#------------------------------------------------------------------------------
# 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, List, Int, Property, Str, Typed, ForwardTyped, set_default
)
from enaml.core.declarative import d_, observe
from .control import Control, ProxyControl
class ProxyComboBox(ProxyControl):
""" The abstract definition of a proxy ComboBox object.
"""
#: A reference to the ComboBox declaration.
declaration = ForwardTyped(lambda: ComboBox)
def set_items(self, items):
raise NotImplementedError
def set_index(self, index):
raise NotImplementedError
def set_editable(self, editable):
raise NotImplementedError
[docs]
class ComboBox(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.
See `ObjectCombo` for a more robust combo box control.
"""
#: The strings to display in the combo box.
items = d_(List(Str()))
#: The integer index of the currently selected item. If the index
#: falls outside the range of items, the item will be deselected.
index = d_(Int(-1))
#: A read only cached property which returns the selected item.
selected_item = d_(Property(cached=True), writable=False)
#: 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 ProxyComboBox object.
proxy = Typed(ProxyComboBox)
[docs]
@selected_item.getter
def get_selected_item(self):
""" The getter function for the selected item property.
If the index falls out of range, the selected item will be an
empty string.
"""
items = self.items
idx = self.index
if idx < 0 or idx >= len(items):
return ''
return items[idx]
#--------------------------------------------------------------------------
# Observers
#--------------------------------------------------------------------------
@observe('index', 'items', 'editable')
def _update_proxy(self, change):
""" An observer which sends state change to the proxy.
"""
# The superclass handler implementation is sufficient.
super(ComboBox, self)._update_proxy(change)
@observe('index', 'items')
def _reset_selected_item(self, change):
""" Reset the selected item when the index or items changes.
"""
if change['type'] == 'update':
self.get_member('selected_item').reset(self)