[sysprof] window: notify the user when no valid samples were collected

[Christian Hergert <chergert src gnome org>]

commit 36008c4ab4a39f0512837bdee93a3686d611806d
Author: Christian Hergert <christian hergert me>
Date:   Fri Apr 15 18:11:31 2016 -0700

    window: notify the user when no valid samples were collected
    
    If we failed to collect any samples in the target profile, let the user
    know why the callgraph is empty.

 src/sp-window.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/src/sp-window.c b/src/sp-window.c
index 36c0e8f..2cf5805 100644
--- a/src/sp-window.c
+++ b/src/sp-window.c
@@ -212,6 +212,11 @@ sp_window_build_profile_cb (GObject      *object,
 
   sp_callgraph_view_set_profile (self->callgraph_view, SP_CALLGRAPH_PROFILE (profile));
   sp_window_set_state (self, SP_WINDOW_STATE_BROWSING);
+
+  if (sp_callgraph_view_get_n_functions (self->callgraph_view) == 0)
+    sp_window_notify_user (self,
+                           GTK_MESSAGE_WARNING,
+                           _("Not enough samples were collected to generate a callgraph"));
 }
 
 static void