qspinbox.3qt

Trolltech公司发布的基于C++图形开发环境

'\" t
.TH QSpinBox 3qt "24 January 2005" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2001 Trolltech AS.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
QSpinBox \- Spin box widget, sometimes called up-down widget, little arrows widget or spin button
.br
.PP
\fC#include <qspinbox.h>\fR
.PP
Inherits QFrame and QRangeControl.
.PP
.SS "Public Members"
.in +1c
.ti -1c
.BI "\fBQSpinBox\fR ( QWidget * " "parent" " = 0, const char * " "name" " = 0 ) "
.br
.ti -1c
.BI "\fBQSpinBox\fR ( int " "minValue" ", int " "maxValue" ", int " "step" " = 1, QWidget * " "parent" " = 0, const char * " "name" " = 0 ) "
.br
.ti -1c
.BI "\fB~QSpinBox\fR () "
.br
.ti -1c
.BI "QString \fBtext\fR () const"
.br
.ti -1c
.BI "virtual QString \fBprefix\fR () const"
.br
.ti -1c
.BI "virtual QString \fBsuffix\fR () const"
.br
.ti -1c
.BI "virtual QString \fBcleanText\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetSpecialValueText\fR ( const QString & text ) "
.br
.ti -1c
.BI "QString \fBspecialValueText\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetWrapping\fR ( bool on ) "
.br
.ti -1c
.BI "bool \fBwrapping\fR () const"
.br
.ti -1c
.BI "enum \fBButtonSymbols\fR { UpDownArrows, PlusMinus }"
.br
.ti -1c
.BI "void \fBsetButtonSymbols\fR ( ButtonSymbols ) "
.br
.ti -1c
.BI "ButtonSymbols \fBbuttonSymbols\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetValidator\fR ( const QValidator * v ) "
.br
.ti -1c
.BI "const QValidator* \fBvalidator\fR () const"
.br
.ti -1c
.BI "void \fBsetMinValue\fR ( int ) "
.br
.ti -1c
.BI "void \fBsetMaxValue\fR ( int ) "
.br
.ti -1c
.BI "void \fBsetLineStep\fR ( int ) "
.br
.in -1c
.SS "Public Slots"
.in +1c
.ti -1c
.BI "virtual void \fBsetValue\fR ( int value ) "
.br
.ti -1c
.BI "virtual void \fBsetPrefix\fR ( const QString & text ) "
.br
.ti -1c
.BI "virtual void \fBsetSuffix\fR ( const QString & text ) "
.br
.ti -1c
.BI "virtual void \fBstepUp\fR () "
.br
.ti -1c
.BI "virtual void \fBstepDown\fR () "
.br
.in -1c
.SS "Signals"
.in +1c
.ti -1c
.BI "void \fBvalueChanged\fR ( int value ) "
.br
.ti -1c
.BI "void \fBvalueChanged\fR ( const QString & valueText ) "
.br
.in -1c
.SS "Protected Members"
.in +1c
.ti -1c
.BI "virtual QString \fBmapValueToText\fR ( int value ) "
.br
.ti -1c
.BI "virtual int \fBmapTextToValue\fR ( bool * ok ) "
.br
.ti -1c
.BI "QString \fBcurrentValueText\fR () "
.br
.ti -1c
.BI "virtual void \fBupdateDisplay\fR () "
.br
.ti -1c
.BI "virtual void \fBinterpretText\fR () "
.br
.ti -1c
.BI "QPushButton* \fBupButton\fR () const"
.br
.ti -1c
.BI "QPushButton* \fBdownButton\fR () const"
.br
.ti -1c
.BI "QLineEdit* \fBeditor\fR () const"
.br
.ti -1c
.BI "virtual void \fBvalueChange\fR () "
.br
.ti -1c
.BI "virtual void \fBrangeChange\fR () "
.br
.ti -1c
.BI "virtual bool \fBeventFilter\fR ( QObject * " "obj" ", QEvent * ev ) "
.br
.in -1c
.SS "Protected Slots"
.in +1c
.ti -1c
.BI "void \fBtextChanged\fR () "
.br
.in -1c
.SS "Properties"
.nf
.TS
l l l l l
- - - - -
l l l l l.
Type	Name	READ	WRITE	Options
QString	text	text
QString	prefix	prefix	setPrefix
QString	suffix	suffix	setSuffix
QString	cleanText	cleanText
QString	specialValueText	specialValueText	setSpecialValueText
bool	wrapping	wrapping	setWrapping
ButtonSymbols	buttonSymbols	buttonSymbols	setButtonSymbols
int	maxValue	maxValue	setMaxValue
int	minValue	minValue	setMinValue
int	lineStep	lineStep	setLineStep
int	value	value	setValue
.TE
.fi

.SH DESCRIPTION
The QSpinBox class provides a spin box widget, sometimes called up-down widget, little arrows widget or spin button.
.PP
QSpinBox allows the user to choose a value, either by clicking the up/down buttons to increase/decrease the value currently displayed, or by typing the value directly into the spin box. Usually the value is an integer.
.PP
Every time the value changes, QSpinBox emits the valueChanged() signal. The current value can be fetched with value() and set with setValue().
.PP
The spin box clamps the value within a numeric range, see QRangeControl for details. Clicking the up/down down buttons (or using the keyboard accelerators: Up-arrow and Down-arrow) will increase or decrease the current value in steps of size lineStep().
.PP
Most spin boxes are directional, but QSpinBox can also operate as a circular spin box, i.e. if the range is 0-99 and the current value is 99, clicking Up will give 0. Use setWrapping() if you want circular behavior.
.PP
The displayed value can be prepended and/or appended with an arbitrary string indicating for example the unit of measurement. See setPrefix() and setSuffix().
.PP
Normally, the spin box displays up and down arrows in the buttons. You can use setButtonSymbols() to change the display to show + and - symbols, if this is clearer for your intended purpose. In either case, the up and down arrow keys always work.
.PP
It is often desirable to give the user a special, often default, choice in addition to the range of numeric values. See setSpecialValueText() for how to do this with QSpinBox.
.PP
The default QWidget::focusPolicy() is StrongFocus.
.PP
QSpinBox can easily be subclassed to allow the user to input other things than an integer value, as long as the allowed input can be mapped down to a range of integers. This can be done by overriding the virtual functions mapValueToText() and mapTextToValue() and setting another, suitable validator using setValidator(). For example, these function could be changed so that the user provided values from 0.0 to 10.0 while the range of integers used inside the program would be 0 to 100:
.PP
.nf
.br
  class MySpinBox : public QSpinBox {
.br
  public:
.br
    ...
.br
.br
    QString     mapValueToText( int value )
.br
    {
.br
      return QString("%1.%2").arg(value/10).arg(value%10);
.br
    }
.br
.br
    int         mapTextToValue( bool* ok )
.br
    {
.br
      return int(text().toFloat()*10);
.br
    }
.br
.br
  };
.fi
.PP
.ce 1
.B "[Image Omitted]"
.PP

.ce 1
.B "[Image Omitted]"
.PP
See also QScrollBar, QSlider and GUI Design Handbook: Spin Box
.SS "Member Type Documentation"
.SH "QSpinBox::ButtonSymbols"
This enum type determines what the buttons in a spin box show. The currently defined values are: 
.TP
\fCUpDownArrows\fR - the buttons show little arrows, in the classic style. This is the default.