python - 基维 : How to use on_key_down and on_key_up keyboard event in Tree View?

Question

我正在使用 python-2.7 和 kivy-1.10.0。
当我单击 name TextInput 时，会显示 TreeView 。我希望使用 up 和 down 键选择标签，当按下 enter 键时，文本被复制，所选文本是当您单击该项目时复制到当前完成的初始表单

测试.py

from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.popup import Popup
from kivy.uix.treeview import TreeView, TreeViewLabel, TreeViewNode
from kivy.uix.label import Label
from kivy.properties import ObjectProperty
Window.size = (500, 200)


def populate_tree_view(tree_view, parent, node):
    if parent is None:
        tree_node = tree_view.add_node(TreeViewLabel(text=node['node_id'],
                                                     is_open=True))
    else:
        tree_node = tree_view.add_node(TreeViewLabel(text=node['node_id'],
                                                     is_open=True), parent)

    for child_node in node['children']:
        populate_tree_view(tree_view, tree_node, child_node)


tree = []
rows = [(1, 'test1', 11), (2, 'test2', 2), (3, 'test3', 3)]
for r in rows:
    tree.append({'node_id': r[1], 'children': []})



class TreeViewLabel(Label, TreeViewNode):
    pass


class TreeviewGroup(Popup):
    treeview = ObjectProperty(None)
    tv = ObjectProperty(None)
    #ti = ObjectProperty()

    def __init__(self, **kwargs):
        super(TreeviewGroup, self).__init__(**kwargs)
        self.tv = TreeView(root_options=dict(text=""),
                       hide_root=False,
                       indent_level=4)
        for branch in tree:
            populate_tree_view(self.tv, None, branch)
        self.remove_widgets()
        self.treeview.add_widget(self.tv)

    def remove_widgets(self):
        for child in [child for child in self.treeview.children]:
            self.treeview.remove_widget(child)

    def select_node(self, node):
        '''Select a node in the tree.
                '''
        if node.no_selection:
            return
        if self._selected_node:
            self._selected_node.is_selected = False
        node.is_selected = True
        self._selected_node = node
        print(node)

class GroupScreen(Screen):
    name = ObjectProperty(None)
    popup = ObjectProperty(None)

    def display_groups(self, instance):
        if len(instance.text) > 0:
            if self.popup is None:
                self.popup = TreeviewGroup()
            #self.popup.filter(instance.text)
            self.popup.open()


    def select_node(self, node):
        '''Select a node in the tree.
                '''
        if node.no_selection:
            return
        if self._selected_node:
            self._selected_node.is_selected = False
        node.is_selected = True
        self._selected_node = node
        print(node)


class Group(App):
    def build(self):
        self.root = Builder.load_file('test.kv')
        return self.root


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

测试.kv

#:kivy 1.10.0

<TreeViewLabel>:
    on_touch_down:
        app.root.name.text = self.text
        app.root.popup.dismiss()

<TreeviewGroup>:
    id: treeview
    treeview: treeview
    title: "Select"
    size_hint: None, None
    size: 400, 200
    auto_dismiss: False

    BoxLayout
        orientation: "vertical"
        #TextInput:
            #id: ti
            #size_hint_y: .1
            #on_text: root.filter(self.text)
        BoxLayout:
            id: treeview
        Button:
            size_hint: 1, 0.1
            text: "Close"
            on_release: root.dismiss()


<CustomLabel@Label>:
    text_size: self.size
    valign: "middle"
    padding_x: 5

<SingleLineTextInput@TextInput>:
    multiline: False

<GreenButton@Button>:
    background_color: 1, 1, 1, 1
    size_hint_y: None
    height: self.parent.height * 0.150

GroupScreen:
    name: name
    test:test

    GridLayout:
        cols: 2
        padding : 30,30
        spacing: 10, 10
        row_default_height: '40dp'

        CustomLabel:
            text: 'Code'

        SingleLineTextInput:
            id: test
            multiline: False
            on_text_validate: name.focus = True


        CustomLabel:
            text: 'Name'

        SingleLineTextInput:
            id: name
            text:' '
            multiline: False
            on_focus: root.display_groups(self)



        GreenButton:
            text: 'Ok'

        GreenButton:
            text: 'Cancel'
            on_press: app.stop()

Answer 1

您的要求可以分为 2 个任务:

• 为此我们使用 Keyboard 检测 key .
• 选择节点，为此我们使用 select_node() TreeView的方法这允许我们选择一个特定的节点，selected_node返回当前选择的节点。 (您不应覆盖 select_node 方法，应将其从您的代码中删除。)

---

....
class TreeviewGroup(Popup):
    treeview = ObjectProperty(None)
    tv = ObjectProperty(None)
    #ti = ObjectProperty()

    def __init__(self, **kwargs):
        super(TreeviewGroup, self).__init__(**kwargs)
        self.tv = TreeView(root_options=dict(text=""),
                       hide_root=False,
                       indent_level=4)
        for branch in tree:
            populate_tree_view(self.tv, None, branch)
        self.remove_widgets()
        self.treeview.add_widget(self.tv)

        self.bind(on_open=self.on_open)

    def on_open(self, *args):
        self._keyboard = Window.request_keyboard(self._keyboard_closed, self)
        self._keyboard.bind(on_key_down=self._on_keyboard_down)
        if self.tv.selected_node is None:
            self.tv.select_node(self.tv.root.nodes[0])

    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):
        node = self.tv.selected_node
        _, key = keycode
        if key in ('down', 'up'):
            parent = node.parent_node
            ix = parent.nodes.index(node)
            nx = ix+1 if 'down' else ix-1
            next_node = parent.nodes[nx % len(parent.nodes)]
            self.tv.select_node(next_node)
            return True
        elif key == 'enter':
            App.get_running_app().root.name.text = node.text
            keyboard.release()
            self.dismiss()

    ...

class GroupScreen(Screen):
    name = ObjectProperty(None)
    popup = ObjectProperty(None)

    def display_groups(self, instance):
        if len(instance.text) > 0:
            if self.popup is None:
                self.popup = TreeviewGroup()
            #self.popup.filter(instance.text)
            self.popup.open()

...