diff -r 99ab0b74865f -r edcd40605fff graphics/GraphicCommons.py
--- a/graphics/GraphicCommons.py	Tue Jan 17 18:46:06 2012 +0100
+++ b/graphics/GraphicCommons.py	Tue Jan 17 20:04:52 2012 +0100
@@ -508,6 +508,21 @@
 Class that implements a custom tool tip
 """
 
+if wx.Platform == '__WXMSW__':
+    faces = { 'times': 'Times New Roman',
+              'mono' : 'Courier New',
+              'helv' : 'Arial',
+              'other': 'Comic Sans MS',
+              'size' : 10,
+             }
+else:
+    faces = { 'times': 'Times',
+              'mono' : 'Courier',
+              'helv' : 'Helvetica',
+              'other': 'new century schoolbook',
+              'size' : 12,
+             }
+
 class ToolTip(wx.PopupWindow):
     
     def __init__(self, parent, tip):
@@ -528,9 +543,18 @@
         self.CurrentPosition = pos
         self.SetPosition(pos)
     
+    def GetTipExtent(self):
+        max_width = 0
+        max_height = 0
+        for line in self.Tip.splitlines():
+            w, h = self.GetTextExtent(line)
+            max_width = max(max_width, w)
+            max_height += h
+        return max_width, max_height
+    
     def RefreshTip(self):
         if self:
-            w, h = self.GetTextExtent(self.Tip)
+            w, h = self.GetTipExtent()
             self.SetSize(wx.Size(w + 4, h + 4))
             self.SetPosition(self.CurrentPosition)
             self.Refresh()
@@ -540,10 +564,15 @@
         dc.Clear()
         dc.SetPen(MiterPen(wx.BLACK))
         dc.SetBrush(wx.Brush(wx.Colour(255, 238, 170)))
+        dc.SetFont(wx.Font(faces["size"], wx.SWISS, wx.NORMAL, wx.NORMAL, faceName = faces["mono"]))
         dc.BeginDrawing()
-        w, h = dc.GetTextExtent(self.Tip)
+        w, h = self.GetTipExtent()
         dc.DrawRectangle(0, 0, w + 4, h + 4)
-        dc.DrawText(self.Tip, 2, 2)
+        offset = 0
+        for line in self.Tip.splitlines():
+            dc.DrawText(line, 2, offset + 2)
+            w, h = dc.GetTextExtent(line)
+            offset += h
         dc.EndDrawing()
         event.Skip()