QValidator¶
The
QValidator
class provides validation of input text. More…
Inherited by: QDoubleValidator, QIntValidator, QRegExpValidator, QRegularExpressionValidator
Synopsis¶
Functions¶
Virtual functions¶
Signals¶
def
changed
()
Detailed Description¶
The class itself is abstract. Two subclasses,
QIntValidator
andQDoubleValidator
, provide basic numeric-range checking, andQRegExpValidator
provides general checking using a custom regular expression.If the built-in validators aren’t sufficient, you can subclass
QValidator
. The class has two virtual functions:validate()
andfixup()
.
validate()
must be implemented by every subclass. It returnsInvalid
,Intermediate
orAcceptable
depending on whether its argument is valid (for the subclass’s definition of valid).These three states require some explanation. An
Invalid
string is clearly invalid.Intermediate
is less obvious: the concept of validity is difficult to apply when the string is incomplete (still being edited).QValidator
definesIntermediate
as the property of a string that is neither clearly invalid nor acceptable as a final result.Acceptable
means that the string is acceptable as a final result. One might say that any string that is a plausible intermediate state during entry of anAcceptable
string isIntermediate
.Here are some examples:
For a line edit that accepts integers from 10 to 1000 inclusive, 42 and 123 are
Acceptable
, the empty string, 5, or 1234 areIntermediate
, and “asdf” and 10114 isInvalid
.For an editable combobox that accepts URLs, any well-formed URL is
Acceptable
, “http://example.com/,” isIntermediate
(it might be a cut and paste action that accidentally took in a comma at the end), the empty string isIntermediate
(the user might select and delete all of the text in preparation for entering a new URL) and “http:///./” isInvalid
.For a spin box that accepts lengths, “11cm” and “1in” are
Acceptable
, “11” and the empty string areIntermediate
, and “http://example.com” and “hour” areInvalid
.
fixup()
is provided for validators that can repair some user errors. The default implementation does nothing.QLineEdit
, for example, will callfixup()
if the user presses Enter (or Return) and the content is not currently valid. This allows thefixup()
function the opportunity of performing some magic to make anInvalid
stringAcceptable
.A validator has a locale, set with
setLocale()
. It is typically used to parse localized data. For example,QIntValidator
andQDoubleValidator
use it to parse localized representations of integers and doubles.
QValidator
is typically used withQLineEdit
,QSpinBox
andQComboBox
.
- class PySide2.QtGui.QValidator([parent=None])¶
- param parent:
Sets up the validator. The
parent
parameter is passed on to theQObject
constructor.
- PySide2.QtGui.QValidator.State¶
This enum type defines the states in which a validated string can exist.
Constant
Description
QValidator.Invalid
The string is clearly invalid.
QValidator.Intermediate
The string is a plausible intermediate value.
QValidator.Acceptable
The string is acceptable as a final result; i.e. it is valid.
- PySide2.QtGui.QValidator.changed()¶
- PySide2.QtGui.QValidator.fixup(arg__1)¶
- Parameters:
arg__1 – str
This function attempts to change
input
to be valid according to this validator’s rules. It need not result in a valid string: callers of this function must re-test afterwards; the default does nothing.Reimplementations of this function can change
input
even if they do not produce a valid string. For example, an ISBN validator might want to delete every character except digits and “-”, even if the result is still not a valid ISBN; a surname validator might want to remove whitespace from the start and end of the string, even if the resulting string is not in the list of accepted surnames.
- PySide2.QtGui.QValidator.locale()¶
- Return type:
Returns the locale for the validator. The locale is by default initialized to the same as QLocale().
See also
setLocale()
QLocale()
- PySide2.QtGui.QValidator.setLocale(locale)¶
- Parameters:
locale –
PySide2.QtCore.QLocale
Sets the
locale
that will be used for the validator. Unless has been called, the validator will use the default locale set withsetDefault()
. If a default locale has not been set, it is the operating system’s locale.See also
locale()
setDefault()
- PySide2.QtGui.QValidator.validate(arg__1, arg__2)¶
- Parameters:
arg__1 – str
arg__2 – int
- Return type:
PyObject
This virtual function returns
Invalid
ifinput
is invalid according to this validator’s rules,Intermediate
if it is likely that a little more editing will make the input acceptable (e.g. the user types “4” into a widget which accepts integers between 10 and 99), andAcceptable
if the input is valid.The function can change both
input
andpos
(the cursor position) if required.
© 2022 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.