#------------------------------------------------------------------------------
# Copyright (c) 2013, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file LICENSE, distributed with this software.
#------------------------------------------------------------------------------
from atom.api import (
Bool, Callable, List, Value, Typed, ForwardTyped, set_default
)
from enaml.core.declarative import d_, observe
from .control import Control, ProxyControl
class ProxyObjectCombo(ProxyControl):
""" The abstract definition of a proxy ObjectCombo object.
"""
#: A reference to the ObjectCombo declaration.
declaration = ForwardTyped(lambda: ObjectCombo)
def set_selected(self, selected):
raise NotImplementedError
def set_editable(self, editable):
raise NotImplementedError
def request_items_refresh(self):
raise NotImplementedError
[docs]
class ObjectCombo(Control):
""" A drop-down list from which one item can be selected at a time.
Use a combo box to select a single item from a collection of items.
"""
#: The list of items to display in the combo box.
items = d_(List())
#: The selected item from the list of items. The default will be
#: the first item in the list of items, or None.
selected = d_(Value())
#: The callable to use to convert the items into strings
#: for display. The default is the builtin 'str'.
to_string = d_(Callable(str))
#: The callable to use to convert the items into icons for
#: display. The default is a lambda which returns None.
to_icon = d_(Callable(lambda item: None))
#: Whether the text in the combo box can be edited by the user.
editable = d_(Bool(False))
#: A combo box hugs its width weakly by default.
hug_width = set_default('weak')
#: A reference to the ProxyObjectCombo object.
proxy = Typed(ProxyObjectCombo)
#--------------------------------------------------------------------------
# Default Value Handlers
#--------------------------------------------------------------------------
def _default_selected(self):
""" The default value handler for the 'selected' member.
"""
items = self.items
if len(items) > 0:
return items[0]
#--------------------------------------------------------------------------
# Observers
#--------------------------------------------------------------------------
@observe('items', 'to_string', 'to_icon')
def _refresh_proxy(self, change):
""" An observer which requests an items refresh from the proxy.
"""
if change['type'] == 'update' and self.proxy_is_active:
self.proxy.request_items_refresh()
@observe('selected', 'editable')
def _update_proxy(self, change):
""" An observer which sends state change to the proxy.
"""
# The superclass handler implementation is sufficient.
super(ObjectCombo, self)._update_proxy(change)