another TokenListControl question

this already the third TokenListControl question in a week... I hope I am not bothering you :)

I am working on a "list control" using TokenListControl:

after the selection is made the list is removed and the question and answer remains...

This all basically works. If I use multiple of these list controls and I resize the terminal window sometimes a line with an already answered question gets lost. I am certain that this issue is caused by how I use prompt-toolkit. I have other probably related issues that I have not investigated enough to describe them here. So my question is how do I control which parts (which TokenListControls) stay on the screen and which parts are cleaned up?

Do I have to call some teardown / cleanup function?

[jonathanslenders]

Hi @markfink,

I'm not exactly sure what's going on. Making things hidden or visible is done by wrapping it in a ConditionalContainer: https://github.com/jonathanslenders/python-prompt-toolkit/blob/28bdee12544492c6400e0c04f531a190b22216f1/prompt_toolkit/layout/containers.py#L1621
ConditionalContainer takes a CLIFilter object that tells whether something is visible or not. An easy way to create such a filter is by using the @condition decorator. See: https://github.com/jonathanslenders/python-prompt-toolkit/blob/28bdee12544492c6400e0c04f531a190b22216f1/prompt_toolkit/filters/base.py#L208
There is no further teardown/cleanup.

Hopefully, that helps,
Jonathan

Hi @jonathanslenders, the ConditionalContainer that you describe I already have:

    layout = HSplit([
        Window(height=D.exact(1),
               content=TokenListControl(get_prompt_tokens, align_center=False)
        ),
        ConditionalContainer(
            Window(
                ic,
                width=D.exact(43),
                height=D(min=3),
                scroll_offsets=ScrollOffsets(top=1, bottom=1)
            ),
            filter=~IsDone()
        )
    ])

I am looking further into this issue and my first impression was that lines are missing from the output. Now I can clearly see that by resizing the terminal window I get additional lines that are not supposed to be there:

I do not think that this is related to my system configuration since I can not reproduce the issue using the prompt feature of prompt-toolkit.

Hi @jonathanslenders, I am now convinced that it is worth to take a deeper look into this since I am able to reproduce this with std. prompt-toolkit.

I use Ubuntu 16.04, Python 2.7.12, prompt_toolkit>=1.0.9, Pygments>=2.1.3

#!/usr/bin/env python
from __future__ import unicode_literals
from prompt_toolkit import prompt


if __name__ == '__main__':
    answers = []
    answers.append(prompt('1. Give me some input: '))
    answers.append(prompt('2. Give me some input: '))
    answers.append(prompt('3. Give me some input: '))
    print('You said: %s' % answers)

result after some resizing of the terminal window:

I tried with a callgraph but there is too many things going on. Any tips on how to investigate what is going on?

[jonathanslenders]

Hi @markfink, the code looks correct. But I can't reproduce it. What terminal are you using?
There are some known limitations to what we can do for handling the rendering during resizing.

Hi @jonathanslenders, I am using GNOME Terminal, 3.18.3.
I really hope you can give me some hints how to analyse this issue so we can get rid of it. I understand that most users probably have OSX but I like to see it working on Linux as well.
I tried with Xterm(322) and could not reproduce the issue either.

Hi @jonathanslenders, can you reproduce the issue using gnome-terminal?
can I do something to support further analysis? just curios what is going on