hub/venv/lib/python3.7/site-packages/ipywidgets/widgets/widget_button.py

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# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.
"""Button class.
Represents a button in the frontend using a widget. Allows user to listen for
click events on the button and trigger backend code when the clicks are fired.
"""
from .domwidget import DOMWidget
from .widget import CallbackDispatcher, register, widget_serialization
from .widget_core import CoreWidget
from .widget_style import Style
from .trait_types import Color, InstanceDict
from traitlets import Unicode, Bool, CaselessStrEnum, Instance, validate, default
import warnings
@register
class ButtonStyle(Style, CoreWidget):
"""Button style widget."""
_model_name = Unicode('ButtonStyleModel').tag(sync=True)
button_color = Color(None, allow_none=True, help="Color of the button").tag(sync=True)
font_weight = Unicode(help="Button text font weight.").tag(sync=True)
@register
class Button(DOMWidget, CoreWidget):
"""Button widget.
This widget has an `on_click` method that allows you to listen for the
user clicking on the button. The click event itself is stateless.
Parameters
----------
description: str
description displayed next to the button
tooltip: str
tooltip caption of the toggle button
icon: str
font-awesome icon name
disabled: bool
whether user interaction is enabled
"""
_view_name = Unicode('ButtonView').tag(sync=True)
_model_name = Unicode('ButtonModel').tag(sync=True)
description = Unicode(help="Button label.").tag(sync=True)
tooltip = Unicode(help="Tooltip caption of the button.").tag(sync=True)
disabled = Bool(False, help="Enable or disable user changes.").tag(sync=True)
icon = Unicode('', help="Font-awesome icon name, without the 'fa-' prefix.").tag(sync=True)
button_style = CaselessStrEnum(
values=['primary', 'success', 'info', 'warning', 'danger', ''], default_value='',
help="""Use a predefined styling for the button.""").tag(sync=True)
style = InstanceDict(ButtonStyle).tag(sync=True, **widget_serialization)
def __init__(self, **kwargs):
super(Button, self).__init__(**kwargs)
self._click_handlers = CallbackDispatcher()
self.on_msg(self._handle_button_msg)
@validate('icon')
def _validate_icon(self, proposal):
"""Strip 'fa-' if necessary'"""
value = proposal['value']
if value.startswith('fa-'):
warnings.warn("icons names no longer start with 'fa-', "
"just use the class name itself (for example, 'check' instead of 'fa-check')", DeprecationWarning)
value = value[3:]
return value
def on_click(self, callback, remove=False):
"""Register a callback to execute when the button is clicked.
The callback will be called with one argument, the clicked button
widget instance.
Parameters
----------
remove: bool (optional)
Set to true to remove the callback from the list of callbacks.
"""
self._click_handlers.register_callback(callback, remove=remove)
def click(self):
"""Programmatically trigger a click event.
This will call the callbacks registered to the clicked button
widget instance.
"""
self._click_handlers(self)
def _handle_button_msg(self, _, content, buffers):
"""Handle a msg from the front-end.
Parameters
----------
content: dict
Content of the msg.
"""
if content.get('event', '') == 'click':
self.click()