Python Kivy在布局中自定义小部件大小

我试图在另一个应用程序的布局中使用自定义小部件，但它没有在布局中正确缩放，而是占据了整个屏幕。以下是.kv文件，分为相关部分（我取出了所有回调，其功能与预期一致）：

盒子布局：
方向：“水平”
大小：root.size
切换按钮：
尺寸提示：0.10345,1
小组：“结束”
背景_正常：“Left_Up.png”
背景：“Left\u down.png”
按钮：
尺寸提示：0.801724，1
背景正常：“居中按钮向上。png”
背景向下：“居中按钮向下。png”
切换按钮：
尺寸提示：0.094827，1
小组：“结束”
背景：正常：“Right\u Up.png”
背景：“Right\u down.png”

下面是从上面导入类并使用它的单独应用程序的.kv文件：

<NodeEditorWidget>:
    GridLayout:
        size: root.size
        cols: 3
        Label:
            text: 'Test 1'
        NodeWidget:
            ...
        Label:
            text: 'Test 3'

：
网格布局：
大小：root.size
科尔斯：3
标签：
文本：“测试1”
NodeWidget：
...
标签：
文本：“测试3”

下面是我现在运行测试应用程序时看到的内容：

---

提前感谢您的帮助

所以我解决了这个问题，把它移回了纯python，没有.kv文件。代码如下：

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.properties import ListProperty, StringProperty, BooleanProperty, ObjectProperty, NumericProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.togglebutton import ToggleButton

#This widget contains two buttons
#The buttons each expose two events
#Names still aren't functioning
class NodeWidget(BoxLayout):

    #We expose events:
    #on_press when the central button is pressed
    #on_release when the central button is released
    #on_press_right when the right button is pressed
    #on_press_left when the left button is pressed
    press = BooleanProperty(False)
    release = BooleanProperty(False)
    press_right = BooleanProperty(False)
    press_left = BooleanProperty(False)
    release_right = BooleanProperty(False)
    release_left = BooleanProperty(False)

    #Properties exposed to set internal properties
    title = StringProperty('')
    left_background_normal = StringProperty('Left_Up.png')
    left_background_down = StringProperty('Left_Down.png')
    center_background_normal = StringProperty('Center_Button_Up.png')
    center_background_down = StringProperty('Center_Button_Down.png')
    right_background_normal = StringProperty('Right_Up.png')
    right_background_down = StringProperty('Right_Down.png')
    font_name = StringProperty('Roboto')
    markup = BooleanProperty(True)
    padding_x = NumericProperty(0)
    padding_y = NumericProperty(0)

    #Which node is active
    active_left = BooleanProperty(False)
    active_right = BooleanProperty(False)

    #Object Properties for internal elements
    left_button = ObjectProperty(None)
    center_button = ObjectProperty(None)
    right_button = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(NodeWidget, self).__init__(**kwargs)
        center = Button()
        left = ToggleButton()
        right = ToggleButton()
        left.size_hint = (0.10345, 1)
        center.size_hint = (0.801724, 1)
        right.size_hint = (0.094827, 1)
        left.background_normal = 'Left_Up.png'
        left.background_down = 'Left_Down.png'
        center.background_normal = 'Center_Button_Up.png'
        center.background_down = 'Center_Button_Down.png'
        right.background_normal = 'Right_Up.png'
        right.background_down = 'Right_Down.png'
        left.group = 'ends'
        right.group = 'ends'
        left.bind(on_press=self.ActivateNode_Left)
        left.bind(on_release=self.ReleaseNode_Left)
        right.bind(on_press=self.ActivateNode_Right)
        right.bind(on_release=self.ReleaseNode_Right)
        center.bind(on_press=self.PressNode)
        center.bind(on_release=self.ReleaseNode)
        self.left_button = left
        self.center_button = center
        self.right_button = right
        self.bind(title=self.SetTitle)
        self.bind(left_background_normal=self.SetLeftBackgroundNormal)
        self.bind(left_background_down=self.SetLeftBackgroundDown)
        self.bind(center_background_normal=self.SetCenterBackgroundNormal)
        self.bind(center_background_down=self.SetCenterBackgroundDown)
        self.bind(right_background_normal=self.SetRightBackgroundNormal)
        self.bind(right_background_down=self.SetRightBackgroundDown)
        self.bind(font_name=self.SetFontName)
        self.bind(markup=self.SetMarkup)
        self.bind(padding_x=self.SetPaddingX)
        self.bind(padding_y=self.SetPaddingY)
        self.add_widget(left)
        self.add_widget(center)
        self.add_widget(right)

    def ActivateNode_Left(self, *args):
        if self.active_left == False:
            self.active_left = True
            self.active_right = False
        else:
            self.active_left = False
            self.active_right = True
        if self.press_left == True:
            self.press_left = False
        else:
            self.press_left = True

    def ActivateNode_Right(self, *args):
        if self.active_right == False:
            self.active_right = True
            self.active_left = False
        else:
            self.active_right = False
            self.active_left = True
        if self.press_right == True:
            self.press_right = False
        else:
            self.press_right = True

    def ReleaseNode_Left(self, *args):
        if self.release_left == True:
            self.release_left == False
        else:
            self.release_left == True

    def ReleaseNode_Right(self, *args):
        if self.release_right == True:
            self.release_right == False
        else:
            self.release_right == True

    def PressNode(self, *args):
        if self.press == True:
            self.press = False
        else:
            self.press = True

    def ReleaseNode(self, *args):
        if self.release == True:
            self.release = False
        else:
            self.release = True

    def SetTitle(self, *args):
        self.center_button.text = self.title

    def SetLeftBackgroundDown(self, *args):
        self.left_button.background_down = self.left_background_down

    def SetLeftBackgroundNormal(self, *args):
        self.left_button.background_normal = self.left_background_normal

    def SetCenterBackgroundDown(self, *args):
        self.center_button.background_down = self.center_background_down

    def SetCenterBackgroundNormal(self, *args):
        self.center_button.background_normal = self.center_background_normal

    def SetRightBackgroundDown(self, *args):
        self.right_button.background_down = self.right_background_down

    def SetRightBackgroundNormal(self, *args):
        self.right_button.background_normal = self.right_background_normal

    def SetFontName(self, *args):
        self.center_button.font_name = self.font_name

    def SetMarkup(self, *args):
        self.center_button.markup = self.markup

    def SetPaddingX(self, *args):
        self.center_button.padding_x = self.padding_x

    def SetPaddingY(self, *args):
        self.center_button.padding_y = self.padding_y

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.properties import ListProperty, StringProperty, BooleanProperty, ObjectProperty, NumericProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.togglebutton import ToggleButton

#This widget contains two buttons
#The buttons each expose two events
#Names still aren't functioning
class NodeWidget(BoxLayout):

    #We expose events:
    #on_press when the central button is pressed
    #on_release when the central button is released
    #on_press_right when the right button is pressed
    #on_press_left when the left button is pressed
    press = BooleanProperty(False)
    release = BooleanProperty(False)
    press_right = BooleanProperty(False)
    press_left = BooleanProperty(False)
    release_right = BooleanProperty(False)
    release_left = BooleanProperty(False)

    #Properties exposed to set internal properties
    title = StringProperty('')
    left_background_normal = StringProperty('Left_Up.png')
    left_background_down = StringProperty('Left_Down.png')
    center_background_normal = StringProperty('Center_Button_Up.png')
    center_background_down = StringProperty('Center_Button_Down.png')
    right_background_normal = StringProperty('Right_Up.png')
    right_background_down = StringProperty('Right_Down.png')
    font_name = StringProperty('Roboto')
    markup = BooleanProperty(True)
    padding_x = NumericProperty(0)
    padding_y = NumericProperty(0)

    #Which node is active
    active_left = BooleanProperty(False)
    active_right = BooleanProperty(False)

    #Object Properties for internal elements
    left_button = ObjectProperty(None)
    center_button = ObjectProperty(None)
    right_button = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(NodeWidget, self).__init__(**kwargs)
        center = Button()
        left = ToggleButton()
        right = ToggleButton()
        left.size_hint = (0.10345, 1)
        center.size_hint = (0.801724, 1)
        right.size_hint = (0.094827, 1)
        left.background_normal = 'Left_Up.png'
        left.background_down = 'Left_Down.png'
        center.background_normal = 'Center_Button_Up.png'
        center.background_down = 'Center_Button_Down.png'
        right.background_normal = 'Right_Up.png'
        right.background_down = 'Right_Down.png'
        left.group = 'ends'
        right.group = 'ends'
        left.bind(on_press=self.ActivateNode_Left)
        left.bind(on_release=self.ReleaseNode_Left)
        right.bind(on_press=self.ActivateNode_Right)
        right.bind(on_release=self.ReleaseNode_Right)
        center.bind(on_press=self.PressNode)
        center.bind(on_release=self.ReleaseNode)
        self.left_button = left
        self.center_button = center
        self.right_button = right
        self.bind(title=self.SetTitle)
        self.bind(left_background_normal=self.SetLeftBackgroundNormal)
        self.bind(left_background_down=self.SetLeftBackgroundDown)
        self.bind(center_background_normal=self.SetCenterBackgroundNormal)
        self.bind(center_background_down=self.SetCenterBackgroundDown)
        self.bind(right_background_normal=self.SetRightBackgroundNormal)
        self.bind(right_background_down=self.SetRightBackgroundDown)
        self.bind(font_name=self.SetFontName)
        self.bind(markup=self.SetMarkup)
        self.bind(padding_x=self.SetPaddingX)
        self.bind(padding_y=self.SetPaddingY)
        self.add_widget(left)
        self.add_widget(center)
        self.add_widget(right)

    def ActivateNode_Left(self, *args):
        if self.active_left == False:
            self.active_left = True
            self.active_right = False
        else:
            self.active_left = False
            self.active_right = True
        if self.press_left == True:
            self.press_left = False
        else:
            self.press_left = True

    def ActivateNode_Right(self, *args):
        if self.active_right == False:
            self.active_right = True
            self.active_left = False
        else:
            self.active_right = False
            self.active_left = True
        if self.press_right == True:
            self.press_right = False
        else:
            self.press_right = True

    def ReleaseNode_Left(self, *args):
        if self.release_left == True:
            self.release_left == False
        else:
            self.release_left == True

    def ReleaseNode_Right(self, *args):
        if self.release_right == True:
            self.release_right == False
        else:
            self.release_right == True

    def PressNode(self, *args):
        if self.press == True:
            self.press = False
        else:
            self.press = True

    def ReleaseNode(self, *args):
        if self.release == True:
            self.release = False
        else:
            self.release = True

    def SetTitle(self, *args):
        self.center_button.text = self.title

    def SetLeftBackgroundDown(self, *args):
        self.left_button.background_down = self.left_background_down

    def SetLeftBackgroundNormal(self, *args):
        self.left_button.background_normal = self.left_background_normal

    def SetCenterBackgroundDown(self, *args):
        self.center_button.background_down = self.center_background_down

    def SetCenterBackgroundNormal(self, *args):
        self.center_button.background_normal = self.center_background_normal

    def SetRightBackgroundDown(self, *args):
        self.right_button.background_down = self.right_background_down

    def SetRightBackgroundNormal(self, *args):
        self.right_button.background_normal = self.right_background_normal

    def SetFontName(self, *args):
        self.center_button.font_name = self.font_name

    def SetMarkup(self, *args):
        self.center_button.markup = self.markup

    def SetPaddingX(self, *args):
        self.center_button.padding_x = self.padding_x

    def SetPaddingY(self, *args):
        self.center_button.padding_y = self.padding_y