Contents

• Public Types
• Properties
• Public Functions
• Reimplemented Public Functions
• Public Slots
• Signals
• Reimplemented Protected Functions
• Detailed Description

Detailed Description

TheQLCDNumber widget displays a number with LCD-like digits.

It can display a number in just about any size. It can display decimal, hexadecimal, octal or binary numbers. It is easy to connect to data sources using thedisplay() slot, which is overloaded to take any of five argument types.

There are also slots to change the base withsetMode() and the decimal point withsetSmallDecimalPoint().

QLCDNumber emits theoverflow() signal when it is asked to display something beyond its range. The range is set bysetDigitCount(), butsetSmallDecimalPoint() also influences it. If the display is set to hexadecimal, octal or binary, the integer equivalent of the value is displayed.

These digits and other symbols can be shown: 0/O, 1, 2, 3, 4, 5/S, 6, 7, 8, 9/g, minus, decimal point, A, B, C, D, E, F, h, H, L, o, P, r, u, U, Y, colon, degree sign (which is specified as single quote in the string) and space.QLCDNumber substitutes spaces for illegal characters.

It is not possible to retrieve the contents of aQLCDNumber object, although you can retrieve the numeric value withvalue(). If you really need the text, we recommend that you connect the signals that feed thedisplay() slot to another slot as well and store the value there.

Incidentally,QLCDNumber is the very oldest part of Qt, tracing its roots back to a BASIC program on theSinclair Spectrum.

LCD number widgets shown in various widget styles (from left to right):Motif,CDE,Windows,Windows XP,Macintosh,Plastique.

Member Type Documentation

enum QLCDNumber::Mode

This type determines how numbers are shown.

If the display is set to hexadecimal, octal or binary, the integer equivalent of the value is displayed.

enum QLCDNumber::SegmentStyle

This type determines the visual appearance of theQLCDNumber widget.

Property Documentation

digitCount :int

This property holds the current number of digits displayed.

Corresponds to the current number of digits. IfQLCDNumber::smallDecimalPoint is false, the decimal point occupies one digit position.

By default, this property contains a value of 5.

This property was introduced in Qt 4.6.

Access functions:

See alsosmallDecimalPoint.

intValue :int

This property holds the displayed value rounded to the nearest integer.

This property corresponds to the nearest integer to the current value displayed by the LCDNumber. This is the value used for hexadecimal, octal and binary modes.

If the displayed value is not a number, the property has a value of 0.

By default, this property contains a value of 0.

Access functions:

mode :Mode

This property holds the current display mode (number base).

Corresponds to the current display mode, which is one ofBin,Oct,Dec (the default) andHex.Dec mode can display floating point values, the other modes display the integer equivalent.

Access functions:

See alsosmallDecimalPoint(),setHexMode(),setDecMode(),setOctMode(), andsetBinMode().

segmentStyle :SegmentStyle

This property holds the style of the LCDNumber.

Outline andFilled will additionally useQPalette::light() andQPalette::dark() for shadow effects.

Access functions:

smallDecimalPoint :bool

This property holds the style of the decimal point.

If true the decimal point is drawn between two digit positions. Otherwise it occupies a digit position of its own, i.e. is drawn in a digit position. The default is false.

The inter-digit space is made slightly wider when the decimal point is drawn between the digits.

Access functions:

See alsomode.

value :double

This property holds the displayed value.

This property corresponds to the current value displayed by the LCDNumber.

If the displayed value is not a number, the property has a value of 0.

By default, this property contains a value of 0.

Access functions:

Member Function Documentation

QLCDNumber::QLCDNumber(QWidget * parent = 0)

Constructs an LCD number, sets the number of digits to 5, the base to decimal, the decimal point mode to 'small' and the frame style to a raised box. ThesegmentStyle() is set toOutline.

Theparent argument is passed to theQFrame constructor.

See alsosetDigitCount() andsetSmallDecimalPoint().

QLCDNumber::QLCDNumber(uint numDigits,QWidget * parent = 0)

Constructs an LCD number, sets the number of digits tonumDigits, the base to decimal, the decimal point mode to 'small' and the frame style to a raised box. ThesegmentStyle() is set toFilled.

Theparent argument is passed to theQFrame constructor.

See alsosetDigitCount() andsetSmallDecimalPoint().

QLCDNumber::~QLCDNumber()

Destroys the LCD number.

bool QLCDNumber::checkOverflow(double num) const

Returns true ifnum is too big to be displayed in its entirety; otherwise returns false.

See alsodisplay(),digitCount(), andsmallDecimalPoint().

bool QLCDNumber::checkOverflow(int num) const

This is an overloaded function.

Returns true ifnum is too big to be displayed in its entirety; otherwise returns false.

See alsodisplay(),digitCount(), andsmallDecimalPoint().

[virtual protected]bool QLCDNumber::event(QEvent * e)

Reimplemented fromQObject::event().

[signal]void QLCDNumber::overflow()

This signal is emitted whenever theQLCDNumber is asked to display a too-large number or a too-long string.

It is never emitted bysetDigitCount().

[virtual protected]void QLCDNumber::paintEvent(QPaintEvent *)

Reimplemented fromQWidget::paintEvent().

[slot]void QLCDNumber::setBinMode()

CallssetMode(Bin). Provided for convenience (e.g. for connecting buttons to it).

See alsosetMode(),setHexMode(),setDecMode(),setOctMode(), andmode().

[slot]void QLCDNumber::setDecMode()

CallssetMode(Dec). Provided for convenience (e.g. for connecting buttons to it).

See alsosetMode(),setHexMode(),setOctMode(),setBinMode(), andmode().

[slot]void QLCDNumber::setHexMode()

CallssetMode(Hex). Provided for convenience (e.g. for connecting buttons to it).

See alsosetMode(),setDecMode(),setOctMode(),setBinMode(), andmode().

[slot]void QLCDNumber::setOctMode()

CallssetMode(Oct). Provided for convenience (e.g. for connecting buttons to it).

See alsosetMode(),setHexMode(),setDecMode(),setBinMode(), andmode().

[virtual]QSize QLCDNumber::sizeHint() const

Reimplemented fromQWidget::sizeHint().