_func)
+    priv->resize_func (widget);
+
   groups = _gtk_widget_get_sizegroups (widget);
 
   for (l = groups; l; l = l->next)
diff --git a/gtk/gtkwidgetprivate.h b/gtk/gtkwidgetprivate.h
index d06db43250..d4a4003834 100644
--- a/gtk/gtkwidgetprivate.h
+++ b/gtk/gtkwidgetprivate.h
@@ -122,6 +122,7 @@ struct _GtkWidgetPrivate
 
   int width_request;
   int height_request;
+  void (* resize_func) (GtkWidget *);
   GtkBorder margin;
 
   /* Animations and other things to update on clock ticks */