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RedHat 9 (Linux i386) - man page for qvalidator (redhat section 3qt)

QValidator(3qt) 								  QValidator(3qt)

NAME
       QValidator - Validation of input text

SYNOPSIS
       #include <qvalidator.h>

       Inherits QObject.

       Inherited by QIntValidator, QDoubleValidator, and QRegExpValidator.

   Public Members
       QValidator ( QObject * parent, const char * name = 0 )
       ~QValidator ()
       enum State { Invalid, Intermediate, Valid = Intermediate, Acceptable }
       virtual State validate ( QString & input, int & pos ) const = 0
       virtual void fixup ( QString & input ) const

DESCRIPTION
       The QValidator class provides validation of input text.

       The class itself is abstract. Two subclasses, QIntValidator and QDoubleValidator, provide
       basic numeric-range checking, and QRegExpValidator 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() and fixup().

       validate() must be implemented by every subclass. It returns Invalid, Intermediate or
       Acceptable 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 slippery when the string is
       incomplete (still being edited). QValidator defines Intermediate 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 an Acceptable string is Intermediate.

       Here are some examples:

       For a line edit that accepts integers from 0 to 999 inclusive, 42 and 666 are Acceptable,
       the empty string and 1114 are Intermediate and asdf is Invalid.

       For an editable combobox that accepts URLs, any well-formed URL is Acceptable,
       "http://www.trolltech.com/," is Intermediate (it might be a cut-and-paste that
       accidentally took in a comma at the end), the empty string is valid (the user might select
       and delete all of the text in preparation of entering a new URL) and" http:///./" is
       Invalid.

       For a spin box that accepts lengths, "11cm" and "1in" are Acceptable, "11" and the empty
       string are Intermediate and" http://www.trolltech.com" and "hour" are Invalid.

       fixup() is provided for validators that can repair some user errors. The default
       implementation does nothing. QLineEdit, for example, will call fixup() if the user presses
       Enter (or Return) and the content is not currently valid. This allows the fixup() function
       the opportunity of performing some magic to make an Invalid string Acceptable.

       QValidator is typically used with QLineEdit, QSpinBox and QComboBox.

       See also Miscellaneous Classes.

   Member Type Documentation
QValidator::State
       This enum type defines the states in which a validated string can exist.

       QValidator::Invalid - the string is clearly invalid.

       QValidator::Intermediate - the string is a plausible intermediate value during editing.

       QValidator::Acceptable - the string is acceptable as a final result, i.e. it is valid.

MEMBER FUNCTION DOCUMENTATION
QValidator::QValidator ( QObject * parent, const char * name = 0 )
       Sets up the validator. The parent and name parameters are passed on to the QObject
       constructor.

QValidator::~QValidator ()
       Destroys the validator, freeing any storage and other resources used.

void QValidator::fixup ( QString & input ) const [virtual]
       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.

State QValidator::validate ( QString & input, int & pos ) const [pure virtual]
       This pure virtual function returns Invalid if input 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) and Acceptable if the input is valid.

       The function can change input and pos (the cursor position) if it wants to.

       Reimplemented in QIntValidator, QDoubleValidator, and QRegExpValidator.

SEE ALSO
       http://doc.trolltech.com/qvalidator.html http://www.trolltech.com/faq/tech.html

COPYRIGHT
       Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the license file included
       in the distribution for a complete license statement.

AUTHOR
       Generated automatically from the source code.

BUGS
       If you find a bug in Qt, please report it as described in
       http://doc.trolltech.com/bughowto.html.	Good bug reports help us to help you. Thank you.

       The definitive Qt documentation is provided in HTML format; it is located at
       $QTDIR/doc/html and can be read using Qt Assistant or with a web browser. This man page is
       provided as a convenience for those users who prefer man pages, although this format is
       not officially supported by Trolltech.

       If you find errors in this manual page, please report them to qt-bugs@trolltech.com.
       Please include the name of the manual page (qvalidator.3qt) and the Qt version (3.1.1).

Trolltech AS				 9 December 2002			  QValidator(3qt)


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