qcombobox.3qt

Linux 下的图形编程环境。

'\" t
.TH QComboBox 3qt "5 March 2001" "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
QComboBox \- Combined button and popup list
.br
.PP
\fC#include <qcombobox.h>\fR
.PP
Inherits QWidget.
.PP
.SS "Public Members"
.in +1c
.ti -1c
.BI "\fBQComboBox\fR ( QWidget * " "parent" "=0, const char * " "name" "=0 ) "
.br
.ti -1c
.BI "\fBQComboBox\fR ( bool " "rw" ", QWidget * " "parent" "=0, const char * " "name" "=0 ) "
.br
.ti -1c
.BI "\fB~QComboBox\fR () "
.br
.ti -1c
.BI "int \fBcount\fR () const"
.br
.ti -1c
.BI "void \fBinsertStringList\fR ( const QStringList &, int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBinsertStrList\fR ( const QStrList &, int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBinsertStrList\fR ( const QStrList *, int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBinsertStrList\fR ( const char **, int " "numStrings" "=-1, int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBinsertItem\fR ( const QString & " "text" ", int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBinsertItem\fR ( const QPixmap & " "pixmap" ", int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBinsertItem\fR ( const QPixmap & " "pixmap" ", const QString & " "text" ", int " "index" "=-1 ) "
.br
.ti -1c
.BI "void \fBremoveItem\fR ( int index ) "
.br
.ti -1c
.BI "void \fBclear\fR () "
.br
.ti -1c
.BI "QString \fBcurrentText\fR () const"
.br
.ti -1c
.BI "QString \fBtext\fR ( int index ) const"
.br
.ti -1c
.BI "const QPixmap* \fBpixmap\fR ( int index ) const"
.br
.ti -1c
.BI "void \fBchangeItem\fR ( const QString & " "text" ", int index ) "
.br
.ti -1c
.BI "void \fBchangeItem\fR ( const QPixmap & " "pixmap" ", int index ) "
.br
.ti -1c
.BI "void \fBchangeItem\fR ( const QPixmap & " "pixmap" ", const QString & " "text" ", int index ) "
.br
.ti -1c
.BI "int \fBcurrentItem\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetCurrentItem\fR ( int index ) "
.br
.ti -1c
.BI "bool autoResize () const \fI(obsolete)\fR"
.br
.ti -1c
.BI "virtual void setAutoResize ( bool ) \fI(obsolete)\fR"
.br
.ti -1c
.BI "virtual void \fBsetBackgroundColor\fR ( const QColor & ) "
.br
.ti -1c
.BI "virtual void \fBsetPalette\fR ( const QPalette & ) "
.br
.ti -1c
.BI "virtual void \fBsetFont\fR ( const QFont & ) "
.br
.ti -1c
.BI "virtual void \fBsetSizeLimit\fR ( int ) "
.br
.ti -1c
.BI "int \fBsizeLimit\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetMaxCount\fR ( int ) "
.br
.ti -1c
.BI "int \fBmaxCount\fR () const"
.br
.ti -1c
.BI "enum \fBPolicy\fR { NoInsertion, AtTop, AtCurrent, AtBottom, AfterCurrent, BeforeCurrent }"
.br
.ti -1c
.BI "virtual void \fBsetInsertionPolicy\fR ( Policy policy ) "
.br
.ti -1c
.BI "Policy \fBinsertionPolicy\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetValidator\fR ( const QValidator * ) "
.br
.ti -1c
.BI "const QValidator* \fBvalidator\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetListBox\fR ( QListBox * ) "
.br
.ti -1c
.BI "QListBox* \fBlistBox\fR () const"
.br
.ti -1c
.BI "QLineEdit* \fBlineEdit\fR () const"
.br
.ti -1c
.BI "virtual void \fBsetAutoCompletion\fR ( bool ) "
.br
.ti -1c
.BI "bool \fBautoCompletion\fR () const"
.br
.ti -1c
.BI "void \fBsetDuplicatesEnabled\fR ( bool enable ) "
.br
.ti -1c
.BI "bool \fBduplicatesEnabled\fR () const"
.br
.ti -1c
.BI "bool \fBeditable\fR () const"
.br
.ti -1c
.BI "void \fBsetEditable\fR ( bool ) "
.br
.in -1c
.SS "Public Slots"
.in +1c
.ti -1c
.BI "void \fBclearValidator\fR () "
.br
.ti -1c
.BI "void \fBclearEdit\fR () "
.br
.ti -1c
.BI "virtual void \fBsetEditText\fR ( const QString & ) "
.br
.in -1c
.SS "Signals"
.in +1c
.ti -1c
.BI "void \fBactivated\fR ( int index ) "
.br
.ti -1c
.BI "void \fBhighlighted\fR ( int index ) "
.br
.ti -1c
.BI "void \fBactivated\fR ( const QString & ) "
.br
.ti -1c
.BI "void \fBhighlighted\fR ( const QString & ) "
.br
.ti -1c
.BI "void \fBtextChanged\fR ( const QString & ) "
.br
.in -1c
.SS "Protected Members"
.in +1c
.ti -1c
.BI "void \fBpopup\fR () "
.br
.in -1c
.SS "Properties"
.nf
.TS
l l l l l
- - - - -
l l l l l.
Type	Name	READ	WRITE	Options
bool	editable	editable	setEditable
int	count	count
QString	currentText	currentText
int	currentItem	currentItem	setCurrentItem
bool	autoResize	autoResize	setAutoResize
int	sizeLimit	sizeLimit	setSizeLimit
int	maxCount	maxCount	setMaxCount
Policy	insertionPolicy	insertionPolicy	setInsertionPolicy
bool	autoCompletion	autoCompletion	setAutoCompletion
bool	duplicatesEnabled	duplicatesEnabled	setDuplicatesEnabled
.TE
.fi

.SH DESCRIPTION
The QComboBox widget is a combined button and popup list.
.PP
A combo box may be defined as a selection widget which displays the current selection, and which can pop up a list of possible selections. Some combo boxes also allow the user to select arbitrary strings, using a line editor.
.PP
Since combo boxes occupy little screen space and always display the current selection, they are very well suited to displaying and selecting modes (such as font family and size): The user can always see what mode he/she is in, and the majority of the screen space is available for real work.
.PP
QComboBox supports three different appearances: Motif 1.x, Motif 2.0 and Windows 95. In Motif 1.x, a combo box was called XmOptionMenu. In Motif 2.0, OSF introduced an improved combo box and named that XmComboBox. QComboBox provides both.
.PP
QComboBox provides two different constructors. The simplest one creates an old-style combo box in Motif style:
.PP
.nf
.br
      QComboBox * c = new QComboBox( this, "read-only combo" );
.fi
.PP
The other one creates a new-style combo box in Motif style, and can create both read-only and read-write combo boxes:
.PP
.nf
.br
      QComboBox * c1 = new QComboBox( FALSE, this, "read-only combo" );
.br
      QComboBox * c2 = new QComboBox( TRUE, this, "read-write combo" );
.fi
.PP
New-style combo boxes use a list box in both Motif and Windows styles, and both the content size and the on-screen size of the list box can be limited. Old-style combo boxes use a popup in Motif style, and that popup will happily grow larger than the desktop if you put enough data in it.
.PP
The two constructors create identical-looking combos in Windows style.
.PP
Combo boxes can contain pixmaps as well as texts; the insert() and changeItem() functions are suitably overloaded. For read-write combo boxes, the function clearEdit() is provided, to clear the displayed string without changing the combo box' contents.
.PP
A combo box emits two signals, activated() and highlighted(), when a new item has been activated (selected) or highlighted (set to current). Both signals exist in two versions, one with a \fCchar*\fR argument and one with an \fCint\fR argument. If the user highlights or activates a pixmap, only the \fCint\fR signals are emitted.
.PP
When the user enters a new string in a read-write combo, the widget may or may not insert it, and it can insert it in several locations. The default policy is is \fCAtBottom,\fR you can change it using setInsertionPolicy().
.PP
It is possible to constrain the input to an editable combo box using QValidator; see setValidator(). By default, all input is accepted.
.PP
A combo box has a default focusPolicy() of \fCTabFocus,\fR i.e. it will not grab focus if clicked. This differs from both Windows and Motif.
.PP
.ce 1
.B "[Image Omitted]"
.PP
(Motif 1, read-only)
.br
.ce 1
.B "[Image Omitted]"
.PP
(Motif 2, read-write)
.br
.ce 1
.B "[Image Omitted]"
.PP
(Motif 2, read-only)
.br
.ce 1
.B "[Image Omitted]"
.PP
(Windows style)
.PP
See also QLineEdit, QListBox, QSpinBox, QRadioButton, QButtonGroup, GUI Design Handbook: Combo Box, and GUI Design Handbook: Drop-Down List Box.
.PP
Examples:
.(l
qmag/qmag.cpp
.)l
.SS "Member Type Documentation"
.SH "QComboBox::Policy"
This enum type specifies what QComboBox should do with a new string entered by the user. The following policies are defined: 
.TP
\fCNoInsertion\fR means not to insert the string in the combo.
.TP
\fCAtTop\fR means to insert the string at the top of the combo box.
.TP
\fCAtCurrent\fR means to replace the previously selected item with the typed string.
.TP
\fCAtBottom\fR means to insert the string at the bottom of the combo box.
.TP
\fCAfterCurrent\fR means to to insert the string just after the previously selected item.
.TP
\fCBeforeCurrent\fR means to to insert the string just before the previously selected item.
.IP
.PP
activated() is always emitted, of course.
.PP
If inserting the new string would cause the combo box to breach its content size limit, the item at the other end of the list is deleted. The definition of "other end" is implementation-dependent.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QComboBox::QComboBox ( QWidget * parent=0, const char * name=0 )"
Constructs a combo box widget with a parent and a name.
.PP
This constructor creates a popup menu if the program uses Motif look and feel; this is compatible with Motif 1.x.
.SH "QComboBox::QComboBox ( bool rw, QWidget * parent=0, const char * name=0 )"