[gtk+/gtk-3-20] scale: Document interaction between rounding and autoscrolling

[Matthias Clasen <matthiasc src gnome org>]

commit 0ba66846d7aef36f7c532223757fd91e09cdcd76
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Aug 24 12:58:54 2016 -0400

    scale: Document interaction between rounding and autoscrolling
    
    This is a bit of a gotcha, so better document it.

 gtk/gtkscale.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkscale.c b/gtk/gtkscale.c
index 84290a5..527d64e 100644
--- a/gtk/gtkscale.c
+++ b/gtk/gtkscale.c
@@ -1107,6 +1107,11 @@ gtk_scale_new_with_range (GtkOrientation orientation,
  * Sets the number of decimal places that are displayed in the value.
  * Also causes the value of the adjustment to be rounded off to this
  * number of digits, so the retrieved value matches the value the user saw.
+ *
+ * Note that rounding to a small number of digits can interfere with
+ * the smooth autoscrolling that is built into #GtkScale. As an alternative,
+ * you can use the #GtkScale::format-value signal to format the displayed
+ * value yourself.
  */
 void
 gtk_scale_set_digits (GtkScale *scale,