P3: Somewhat important QSpinBox (QAbstractSpinBox) allows custom validation by re-implementing validate and fixup.
fixup signature is void fixup(QString &) and is supposed to alter the input passed by reference. In PySide, the signature is adjusted so that the function returns a string. However, this does not seem to work. The returned value is ignored.
See the example below. It shows a QSpinBox that would allow only multiples of 5. Type a number that is not a multiple of five, and unfocus the window.
Expected behavior: the value is rounded to the next 5, e.g. typing in 6 should change the text to 10.
Observed behavior: the previous value in the spinbox (for example 0) is restored no matter what the input was.
from PySide6.QtGui import QValidator
from PySide6.QtWidgets import QApplication, QSpinBox
class MySpinBox(QSpinBox):
def __init__(self, parent=None):
super().__init__(parent)
def stepBy(self, steps):
self.setValue(self.value() + 5 * steps)
def validate(self, input, pos):
if not input:
return QValidator.State.Intermediate
try:
number = int(input)
except ValueError:
return QValidator.State.Invalid
if number % 5 == 0:
return QValidator.State.Acceptable
else:
return QValidator.State.Intermediate
def fixup(self, input):
number = int(input)
# Round up to next multiple of 5.
number += 5 - number % 5
return str(number)
if __name__ == "__main__":
app = QApplication()
spinbox = MySpinBox()
spinbox.show()
app.exec()
See also a similar previous issue affecting QValidator https://bugreports.qt.io/browse/PYSIDE-106