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# Copyright (c) 2012 - 2023, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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""" Provide the Auto property.

"""

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# Boilerplate
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from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

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# Imports
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# Bokeh imports
from .enum import Enum

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# Globals and constants
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__all__ = (
    'Auto',
)

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# General API
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class Auto(Enum):
    """ Accepts only the string "auto".

    Useful for properties that can be configured to behave "automatically".

    Example:

        This property is often most useful in conjunction with the
        :class:`~bokeh.core.properties.Either` property.

        .. code-block:: python

            >>> class AutoModel(HasProps):
            ...     prop = Either(Float, Auto)
            ...

            >>> m = AutoModel()

            >>> m.prop = 10.2

            >>> m.prop = "auto"

            >>> m.prop = "foo"      # ValueError !!

            >>> m.prop = [1, 2, 3]  # ValueError !!

    """
    def __init__(self) -> None:
        super().__init__("auto")

    def __str__(self) -> str:
        return self.__class__.__name__

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# Dev API
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# Private API
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#-----------------------------------------------------------------------------
# Code
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