[gnome-calculator] Fixed history scrolling

[Robert Roth <robertroth src gnome org>]

commit 49e87682b3d7a846e30e2073ec0e86b88621c012
Author: Robert Roth <robert roth off gmail com>
Date:   Sun Sep 25 04:24:36 2016 +0300

    Fixed history scrolling

 data/history-view.ui  |    2 +-
 src/math-history.vala |    2 ++
 2 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/data/history-view.ui b/data/history-view.ui
index 910f144..be53859 100644
--- a/data/history-view.ui
+++ b/data/history-view.ui
@@ -10,7 +10,7 @@
     <property name="vexpand">True</property>
     <property name="hscrollbar_policy">never</property>
     <property name="shadow_type">etched-out</property>
-    <signal name="size-allocate" handler="scroll_bottom" swapped="no"/>
+    <signal name="row_added" handler="scroll_bottom" swapped="no"/>
     <child>
       <object class="GtkViewport" id="viewport">
         <property name="visible">True</property>
diff --git a/src/math-history.vala b/src/math-history.vala
index 398b165..8a12637 100644
--- a/src/math-history.vala
+++ b/src/math-history.vala
@@ -24,6 +24,7 @@ public class HistoryView : Gtk.ScrolledWindow
 
     public signal void answer_clicked   (string ans);
     public signal void equation_clicked (string equation);
+    public signal void row_added       ();
 
 
     [GtkCallback]
@@ -59,6 +60,7 @@ public class HistoryView : Gtk.ScrolledWindow
 
         last_answer = answer_nine_digits;
         last_equation = equation;
+        row_added ();
     }
 }