如何从 BoxLayout 重新定位小部件

Question

我正在使用最新版本的 kivy: v1.10.1.dev0, git-Unknown, 20171208, python v3.6.2, mac os.

我想实现以下目标：当我使用更改后的设置更新设置 reposition/redraw BoxLayout 中的值时，在我的例子中，我正在更新 size_hint 值。这是我目前的工作：

my.py

from kivy.app import App


class MyApp(App):
    def build_config(self, config):
        config.read('./my.ini')

    def build_settings(self, settings):
        settings.add_json_panel('Test', self.config, filename='my.json')

    def on_config_change(self, config, section, key, value):
        if section in ('layout',) and key in ('size_hint',):
            # NOT WORKING!!
            # print(self.root.canvas.clear())
            # self.root.canvas.ask_update()
            # self.root.canvas.draw()

            # NOT WORKING!!
            print(self.root)
            print(self.root.do_layout())

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

my.kv

#:import SettingsWithSidebar kivy.uix.settings.SettingsWithSidebar
BoxLayout:
    RecycleView:
        size_hint: float(app.config.get('layout', 'size_hint')), 1
        Button:
            text: 'Open Settings'
            on_touch_down: app.settings_cls = SettingsWithSidebar; app.open_settings()
    RecycleView:
        size_hint: 1-float(app.config.get('layout', 'size_hint')), 1
        Button:
            text: 'Just a test'

my.ini

[layout]
size_hint = 0.6

my.json

[
  {
        "type": "string",
        "title": "Size Hint",
        "desc": "Size Hint",
        "section": "layout",
        "key": "size_hint"
    }
]

那么，当我 close 设置 window 时，如何看到新布局更新为 size_hint 的新值？

谢谢！

Answer 1

好的，在 IRC #Kivy 的帮助下，解决方案是不在 .kv 文件中直接使用 app.config.get('layout', 'size_hint')，而是使用 Properties。

my.kv

BoxLayout:
    RecycleView:
        size_hint: app.size_hint, 1
        Button:
            text: 'Open Settings'
            on_touch_down: app.open_settings()
    RecycleView:
        size_hint: 1-app.size_hint, 1
        Button:
            text: 'Just a test'

my.py

from kivy.app import App
from kivy.properties import NumericProperty
from kivy.uix.settings import SettingsWithSidebar


class MyApp(App):
    settings_cls = SettingsWithSidebar
    size_hint = NumericProperty()

    def build_config(self, config):
        config.read('./my.ini')

    def build_settings(self, settings):
        settings.add_json_panel('Test', self.config, filename='my.json')

    def load_config(self):
        config = super(MyApp, self).load_config()
        self.size_hint = config.getfloat('layout', 'size_hint')
        return config

    def on_config_change(self, config, section, key, value):
        if section in ('layout',) and key in ('size_hint',):
            self.size_hint = value


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

如何从 BoxLayout 重新定位小部件

How to reposition Widgets from BoxLayout

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