app: add gimp_prop_range_set_ui_limits()

... which sets the limits of the range-widget's handle-bar
explicitly, instead of using the lower/upper properties' limits.

(cherry picked from commit ce8235e977)

app/widgets/gimppropwidgets.c

@@ -1131,6 +1131,8 @@ gimp_prop_range_new (GObject     *config,
 
   gimp_handle_bar_connect_events (GIMP_HANDLE_BAR (handle_bar), color_bar);
 
+  g_object_set_data (G_OBJECT (vbox), "gimp-range-handle-bar", handle_bar);
+
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, FALSE, 0);
   gtk_widget_show (hbox);
@@ -1161,6 +1163,20 @@ gimp_prop_range_new (GObject     *config,
   return vbox;
 }
 
+void
+gimp_prop_range_set_ui_limits (GtkWidget *widget,
+                               gdouble    lower,
+                               gdouble    upper)
+{
+  GimpHandleBar *handle_bar;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  handle_bar = g_object_get_data (G_OBJECT (widget), "gimp-range-handle-bar");
+
+  gimp_handle_bar_set_limits (handle_bar, lower, upper);
+}
+
 
 /**********/
 /*  view  */

app/widgets/gimppropwidgets.h

@@ -90,6 +90,9 @@ GtkWidget * gimp_prop_range_new             (GObject       *config,
                                              gdouble        page_increment,
                                              gint           digits,
                                              gboolean       sorted);
+void        gimp_prop_range_set_ui_limits   (GtkWidget     *widget,
+                                             gdouble        lower,
+                                             gdouble        upper);
 
 
 /*  GParamObject (GimpViewable)  */