Detailed Description
The QIntValidator class provides a validator that ensures a string contains a valid integer within a specified range.
Example of use:
QValidator *validator = new QIntValidator(100, 999, this);
QLineEdit *edit = new QLineEdit(this);
edit->setValidator(validator);
Below we present some examples of validators. In practice they would normally be associated with a widget as in the example above.
QString str;
int pos = 0;
QIntValidator v(100, 900, this);
str = "1";
v.validate(str, pos);
str = "012";
v.validate(str, pos);
str = "123";
v.validate(str, pos);
str = "678";
v.validate(str, pos);
str = "999";
v.validate(str, pos);
str = "1234";
v.validate(str, pos);
str = "-123";
v.validate(str, pos);
str = "abc";
v.validate(str, pos);
str = "12cm";
v.validate(str, pos);
Notice that the value 999 returns Intermediate. Values consisting of a number of digits equal to or less than the max value are considered intermediate. This is intended because the digit that prevents a number to be in range is not necessarily the last digit typed. This also means that an intermediate number can have leading zeros.
The minimum and maximum values are set in one call with setRange(), or individually with setBottom() and setTop().
QIntValidator uses its locale() to interpret the number. For example, in Arabic locales, QIntValidator will accept Arabic digits. In addition, QIntValidator is always guaranteed to accept a number formatted according to the "C" locale.
See also QDoubleValidator, QRegExpValidator, and Line Edits Example.
Property Documentation
bottom : int
This property holds the validator's lowest acceptable value.
By default, this property's value is derived from the lowest signed integer available (typically -2147483647).
Access functions:
- int bottom () const
- void setBottom ( int )
See also setRange().
top : int
This property holds the validator's highest acceptable value.
By default, this property's value is derived from the highest signed integer available (typically 2147483647).
Access functions:
- int top () const
- void setTop ( int )
See also setRange().
Member Function Documentation
QIntValidator::QIntValidator ( QObject * parent )
Constructs a validator with a parent object that accepts all integers.
QIntValidator::QIntValidator ( int minimum, int maximum, QObject * parent )
Constructs a validator with a parent, that accepts integers from minimum to maximum inclusive.
QIntValidator::~QIntValidator ()
Destroys the validator.
void QIntValidator::setRange ( int bottom, int top ) [virtual]
Sets the range of the validator to only accept integers between bottom and top inclusive.
QValidator::State QIntValidator::validate ( QString & input, int & pos ) const [virtual]
Returns Acceptable if the input is an integer within the valid range, Intermediate if the input is a prefix of an integer in the valid range, and Invalid otherwise.
If the valid range consists of just positive integers (e.g., 32 to 100) and input is a negative integer, then Invalid is returned. (On the other hand, if the range consists of negative integers (e.g., -100 to -32) and input is a positive integer, then Intermediate is returned, because the user might be just about to type the minus (especially for right-to-left languages).
int pos = 0;
s = "abc";
v.validate(s, pos);
s = "5";
v.validate(s, pos);
s = "50";
v.validate(s, pos);
By default, the pos parameter is not used by this validator.
Reimplemented from QValidator.