Add a hook for toga

[davetapley]

https://github.com/beeware/toga

[rokm]

Looks like linux runner will require gir1.2-gtk-3.0 and libgirepository1.0-dev to be installed for PyGObject (dependency of toga-gtk).

[bwoodsend]

All packages have metadata. It's really about whether a package feels the need to loop it up at runtime.

[rokm]

Reckon we should add couple of more examples to complement

pyinstaller-hooks-contrib/news/README.txt

Line 38 in d40669c

Add a hook for ``foobar``, which has a hidden import.

[davetapley]

@rokm @bwoodsend getting to the limit of my knowledge of PyInstaller with this one :|

Couple notes:

• Maintainers of toga have their own 'make it a binary' tool briefcase, so likely aren't going to be super motivated to work on PyInstaller support.

• Whole point of toga (and briefcase) is to target different OS as well. I know PyInstaller does too, but probably brings a lot more complexity, I started to tackle that here:
  

  pyinstaller-hooks-contrib/_pyinstaller_hooks_contrib/stdhooks/hook-toga.py

  Lines 13 to 23 in b2a397f

  	from PyInstaller.compat import is_darwin, is_linux
  	from PyInstaller.utils.hooks import copy_metadata, collect_entry_point
  	if is_darwin:
  	backend = 'cocoa'
  	elif is_linux:
  	backend = 'gtk'
  	else:
  	backend = 'winforms'
  	hiddenimports = [f'toga_{backend}', f'toga_{backend}.factory']

I've got pyinstaller-hooks-contrib cloned on a Mac, so targeting that for right now, it uses their cocoa engine.

Failing with:

 File "toga_cocoa/icons.py", line 21, in __init__
  File "pathlib.py", line 1162, in __init__
  File "pathlib.py", line 373, in __init__
TypeError: argument should be a str or an os.PathLike object where __fspath__ returns a str, not 'NoneType'

Probably because we get in to Objective C bindings pretty quick (via this package).

Question: Do you think this will be implementable without a huge amount of effort?

[freakboy3742]

• Maintainers of toga have their own 'make it a binary' tool briefcase, so likely aren't going to be super motivated to work on PyInstaller support.

BeeWare maintainer here! You're correct in guessing that working on PyInstaller support isn't high on our list of priorities. However, that doesn't mean we're hostile to PyInstaller. Having more options for installing Toga apps is a good thing, as far as I'm concerned.

To that end - if there's something Toga could do that is preventing it from working with PyInstaller, or there's a change we can make that will make PyInstaller packaging easier, we're not fundamentally opposed to making those changes - especially if that change is based around compliance with existing PEPs. However, it's up to someone else to propose what those changes would be.

[rokm]

I've opened a new PR (#804) with additional commits on top of yours, because I do not seem to have permissions to push into this one. Will first try to sort out linux and Windows, though, because they seem more straightforward, and then move on to macOS.

[rokm]

And the problem on macOS is that toga assumes that the frozen/stand-alone bundled application is always an .app bundle (I assume briefcase builds only .app bundles for macOS).

So it tries to retrieve the .app bundles icon by querying CFBundleIconFile key, and passes the result to pathlib.Path without checking if is valid (not None). So this breaks when you build PyInstaller POSIX executable, but works if you build the .app bundle instead.

I think changing these lines from

            bundle_icon = Path(
                NSBundle.mainBundle.objectForInfoDictionaryKey("CFBundleIconFile")
            )
            path = NSBundle.mainBundle.pathForResource(
                bundle_icon.stem,
                ofType=".icns",
            )

to

            bundle_icon = NSBundle.mainBundle.objectForInfoDictionaryKey("CFBundleIconFile")
            if bundle_icon is None:
                # Not an .app bundle (e.g., POSIX build made with PyInstaller)
                raise FileNotFoundError()
            path = NSBundle.mainBundle.pathForResource(
                Path(bundle_icon).stem,
                ofType=".icns",
            )

should fix it. cc @freakboy3742

[freakboy3742]

And the problem on macOS is that toga assumes that the frozen/stand-alone bundled application is always an .app bundle (I assume briefcase builds only .app bundles for macOS).

That's correct - and icon handling is one of many reasons for this.

I think changing

Makes sense. PRs welcome :-)

[rokm]

Superseded by #804.