Kivy自定义事件传播

Question

我正在制作用于互联网连接设备的Python / Kivy GUI。 由于该设备使用WAMP pub / sub方法进行通信，因此发生了很多同步事情。 问题是我不知道如何将自定义事件（例如on_connect，on_disconnect等）从kivy应用程序传播到适当的kivy小部件。

这就是我现在所拥有的，为了获得更好的可读性，剥去了最低限度的要求，还有模拟连接事件的虚拟连接按钮。

MyApp.py：

from kivy.app import App
from kivy.config import Config
from MainPage import MainPage
from AboutPage import AboutPage
from MainContainer import MainContainer

class MyApp(App):
    def build(self):
        self.container = MainContainer()
        self.register_event_type('on_connect')
        return self.container

    def on_session(self, session):
        print("session connected!")
        self.session = session
        self.dispatch('on_connect')

    def on_connect(self, *args):
        pass
MyApp().run()

my.kv：

#:kivy 1.10.1
#:import CardTransition kivy.uix.screenmanager.CardTransition
#:set menucolor1 0, 0.603, 0.784, 1
#:set menucolor2 0, 0.203, 0.384, 1
#:set backgroundcolor 0.95, 0.95, 0.95, 1

<MenuButton@Button>:
    size_hint_y: None
    height: 50
    markup: True

<MenuSpacer@Label>:
    size_hint_y: None
    height: 3
    canvas.before:
        Color:
            rgba: menucolor1
        Rectangle:
            pos: self.pos
            size: self.size
<MainPage>:
    canvas.before:
        Color:
            rgba: backgroundcolor
        Rectangle:
            pos: self.pos
            size: self.size
    name: 'main_screen'
    Label:
        color: menucolor1
        text: "Hi I'm Main Screen"

<AboutPage>:
    canvas:
        Color:
            rgba: backgroundcolor
        Rectangle:
            pos: self.pos
            size: self.size
    name: 'about_screen'
    Label:
        color: menucolor1
        text: "Hi I'm About Screen"


<MainContainer>:
    manager: manager
    canvas:
        Color:
            rgba: backgroundcolor
        Rectangle:
            pos: self.pos
            size: self.size
    BoxLayout:
        size: root.size
        orientation: 'horizontal'
        BoxLayout:
            orientation: 'vertical'
            width: 150
            size_hint_x: None
            MenuButton:
                text: '[b]Main[/b]'
                on_press: root.switch_to('main_screen')
            MenuSpacer:
            MenuButton:
                text: "[b]About[/b]"
                on_press: root.switch_to('about_screen')
            MenuSpacer:
            MenuButton:
                text: "[b]DummyConnect[/b]"
                on_press: root.dummyconnect()
            Widget:
                canvas.before:
                    Color:
                        rgba: menucolor1
                    Rectangle:
                        pos: self.pos
                        size: self.size
        ScreenManager:
            id:manager
            transition: CardTransition(direction='right',mode='push',duration=0.2)
            MainPage:
            AboutPage:

MainContainer.py

from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty
from kivy.app import App

class MainContainer(Widget):

    manager = ObjectProperty(None)

    def __init__(self, **kwargs):
        self.register_event_type('on_connect')
        super(MainContainer,self).__init__(**kwargs)
        print(self.children)

    def switch_to(self,name):
        self.manager.current = name

    def on_connect(self, *args):
        print("hello there")

    def dummyconnect(self):
        App.get_running_app().on_session("dummysession")

MainPage.py

from kivy.uix.screenmanager import Screen

class MainPage(Screen):
    pass

AboutPage.py

from kivy.uix.screenmanager import Screen

class AboutPage(Screen):
    pass

因此，基本上，我希望在MyApp中调度的on_connect事件传播到MainPage和AboutPages，目前只有MainContainer定义了on_connect，但即使这样也不会触发。

我想我可以通过将其自己传播给每个小部件的所有孩子来做到这一点，但是我还需要对所有的boxlayouts，screenmanagers和screen都实现它吗？ 我认为有更好的方法可以做到这一点，但我还没有找到。

任何帮助表示赞赏！

Answer 1

解

要将on_connect传播到所有屏幕，即MainPage和AboutPage。 有关详细信息，请参阅示例。

1. 为MainPage和AboutPage添加了ID
2. 将回调绑定到它们。 调度事件后，将使用与该特定事件相关的参数来调用您的回调。
3. return True ，表明我们已经消耗了触摸并且不希望其进一步传播。
4. 删除了App（main.py）中的代码，并在MainContainer.py中添加了一些代码

注意

我已注释掉return True以显示事件传播。 尝试取消注释return True以显示传播已停止。

片段

mainContainer上

def __init__(self, **kwargs):
    super(MainContainer, self).__init__(**kwargs)
    self.register_event_type('on_connect')
    print(self.children)
    self.bind(on_connect=self.ids.main_page.on_connect)
    self.bind(on_connect=self.ids.about_page.on_connect)
...
def on_connect(self, *args):
    print("\nMainContainer.on_connect()")
    print("hello there")
    # return True   # indicating that we have consumed the touch and don’t want it to propagate any further.

例

main.py

from kivy.app import App
from kivy.config import Config
from MainPage import MainPage
from AboutPage import AboutPage
from MainContainer import MainContainer


class MyApp(App):

    def build(self):
        return MainContainer()


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

my.kv

#:kivy 1.10.1
#:import CardTransition kivy.uix.screenmanager.CardTransition
#:set menucolor1 0, 0.603, 0.784, 1
#:set menucolor2 0, 0.203, 0.384, 1
#:set backgroundcolor 0.95, 0.95, 0.95, 1

<MenuButton@Button>:
    size_hint_y: None
    height: 50
    markup: True

<MenuSpacer@Label>:
    size_hint_y: None
    height: 3
    canvas.before:
        Color:
            rgba: menucolor1
        Rectangle:
            pos: self.pos
            size: self.size
<MainPage>:
    canvas.before:
        Color:
            rgba: backgroundcolor
        Rectangle:
            pos: self.pos
            size: self.size
    name: 'main_screen'
    Label:
        color: menucolor1
        text: "Hi I'm Main Screen"

<AboutPage>:
    canvas:
        Color:
            rgba: backgroundcolor
        Rectangle:
            pos: self.pos
            size: self.size
    name: 'about_screen'
    Label:
        color: menucolor1
        text: "Hi I'm About Screen"


<MainContainer>:
    manager: manager
    canvas:
        Color:
            rgba: backgroundcolor
        Rectangle:
            pos: self.pos
            size: self.size
    BoxLayout:
        size: root.size
        orientation: 'horizontal'
        BoxLayout:
            orientation: 'vertical'
            width: 150
            size_hint_x: None
            MenuButton:
                text: '[b]Main[/b]'
                on_press: root.switch_to('main_screen')
            MenuSpacer:
            MenuButton:
                text: "[b]About[/b]"
                on_press: root.switch_to('about_screen')
            MenuSpacer:
            MenuButton:
                text: "[b]DummyConnect[/b]"
                on_press:
                    root.on_session()
            Widget:
                canvas.before:
                    Color:
                        rgba: menucolor1
                    Rectangle:
                        pos: self.pos
                        size: self.size
        ScreenManager:
            id: manager
            transition: CardTransition(direction='right',mode='push',duration=0.2)

            MainPage:
                id: main_page

            AboutPage:
                id: about_page

MainContainer.py

from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty


class MainContainer(Widget):

    manager = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(MainContainer, self).__init__(**kwargs)
        self.register_event_type('on_connect')
        print(self.children)
        self.bind(on_connect=self.ids.main_page.on_connect)
        self.bind(on_connect=self.ids.about_page.on_connect)

    def switch_to(self, name):
        self.manager.current = name

    def on_connect(self, *args):
        print("\nMainContainer.on_connect()")
        print("hello there")
        # return True   # indicating that we have consumed the touch and don’t want it to propagate any further.

    def on_session(self):
        print("session connected!")
        self.dispatch('on_connect')

MainPage.py

from kivy.uix.screenmanager import Screen


class MainPage(Screen):

    def on_connect(self, *args):
        print("\nMainPage.on_connect()")
        # return True   # indicating that we have consumed the touch and don’t want it to propagate any further.

AboutPage

from kivy.uix.screenmanager import Screen


class AboutPage(Screen):

    def on_connect(self, *args):
        print("\nAboutPage.on_connect()")
        # return True   # indicating that we have consumed the touch and don’t want it to propagate any further.

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