pacman style progress bar

[FredBrockstedt]

I fail to make a pacman style progress bar with:
pacman = standard_bar_factory(borders="[]", tip=None, chars="Cc-", blank=" o")

It works sort of, but the dots move "away" from the "pacman".
Example:

[----------C  o  o  o  o  o  o  o  o  o  o]
[-----------C  o  o  o  o  o  o  o  o  o  ]
[------------C  o  o  o  o  o  o  o  o  o]

ideally the dots would stay in place, like this:

[----------C  o  o  o  o  o  o  o  o  o  o]
[----------c  o  o  o  o  o  o  o  o  o  o]
[-------------------------C  o  o  o  o]

The problem arises from how the padding (right part of the progress bar) is handled in bars.py.
My idea would be using some module tricks to scroll the padding. There is probably a better way.

[rsalmei]

Hello @FredBrockstedt

The problem is because you are using two characters for a "blank", it should be a single char.
Experiment with a simple . or use the print_chars utility to find a more suitable char.

But it is a nice idea nevertheless! I liked it.
I'm going to include this support in the next version!
Yeah, it is a bit different than scrolling it, but instead of a blank argument, it would be something like a background, a text of any size that the bar would appear to roll over... It will be a nice effect!

It will maybe take a little while, because I'm in the middle of a big refactor in the whole alive_progress project, but I will surely include this new feature in it, I'll let you know.
Thanks!

[FredBrockstedt]

Just as you reply... here is the solution, after thinking about it some time.
Replace: padding in bars.py line 19 with:
padding[::-1][:length - len(fill) - len(tip)][::-1]
Super easy right? The padding is created by repeating the padding letters and then cutting them off to the right length. This is pretty smart, but has the side effect of the letters appearing to be pushed to the right with progress.
By flipping, then truncating and flipping again, we subtract the letters on the left side, instead of the right. And no modulo BS.

[FredBrockstedt]

And this can be done even simpler by:
padding[-length - len(fill) - len(tip):]
Let me get back to you on Sunday. If you like with a pull request.

[rsalmei]

Actually I just did `padding[len(fill):]` and it works. It discards the first characters, where the bar will appear, you do not need to get the last chars. And it also need a small fix in the padding and blanks generation, as it will gen a way bigger than needed string.

[FredBrockstedt]

That is very elegant. I don't think it will get better than this.
I'm closing this issue. Thank you for your support!
For the record: I use Arch Linux. Haha ;)

[rsalmei]

You're welcome man!
Thank you for the idea! I'll let you know when it is available.

I didn't get Arch Linux joke 🤔
I use macOS 😉

[FredBrockstedt]

Pacman is the official package manager for Arch Linux (similar to pip for python). Pacman has a easter egg, where the progress bar mimics pacman. There is also a joke, that you find out that someone uses Arch Linux, because they will tell you ;)

…

On 1. May 2020, at 17:36, Rogério Sampaio de Almeida ***@***.***> wrote: You're welcome man! Thank you for the idea! I'll let you know when it is available. I didn't get Arch Linux joke 🤔 I use macOS 😉 — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#34 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA2DDPXURVLX5QJ2S2OLQM3RPLUA5ANCNFSM4MXCL4WQ>.

[rsalmei]

Ohhh right, I see! lol
Nice!

[rsalmei]

Hey @FredBrockstedt , I'm releasing the "Pacman" support at this moment!

[rsalmei]

Done. Care to test it again?

[FredBrockstedt]

Outstanding work. There is a little bug. math.ceil returns a float and that can't be used to repeat a string. The first part is a little surprising, atleast to me. I send you a pull request with the little fix and the progress bar and a demo file, if you like to try for yourself.

[rsalmei]

Thanks man.

That's odd, I did test it, thoroughly. It is working.
Which python version are you using?

[rsalmei]

Python 3.7.6 (default, Mar 10 2020, 07:42:52)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.13.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import math

In [2]: math.ceil(3.1)
Out[2]: 4

In [3]: type(_)
Out[3]: int

[FredBrockstedt]

My bad, I must have run it in python 2 without realizing. I checked the documentation and python 3 will return an integer as expected. In python 2 ceil returns a float, because an int might overflow. Funny thing, with the cast to int, it runs perfectly in 2.7, maybe that is the reason I didn't notice?

[rsalmei]

Yeah, I do support python 2, it should really work. I'll drop python 2 support only in the next major version, 2.0, which is in the works.
In that sense, it really is a bug, forgot about ceil in py2... Thanks.

[rsalmei]

Fixed that small python2 bug in #38.

Your PR #37 will still be open for a while, and will be the basis for the contrib feature, ok?

And I've enjoyed our chat, Thank you! 👍