kivymd的WindowController使用

1、kivymd的WindowController使用

这是一个很简单的类，用于getting information about the state of the current application window.

2、使用

2.1、属性：

• window_resizing_direction：窗口宽度变换的状态，left：变窄；right：变宽
• real_device_type：通过宽度判断设备类型
  • 宽度<dp(500)：是mobile
  • 宽度<dp(1100)：是tablet
  • 否则是desktop

2.2、方法

• on_size：设置real_device_type
• get_real_device_type：返回real_device_type

2.3、注意事项

• 重载on_size的时候需要调用父类的on_size，否则不会设置real_device_type字段。

2.4 案例

# When resizing the application window, the direction of change will be
# printed - 'left' or 'right'.

from kivymd.app import MDApp
from kivymd.uix.controllers import WindowController
from kivymd.uix.screen import MDScreen


class MyScreen(MDScreen, WindowController):
    def on_width(self, *args):
        print(self.get_window_width_resizing_direction())
        print(self.get_real_device_type())

    def on_size(self, *args):
        # super().on_size(*args)
        # 明确调用 WindowController 的 on_size
        WindowController.on_size(self, *args)
        print(args)


class Test(MDApp):
    def build(self):
        return MyScreen()


Test().run()

3、源码

from kivy.core.window import Window
from kivy.core.window.window_sdl2 import WindowSDL
from kivy.metrics import dp


class WindowController:
    def __init__(self):
        self.window_resizing_direction = "unknown"
        self.real_device_type = "unknown"
        self.__width = Window.width
        Window.bind(on_resize=self._on_resize)

    def on_size(self, instance, size: list) -> None:
        """Called when the application screen size changes."""

        window_width = size[0]

        if window_width < dp(500):
            self.real_device_type = "mobile"
        elif window_width < dp(1100):
            self.real_device_type = "tablet"
        else:
            self.real_device_type = "desktop"

    def get_real_device_type(self) -> str:
        """Returns the device type - 'mobile', 'tablet' or 'desktop'."""

        return self.real_device_type

    def get_window_width_resizing_direction(self) -> str:
        """Return window width resizing direction - 'left' or 'right'."""

        return self.window_resizing_direction

    def _set_window_width_resizing_direction(self, width: int) -> None:
        if self.__width > width:
            self.window_resizing_direction = "left"
        elif self.__width < width:
            self.window_resizing_direction = "right"

    def _on_resize(
        self, window_sdl2: WindowSDL, width: int, height: int
    ) -> None:
        self._set_window_width_resizing_direction(width)
        self.__width = width

流程图