如何在 KDE Wayland 中获取当前活动屏幕（带鼠标的屏幕）？答案

【问题标题】：How can I get current active screen (a screen with mouse) in KDE wayland?如何在 KDE Wayland 中获取当前活动屏幕（带鼠标的屏幕）？
【发布时间】：2022-06-20 09:03:36
【问题描述】：

我希望能够从我的 python 脚本中检测 KDE 中的活动屏幕。以前我用 Xlib 并像这样用鼠标寻找屏幕：

from Xlib import display
def mousepos():
    data = display.Display().screen().root.query_pointer()._data
    return data["root_x"], data["root_y"]

current_pos = mousepos()
x_pos = current_pos[0]
y_pos = current_pos[1]

names_handling_y = []
names_handling_x = []
...
    if x_pos >= output["pos"]["x"] and x_pos <= output["pos"]["x"] + output["size"]["width"]:
        names_handling_x.append(output["name"])
    if y_pos >= output["pos"]["y"] and y_pos <= output["pos"]["y"] + output["size"]["height"]:
        names_handling_y.append(output["name"])
...
for name in names_handling_x:
    if name in names_handling_y:
        target_output = name

但是在使用 Wayland 时我该如何做类似的事情呢？

【问题讨论】：

标签： python x11 kde-plasma wayland

【解决方案1】：

我找到了以下方法。您可以对活动屏幕运行 dbus 查询（请参阅 api，在 commit 中添加）或运行 kwin 脚本。可以从另一个脚本run a kwin script。所以我可以这样做：

#!/usr/bin/env python3
import subprocess
from datetime import datetime

# KDE Active screen is a screen with mouse cursor.

def get_active_screen_id():
    datetime_now = datetime.now()

    file = open("/tmp/get_active_screen.js", "w")
    script = """
    as = workspace.activeScreen;
    print(as + 1)
    """
    file.write(script)
    file.close
    del file, script

    script = "/tmp/get_active_screen.js"

    reg_script_number = subprocess.run("dbus-send --print-reply --dest=org.kde.KWin \
                            /Scripting org.kde.kwin.Scripting.loadScript \
                            string:" + script + " | awk 'END {print $2}'",
                            capture_output=True, shell=True).stdout.decode().split("\n")[0]

    subprocess.run("dbus-send --print-reply --dest=org.kde.KWin /" + reg_script_number + " org.kde.kwin.Script.run",
                    shell=True, stdout=subprocess.DEVNULL)
    subprocess.run("dbus-send --print-reply --dest=org.kde.KWin /" + reg_script_number + " org.kde.kwin.Script.stop",
                    shell=True, stdout=subprocess.DEVNULL)  # unregister number

    since = str(datetime_now)

    msg = subprocess.run("journalctl _COMM=kwin_wayland -o cat --since \"" + since + "\"",
                            capture_output=True, shell=True).stdout.decode().rstrip().split("\n")
    msg = [el.lstrip("js: ") for el in msg]
    if len(msg) != 1:
        exit(1)

    return int(msg[0])


active_screen_id = get_active_screen_id()

然后我可以在my script 中使用该ID。这种方法比Xlib方法中确定鼠标位置的屏幕坐标还要好。

【讨论】：