def __enter__(self):
"""
Enter the restricted output context
EXAMPLES::
sage: from sage.repl.rich_output.display_manager import (
....: get_display_manager, restricted_output)
sage: dm = get_display_manager()
sage: len(dm.supported_output()) > 1
True
sage: with restricted_output(dm, [dm.types.OutputPlainText]):
....: dm.supported_output()
frozenset({<class 'sage.repl.rich_output.output_basic.OutputPlainText'>})
sage: dm.preferences.supplemental_plot
'never'
sage: dm.preferences.supplemental_plot = 'always'
sage: with restricted_output(dm, [dm.types.OutputPlainText]):
....: dm.preferences
Display preferences:
* graphics = disable
* supplemental_plot = never
* text is not specified
sage: dm.preferences.supplemental_plot = 'never'
"""
dm = self._display_manager
self._original = dm._supported_output
dm._supported_output = self._output_classes
self._original_prefs = DisplayPreferences(dm.preferences)
dm.preferences.graphics = 'disable'
dm.preferences.supplemental_plot = 'never'
def default_preferences(self):
"""
Return the backend's display preferences
The default for the commandline is to not plot graphs since
the launching of an external viewer is considered too
disruptive.
OUTPUT:
Instance of
:class:`~sage.repl.rich_output.preferences.DisplayPreferences`.
EXAMPLES::
sage: from sage.repl.rich_output.backend_ipython import BackendIPythonCommandline
sage: backend = BackendIPythonCommandline()
sage: backend.default_preferences()
Display preferences:
* graphics is not specified
* supplemental_plot = never
* text is not specified
"""
from sage.repl.rich_output.preferences import DisplayPreferences
return DisplayPreferences(supplemental_plot='never')
def switch_backend(self, backend, **kwds):
"""
Switch to a new backend
INPUT:
- ``backend`` -- instance of
:class:`~sage.repl.rich_output.backend_base.BackendBase`.
- ``kwds`` -- optional keyword arguments that are passed on to
the
:meth:`~sage.repl.rich_output.backend_base.BackendBase.install`
method.
OUTPUT:
The previous backend.
EXAMPLES::
sage: from sage.repl.rich_output.backend_base import BackendSimple
sage: simple = BackendSimple()
sage: from sage.repl.rich_output import get_display_manager
sage: dm = get_display_manager(); dm
The Sage display manager using the doctest backend
sage: previous = dm.switch_backend(simple)
sage: dm
The Sage display manager using the simple backend
Restore the doctest backend::
sage: dm.switch_backend(previous) is simple
True
"""
from sage.repl.rich_output.backend_base import BackendBase
if not isinstance(backend, BackendBase):
raise ValueError('backend must be instance of BackendBase class')
supported = backend.supported_output()
if not any(issubclass(out, OutputPlainText) for out in supported):
raise ValueError('every backend must support plain text')
try:
self._backend.uninstall()
except AttributeError:
pass # first time we switch
# clear caches
self._output_promotions = dict()
self._supported_output = frozenset(
map(self._demote_output_class, backend.supported_output()))
# install new backend
try:
old_backend = self._backend
except AttributeError:
old_backend = None
self._backend = backend
self._backend.install(**kwds)
self._preferences = DisplayPreferences(
self._backend.default_preferences())
return old_backend
def default_preferences(self):
"""
Return the backend's display preferences
Matches the IPython command line display preferences to keep
the differences between that and the doctests to a minimum.
OUTPUT:
Instance of
:class:`~sage.repl.rich_output.preferences.DisplayPreferences`.
EXAMPLES::
sage: from sage.repl.rich_output.backend_ipython import BackendIPythonCommandline
sage: backend = BackendIPythonCommandline()
sage: backend.default_preferences()
Display preferences:
* graphics is not specified
* supplemental_plot = never
* text is not specified
"""
from sage.repl.rich_output.preferences import DisplayPreferences
return DisplayPreferences(supplemental_plot='never')
def default_preferences(self):
"""
Return the backend's display preferences
Override this method to change the default preferences when
using your backend.
OUTPUT:
Instance of
:class:`~sage.repl.rich_output.preferences.DisplayPreferences`.
EXAMPLES::
sage: from sage.repl.rich_output.backend_base import BackendBase
sage: backend = BackendBase()
sage: backend.default_preferences()
Display preferences:
* graphics is not specified
* supplemental_plot is not specified
* text is not specified
"""
from sage.repl.rich_output.preferences import DisplayPreferences
return DisplayPreferences()
def default_preferences(self):
return DisplayPreferences(text=self.__text)
def default_preferences(self):
if self.state.latex:
text = 'latex'
else:
text = None
return DisplayPreferences(text=text)