Re: Updating TextView and StatusBar problem

[Peter Krueger <pkrueger appss de>]

On Sat, 3 Apr 2004, Miguel Figueiredo wrote:
> I created a window which has a textview, a button and a statusbar. When I
> press the button, I want to call a func that inserts text in both the
> textview and the statusbar over a certain amount of time. The problem is that
> this text is only visible when the function ends. The purpose is to display
> the text as soon as it is inserted in the textview and/or statusbar.
Hi Miguel,
GTK does its user interface updates in the main loop. When you press the
button the mainloop does not run until your event handler returns, that's
why you don't see the updates of your text changes. To overcome this you
can use
    while (gtk_events_pending()) {
      gtk_main_iteration();
    }
after you changed texts but before the time consuming task. When you
enter your callback you should call gtk_widget_set_sensitive(button,
false) to prevent that the user presses the button again before its first
event handling is finished. Right before exiting the callback enable it
again with gtk_widget_set_sensitive(button, true).

If your task is really time consuming (more than 1 second) you should do
it in a separate thread. A program with a graphical user interface should
always react to user input (like moving/resizing the window) and refresh
its display e.g. after it was covered by another application. Else the
user will think that your program crashed.

Regards,
                            Peter
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