Re: Progressbar does not get totally filled

[Rob Pearce <rob bdt-home demon co uk>]

On Thursday 19 June 2008, John Smith wrote:
> Due to the nature of floating point numbers and depending on the value of
> self.step, you may have a value just less than 1.0 on one step and a value
> greater than 1.0 on the next. Try adding:
>
>     if (self.x> 1.0) self.x = 1.0;
>
> snafu

Indeed. Always try to do The Right Thing and design your code not to rely on 
exact results from floating point, since it NEVER gives them. In your case, 
don't use addition:

# don't do self.step = 1./self.seq
for i in range(start,end):
    self.processedfiles += 1
    #don't do self.x += self.step, instead do
    self.x = 1.*self.processedfiles/(end-start)
    self.progressbar.set_fraction(self.x)
    while gtk.events_pending(): gtk.main_iteration()

Since self.processedfiles, end and start are all integers, the calculation for 
self.x is now properly bounded. There are still rounding errors, but they 
don't accumulate so they never become significant.