带有复选框的 Kivy 多项选择

Here is a quick example showing what I've tried.

from kivy.app import App
from kivy.properties import StringProperty, ListProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.selectableview import SelectableView
from kivy.uix.togglebutton import ToggleButtonBehavior
from kivy.adapters.models import SelectableDataItem
from kivy.lang import Builder

Builder.load_string("""
#: import ListAdapter kivy.adapters.listadapter.ListAdapter
#: import Factory kivy.factory.Factory

<MyListItem>:
    height: 50

    on_state: root.is_selected = args[1] == "down"
    state: "down" if root.is_selected else "normal"

    BoxLayout:
        spacing: 10

        CheckBox:
            on_state: root.is_selected = args[1] == "down"
            state: "down" if root.is_selected else "normal"
            # on_state: root.state = args[1]
            # state: root.state

        Label:
            text: root.name

<Page>:
    orientation: "vertical"

    ListView:
        id: LV
        adapter: ListAdapter(data=root.data, cls=Factory.MyListItem, args_converter=root.args_converter, selection_mode="multiple", propagate_selection_to_data=True)

    Button:
        size_hint_y: None
        text: "print selection"
        on_press: print(LV.adapter.selection)
""")

class MyListItem(ToggleButtonBehavior, SelectableView, BoxLayout):
    name = StringProperty()

    def __repr__(self):
        return "%s(name=%r)" % (type(self).__name__, self.name)

    def on_state(self, me, state):
        print me, state
        if state == "down":
            self.select()
        else:
            self.deselect()
        # self.is_selected = state == "down"

class DataItem(SelectableDataItem):
    def __init__(self, name, **kwargs):
        super(DataItem, self).__init__(**kwargs)
        self.name = name

    def __repr__(self):
        return "%s(name=%r, is_selected=%r)" % (type(self).__name__, self.name, self.is_selected)


class Page(BoxLayout):
    data = ListProperty()

    def __init__(self, **kwargs):
        super(Page, self).__init__(**kwargs)
        self.data = [DataItem("Item {}".format(i), is_selected=True) for i in range(10)]

    def args_converter(self, index, data_item):
        return {
            "index": index,
             "name": data_item.name,
        }


class ExampleApp(App):
    def build(self):
        return Page()


if __name__ == "__main__":
    ExampleApp().run()

我正在使用 Kivy v1.9.1-dev