#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2019, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Various kinds of input widgets and form controls.

'''

#-----------------------------------------------------------------------------
# Boilerplate
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from __future__ import absolute_import, division, print_function, unicode_literals

import logging
log = logging.getLogger(__name__)

#-----------------------------------------------------------------------------
# Imports
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# Standard library imports

# External imports

# Bokeh imports
from ...core.has_props import abstract
from ...core.properties import Date, Either, Float, Instance, Int, List, String, Tuple, Dict

from ..callbacks import Callback

from .widget import Widget

#-----------------------------------------------------------------------------
# Globals and constants
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__all__ = (
    'AutocompleteInput',
    'DatePicker',
    'InputWidget',
    'MultiSelect',
    'PasswordInput',
    'Select',
    'TextInput',
    'TextAreaInput'
)

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# Dev API
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@abstract
class InputWidget(Widget):
    ''' Abstract base class for input widgets.

    '''

    title = String(default="", help="""
    Widget's label.
    """)

    @classmethod
    def coerce_value(cls, val):
        prop_obj = cls.lookup('value')
        if isinstance(prop_obj, Float):
            return float(val)
        elif isinstance(prop_obj, Int):
            return int(val)
        elif isinstance(prop_obj, String):
            return str(val)
        else:
            return val

#-----------------------------------------------------------------------------
# General API
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class TextInput(InputWidget):
    ''' Single-line input widget.

    '''

    value = String(default="", help="""
    Initial or entered text value.
    """)

    callback = Instance(Callback, help="""
    A callback to run in the browser whenever the user unfocuses the
    ``TextInput`` widget by hitting Enter or clicking outside of the text box
    area.
    """)

    placeholder = String(default="", help="""
    Placeholder for empty input field
    """)


class TextAreaInput(TextInput):
    ''' Multi-line input widget.

    '''

    cols = Int(default=20, help="""
    Specifies the width of the text area (in average character width). Default: 20
    """)

    rows = Int(default=2, help="""
    Specifies the height of the text area (in lines). Default: 2
    """)

    max_length = Int(default=500, help="""
    Max count of characters in field
    """)


class PasswordInput(TextInput):
    ''' Single-line password input widget.
        Note: Despite ``PasswordInput`` inheriting from ``TextInput`` the
        password cannot be inspected on the field ``value``. Also, note that
        this field functionally just hides the input on the browser,
        transmitting safely a password as a callback, e.g., to a bokeh
        server would require some secure connection.

    '''


class AutocompleteInput(TextInput):
    ''' Single-line input widget with auto-completion.

    '''

    completions = List(String, help="""
    A list of completion strings. This will be used to guide the
    user upon typing the beginning of a desired value.
    """)


class Select(InputWidget):
    ''' Single-select widget.

    '''
    options = Either( List(Either(String, Tuple(Either(Int,String), String))),
        Dict(String, List(Either(String, Tuple(Either(Int,String), String)))), help="""
    Available selection options. Options may be provided either as a list of
    possible string values, or as a list of tuples, each of the form
    ``(value, label)``. In the latter case, the visible widget text for each
    value will be corresponding given label. Option groupings can be provided
    by supplying a dictionary object whose values are in the aforementioned
    list format
    """)

    value = String(default="", help="""
    Initial or selected value.
    """)

    callback = Instance(Callback, help="""
    A callback to run in the browser whenever the current Select dropdown
    value changes.
    """)

class MultiSelect(InputWidget):
    ''' Multi-select widget.

    '''

    options = List(Either(String, Tuple(String, String)), help="""
    Available selection options. Options may be provided either as a list of
    possible string values, or as a list of tuples, each of the form
    ``(value, label)``. In the latter case, the visible widget text for each
    value will be corresponding given label.
    """)

    value = List(String, help="""
    Initial or selected values.
    """)

    callback = Instance(Callback, help="""
    A callback to run in the browser whenever the current selection value
    changes.
    """)

    size = Int(default=4, help="""
    The number of visible options in the dropdown list. (This uses the
    ``select`` HTML element's ``size`` attribute. Some browsers might not
    show less than 3 options.)
    """)

class DatePicker(InputWidget):
    ''' Calendar-based date picker widget.

    '''

    value = Date(help="""
    The initial or picked date.
    """)

    min_date = Date(default=None, help="""
    Optional earliest allowable date.
    """)

    max_date = Date(default=None, help="""
    Optional latest allowable date.
    """)

    callback = Instance(Callback, help="""
    A callback to run in the browser whenever the current date value changes.
    """)

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