From: Alexander Kellett <ruby-lists@...>
Date: 2004-12-20T01:56:47+09:00
Subject: Re: rubyqt,   popen  problem in a log viewer

or use qt::eventloop::processevents (something like that :P)
Alex

On Dec 19, 2004, at 1:47 PM, Richard Dale wrote:

> Bauduin Raphael wrote:
>
>> Hi,
>>
>> Thanks for the tip about QProcess, I'll experiment with it later.
>> For the time being, I've implemented nobu nokada's suggestion.
>>
>> I still have the problem refreshing the widget though....
>>
>> With this code:
>>
>>          Thread.new("/tmp/test") do |f|
>>              begin
>>                  tail = IO.popen("/usr/bin/tail -f #{f}","r")
>>                  while line = tail.gets
>>                      hello.append line.chomp
>>                      puts line.chomp
>>                  end
>>
>>              ensure
>>                  puts "killing #{tail.pid}"
>>                  Process.kill("INT", tail.pid)
>>                  tail.close
>>              end
>>          end
>>
>> the while loops (updating the widget AND printing line in the 
>> terminal)
>> seems to be run only when activity occurs in the window (click, 
>> entering
>> window).
>>
>> How comes the line is printed in the terminal only when activity 
>> occurs
>> in the window?
> Ruby threads aren't compatible with QtRuby - you have to always use 
> the same
> ruby thread to make Qt calls. Another approach would be to use a 
> Qt::Timer
> to periodically poll for input from tail:
>
> �slots 'input()'
> �
> �def initialize()
> � super()
> � @timer = Qt::Timer.new
> � connect(@timer, SIGNAL('timeout()'), SLOT('input()'))
> � @timer.start(200)
> �end
>
> �def input
>   # Read from the pipe, append text to the Qt::TextEdit widget
> �end
>
> -- Richard
>