Re: [Gramps-devel] Progress bar while running filter rule

[Kees B. <kee...@xs...>]

On Friday 12 December 2008, Benny Malengier wrote:
> 2008/12/12 Kees Bakker <kee...@xs...>
> 
> > Hi,
> >
> > While I was running the "has common ancestors with" filter rule, I
> > realized that gramps can be totally dead for a long time. A user
> > may not know what is going on, and whether gramps makes any
> > progress at all. This filter, and perhaps other filters too, can take
> > several minutes.
> >
> > Can we (or should we) allow a filter to display progress bar updates?
> > Of course the caller of the filter only knows the context, so I think
> > the caller must (optionally) create a new Utils.ProgressMeter. And
> > the filter can call step().
> >
> > How about the following?
> >
> > class GenericFilter:
> >    """Filter class that consists of several rules."""
> >
> >    logical_functions = ['or', 'and', 'xor', 'one']
> >
> >    def __init__(self, source=None, progress=None):
> > ...
> >    def check_foo(self, db, id_list):
> > ...
> >                    if progress:
> >                        progress.step()
> >                    if not rule.apply(db, person):
> >                        val = False
> >                        break
> >
> > This latter piece of code is found several times in
> > src/Filters/_GenericFilter.py so I don't know if there is a better
> > place for this.
> 
> 
> The idea of progress indication is a good idea.

OK. I'll give it try. But I was hoping someone would jump in with a definite
solution. :-)

> For the practical implementation I have no clue, but some points:
> 1. for a progressmeter you need to know beforehand an estimate of the time,
> no? I don't think that is available

This is doable, all the information is there at the right place. The filter
is given the list of items (id_list most of the time). So the caller knows
the "length" of the progress bar. And the filter needs to make a step for
each element in the list.

A larger extract from _GenericFilter shows it.

            for handle in id_list:
                person = self.find_from_handle(db, handle)
                val = True
==>             if progress: progress.step()
                for rule in flist:
                    if not rule.apply(db, person):
                        val = False
                        break
                if val != self.invert:
                    final_list.append(handle)


> 2. perhaps is suffices to change the icon and have it rotate like in a
> webbrowser?

That's an alternative if the above doesn't work. Except, the user still has
no clue how long Gramps will be busy.
--