[gtk+] GtkScaleButton: Set +/- sensitivity

[Matthias Clasen <matthiasc src gnome org>]

commit 0a3463391406ca95b5c5538c7b777ae7e82effe5
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jul 8 10:27:30 2014 -0400

    GtkScaleButton: Set +/- sensitivity
    
    The buttons should go insensitive when we are at their end of
    the scale.

 gtk/gtkscalebutton.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkscalebutton.c b/gtk/gtkscalebutton.c
index 11aee50..b4bda76 100644
--- a/gtk/gtkscalebutton.c
+++ b/gtk/gtkscalebutton.c
@@ -1040,11 +1040,17 @@ cb_scale_value_changed (GtkRange *range,
 {
   GtkScaleButton *button = user_data;
   gdouble value;
+  gdouble upper, lower;
 
   value = gtk_range_get_value (range);
+  upper = gtk_adjustment_get_upper (button->priv->adjustment);
+  lower = gtk_adjustment_get_lower (button->priv->adjustment);
 
   gtk_scale_button_update_icon (button);
 
+  gtk_widget_set_sensitive (button->priv->plus_button, value < upper);
+  gtk_widget_set_sensitive (button->priv->minus_button, lower < value);
+
   g_signal_emit (button, signals[VALUE_CHANGED], 0, value);
   g_object_notify (G_OBJECT (button), "value");
 }