def responds_to_cpr(self) -> bool:
# When the input is a tty, we assume that CPR is supported.
# It's not when the input is piped from Pexpect.
if os.environ.get("PROMPT_TOOLKIT_NO_CPR", "") == "1":
return False
if is_dumb_terminal():
return False
try:
return self.stdin.isatty()
except ValueError:
return False # ValueError: I/O operation on closed file
def get_default_color_depth(self) -> ColorDepth:
"""
Return the default color depth for a vt100 terminal, according to the
our term value.
We prefer 256 colors almost always, because this is what most terminals
support these days, and is a good default.
"""
if self.default_color_depth is not None:
return self.default_color_depth
term = self.term
if term is None:
return ColorDepth.DEFAULT
if is_dumb_terminal(term):
return ColorDepth.DEPTH_1_BIT
if term in ("linux", "eterm-color"):
return ColorDepth.DEPTH_4_BIT
return ColorDepth.DEFAULT
def default(cls, term: Optional[str] = None) -> "ColorDepth":
"""
Return the default color depth, according to the $TERM value.
We prefer 256 colors almost always, because this is what most terminals
support these days, and is a good default.
The $PROMPT_TOOLKIT_COLOR_DEPTH environment variable can be used to
override this outcome. This is a way to enforce a certain color depth
in all prompt_toolkit applications.
If no `term` parameter is given, we use the $TERM environment variable.
"""
# Take `TERM` value from environment variable if nothing was passed.
if term is None:
term = os.environ.get("TERM", "")
if is_dumb_terminal(term):
return cls.DEPTH_1_BIT
if term in ("linux", "eterm-color"):
return cls.DEPTH_4_BIT
# For now, always use 4 bit color on Windows 10 by default, even when
# vt100 escape sequences with ENABLE_VIRTUAL_TERMINAL_PROCESSING are
# supported. We don't have a reliable way yet to know whether our
# console supports true color or only 4-bit.
if is_windows() and "PROMPT_TOOLKIT_COLOR_DEPTH" not in os.environ:
return cls.DEPTH_4_BIT
# Check the `PROMPT_TOOLKIT_COLOR_DEPTH` environment variable.
all_values = [i.value for i in ColorDepth]
if os.environ.get("PROMPT_TOOLKIT_COLOR_DEPTH") in all_values:
return cls(os.environ["PROMPT_TOOLKIT_COLOR_DEPTH"])
return cls.DEPTH_8_BIT
