Gtk小部件显示延迟 [英] Gtk widget shows up with delay

问题描述

使用python3和gi.repository，我想要一个带有Gtk.Button的Gtk.HeaderBar，只要点击它就可以被Gtk.Spinner取代。在计算之后，按钮应该再次出现。

Using python3 and gi.repository, I want to have a Gtk.HeaderBar with a Gtk.Button that is replaced by a Gtk.Spinner as soon as you click on it. After a calculation the button should appear again.

这是一个我认为应该如何运作的例子，但是Gtk.Spinner仅在之后显示在很短的时间内计算（在这个例子中是睡眠）。我怎样才能达到微调显示整个计算（或睡眠）？

Here is an example of how I think it should work but the Gtk.Spinner only shows up after the calculation (in this example sleep) for a very short time. How can I achieve that the spinner shows up for the whole calculation (or sleep)?

from gi.repository import Gtk
import time

class window:
    def __init__(self):
        self.w = Gtk.Window()
        self.button = Gtk.Button('x')
        self.button.connect('clicked', self.on_button_clicked)
        self.spinner = Gtk.Spinner()
        self.hb = Gtk.HeaderBar()
        self.hb.props.show_close_button = True
        self.hb.pack_start(self.button)
        self.w.set_titlebar(self.hb)
        self.w.connect('delete-event', Gtk.main_quit)
        self.w.show_all()

    def on_button_clicked(self, widget):
        self.button.hide()
        self.hb.pack_start(self.spinner)
        self.spinner.show()
        self.spinner.start()
        time.sleep(5)
        self.spinner.stop()
        self.hb.remove(self.spinner)
        self.button.show()

if __name__ == '__main__':
    w = window()
    Gtk.main()

推荐答案

GTK +是一个事件驱动的系统，其中主循环应该可以自由更新UI和需要时间的一切就像从文件中读取数据，建立网络连接，长时间计算）应该是异步的。

GTK+ is an event driven system where the mainloop should be left free to update the UI and everything that takes time (like reading from a file, making a network connection, long calculations) should happen asynchronously.

在你的情况下，这看起来像这样：

In your case this would look something like this:

def on_button_clicked(self, widget):
    self.button.hide()
    self.spinner.show()
    self.spinner.start()
    GLib.timeout_add_seconds (5, self.processing_finished)

def processing_finished(self):
    self.spinner.stop()
    self.spinner.hide()
    self.button.show()

请注意，我删除了包并删除了调用：在 __ init __（）中执行。你也可以在这里使用gi.repository import GLib 来获得。

Note that I removed the pack and remove calls: do those in __init__(). You'll want from gi.repository import GLib in there as well.

这样主循环是免费的根据需要随时更新UI。如果你真的想使用像sleep（）那样的阻塞调用，那么你需要在另一个线程中这样做，但我的建议是使用类似于 timeout_add_seconds（）电话。

This way the main loop is free to update the UI as often as it wants. If you really want to use a blocking call like sleep(), then you'll need to do that in another thread, but my suggestion is to use libraries that are asychronous like that timeout_add_seconds() call.

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