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QDoubleValidator Class Reference
[QtGui module]

The QDoubleValidator class provides range checking of floating-point numbers. More...

 #include <QDoubleValidator>

Inherits QValidator.

Public Types

Properties

Public Functions

Additional Inherited Members


Detailed Description

The QDoubleValidator class provides range checking of floating-point numbers.

QDoubleValidator provides an upper bound, a lower bound, and a limit on the number of digits after the decimal point. It does not provide a fixup() function.

You can set the acceptable range in one call with setRange(), or with setBottom() and setTop(). Set the number of decimal places with setDecimals(). The validate() function returns the validation state.

QDoubleValidator uses its locale() to interpret the number. For example, in the German locale, "1,234" will be accepted as the fractional number 1.234. In Arabic locales, QDoubleValidator will accept Arabic digits.

In addition, QDoubleValidator is always guaranteed to accept a number formatted according to the "C" locale. QDoubleValidator will not accept numbers with thousand-seperators.

See also QIntValidator, QRegExpValidator, and Line Edits Example.


Member Type Documentation

enum QDoubleValidator::Notation

This enum defines the allowed notations for entering a double.

ConstantValueDescription
QDoubleValidator::StandardNotation0The string is written as a standard number (i.e. 0.015).
QDoubleValidator::ScientificNotation1The string is written in scientific form. It may have an exponent part(i.e. 1.5E-2).

This enum was introduced in Qt 4.3.


Property Documentation

bottom : double

This property holds the validator's minimum acceptable value.

By default, this property contains a value of -infinity.

Access functions:

See also setRange().

decimals : int

This property holds the validator's maximum number of digits after the decimal point.

By default, this property contains a value of 1000.

Access functions:

See also setRange().

notation : Notation

This property holds the notation of how a string can describe a number.

By default, this property is set to ScientificNotation.

This property was introduced in Qt 4.3.

Access functions:

See also Notation.

top : double

This property holds the validator's maximum acceptable value.

By default, this property contains a value of infinity.

Access functions:

See also setRange().


Member Function Documentation

QDoubleValidator::QDoubleValidator ( QObject * parent )

Constructs a validator object with a parent object that accepts any double.

QDoubleValidator::QDoubleValidator ( double bottom, double top, int decimals, QObject * parent )

Constructs a validator object with a parent object. This validator will accept doubles from bottom to top inclusive, with up to decimals digits after the decimal point.

QDoubleValidator::~QDoubleValidator ()

Destroys the validator.

void QDoubleValidator::setRange ( double minimum, double maximum, int decimals = 0 )   [virtual]

Sets the validator to accept doubles from minimum to maximum inclusive, with at most decimals digits after the decimal point.

QValidator::State QDoubleValidator::validate ( QString & input, int & pos ) const   [virtual]

Returns Acceptable if the string input contains a double that is within the valid range and is in the correct format.

Returns Intermediate if input contains a double that is outside the range or is in the wrong format; e.g. with too many digits after the decimal point or is empty.

Returns Invalid if the input is not a double.

Note: If the valid range consists of just positive doubles (e.g. 0.0 to 100.0) and input is a negative double then Invalid is returned. If notation() is set to StandardNotation, and the input contains more digits before the decimal point than a double in the valid range may have, Invalid is returned. If notation() is ScientificNotation, and the input is not in the valid range, Intermediate is returned. The value may yet become valid by changing the exponent.

By default, the pos parameter is not used by this validator.

Reimplemented from QValidator.


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Qt 4.5.3