Measuring distance in ArcGlobe using Python AddIn

I want to make a Python script that will calculate the distance of the line I drew and output it in a special form, but I can’t figure out what I’m doing wrong.

import arcpy
import pythonaddins

class ToolClass2(object):
    """Implementation for probn_addin.tool (Tool)"""
    def __init__(self):
        self.enabled = True
        self.shape = "Line" # Can set to "Line", "Circle" or "Rectangle" for interactive shape drawing and to activate the onLine/Polygon/Circle event sinks.
    def onMouseDown(self, x, y, button, shift):
        pass
    def onMouseDownMap(self, x, y, button, shift):
        print(x,y)
        return(x,y)
    def onMouseUp(self, x, y, button, shift):
        pass
    def onMouseUpMap(self, x, y, button, shift):
        print(x,y)
        return(x,y)
    def onMouseMove(self, x, y, button, shift):
        pass
    def onMouseMoveMap(self, x, y, button, shift):
        pass
    def onDblClick(self):
        pass
    def onKeyDown(self, keycode, shift):
        pass
    def onKeyUp(self, keycode, shift):
        pass
    def deactivate(self):
        pass
    def onCircle(self, circle_geometry):
        pass
    def onLine(self, line_geometry):
        onMouseDownMap(x1,y1)
        onMouseUpMap(x2,y2)
        dist = math.sqrt((x2 - x1)**2 + (y2 - y1)**2)
        message = "Your lenght:" + str(dist)
        pythonaddins.MessageBox(message, "Ruler")
    def onRectangle(self, rectangle_geometry):
        pass