Add compatibility layer for keywords arguments of `QFileDialog ` `get*` class methods

[Czaki]

Add compatibility layer for keywords arguments of `QFileDialog ` `get*` class methods

[dalthviz]

Hi @Czaki thank you for the feedback! I think that makes sense to improve the situation here with the QFileDialog 👍

Thinking about this, not totally sure but, maybe this is already covered by the wrapper function we have for the QFileDialog at:

qtpy/qtpy/compat.py

Lines 82 to 102 in 1874fba

	def _qfiledialog_wrapper(attr, parent=None, caption='', basedir='',
	filters='', selectedfilter='', options=None):
	if options is None:
	options = QFileDialog.Option(0)
	func = getattr(QFileDialog, attr)
	# Calling QFileDialog static method
	if sys.platform == "win32":
	# On Windows platforms: redirect standard outputs
	_temp1, _temp2 = sys.stdout, sys.stderr
	sys.stdout, sys.stderr = None, None
	result = func(parent, caption, basedir, filters, selectedfilter, options)
	if sys.platform == "win32":
	# On Windows platforms: restore standard outputs
	sys.stdout, sys.stderr = _temp1, _temp2
	output, selectedfilter = result
	# Always returns the tuple (output, selectedfilter)
	return output, selectedfilter

And the respective functions for the static methods like for example getSaveFileName at:

qtpy/qtpy/compat.py

Lines 129 to 138 in 1874fba

	def getsavefilename(parent=None, caption='', basedir='', filters='',
	selectedfilter='', options=None):
	"""Wrapper around QtGui.QFileDialog.getSaveFileName static method
	Returns a tuple (filename, selectedfilter) -- when dialog box is canceled,
	returns a tuple of empty strings
	Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
	return _qfiledialog_wrapper('getSaveFileName', parent=parent,
	caption=caption, basedir=basedir,
	filters=filters, selectedfilter=selectedfilter,
	options=options)

?

Let us know if the current wrapper definition helps or if some modification needs to be done and of course happy to see a PR if that is the case!

[Czaki]

This wrapper looks to solve the problem, but I need to figure out the discoverability of this feature as many people may use only Qt/PySide documentation and do not find the compat module.

[ccordoba12]

I took a quick look to @Czaki's PR and I think it's a good idea because it'd make things consistent between PyQt and PySide.

[dalthviz]

That's a good point! Just in case, for the moment we have a very basic reference to the compat module in the README any idea to improve that is appreciated!

[hmaarrfk]

One aspect in which the provided wrappers are not feature complete is when applications wish to customize the user experience such as with the "history"

napari uses:

dlg = QFileDialog()
hist = get_save_history()
dlg.setHistory(hist)

filename, selected_filter = dlg.getSaveFileName(
    parent=self,
    caption=trans._('Save {msg} layers', msg=msg),
    directory=hist[0],  # home dir by default,
    ....
)

which requires:

1. The use of the method setHistory
2. a common interface for directory vs dir

Maybe I am missing one aspect of the compat module, but I didn't see a clear way of getting there from browsing the source of the compat.py module.

[Czaki]

I have created #433 which may be a proper solution. There are currently no tests so it is marked as a draft but I would like to hear what did you think about this.

[dalthviz]

Thanks for the feedback and proposing a solution! To be honest I'm not totally sure what could be the best here 🤔, what do you think @ccordoba12 ?