Validate if editable QCombobox input is a directory via QValidator

Question

I try to validate if a editable QCombobox input is a directory or not before it gets added to the QCombobox.

from PySide import QtGui, QtCore

class DirValidator(QtGui.QValidator):
    def __init__(self, cb_input):
        super(DirValidator, self).__init__()
        self._input = cb_input

    def validate(self, _text, _pos):
        _dir = QtCore.QDir(_text)
        if self._input.hasFocus():  # ignore validation while editing not complete
            return QtGui.QValidator.Acceptable
        if QtCore.QDir.exists(_dir):
            return QtGui.QValidator.Acceptable
        return QtGui.QValidator.Invalid


dir_validator = DirValidator(self.cb_path.lineEdit())
self.cb_path.setValidator(dir_validator)

sadly it does not work properly because every input still gets added to the combobox when i hit enter. Any suggestions?

EDIT: i also tried to use the validator on the QLineEdit like so:

dir_validator = DirValidator(self.cb_path.lineEdit())
self.cb_path.lineEdit().setValidator(dir_validator)

Does not work either.

EDIT: It kinda works...but when i press return "hasFocus" is still True so it is just accepting the input and then of course adding it to the combobox. if i get rid of "if self._input.hasFocus():" it does not accept any input if i type it in...just if a paste a complete directory path. So what i need is a way to check if the edit is finished to then check if it is a directory. And as far as i understand i can only check this in a combobox via QValidator...because it adds the input to the box right away...before i can intercept it in any way.

EDIT: i did find solution for my case. I just abandoned the whole validator approach. The purpose of that was to prevent the combobox from creating a new item if it was no valid directory...what i now did instead was to validate the input after it was finished by taking advantage of the QLineEdit().editingFinished() signal. After it created the new Item i just removed it again if the input was not valid and it also gave me the opportunity to add a error Popup telling the user that the input was no directory.

I think the hasFocus() is not necessary, why do you think it is necessary? — eyllanesc, Nov 30 '18 at 13:30
you are very right, it is not necessary...i just didnt know any better as i didnt know the value of intermediate — zwusel, Dec 02 '18 at 09:49

score 2 · Accepted Answer · answered Nov 30 '18 at 13:34

2

I do not see the need for hasFocus(), because if you are writing to the QLineEdit it obviously has the focus. If the path is incorrect then you must return a QValidator::Intermediate:

from PySide import QtGui, QtCore

class DirValidator(QtGui.QValidator):
    def validate(self, _text, _pos):
        _dir = QtCore.QDir(_text)
        if _dir.exists():
            return QtGui.QValidator.Acceptable
        return QtGui.QValidator.Intermediate

if __name__ == '__main__':
    import sys
    app = QtGui.QApplication(sys.argv)
    combo = QtGui.QComboBox(editable=True)
    dir_validator = DirValidator(combo.lineEdit())
    combo.setValidator(dir_validator)
    combo.show()
    sys.exit(app.exec_())

answered Nov 30 '18 at 13:34

eyllanesc

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You did it...now i know how to use Intermediate properly. Ty very much! – zwusel Nov 30 '18 at 13:47
the only thing that bothers me still somehow with this solution is that it checks the filedir everytime i type a letter...that is of course not ideal...but for now i dont see a better solution ;) – zwusel Nov 30 '18 at 13:53
@zwusel Why is not it ideal ?, Whenever you indicate something, argue it, for me it is correct since there may be folders with the name of one, two, ... letters – eyllanesc Nov 30 '18 at 13:58
i did argue it ;) as i said i feel it is not nessecary to validate every letter typed but only if the edit is finished...at least for my application. dont get me wrong...it is still the best solution i have for now. ty – zwusel Dec 02 '18 at 09:48
btw i did find a better solution for my case. I just abandoned the whole validator approach. The purpose of that was to prevent the combobox from creating a new item if it was no valid directory...what i now did instead was to validate the input after it was finished and if it was not valid i just removed the item and also added a error popup, telling the input is not valid. But...and this is most imprtant...i learned a lot about the QValidator...so really ty a lot ;) – zwusel Dec 02 '18 at 09:54

Validate if editable QCombobox input is a directory via QValidator

1 Answers1