Don't refresh observer table view if there was no change

Avoid refreshing the list of tables every refresh interval
(by default 10 secs) if the content did not change.
Because of the refresh the list was scrolled to the begining
and current selection was lost which could be quite anoying.

1 files changed, 10 insertions, 4 deletions

diff --git a/lib/observer/src/observer_tv_wx.erl b/lib/observer/src/observer_tv_wx.erl
index da4cb8e041..acfa6a2a99 100644
--- a/lib/observer/src/observer_tv_wx.erl
+++ b/lib/observer/src/observer_tv_wx.erl
@@ -176,10 +176,16 @@ handle_call(Event, From, _State) ->
 handle_cast(Event, _State) ->
     error({unhandled_cast, Event}).
 
-handle_info(refresh_interval, State = #state{node=Node, grid=Grid, opt=Opt}) ->
-    Tables = get_tables(Node, Opt),
-    Tabs = update_grid(Grid, Opt, Tables),
-    {noreply, State#state{tabs=Tabs}};
+handle_info(refresh_interval, State = #state{node=Node, grid=Grid, opt=Opt,
+                                             tabs=OldTabs}) ->
+    case get_tables(Node, Opt) of
+        OldTabs ->
+            %% no change
+            {noreply, State};
+        Tables ->
+            Tabs = update_grid(Grid, Opt, Tables),
+            {noreply, State#state{tabs=Tabs}}
+    end;
 
 handle_info({active, Node}, State = #state{parent=Parent, grid=Grid, opt=Opt,
 					   timer=Timer0}) ->