Stop pygtk GUI from locking up during long-running process

Question

I have a process that will take a while (maybe a minute or two) to complete. When I call this from my pygtk GUI the window locks up (darkens and prevents user action) after

Answer 1

You should reimplement Thread.run for each of your threads, and start a event loop in them.

Also, you could make the button press call the start method for a thread, which will then call run, and do your long task. This way, you don't need an event loop in each thread.

Here is some simple code to explain what I mean for the second option:

class MyThread(threading.Thread):

    def __init__(self, label, button):
        threading.Thread.__init__(self)
        self.label = label
        self.button = button
        self.counter = 0

    def run(self):
        time.sleep(20)

def callback():
    label.set_text("Counter: %i" % thread.counter)
    thread.start()

window = gtk.Window()
label = gtk.Label()
box = gtk.VBox()
button = gtk.Button('Test')
box.pack_start(label)
box.pack_start(button)
window.add(box)
window.show_all()

thread = MyThread(label, button)
button.connect('clicked', callback)

I use a callback function because I doubt that set_text is thread-safe.