|
|
#!/usr/bin/env python
|
|
|
# encoding: utf-8
|
|
|
"""
|
|
|
A context manager for handling sys.displayhook.
|
|
|
|
|
|
Authors:
|
|
|
|
|
|
* Robert Kern
|
|
|
* Brian Granger
|
|
|
"""
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Copyright (C) 2008-2009 The IPython Development Team
|
|
|
#
|
|
|
# Distributed under the terms of the BSD License. The full license is in
|
|
|
# the file COPYING, distributed as part of this software.
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Imports
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
import sys
|
|
|
|
|
|
from IPython.core.component import Component
|
|
|
|
|
|
from IPython.utils.autoattr import auto_attr
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Classes and functions
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
class DisplayTrap(Component):
|
|
|
"""Object to manage sys.displayhook.
|
|
|
|
|
|
This came from IPython.core.kernel.display_hook, but is simplified
|
|
|
(no callbacks or formatters) until more of the core is refactored.
|
|
|
"""
|
|
|
|
|
|
def __init__(self, parent, hook):
|
|
|
super(DisplayTrap, self).__init__(parent, None, None)
|
|
|
self.hook = hook
|
|
|
self.old_hook = None
|
|
|
# We define this to track if a single BuiltinTrap is nested.
|
|
|
# Only turn off the trap when the outermost call to __exit__ is made.
|
|
|
self._nested_level = 0
|
|
|
|
|
|
@auto_attr
|
|
|
def shell(self):
|
|
|
return Component.get_instances(
|
|
|
root=self.root,
|
|
|
klass='IPython.core.iplib.InteractiveShell')[0]
|
|
|
|
|
|
def __enter__(self):
|
|
|
if self._nested_level == 0:
|
|
|
self.set()
|
|
|
self._nested_level += 1
|
|
|
return self
|
|
|
|
|
|
def __exit__(self, type, value, traceback):
|
|
|
if self._nested_level == 1:
|
|
|
self.unset()
|
|
|
self._nested_level -= 1
|
|
|
return True
|
|
|
|
|
|
def set(self):
|
|
|
"""Set the hook."""
|
|
|
if sys.displayhook is not self.hook:
|
|
|
self.old_hook = sys.displayhook
|
|
|
sys.displayhook = self.hook
|
|
|
|
|
|
def unset(self):
|
|
|
"""Unset the hook."""
|
|
|
sys.displayhook = self.old_hook
|
|
|
|
|
|
|
