qvaluelist.3qt

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

.TH QValueList 3qt "10 November 2000" "Trolltech AS" \" -*- nroff -*-
.\" Copyright 1992-2000 Trolltech AS.  All rights reserved.  See the
.\" license file included in the distribution for a complete license
.\" statement.
.\"
.ad l
.nh
.SH NAME
QValueList \- Value based template class that provides doubly linked lists
.SH SYNOPSIS
.br
.PP
\fC#include <qvaluelist.h>\fR
.PP
.SS "Public Members"
.in +1c
.ti -1c
.BI "\fBQValueList\fR () "
.br
.ti -1c
.BI "\fBQValueList\fR ( const QValueList<T> & l ) "
.br
.ti -1c
.BI "\fB~QValueList\fR () "
.br
.ti -1c
.BI "QValueList<T>& \fBoperator=\fR ( const QValueList<T> & l ) "
.br
.ti -1c
.BI "QValueList<T> \fBoperator+\fR ( const QValueList<T> & l ) const"
.br
.ti -1c
.BI "QValueList<T>& \fBoperator+=\fR ( const QValueList<T> & l ) "
.br
.ti -1c
.BI "bool \fBoperator==\fR ( const QValueList<T> & l ) const"
.br
.ti -1c
.BI "bool \fBoperator!=\fR ( const QValueList<T> & l ) const"
.br
.ti -1c
.BI "Iterator \fBbegin\fR () "
.br
.ti -1c
.BI "ConstIterator \fBbegin\fR () const"
.br
.ti -1c
.BI "Iterator \fBend\fR () "
.br
.ti -1c
.BI "ConstIterator \fBend\fR () const"
.br
.ti -1c
.BI "Iterator \fBfromLast\fR () "
.br
.ti -1c
.BI "ConstIterator \fBfromLast\fR () const"
.br
.ti -1c
.BI "bool \fBisEmpty\fR () const"
.br
.ti -1c
.BI "Iterator \fBinsert\fR ( Iterator " "it" ", const T & x ) "
.br
.ti -1c
.BI "Iterator \fBappend\fR ( const T & x ) "
.br
.ti -1c
.BI "Iterator \fBprepend\fR ( const T & x ) "
.br
.ti -1c
.BI "Iterator \fBremove\fR ( Iterator it ) "
.br
.ti -1c
.BI "void \fBremove\fR ( const T & x ) "
.br
.ti -1c
.BI "T& \fBfirst\fR () "
.br
.ti -1c
.BI "const T& \fBfirst\fR () const"
.br
.ti -1c
.BI "T& \fBlast\fR () "
.br
.ti -1c
.BI "const T& \fBlast\fR () const"
.br
.ti -1c
.BI "T& \fBoperator[]\fR ( uint i ) "
.br
.ti -1c
.BI "const T& \fBoperator[]\fR ( uint i ) const"
.br
.ti -1c
.BI "Iterator \fBat\fR ( uint i ) "
.br
.ti -1c
.BI "ConstIterator \fBat\fR ( uint i ) const"
.br
.ti -1c
.BI "Iterator \fBfind\fR ( const T & x ) "
.br
.ti -1c
.BI "ConstIterator \fBfind\fR ( const T & x ) const"
.br
.ti -1c
.BI "Iterator \fBfind\fR ( Iterator " "it" ", const T & x ) "
.br
.ti -1c
.BI "ConstIterator \fBfind\fR ( ConstIterator " "it" ", const T & x ) const"
.br
.ti -1c
.BI "int \fBfindIndex\fR ( const T & x ) const"
.br
.ti -1c
.BI "uint \fBcontains\fR ( const T & x ) const"
.br
.ti -1c
.BI "uint \fBcount\fR () const"
.br
.ti -1c
.BI "void \fBclear\fR () "
.br
.ti -1c
.BI "QValueList<T>& \fBoperator+=\fR ( const T & x ) "
.br
.ti -1c
.BI "QValueList<T>& \fBoperator<<\fR ( const T & x ) "
.br
.in -1c
.SS "Protected Members"
.in +1c
.ti -1c
.BI "void \fBdetach\fR () "
.br
.in -1c
.SH RELATED FUNCTION DOCUMENTATION
(Note that these are not member functions.)
.in +1c
.ti -1c
.BI "QDataStream& \fBoperator<<\fR (QDataStream & " "s" ", const QValueList<T> & " "l" ")"
.br
.ti -1c
.BI "QDataStream& \fBoperator>>\fR (QDataStream & " "s" ", QValueList<T> & " "l" ")"
.br
.in -1c
.SH DESCRIPTION
The QValueList class is a value based template class that provides doubly linked lists.
.PP
Define a template instance QValueList<X> to create a list of values which all have the class X. Please notice that QValueList does not store pointers to the members of the list. It holds a copy of every member. That is the reason why this kind of classes are called "value based" while QList and QDict are "reference based".
.PP
Some classes can not be used within a QValueList, for example everything derived from QObject and thus all classes that implement widgets. Only values can be used in a QValueList. To qualify as a value, the class must provide
.TP
a copy constructor,
.TP
an assignment operator and
.TP
a default constructor, i.e. a constructor that does not take any arguments.
.PP
Note that C++ defaults to field-by-field assignment operators and copy constructors if no explicit version is supplied. In many cases, this is sufficient.
.PP
Example:
.PP
.nf
.br
    #include <qvaluelist.h>
.br
    #include <qstring.h>
.br
    #include <stdio.h>
.br
.br
    class Employee
.br
    {
.br
    public:
.br
        Employee(): s(0) {}
.br
        Employee( const QString& name, int salary )
.br
            : n(name), s(salary)
.br
        {}
.br
.br
        QString     name()   const              { return n; }
.br
        int         salary() const              { return s; }
.br
        void        setSalary( int salary )     { s = salary; }
.br
    private:
.br
        QString     n;
.br
        int         s;
.br
    };
.br
.br
    void main()
.br
    {
.br
        typedef QValueList<Employee> EmployeeList;
.br
        EmployeeList list;              // list of Employee
.br
.br
        list.append( Employee("Bill", 50000) );
.br
        list.append( Employee("Steve",80000) );
.br
        list.append( Employee("Ron",  60000) );
.br
.br
        Employee joe( "Joe", 50000 );
.br
        list.append( joe );
.br
        joe.setSalary( 4000 );