Source code for enaml.widgets.combo_box

# 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)