--- a/GraphicViewer.py	Fri Jul 13 12:27:05 2012 +0200
+++ b/GraphicViewer.py	Fri Jul 13 12:42:02 2012 +0200
@@ -75,12 +75,14 @@
         self.Canvas.SetYSpec('border')
         self.Canvas.canvas.Bind(wx.EVT_LEFT_DOWN, self.OnCanvasLeftDown)
         self.Canvas.canvas.Bind(wx.EVT_LEFT_UP, self.OnCanvasLeftUp)
+        self.Canvas.canvas.Bind(wx.EVT_MIDDLE_DOWN, self.OnCanvasMiddleDown)
+        self.Canvas.canvas.Bind(wx.EVT_MIDDLE_UP, self.OnCanvasMiddleUp)
         self.Canvas.canvas.Bind(wx.EVT_MOTION, self.OnCanvasMotion)
         self.Canvas.canvas.Bind(wx.EVT_MOUSEWHEEL, self.OnCanvasMouseWheel)
         self.Canvas.canvas.Bind(wx.EVT_SIZE, self.OnCanvasResize)
         main_sizer.AddWindow(self.Canvas, 0, border=0, flag=wx.GROW)
         
-        range_sizer = wx.FlexGridSizer(cols=9, hgap=5, rows=1, vgap=0)
+        range_sizer = wx.FlexGridSizer(cols=10, hgap=5, rows=1, vgap=0)
         range_sizer.AddGrowableCol(5)
         range_sizer.AddGrowableRow(0)
         main_sizer.AddSizer(range_sizer, 0, border=5, flag=wx.GROW|wx.ALL)
@@ -131,6 +133,13 @@
         self.Bind(wx.EVT_BUTTON, self.OnCurrentButton, self.CurrentButton)
         range_sizer.AddWindow(self.CurrentButton, 0, border=0, flag=0)
         
+        self.ResetZoomOffsetButton = wx.lib.buttons.GenBitmapButton(self.Editor, 
+              bitmap=GetBitmap("fit"), size=wx.Size(28, 28), style=wx.NO_BORDER)
+        self.CurrentButton.SetToolTipString(_("Reset zoom and offset"))
+        self.Bind(wx.EVT_BUTTON, self.OnResetZoomOffsetButton, 
+              self.ResetZoomOffsetButton)
+        range_sizer.AddWindow(self.ResetZoomOffsetButton, 0, border=0, flag=0)
+        
         self.ExportGraphButton = wx.lib.buttons.GenBitmapButton(self.Editor, 
               bitmap=GetBitmap("export_graph"), size=wx.Size(28, 28), style=wx.NO_BORDER)
         self.ExportGraphButton.SetToolTipString(_("Export graph values to clipboard"))
@@ -162,7 +171,7 @@
         self.MinValue = None
         self.MaxValue = None
         self.YCenter = 0
-        self.CurrentZoom = 1
+        self.CurrentZoom = 1.0
         self.Fixed = False
         self.Ticktime = self.DataProducer.GetTicktime()
         self.RefreshCanvasRange()
@@ -285,7 +294,8 @@
         return self.InstancePath == tagname
     
     def NewValue(self, tick, value, forced=False):
-        self.Datas.append((float(tick), {True:1., False:0.}.get(value, float(value))))
+        value = {True:1., False:0.}.get(value, float(value))
+        self.Datas.append((float(tick), value))
         if self.MinValue is None:
             self.MinValue = value
         else:
@@ -340,10 +350,11 @@
         event.Skip()
     
     def OnPositionChanging(self, event):
-        self.ResetBounds()
-        self.StartTick = self.Datas[0][0] + event.GetPosition()
-        self.Fixed = True
-        self.NewDataAvailable(True)
+        if len(self.Datas) > 0:
+            self.ResetBounds()
+            self.StartTick = self.Datas[0][0] + event.GetPosition()
+            self.Fixed = True
+            self.NewDataAvailable(True)
         event.Skip()
 
     def OnResetButton(self, event):
@@ -352,10 +363,21 @@
         event.Skip()
 
     def OnCurrentButton(self, event):
-        self.ResetBounds()
-        self.StartTick = max(self.Datas[0][0], self.Datas[-1][0] - self.CurrentRange)
-        self.Fixed = False
-        self.NewDataAvailable(True)
+        if len(self.Datas) > 0:
+            self.ResetBounds()
+            self.StartTick = max(self.Datas[0][0], self.Datas[-1][0] - self.CurrentRange)
+            self.Fixed = False
+            self.NewDataAvailable(True)
+        event.Skip()
+    
+    def OnResetZoomOffsetButton(self, event):
+        if len(self.Datas) > 0:
+            self.YCenter = (self.MaxValue + self.MinValue) / 2
+        else:
+            self.YCenter = 0.0
+        self.CurrentZoom = 1.0
+        self.CanvasZoom.SetSelection(0)
+        wx.CallAfter(self.RefreshView, True)
         event.Skip()
     
     def OnExportGraphButtonClick(self, event):
@@ -380,7 +402,7 @@
                 self.CurrentMousePos = event.GetPosition()
                 self.CurrentMotionValue = self.Datas[self.StartIdx][0]
         event.Skip()
-        
+    
     def OnCanvasLeftUp(self, event):
         self.Dragging = False
         if self.Mode == MODE_MOTION:
@@ -389,6 +411,22 @@
         if self.Canvas.canvas.HasCapture():
             self.Canvas.canvas.ReleaseMouse()
         event.Skip()
+    
+    def OnCanvasMiddleDown(self, event):
+        self.Fixed = True
+        self.Canvas.canvas.CaptureMouse()
+        if len(self.Datas) > 0:
+            self.GetBounds()
+            self.CurrentMousePos = event.GetPosition()
+            self.CurrentMotionValue = self.Datas[self.StartIdx][0]
+        event.Skip()
+        
+    def OnCanvasMiddleUp(self, event):
+        self.CurrentMousePos = None
+        self.CurrentMotionValue = None
+        if self.Canvas.canvas.HasCapture():
+            self.Canvas.canvas.ReleaseMouse()
+        event.Skip()
         
     def OnCanvasMotion(self, event):
         if self.Mode == MODE_SELECTION and self.Dragging: