Re: Stuck inside button click callback

Fabio Margarido wrote:
Hey there folks,

I'm new to this list, and tried to search for similar questions, but
couldn't find anything (actually I was not quite sure how to search
for this :)), so sorry if this has been answered here before.
As a matter of fact, I'm a GTK newbie, and this is my first try. I'm
trying to create a GUI with some buttons, text entry fields and a
progress bar. When the user clicks the Run button, I want to make
everything in the window uneditable and unclickable while processing
is taking place, while I update the progress bar. The problem is that
when I click the run button, the callback attached is called, and it
seems the window only gets refreshed when the callback function
finishes running, i. e., the button remains clicked through all the
processing, and when it comes back, the progress bar is already at
100%. I would like to know how to make the window immediately reflect
the changes I make to the other widgets while inside the button click

   The problem is that you are hijacking the main loop, there are a few
ways you can get around this:

    - Split up your "Run" code whatever it is into small itterations and
      run one itteration at a time in an idle or timeout handler
      (see glib API reference "Mainloop and events bla bla section")
      This is what I'd recommend.

    - Inside your run code while loop, insert the lines
        while (gtk_events_pending())
           gtk_main_itteration (FALSE);
      at the end of every itteration.

    - If you are calling a third party library function that takes
      a long time to finish and cannot split up into itterations,
      you'll have to use threads, WAIT, this does *not* mean that
      you need to use the gdk_threads_mutex described in the API/tutorial,
      you only need to report your progress via a g_idle_add and
      *dont make any gtk+ calls from your thread*.

The moral of the story is; no `while (1)'s in your code, and when you would
usually do something like `sched_yield()', just `return' instead ;-)


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