Looking at Package Management for Karmic or Karmic+1

[Matthew Paul Thomas]

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Evan wrote on 01/04/09 22:21:
> 
> On Wed, Apr 1, 2009 at 10:25 AM, Matthew Paul Thomas <mpt at canonical.com
> <mailto:mpt at canonical.com>> wrote:
>...
>>> The front end would display two progress bars, one for download and
>>> one for installation.
>>
>> Hopefully that isn't necessary. I shouldn't see two progress bars for
>> something that, from my point of view, is a single task.
> 
> I'm not so sure. If they are going to be happening in parallel, then
> they will have different % complete values. You could combine them, but
> I think that would jump around enough to be confusing.

Combining subtasks into a single non-jumping progress bar takes a bit of
developer effort, but the overall method is fairly simple. First, with a
variety of representative tasks on a variety of representative machines,
measure how long each subtask takes. Then take the average proportion of
the time taken by each subtask, and allocate that much of the progress
bar to the subtask. For greater accuracy, adjust the proportions
dynamically based on what the program knows at the start about the
subtasks of this particular task, and/or the time taken by previous
tasks on the same machine.

For example here, if measurement has shown that downloading on average
takes 60% of the time and installing on average takes 40 % of the time,
and you're installing updates where the downloading is 80 % complete and
the installation is 10 % complete, the progress bar should be 60 % × 80
% + 40 % × 10 % = 34 % full.

> As a note, I see two separate progress bars in Windows app installers
> all the time. For all I know this could be their usability issue, and
> not something to emulate, but I'm just saying that it is done.

Yes, we have higher standards. :-)

>...
>> It wouldn't be necessary to put the queue in a separate window. It
>> could be a viewable item in the main window, as it is in Miro for
>> example.
> 
> I hadn't even considered this, but it does make sense, especially if
> (as the blueprint suggests) there will be only one GUI for all four of
> the current ones, and thus no separate command sources to consider. If
> this becomes the case, I would ask for the ability to hide all but the
> install progress so that it doesn't take up as much screen space.
>...

Another good idea, thanks. I've added it to the wiki page.

Cheers
- --
Matthew Paul Thomas
http://mpt.net.nz/
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