标签一直跑出 ScrollView 屏幕 x 轴 Kivy 的边缘

Question

我正在创建一个聊天屏幕，每次按下发送按钮时都会在我的GridLayout 中添加一个Label。但是，当文本变得太长时，我的Labels 会从屏幕一侧跑出，我希望它们环绕并且文本进入新行，但这没有发生，我不知道为什么。

<ChatPage>:
    name: "chat_page"
    layout_content: layout_content

    NavigationLayout:
        id: nav_layout
        MDNavigationDrawer:
            NavigationDrawerIconButton:
                text: "Test"
                on_release: app.root.current = "login"

        FloatLayout:
            MDToolbar:
                pos_hint: {'top': 1}
                md_bg_color: 0.2, 0.6, 1, 1
                left_action_items: [['menu', lambda x: root.ids.nav_layout.toggle_nav_drawer()]]

            ScrollView:
                size_hint: 0.95, 0.6
                pos_hint: {"x": 0.025, "top" : 0.8, "bottom" : 0.5}
                do_scroll_x: False
                GridLayout:
                    id: layout_content
                    cols: 2
                    size_hint_y: None
                    spacing: 10
                    height: self.minimum_height
                    canvas:
                        Color:
                            rgba: (1, 1, 1, 1)
                        Rectangle:
                            size: self.size
                            pos: self.pos

            BoxLayout:
                TextInput:
                    id: msg
                    hint_text: "Type your message here"
                    pos_hint: {"x": 0, "top": 0.15}
                    size_hint: 0.75, 0.15
                Button:
                    text: "Send"
                    background_normal: ""
                    background_color: 0, 0.6, 0, 1
                    pos_hint: {"x": 0.75, "top": 0.15}
                    size_hint: 0.25, 0.15
                    on_release: root.btn_press()

<SmoothLabel>:
    size_hint: None, None
    size: self.texture_size
    padding: 10, 10
    multiline: True
    background_color: 0,0,0,0
    background_normal: ""
    back_color: 1,0,1,1
    border_radius: [6]
    canvas.before:
        Color:
            rgba: 0.2,0.6,1,1 #This changes the label colour
        RoundedRectangle:
            size: self.size
            pos: self.pos
            radius: self.border_radius

py 文件

import kivy
from kivy.app import App
from kivy.properties import ObjectProperty, StringProperty, NumericProperty, ListProperty
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.uix.popup import Popup
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.core.window import Window
from kivymd.theming import ThemeManager
import mysql.connector
from kivymd.uix.picker import MDDatePicker
from kivy.uix.scrollview import ScrollView

Window.clearcolor = (1,1,1,1)


class SmoothLabel(Label):
    pass


class ChatPage(Screen):
    layout_content = ObjectProperty(None)
    def btn_press(self):
        if self.ids.msg.text:
            lab1 = Label()
            self.layout_content.add_widget(SmoothLabel(text=self.ids.msg.text))
            self.layout_content.add_widget(lab1)
            self.ids.msg.text = ""
        else:
            pass


class WindowManager(ScreenManager):
    pass


class MyApp(App):
    theme_cls = ThemeManager()

    def build(self):
        kv = Builder.load_file("kivy.kv")
        sm = WindowManager()

        screens = [ChatPage(name="chat_page")]
        for screen in screens:
            sm.add_widget(screen)

        sm.current = "chat_page"
        return sm


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

Answer 1

在您的 btn_press 方法中，更改：

self.layout_content.add_widget(SmoothLabel(text=self.ids.msg.text))

到：

self.layout_content.add_widget(SmoothLabel(text=self.ids.msg.text, text_size=(self.layout_content.width, None)))

添加text_size 允许Label 以指定的宽度换行。

Answer 2

我应该坚持将您的新问题作为单独的帖子提交。但这是另一个可以解决您两个问题的答案：

使用text_size 的概念以及使用kivy.core.text.Label 计算SmoothLabel 大小，可以创建调整大小的SmoothLabel。

给SmoothLabel添加静态方法：

class SmoothLabel(Label):
    @staticmethod
    def create_sized_label(**kwargs):
        max_width = kwargs.pop('max_width', 0)
        if max_width <= 0:
            # just create a SmoothLabel without a text_size
            return SmoothLabel(**kwargs)

        # calculate what the SmoothLabel size will be
        core_label = CoreLabel(padding=[10,10], **kwargs)  # use same padding as SmoothLabel
        core_label.refresh()

        if core_label.width > max_width:
            # width is too big, use text_size to force wrapping
            return SmoothLabel(text_size=(max_width,None), **kwargs)
        else:
            # width is OK, no need for text_size
            return SmoothLabel(**kwargs)

然后在ChatPage中使用那个方法：

class ChatPage(Screen):
    layout_content = ObjectProperty(None)
    def btn_press(self):
        if self.ids.msg.text:
            lab1 = Label()

            # calculate max allowable width in the GridLayout
            max_width = self.layout_content.width - self.layout_content.spacing[0] - self.layout_content.padding[0] - self.layout_content.padding[2]

            # specify font and font_size (so that the CoreLabel uses the same)
            self.layout_content.add_widget(SmoothLabel.create_sized_label(text=self.ids.msg.text, max_width=max_width, font_name='Roboto', font_size=15))

            self.layout_content.add_widget(lab1)
            self.ids.msg.text = ""
        else:
            pass