grapher: scroll continuously with time

Don't scale graph based on how much data will fit. This didn't work
very well and resulted in distracting, weird scale changes. We now
assume that scripts output their time (x axis) in milliseconds.

* grapher/Graph.hxx (setCurrentTime): New function.
* grapher/Graph.cxx (Graph::draw): Assume a fixed default scale of 1
  pixel = 5 milliseconds and don't do any autoscaling.
* grapher/GraphWidget.cxx (GraphWidget constructor): Set global time
  base on startup.
  (on_expose_event): Don't search graphs for earliest time.
* grapher/GraphWidget.hxx (_timeBaseInitialized): delete
* grapher/Time.hxx: new file; interface to timeval.

1 files changed, 5 insertions, 20 deletions

diff --git a/grapher/GraphWidget.cxx b/grapher/GraphWidget.cxx
index db7493fb..be1ebdcd 100644
--- a/grapher/GraphWidget.cxx
+++ b/grapher/GraphWidget.cxx
@@ -23,6 +23,7 @@
 
 #include "GraphWidget.hxx"
 #include "CairoWidget.hxx"
+#include "Time.hxx"
 
 namespace systemtap
 {
@@ -33,7 +34,7 @@ using namespace std::tr1;
     
 GraphWidget::GraphWidget()
   : _trackingDrag(false), _width(600), _height(200), _mouseX(0.0),
-    _mouseY(0.0), _globalTimeBase(0), _timeBaseInitialized(false)
+    _mouseY(0.0), _globalTimeBase(Time::getAbs() / 1000)
 {
   add_events(Gdk::POINTER_MOTION_MASK | Gdk::BUTTON_PRESS_MASK
              | Gdk::BUTTON_RELEASE_MASK | Gdk::SCROLL_MASK);
@@ -157,27 +158,11 @@ bool GraphWidget::on_expose_event(GdkEventExpose* event)
   cr->save();
   cr->set_source_rgba(0.0, 0.0, 0.0, 1.0);
   cr->paint();
-  if (!_timeBaseInitialized && !getGraphData().empty())
-    {
-      GraphDataList& graphData = getGraphData();
-      int64_t earliest = INT64_MAX;
-      for (GraphDataList::iterator gd = graphData.begin(),
-             end = graphData.end();
-           gd != end;
-           ++gd)
-        {
-          if (!(*gd)->times.empty() && (*gd)->times[0] < earliest)
-            earliest = (*gd)->times[0];
-        }
-      if (earliest != INT64_MAX)
-        {
-          _globalTimeBase = earliest;
-          _timeBaseInitialized = true;
-        }
-    }
+  int64_t currentTime = Time::getAbs();
+  Graph::setCurrentTime(currentTime);
   for (GraphList::iterator g = _graphs.begin(); g != _graphs.end(); ++g)
     {
-      if (_displayRelativeTimes && _timeBaseInitialized)
+      if (_displayRelativeTimes)
         (*g)->_timeBase = _globalTimeBase;
       else
         (*g)->_timeBase = 0.0;