"""A `wx.Timer` subclass that invokes a specified callback
periodically.
"""
# Author: Prabhu Ramachandran <prabhu@aero.iitb.ac.in>
# Copyright (c) 2006-2007,  Enthought, Inc.
# License: BSD Style.

# Standard library imports.
import wx

######################################################################
# `Timer` class.
class Timer(wx.Timer):
    """Simple subclass of wx.Timer that allows the user to have a
    function called periodically.

    Any exceptions raised in the callable are caught.  If
    `StopIteration` is raised the timer stops.  If other exceptions are
    encountered the timer is stopped and the exception re-raised.
    """
    
    def __init__(self, millisecs, callable, *args, **kw_args):
        """Initialize instance to invoke the given `callable` with
        given arguments and keyword args after every `millisecs`
        (milliseconds).
        """
        wx.Timer.__init__(self, id=wx.NewId())
        self.callable = callable
        self.args = args
        self.kw_args = kw_args
        self.Start(millisecs)

    def Notify(self):
        """Overridden to call the given callable.  Exceptions raised
        in the callable are caught.  If `StopIteration` is raised the
        timer stops.  If other exceptions are encountered the timer is
        stopped and the exception re-raised.
        """
        try:
            self.callable(*self.args, **self.kw_args)
        except StopIteration:
            self.Stop()
        except:
            self.Stop()
            raise