[gtk+] widget: Warn if size-unqueried widgets get allocated

[Benjamin Otte <otte src gnome org>]

commit 3e3f17576e07334e6c5be12fee9ed78f13f0cc24
Author: Benjamin Otte <otte redhat com>
Date:   Mon Sep 28 05:21:06 2015 +0200

    widget: Warn if size-unqueried widgets get allocated
    
    Widgets should have gtk_widget_get_preferred_width/height() called
    on them before gtk_widget_size_allocate() gets called.
    Add a check for this.

 gtk/gtkwidget.c        |    7 +++++++
 gtk/gtkwidgetprivate.h |    6 ++++++
 2 files changed, 13 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index f6c7699..15579a9 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -5845,6 +5845,13 @@ gtk_widget_size_allocate_with_baseline (GtkWidget     *widget,
   gtk_widget_push_verify_invariants (widget);
 
 #ifdef G_ENABLE_DEBUG
+  if (gtk_widget_get_resize_needed (widget))
+    {
+      g_warning ("Allocating size to %s %p without calling gtk_widget_get_preferred_width/height(). "
+                 "How does the code know the size to allocate?",
+                 gtk_widget_get_name (widget), widget);
+    }
+
   if (GTK_DEBUG_CHECK (GEOMETRY))
     {
       gint depth;
diff --git a/gtk/gtkwidgetprivate.h b/gtk/gtkwidgetprivate.h
index 2e02308..566a562 100644
--- a/gtk/gtkwidgetprivate.h
+++ b/gtk/gtkwidgetprivate.h
@@ -288,6 +288,12 @@ gboolean          gtk_widget_has_size_request              (GtkWidget *widget);
 
 /* inline getters */
 
+static inline gboolean
+gtk_widget_get_resize_needed (GtkWidget *widget)
+{
+  return widget->priv->resize_needed;
+}
+
 static inline GtkWidget *
 _gtk_widget_get_parent (GtkWidget *widget)
 {