option to display graph times relative to the start time

This avoids having humongous numbers displayed on the graphs' x
axis. Also, the dialog for adding a data set to a graph was cleaned
up.

* grapher/graph-dialog.glade: Add check box for display of relative
  time and a label for the data set list. Force the list of data sets
  to be larger.
* grapher/Graph.hxx (_timeBase): new member
* grapher/Graph.cxx (draw): Subtract _timeBase from displayed time
  value.
* grapher/GraphWidget.hxx (DataModelColumns): Add a column for a data
  set's title, which is optional at the moment.
* grapher/GraphWidget.hxx (_globalTimeBase, _timeBaseInitialized,
  _relativeTimesButton, _displayRelativeTimes): new members
* grapher/GraphWidget.hxx (GraphWidget): Hook up check button for
  displaying relative time.
  (on_expose_event): Determine base time if needed; set base time in
  graphs.
  (onDataDialogOpen): Insert graph data set's name (key) and title
  into the list of data sets.

1 files changed, 7 insertions, 0 deletions

diff --git a/grapher/GraphWidget.hxx b/grapher/GraphWidget.hxx
index 61d50e70..ea10720c 100644
--- a/grapher/GraphWidget.hxx
+++ b/grapher/GraphWidget.hxx
@@ -19,9 +19,11 @@ namespace systemtap
     DataModelColumns()
     {
       add(_dataName);
+      add(_dataTitle);
       add(_graphData);
     }
     Gtk::TreeModelColumn<Glib::ustring> _dataName;
+    Gtk::TreeModelColumn<Glib::ustring> _dataTitle;
     Gtk::TreeModelColumn<std::tr1::shared_ptr<GraphDataBase> > _graphData;
   };
   
@@ -72,8 +74,13 @@ namespace systemtap
     std::tr1::shared_ptr<CairoTextBox> _hoverText;
     double _mouseX;
     double _mouseY;
+    int64_t _globalTimeBase;
+    bool _timeBaseInitialized;
     std::tr1::shared_ptr<Graph> getGraphUnderPoint(double x, double y);
     void establishHoverTimeout();
+    Gtk::CheckButton* _relativeTimesButton;
+    bool _displayRelativeTimes;
+    void onRelativeTimesButtonClicked();
   };
 }
 #endif // SYSTEMTAP_GRAPHWIDGET_H