Fusion: automatic installation of PySide2

[kalisp]

Changelog Description

This PR adds hook which tries to check if PySide2 is installed in Python used by Fusion and if not, it tries to install it automatically.

Additional info

This is customer requirement. Even that there is explicit (which stays there) menu option inside of Fusion, it is happening that artists will not press it.
Hook is based on Blender approach, but checking for PySide2 is simplified as there is some issue about missing dataclass for click in Python3.6

Testing notes:

1. uninstall PySide2 from Python 3.6 used by Fusion (you could learn where that Python is located directly in Fusion console:
   
2. launch Fusion - it should install PySide2
3. launch Fusion again - it shouldn't do anything

[ynbot]

Task linked: OP-7450 Fusion: setup PySide2

[BigRoy]

I assume this will make the fusion launch as slow as blender launch - can we make this optional somehow. We have no need for this feature and definitely want to avoid those speed issues.

Also, is there a reason we're not defaulting to PySide6?

[kalisp]

I assume this will make the fusion launch as slow as blender launch - can we make this optional somehow. We have no need for this feature and definitely want to avoid those speed issues.

Also, is there a reason we're not defaulting to PySide6?

Would there be really difference in running and handling python-c import PySide2?

But I was thinking about making this optional, I don't think we have optionality in hooks. Created an issue for that #6112.

[BigRoy]

But I was thinking about making this optional, I don't think we have optionality in hooks. Created an issue for that #6112.

You could always just check a project (or system) setting inside its execute method so it ends up doing nothing if force_install_pyside2 is e.g. disabled.

Would there be really difference in running and handling python-c import PySide2?

Difference from what?

[kalisp]

Time wise difference. I am assuming that Blender might be a bit slower as it loops through all packages, but this one should be pretty fast, imho.

[antirotor]

I know it can run in totally different python environment than AYON is, but should we at least try to install pyside version defined by the AYON launcher/addon itself in pyproject.toml? I mean this can in theory pull in latest version of pyside for given python that might not be exactly compatible with other tools. Or am I to paranoid?

[kalisp]

Added optionality:

Made query for existence of PySide more generic, it should handle different versions of PySide in the future.

[kalisp]

I know it can run in totally different python environment than AYON is, but should we at least try to install pyside version defined by the AYON launcher/addon itself in pyproject.toml? I mean this can in theory pull in latest version of pyside for given python that might not be exactly compatible with other tools. Or am I to paranoid?

I don't think we can install same version of PySide in Python 3.6 as is for more up-to-date versions of Python.

[BigRoy]

I know it can run in totally different python environment than AYON is, but should we at least try to install pyside version defined by the AYON launcher/addon itself in pyproject.toml? I mean this can in theory pull in latest version of pyside for given python that might not be exactly compatible with other tools. Or am I to paranoid?

I don't think we can install same version of PySide in Python 3.6 as is for more up-to-date versions of Python.

Note that we're not using Python 3.6 with Fusion but Python 3.9 (matching version with OP). Py3.6 is one of the supported versions - not necessarily the best version to use. ;)

[jakubjezek001]

LGTM! tested on Ayon and works perfect

[kalisp]

Added headless possibility of PySide2 installation in Windows if no admin privileges required.

[jakubjezek001]

I wonder if this menu item makes any sense at all now.

[jakubjezek001]

Also the installation is happening silently which is ok, but since it is taking some time it made me wonder what is going on, since no UX feedback was given. Shouldn't some informative message popup and say, Ayon is preparing Fusion to first run, please be patient, it will take a minute. Or, you know, something like this.

[jakubjezek001]

works as advertized

[BigRoy]

I wonder if this menu item makes any sense at all now.

I'd personally prefer that menu entry to exist on our end - and disable the auto-install feature due to the influence it has on the startup speed for Fusion from the launcher (all the time). I'd rather have it fail to launch once inside Fusion - then make the user aware of the 'install it' instead of it continuously influencing the performance of the launch times.

But maybe I just have had to deal with too many people that want applications to launch in less than a few seconds. :)

[kalisp]

Yeah, the option must stay there as this hook is optional.

I don't believe that this hook takes too long after pyside is installed.

I couldn't find any dialog that could be thrown in Launcher during pre-launch hook, I am logging that PySide2 is being installed, but that will show up only in ayon_console.

[BigRoy]

Isn't this functionality technically wrong if the application environment settings is providing a PYTHONPATH that has PySide2 available? Somehow this PR requires PySide2 to be directly installed INTO the interpreters location, no?

It should actually be doing the check from within the environment of the application to run, e.g. Fusion's Python environment as defined by application settings?

[iLLiCiTiT]

If you provide PYTHONPATH with PySide, you'll probably disable the prelaunch hook.