如何定期更新Gtk3标签文本? [英] How to periodically update Gtk3 Label text?

问题描述

我正在Ubuntu 18.04上编写一个应用程序指示器.入门是最困难的部分.文档没有太大帮助.我发现了此博客而且我有一个POC，它只在我的应用程序栏上显示固定文本，例如-
我还无法弄清楚如何定期或动态更新此文本以显示我需要的实际信息，例如: CPU频率，温度等.

I am writing an app-indicator on Ubuntu 18.04. Getting started was the most difficult part. Docs don't help much. I found this blog and I have a POC that just shows a fixed text on my application bar like this -

What I have not been able to figure out is how to update this text periodically or dynamically to display actual information that I need for example: CPU frequency, temperature etc.

我看过以下几个地方，但是我认为我缺少一些东西.
https://lazka.github.io/pgi-docs/Gtk-3.0/classes/Label.html
https://askubuntu.com/questions/108035/writing-indicators-with- python-gir-and-gtk3
https://lazka.github. io/pgi-docs/AppIndicator3-0.1/classes/Indicator.html#AppIndicator3.Indicator.set_label

I have looked at the following places, however I think i am missing something.
https://lazka.github.io/pgi-docs/Gtk-3.0/classes/Label.html
https://askubuntu.com/questions/108035/writing-indicators-with-python-gir-and-gtk3
https://lazka.github.io/pgi-docs/AppIndicator3-0.1/classes/Indicator.html#AppIndicator3.Indicator.set_label

我的工作代码是-

import os
import signal
from gi.repository import Gtk as gtk
from gi.repository import AppIndicator3 as appindicator

APPINDICATOR_ID = 'myappindicator'

def main():
    indicator = appindicator.Indicator.new(APPINDICATOR_ID, gtk.STOCK_INFO, appindicator.IndicatorCategory.SYSTEM_SERVICES)
    indicator.set_status(appindicator.IndicatorStatus.ACTIVE)
    indicator.set_menu(build_menu())
    indicator.set_label('world', '8.8')
    gtk.main()

def build_label():
    label = gtk.Label()
    return label

def build_menu():
    menu = gtk.Menu()
    item_quit = gtk.MenuItem('Quit')
    item_quit.connect('activate', quit)
    menu.append(item_quit)
    menu.show_all()
    return menu

def quit(source):
    gtk.main_quit()

if __name__ == "__main__":
    signal.signal(signal.SIGINT, signal.SIG_DFL)
    main()

指的是类似这样的帖子，以及

Referring to this similar SO post, and this apparently working example, I tried adding timeout_add_seconds, and timeout_add however the text doesn't change at all, it displays only the first call. I inserted a print statement there too, and surprisingly, that also prints only once. Don't know why that is happening -
New code attempt-

import random
from gi.repository import Gtk, GLib
from gi.repository import AppIndicator3 as appindicator

APPINDICATOR_ID = 'myappindicator'

def cb_exit(w, data):
   Gtk.main_quit()

def change_label(ind_app):
    text = 'Hello World, what a great day'.split()
    t = random.choice(text)
    print(t)
    ind_app.set_label(t , '')

ind_app = appindicator.Indicator.new(APPINDICATOR_ID, Gtk.STOCK_INFO, appindicator.IndicatorCategory.SYSTEM_SERVICES)
ind_app.set_status(appindicator.IndicatorStatus.ACTIVE)

# create a menu
menu = Gtk.Menu()
menu_items = Gtk.MenuItem("Exit")
menu.append(menu_items)
menu_items.connect("activate", cb_exit, '')
menu_items.show_all()
ind_app.set_menu(menu)
GLib.timeout_add(1000, change_label, ind_app)
Gtk.main()

推荐答案

我自己弄清楚了这一点.我没有正确使用timeout_add函数.被调用的函数必须返回任何非false值，以使计时器继续运行.在我的情况下，它什么也不返回，因此计时器正在自我毁灭. 此处的文档和此 SO帖子帮助我弄清楚了这一点出去.所以代码最终看起来像这样-

I figured this out myself. I was using the timeout_add function incorrectly. The called function must return anything non false for the timer to continue. In my case it is returning nothing, hence the timer was destroying itself. The docs here and this SO post helped me figure this out. SO the code finally looks like this -

import random
from gi.repository import Gtk, GLib
from gi.repository import AppIndicator3 as appindicator

APPINDICATOR_ID = 'myappindicator'

def change_label(ind_app):
    text = 'Hello world, what a beautiful day'.split()
    t = random.choice(text)
    print(t)
    ind_app.set_label(t , '')
    return True

def quit(source):
    Gtk.main_quit()

ind_app = appindicator.Indicator.new(APPINDICATOR_ID, Gtk.STOCK_INFO, appindicator.IndicatorCategory.SYSTEM_SERVICES)
ind_app.set_status(appindicator.IndicatorStatus.ACTIVE)

# create a menu
menu = Gtk.Menu()
menu_items = Gtk.MenuItem("Exit")
menu.append(menu_items)
menu_items.connect("activate", quit)
menu_items.show_all()
ind_app.set_menu(menu)
GLib.timeout_add(1000, change_label, ind_app)
Gtk.main()

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