"""Implements the Python representation of the Accessibility module."""
from typing import Optional, Any
from copy import deepcopy
from validator_collection import validators
from highcharts_core.metaclasses import HighchartsMeta, JavaScriptDict
from highcharts_core.decorators import class_sensitive
from highcharts_core import constants, errors
from highcharts_core.options.accessibility.announce_new_data import AnnounceNewData
from highcharts_core.options.accessibility.high_contrast_theme import HighContrastTheme
from highcharts_core.options.accessibility.keyboard_navigation import KeyboardNavigation
from highcharts_core.options.accessibility.point import AccessibilityPoint
from highcharts_core.options.accessibility.screen_reader_section import ScreenReaderSection
from highcharts_core.options.accessibility.series import SeriesAccessibility
[docs]class CustomAccessibilityComponents(JavaScriptDict):
"""JavaScript object which contains a map of component names to instances of classes
inheriting from the (JavaScript)
`Highcharts.AccessibilityComponent <https://api.highcharts.com/class-reference/Highcharts.AccessibilityComponent>`_
base class.
.. tip::
Remember to add the component to the :meth:`keyboard_navigation.order`
for the keyboard navigation to be usable.
"""
_valid_value_types = str
_allow_empty_value = True
[docs]class Accessibility(HighchartsMeta):
"""Options for configuring accessibility for the chart."""
def __init__(self, **kwargs):
self._announce_new_data = None
self._custom_components = None
self._description = None
self._enabled = True
self._high_contrast_theme = None
self._keyboard_navigation = None
self._landmark_verbosity = None
self._linked_description = None
self._point = None
self._screen_reader_section = None
self._series = None
self._type_description = None
self.announce_new_data = kwargs.get('announce_new_data', None)
self.custom_components = kwargs.get('custom_components', None)
self.description = kwargs.get('description', None)
self.enabled = kwargs.get('enabled', None)
self.high_contrast_theme = kwargs.get('high_contrast_theme', None)
self.keyboard_navigation = kwargs.get('keyboard_navigation', None)
self.landmark_verbosity = kwargs.get('landmark_verbosity', None)
self.linked_description = kwargs.get('linked_description', None)
self.point = kwargs.get('point', None)
self.screen_reader_section = kwargs.get('screen_reader_section', None)
self.series = kwargs.get('series', None)
self.type_description = kwargs.get('type_description', None)
@property
def announce_new_data(self) -> Optional[AnnounceNewData]:
"""Options for announcing new data to screen reader users.
.. tip::
Useful for dynamic data applications and drilldown.
Keep in mind that frequent announcements will not be useful to users, as they
won't have time to explore the new data. For these applications, consider making
snapshots of the data accessible, and do the announcements in batches.
:returns: Configuration for the announcement of new data to screen reader users.
:rtype: :class:`AnnounceNewData` or :obj:`None <python:None>`
"""
return self._announce_new_data
@announce_new_data.setter
@class_sensitive(AnnounceNewData)
def announce_new_data(self, value):
self._announce_new_data = value
@property
def custom_components(self) -> Optional[CustomAccessibilityComponents]:
"""Property which supports the definition of custom components added to the
accessibility module. Defaults to :obj:`None <python:None>`.
.. tip::
Remember to add the component to the :meth:`keyboard_navigation.order`
for the keyboard navigation to be usable.
:returns: Custom components that have been added to the accessibility module.
:rtype: :class:`CustomAccessibilityComponents` or :obj:`None <python:None>`
"""
return self._custom_components
@custom_components.setter
@class_sensitive(CustomAccessibilityComponents)
def custom_components(self, value):
self._custom_components = value
@property
def description(self) -> Optional[str]:
"""A text description of the chart.
If the Accessibility module is loaded, this option is included by default as a
long description of the chart in the hidden screen reader information region.
.. warning::
Prefer using :meth:`Accessibility.linked_description` and
:meth:`Options.caption` instead.
Since Highcharts now supports captions and linked descriptions, it is preferred
to define the description using those methods, as a visible caption/description
benefits all users. If the ``accessibility.description`` option is defined, the
linked description is ignored, and the caption is hidden from screen reader
users.
:returns: The description of the chart or :obj:`None <python:None>`
:rtype: :class:`str <python:str>` or :obj:`None <python:None>`
"""
return self._description
@description.setter
def description(self, value):
value = validators.string(value, allow_empty = True)
self._description = value
@property
def enabled(self) -> Optional[bool]:
"""If ``True``, enables accessibility functionality for the chart. Defaults to
``True``.
.. seealso::
For more information on how to include these features, and why this is
recommended, see
`Highcharts Accessibility <https://www.highcharts.com/docs/accessibility/accessibility-module>`_
.. note::
Highcharts will by default emit a warning to the console if the accessibility
module is not loaded. Setting this option to false will override and silence the
warning.
Once the module is loaded, setting this option to false will disable the module
for this chart.
:returns: Flag indicating whether the :class:`Accessibility` module is enabled
for the chart.
:rtype: :class:`bool <python:bool>` or :obj:`None <python:None>`
"""
return self._enabled
@enabled.setter
def enabled(self, value):
if value is None:
self._enabled = None
else:
self._enabled = bool(value)
@property
def high_contrast_theme(self) -> Any:
"""Theme to apply to the chart when Windows High Contrast Mode is detected.
By default, a high contrast theme matching the high contrast system system colors
is used.
:returns: Theme to apply to the chart when high contrast mode is detected.
:rtype: :class:`HighContrastTheme` or :obj:`None <python:None>`
"""
return self._high_contrast_theme
@high_contrast_theme.setter
def high_contrast_theme(self, value):
self._high_contrast_theme = value
@property
def keyboard_navigation(self) -> Optional[KeyboardNavigation]:
"""Options for keyboard navigation.
:returns: Configuration for keyboard navigation.
:rtype: :class:`KeyboardNavigation` or :obj:`None <python:None>`
"""
return self._keyboard_navigation
@keyboard_navigation.setter
@class_sensitive(KeyboardNavigation)
def keyboard_navigation(self, value):
self._keyboard_navigation = value
@property
def landmark_verbosity(self) -> Optional[str]:
"""Amount of landmarks/regions to create for screen reader users.
More landmarks can make navigation with screen readers easier, but can be
distracting if there are lots of charts on the page.
Three modes are available:
* ``'all'``: Adds regions for all series, legend, information region.
* ``'one'``: Adds a single landmark per chart.
* ``'disabled'``: No landmarks are added.
Defaults to ``'all'``.
:returns: The landmark verbosity for screen readers to use.
:rtype: :class:`str` or :obj:`None <python:None>`
"""
return self._landmark_verbosity
@landmark_verbosity.setter
def landmark_verbosity(self, value):
if not value:
self._landmark_verbosity = None
else:
value = validators.string(value)
value = value.lower()
if value not in constants.LANDMARK_VERBOSITY_VALUES:
raise errors.HighchartsValueError(f'landmark_verbosity must be "all", '
f'"one", or "disabled". Was: {value}')
self._landmark_verbosity = value
@property
def linked_description(self) -> Optional[str]:
"""Link the chart to an HTML element describing the contents of the chart.
.. hint::
It is always recommended to describe charts using visible text, to improve SEO
as well as accessibility for users with disabilities.
This option lets an HTML element with a description be linked to the chart, so
that screen reader users can connect the two.
By setting this option to a string, Highcharts runs the string as an HTML selector
query on the entire document. If there is only a single match, this element is
linked to the chart. The content of the linked element will be included in the
chart description for screen reader users.
By default, the chart looks for an adjacent sibling element with the
``highcharts-description`` (CSS) class.
The feature can be disabled by setting the option to an empty string, or
overridden by providing the :meth`Accessibility.description` option.
Alternatively, the HTML element to link can be passed in directly as an HTML node.
.. hint::
If you need the description to be part of the exported image, consider using the
caption feature.
If you need the description to be hidden visually, use the
:meth:`Accessibility.description` option.
Defaults to ``'*[data-highcharts-chart="{index}"] + .highcharts-description'``.
:returns: The CSS selector used to indicate the HTML element containing a
description of the chart.
:rtype: :class:`str <python:str>` or :obj:`None <python:None>`
"""
return self._linked_description
@linked_description.setter
def linked_description(self, value):
self._linked_description = validators.string(value, allow_empty = True)
@property
def point(self) -> Optional[AccessibilityPoint]:
"""Options for describing individual points.
:returns: Configuration for how to describe individual points on the chart.
:rtype: :class:`AccessibilityPoint` or :obj:`None <python:None>`
"""
return self._point
@point.setter
@class_sensitive(AccessibilityPoint)
def point(self, value):
self._point = value
@property
def screen_reader_section(self) -> Optional[ScreenReaderSection]:
"""Accessibility options for the screen reader information sections added before
and after the chart.
:returns: Configuration for the screen reader sections before and after the chart.
:rtype: :class:`ScreenReaderSection` or :obj:`None <python:None>`
"""
return self._screen_reader_section
@screen_reader_section.setter
@class_sensitive(ScreenReaderSection)
def screen_reader_section(self, value):
self._screen_reader_section = value
@property
def series(self) -> Optional[SeriesAccessibility]:
"""Accessibility options global to all data series.
.. hint::
Individual series can also have specific accessibility options set.
:returns: Global accessibility options applied to all data series.
:rtype: :class:`SeriesAccessibility` or :obj:`None <python:None>`
"""
return self._series
@series.setter
@class_sensitive(SeriesAccessibility)
def series(self, value):
self._series = value
@property
def type_description(self) -> Optional[str]:
"""A text description of the chart type.
If the Accessibility module is loaded, this will be included in the description
of the chart in the screen reader information region.
.. note::
Highcharts will by default attempt to guess the chart type, but for more complex
charts it is recommended to specify this property for clarity.
:returns: A description fo the chart type.
:rtype: :class:`str <python:str>` or :obj:`None <python:None>`
"""
return self._type_description
@type_description.setter
def type_description(self, value):
self._type_description = validators.string(value, allow_empty = True)
@classmethod
def _get_kwargs_from_dict(cls, as_dict):
kwargs = {
'announce_new_data': as_dict.get('announceNewData', None),
'custom_components': as_dict.get('customComponents', None),
'description': as_dict.get('description', None),
'enabled': as_dict.get('enabled', None),
'high_contrast_theme': as_dict.get('highContrastTheme', None),
'keyboard_navigation': as_dict.get('keyboardNavigation', None),
'landmark_verbosity': as_dict.get('landmarkVerbosity', None),
'linked_description': as_dict.get('linkedDescription', None),
'point': as_dict.get('point', None),
'screen_reader_section': as_dict.get('screenReaderSection', None),
'series': as_dict.get('series', None),
'type_description': as_dict.get('typeDescription', None)
}
return kwargs
def _to_untrimmed_dict(self, in_cls = None) -> dict:
untrimmed = {
'announceNewData': self.announce_new_data,
'customComponents': self.custom_components,
'description': self.description,
'enabled': self.enabled,
'highContrastTheme': self.high_contrast_theme,
'keyboardNavigation': self.keyboard_navigation,
'landmarkVerbosity': self.landmark_verbosity,
'linkedDescription': self.linked_description,
'point': self.point,
'screenReaderSection': self.screen_reader_section,
'series': self.series,
'typeDescription': self.type_description
}
return untrimmed
__all__ = [
'Accessibility',
'AnnounceNewData',
'HighContrastTheme',
'KeyboardNavigation',
'AccessibilityPoint',
'ScreenReaderSection',
'SeriesAccessibility'
]