Python-Kivy：在RecycleView中，垂直滚动不适用于向上/向下箭头键

Question

我正在使用Python-2.7和kivy。

通过运行test.py，然后单击“测试”菜单，它显示带有RecycleView的列表。

我想按UP and Down arrow Key滚动列表 有人可以告诉我该怎么做。

注意：

使用鼠标滚动可以正常工作

我正在尝试将代码 rv.scroll_to（self）放入下面的apply_selection函数中，但是它给出了一个错误：

     def apply_selection(self, rv, index, is_selected):
          ''' Respond to the selection of items in the view. '''
          self.selected = is_selected
          self.text_size = self.size

          if self.selected:
             rv.scroll_to(self)


File "/usr/share/kivi-examples/gst_fact/test.py", line 133, in apply_selection
     rv.scroll_to(self)
   File "/usr/local/lib/python2.7/dist-packages/kivy/uix/scrollview.py", line 901, in scroll_to
     if self._viewport._trigger_layout.is_triggered:
 AttributeError: 'function' object has no attribute 'is_triggered'

test.py

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import BooleanProperty, ListProperty, ObjectProperty, NumericProperty, DictProperty

from kivy.uix.recycleview.views import RecycleDataViewBehavior
from kivy.uix.button import Button
from kivy.uix.recyclegridlayout import RecycleGridLayout
from kivy.uix.behaviors import FocusBehavior
from kivy.uix.recycleview.layout import LayoutSelectionBehavior
from kivy.uix.popup import Popup
from kivy.core.window import Window
from kivy.clock import Clock
from kivy.uix.scrollview import ScrollView
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.recycleview import RecycleView
import sqlite3 as lite
import re

Window.size = (600, 325)


class PopupLabelCell(Label):
    pass


class EditPopup(Popup):

    def __init__(self, obj, **kwargs):
        super(EditPopup, self).__init__(**kwargs)
        self.populate_content(obj)

    def populate_content(self, obj):
        print('hello')


class SelectableRecycleGridLayout(FocusBehavior, LayoutSelectionBehavior,
                                  RecycleGridLayout):
    ''' Adds selection and focus behaviour to the view. '''

    selected_row = NumericProperty(0)
    obj = ObjectProperty(None)

    def get_nodes(self):
        nodes = self.get_selectable_nodes()
        if self.nodes_order_reversed:
            nodes = nodes[::-1]
        if not nodes:
            return None, None

        selected = self.selected_nodes
        if not selected:  # nothing selected, select the first
            self.selected_row = 0
            self.select_row(nodes)
            return None, None

        if len(nodes) == 1:  # the only selectable node is selected already
            return None, None

        last = nodes.index(selected[-1])
        self.clear_selection()
        return last, nodes

    def select_next(self, obj):
        ''' Select next row '''
        self.obj = obj
        last, nodes = self.get_nodes()
        if not nodes:
            return

        if last == len(nodes) - 1:
            self.selected_row = nodes[0]
        else:
            self.selected_row = nodes[last]
            self.selected_row += self.obj.total_col_headings

        self.select_row(nodes)

    def select_previous(self, obj):
        ''' Select previous row '''
        self.obj = obj
        last, nodes = self.get_nodes()
        if not nodes:
            return

        if not last:
            self.selected_row = nodes[-1]
        else:
            self.selected_row = nodes[last - 1]

        self.selected_row -= self.obj.total_col_headings
        self.select_row(nodes)

    def select_current(self, obj):
        ''' Select current row '''
        self.obj = obj
        last, nodes = self.get_nodes()
        if not nodes:
            return

        self.select_row(nodes)

    def select_row(self, nodes):
        col = self.obj.rv_data[self.selected_row]['range']
        for x in range(col[0], col[1] + 1):
            self.select_node(nodes[x])


class SelectableButton(RecycleDataViewBehavior, Button):
    ''' Add selection support to the Button '''
    index = None
    selected = BooleanProperty(False)
    selectable = BooleanProperty(True)

    def refresh_view_attrs(self, rv, index, data):
        ''' Catch and handle the view changes '''
        self.index = index
        return super(SelectableButton, self).refresh_view_attrs(rv, index, data)

    def on_touch_down(self, touch):
        ''' Add selection on touch down '''
        if super(SelectableButton, self).on_touch_down(touch):
            return True
        if self.collide_point(*touch.pos) and self.selectable:
            print("on_touch_down: self=", self)
            return self.parent.select_with_touch(self.index, touch)

    def apply_selection(self, rv, index, is_selected):
        ''' Respond to the selection of items in the view. '''
        self.selected = is_selected
        self.text_size = self.size
        #rv.scroll_to(self)


class HeaderCell(Label):
    pass


class TableHeader(ScrollView):
    """Fixed table header that scrolls x with the data table"""
    header = ObjectProperty(None)
    col_headings = ListProperty([])
    cols_minimum = DictProperty({})

    def __init__(self, **kwargs):
        super(TableHeader, self).__init__(**kwargs)
        self.get_table_column_headings()

    def get_table_column_headings(self):
        col_headings = ['SN','State']

        for col_index, col_heading in enumerate(col_headings):
            self.cols_minimum[col_index] = 100

            self.col_headings.append(col_heading)

            self.header.add_widget(HeaderCell(text=col_heading, width=self.cols_minimum[col_index]))


class RV(RecycleView):
    row_data = ()
    rv_data = ListProperty([])
    row_controller = ObjectProperty(None)
    total_col_headings = NumericProperty(0)
    cols_minimum = DictProperty({})
    table_header = ObjectProperty(None)

    def __init__(self, table_header, **kwargs):
        super(RV, self).__init__(**kwargs)
        self.table_header = table_header
        self.total_col_headings = len(table_header.col_headings)
        self.cols_minimum = table_header.cols_minimum
        self.get_states()
        Clock.schedule_once(self.set_default_first_row, .0005)
        self._request_keyboard()

    def _request_keyboard(self):
        self._keyboard = Window.request_keyboard(
            self._keyboard_closed, self, 'text'
        )
        if self._keyboard.widget:
            # If it exists, this widget is a VKeyboard object which you can use
            # to change the keyboard layout.
            pass
        self._keyboard.bind(on_key_down=self._on_keyboard_down)

    def _keyboard_closed(self):
        self._keyboard.unbind(on_key_down=self._on_keyboard_down)
        self._keyboard = None

    def _on_keyboard_down(self, keyboard, keycode, text, modifiers):
        if keycode[1] == 'down':    # keycode[274, 'down'] pressed
            # Respond to keyboard down arrow pressed
            self.display_keystrokes(keyboard, keycode, text, modifiers)
            self.row_controller.select_next(self)

        elif keycode[1] == 'up':    # keycode[273, 'up] pressed
            # Respond to keyboard up arrow pressed
            self.display_keystrokes(keyboard, keycode, text, modifiers)
            self.row_controller.select_previous(self)

        elif len(modifiers) > 0 and modifiers[0] == 'ctrl' and text == 'e':     # ctrl + e pressed
            # Respond to keyboard ctrl + e pressed, and call Popup
            self.display_keystrokes(keyboard, keycode, text, modifiers)
            self.on_keyboard_select()

        # Keycode is composed of an integer + a string
        # If we hit escape, release the keyboard
        if keycode[1] == 'escape':
            keyboard.release()

        # Return True to accept the key. Otherwise, it will be used by
        # the system.
        return True

    def display_keystrokes(self, keyboard, keycode, text, modifiers):
        print("\nThe key", keycode, "have been pressed")
        print(" - text is %r" % text)
        print(" - modifiers are %r" % modifiers)

    def on_keyboard_select(self):
        ''' Respond to keyboard event to call Popup '''

        # setup row data for Popup
        self.setup_row_data(self.rv_data[self.row_controller.selected_row]['Index'])

        # call Popup
        self.popup_callback()

    def on_mouse_select(self, instance):
        ''' Respond to mouse event to call Popup '''

        if self.row_controller.selected_row != instance.index:
            # Mouse clicked on row is not equal to current selected row
            self.row_controller.selected_row = instance.index

            # Hightlight mouse clicked/selected row
            self.row_controller.select_current(self)

        # setup row data for Popup
        self.setup_row_data(self.rv_data[instance.index]['Index'])

        # call Popup
        self.popup_callback()

        # enable keyboard request
        self._request_keyboard()

    def setup_row_data(self, value):
        self.row_data = {'value': value}

    def popup_callback(self):
        ''' Instantiate and Open Popup '''
        popup = EditPopup(self)
        popup.open()

    def set_default_first_row(self, dt):
        ''' Set default first row as selected '''
        self.row_controller.select_next(self)

    def get_states(self):
        rows = [(1, 'A'), (2, 'B'), (3, 'c'), (4, 'd'), (5, 'e'), (6, 'f'), (7, 'g'), (8, 'h'), (9, 'i'), (10, 'j'), (11, 'k'), (12, 'l'), (13, 'm')]

        data = []
        low = 0

        print(self.total_col_headings)
        high = self.total_col_headings - 1
        for row in rows:
            data.append([row[0], row[0], [low, high]])
            data.append([row[1], row[0], [low, high]])

            low += self.total_col_headings
            high += self.total_col_headings

        self.rv_data = [{'text': str(x[0]), 'Index': str(x[1]), 'range': x[2], 'selectable': True} for x in data]


class Table(BoxLayout):
    rv = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(Table, self).__init__(**kwargs)
        self.orientation = "vertical"
        self.header = TableHeader()
        self.rv = RV(self.header)

        self.rv.fbind('scroll_x', self.scroll_with_header)

        self.add_widget(self.header)
        self.add_widget(self.rv)

    def scroll_with_header(self, obj, value):
        self.header.scroll_x = value


class MainMenu(BoxLayout):
    states_cities_or_areas = ObjectProperty(None)
    table = ObjectProperty(None)

    def display_states(self):
        self.remove_widgets()
        self.table = Table()
        self.states_cities_or_areas.add_widget(self.table)

    def remove_widgets(self):
        self.states_cities_or_areas.clear_widgets()


class TestApp(App):
    title = "test"

    def build(self):
        return MainMenu()


if __name__ == '__main__':
    TestApp().run()

test.kv

#:kivy 1.10.0

<PopupLabelCell>
    size_hint: (None, None)
    height: 30
    text_size: self.size
    halign: "left"
    valign: "middle"

<EditStatePopup>:

<SelectableButton>:
    canvas.before:
        Color:
            rgba: (0, 0.517, 0.705, 1) if self.selected else (0, 0.517, 0.705, 1)
        Rectangle:
            pos: self.pos
            size: self.size
    background_color: [1, 0, 0, 1]  if self.selected else [1, 1, 1, 1]  # dark red else dark grey
    on_press: app.root.table.rv.on_mouse_select(self)
    halign: 'center'

<HeaderCell>
    size_hint: (None, None)
    height: 25
    text_size: self.size
    halign: "left"
    valign: "middle"
    background_disabled_normal: ''
    disabled_color: (1, 1, 1, 1)

    canvas.before:
        Color:
            rgba: 1, 0.502, 0, 1
        Rectangle:
            pos: self.pos
            size: self.size

<TableHeader>:
    header: header
    bar_width: 0
    do_scroll: False
    size_hint: (1, None)
    height: 25
    effect_cls: "ScrollEffect"

    GridLayout:
        id: header
        rows: 1
        cols_minimum: root.cols_minimum
        size_hint: (None, None)
        width: self.minimum_width
        height: self.minimum_height

<RV>:
    row_controller: row_controller

    bar_width: 10
    bar_color: 1, 0, 0, 1   # red
    bar_inactive_color: 0, 0, 1, 1   # blue
    effect_cls: "ScrollEffect"
    scroll_type: ['bars']

    data: root.rv_data
    viewclass: 'SelectableButton'

    SelectableRecycleGridLayout:
        id: row_controller
        key_selection: 'selectable'
        cols: root.total_col_headings
        cols_minimum: root.cols_minimum
        default_size: None, dp(26)
        default_size_hint: 1, None
        size_hint: None, None
        height: self.minimum_height
        width: self.minimum_width
        orientation: 'vertical'
        multiselect: True
        touch_multiselect: True


<MenuButton@Button>:
    text_size: self.size
    valign: "middle"
    padding_x: 5
    size : (80,30)
    size_hint : (None, None)
    background_color: 90 , 90, 90, 90
    background_normal: ''
    color: 0, 0.517, 0.705, 1
    border: (0, 10, 0, 0)


<MainMenu>:
    states_cities_or_areas: states_cities_or_areas

    BoxLayout:
        orientation: 'vertical'

        BoxLayout:
            canvas.before:
                Rectangle:
                    pos: self.pos
                    size: self.size

            size_hint_y: 1

            MenuButton:
                id: btn
                text: 'Test'
                size : (60,30)
                on_release: root.display_states()
                size_hint_x: 45

        BoxLayout:
            id: states_cities_or_areas
            size_hint_y: 10

        Label:
            size_hint_y: 1

屏幕截图