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QLCDNumber Class Reference
[com.trolltech.qt.gui module]

The QLCDNumber widget displays a number with LCD-like digits. More...

Inherits QFrame.


Detailed Description

The QLCDNumber 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 the display slot, which is overloaded to take any of five argument types.

There are also slots to change the base with setMode and the decimal point with setSmallDecimalPoint.

QLCDNumber emits the overflow signal when it is asked to display something beyond its range. The range is set by setNumDigits, but setSmallDecimalPoint 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 a QLCDNumber object, although you can retrieve the numeric value with value. If you really need the text, we recommend that you connect the signals that feed the display 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 the Sinclair Spectrum.

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

See also QLabel, QFrame, Digital Clock Example, and Tetrix Example.


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Qt Jambi 4.3.4_01