Source code for pyface.fields.i_field
# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
# All rights reserved.
#
# This software is provided without warranty under the terms of the BSD
# license included in LICENSE.txt and may be redistributed only under
# the conditions described in the aforementioned license. The license
# is also available online at http://www.enthought.com/licenses/BSD.txt
#
# Thanks for using Enthought open source!
""" The field interface. """
from traits.api import Any, HasTraits
from pyface.i_layout_widget import ILayoutWidget
from pyface.ui_traits import Alignment
[docs]class IField(ILayoutWidget):
""" The field interface.
A field is a widget that displays a value and (potentially) allows a user
to interact with it.
"""
#: The value held by the field.
value = Any()
#: The alignment of the field's content.
alignment = Alignment()
[docs]class MField(HasTraits):
""" The field mix-in. """
#: The value held by the field.
value = Any()
#: The alignment of the text in the field.
alignment = Alignment()
# ------------------------------------------------------------------------
# IWidget interface
# ------------------------------------------------------------------------
[docs] def create(self, parent=None):
""" Creates the toolkit specific control.
This method should create the control and assign it to the
:py:attr:``control`` trait.
"""
super().create(parent=parent)
self.show(self.visible)
self.enable(self.enabled)
def _initialize_control(self):
""" Perform any post-creation initialization for the control.
"""
super()._initialize_control()
self._set_control_value(self.value)
if self.alignment != 'default':
self._set_control_alignment(self.alignment)
def _add_event_listeners(self):
""" Set up toolkit-specific bindings for events """
super()._add_event_listeners()
self.observe(self._value_updated, "value", dispatch="ui")
self.observe(self._alignment_updated, "alignment", dispatch="ui")
def _remove_event_listeners(self):
""" Remove toolkit-specific bindings for events """
self.observe(
self._value_updated, "value", dispatch="ui", remove=True
)
self.observe(
self._alignment_updated, "alignment", dispatch="ui", remove=True
)
super()._remove_event_listeners()
# ------------------------------------------------------------------------
# Private interface
# ------------------------------------------------------------------------
def _get_control(self):
""" If control is not passed directly, get it from the trait. """
control = self.control
if control is None:
raise RuntimeError("Toolkit control does not exist.")
return control
# Toolkit control interface ---------------------------------------------
def _get_control_value(self):
""" Toolkit specific method to get the control's value. """
raise NotImplementedError()
def _set_control_value(self, value):
""" Toolkit specific method to set the control's value. """
raise NotImplementedError()
def _get_control_alignment(self):
""" Toolkit specific method to get the control's read_only state. """
raise NotImplementedError()
def _set_control_alignment(self, alignment):
""" Toolkit specific method to set the control's alignment. """
raise NotImplementedError()
# Trait change handlers -------------------------------------------------
def _value_updated(self, event):
value = event.new
if self.control is not None:
self._set_control_value(value)
def _alignment_updated(self, event):
alignment = event.new
if self.control is not None:
self._set_control_alignment(alignment)