How to pause a program while button is not 3???


I have a "simple" problem with mpl, but didn't find a way to solve it so
Let's say I have a set of three 2Darrays I would like to :

- load using imshow
- then connect to the mouse click event and add all X and Y coordinates
obtained when clicking
(so each time I click, I'll get xc += event.x for example)
  and PAUSE the program until I get a click on the right button of the mouse
- when I click on the right button of the mouse, I want the program to
go on and load the second data array
- ... and continue until all data arrays have been looked at in that way.

So in principle it would look like the script below. But of course this
So I would welcome any suggestion of how to solve this problem....



import numpy as num

class offset:
   def __init__(self) :
      self.xc = 0.
      self.yc = 0.
      self.stay = 1
   def on_click(self, event) :
      if event.button == 1:
         if event.inaxes is not None:
            self.xc += event.xdata
            self.yc += event.ydata
      elif event.button == 3:
         self.stay = 0

data1 = num.random.rand(10,10)
data2 = num.random.rand(10,10)
data3 = num.random.rand(10,10)
alldata = [data1, data2, data3]
for i in range(len(alldata)) :
   newoffset = offset()
   binding = connect('button_press_event', newoffset.on_click)
   while newoffset.stay :

   print newoffset.xc, newoffset.yc