Qt IP输入控件

Qt 本身不带IP输入控件，刚开始使用的代码发现位置调整有问题。最后找到了一个写得很好的代码，加上自己的修改：

head_file

#include <QFrame>
#include <QLineEdit>
#include <QIntValidator>
//#include "stdint.h"
#include <QHBoxLayout>
#include <QFont>
#include <QLabel>
#include <QKeyEvent>
#include <QHostAddress>

class IPCtrl : public QFrame
{
    Q_OBJECT

public:
    IPCtrl(QWidget *parent = 0);
    ~IPCtrl();

    virtual bool eventFilter( QObject *obj, QEvent *event );
    bool IPCtrl::getIP(QHostAddress *haddr);
public slots:
    void slotTextChanged( QLineEdit* pEdit );
    void lineEditChanged();
signals:
    void signalTextChanged( QLineEdit* pEdit );

private:
    enum
    {
        QTUTL_IP_SIZE   = 4,//
        MAX_DIGITS      = 3 //
    };

    QLineEdit *(m_pLineEdit[QTUTL_IP_SIZE]);
    QLabel *(pDot[QTUTL_IP_SIZE-1]);
    void MoveNextLineEdit (int i);
    void MovePrevLineEdit (int i);

};

cpp file

#include "ipctrl.h"
#include <QDebug>
#include <QMessageBox>
IPCtrl::IPCtrl(QWidget *parent) : QFrame(parent)
{
    setFrameShape( QFrame::StyledPanel );
    setFrameShadow( QFrame::Sunken );

    QHBoxLayout* pLayout = new QHBoxLayout( this );
    setLayout( pLayout );
    pLayout->setContentsMargins( 0, 0, 0, 0 );
    pLayout->setSpacing( 0 );

    for ( int i = 0; i != QTUTL_IP_SIZE; ++i )
    {
        if ( i != 0 )
        {
            pDot[i-1] = new QLabel( ".", this );
            pDot[i-1]->setStyleSheet( "background: white" );
            pLayout->addWidget( pDot[i-1] );
            pLayout->setStretch( pLayout->count(), 0 );
        }

        m_pLineEdit[i] = new QLineEdit( this );
        QLineEdit* pEdit = m_pLineEdit[i];
        pEdit->installEventFilter( this );

        pLayout->addWidget( pEdit );
        pLayout->setStretch( pLayout->count(), 1 );

        pEdit->setFrame( false );
        pEdit->setAlignment( Qt::AlignCenter );

        QFont font = pEdit->font();
        font.setStyleHint( QFont::Monospace );
        font.setFixedPitch( true );
        pEdit->setFont( font );

        QRegExp rx ( "^(0|[1-9]|[1-9][0-9]|1[0-9][0-9]|2([0-4][0-9]|5[0-5]))$" );
        QValidator *validator = new QRegExpValidator(rx, pEdit);
        pEdit->setValidator( validator );

    }
    setMaximumWidth( 30 * QTUTL_IP_SIZE );
    setMaximumHeight(25);
    connect( this, SIGNAL(signalTextChanged(QLineEdit*)),
             this, SLOT(slotTextChanged(QLineEdit*)),
             Qt::QueuedConnection );
    for(int i=0;i<QTUTL_IP_SIZE;i++)
    {
        connect(m_pLineEdit[i],SIGNAL(textChanged(QString)),this,SLOT(lineEditChanged()));
    }
}

IPCtrl::~IPCtrl()
{
    delete [] *pDot;
    delete [] *m_pLineEdit;
}


void IPCtrl::lineEditChanged()
{
    QLineEdit* pEdit = qobject_cast<QLineEdit*>(sender());
    for ( unsigned int i = 0; i != QTUTL_IP_SIZE; ++i )
    {
        if(pEdit==m_pLineEdit[i])
        {
           if(pEdit->text().size() == MAX_DIGITS&&pEdit->text().size() == pEdit->cursorPosition() )
           {
               if ( i+1 != QTUTL_IP_SIZE )
               {
                  m_pLineEdit[i+1]->setFocus();
                  m_pLineEdit[i+1]->selectAll();
               }
           }
        }
    }
}
void IPCtrl::slotTextChanged( QLineEdit* pEdit )
{
    for ( unsigned int i = 0; i != QTUTL_IP_SIZE; ++i )
    {
        if ( pEdit == m_pLineEdit[i] )
        {
            if ( ( pEdit->text().size() == MAX_DIGITS &&  pEdit->text().size() == pEdit->cursorPosition() ) || ( pEdit->text() == "0") )
            {
                if ( i+1 != QTUTL_IP_SIZE )
                {
                   m_pLineEdit[i+1]->setFocus();
                   m_pLineEdit[i+1]->selectAll();
                }
            }
        }
    }
}

bool IPCtrl::eventFilter(QObject *obj, QEvent *event)
{
    bool bRes = QFrame::eventFilter(obj, event);

    if ( event->type() == QEvent::KeyPress )
    {
        QKeyEvent* pEvent = dynamic_cast<QKeyEvent*>( event );
        if ( pEvent )
        {
            for ( unsigned int i = 0; i != QTUTL_IP_SIZE; ++i )
            {
                QLineEdit* pEdit = m_pLineEdit[i];
                if ( pEdit == obj )
                {
                    switch ( pEvent->key() )
                    {
                    case Qt::Key_Left:
                        if ( pEdit->cursorPosition() == 0 )
                        {
                            // user wants to move to previous item
                            MovePrevLineEdit(i);
                        }
                        break;

                    case Qt::Key_Right:
                        if ( pEdit->text().isEmpty() || (pEdit->text().size() == pEdit->cursorPosition()) )
                        {
                            // user wants to move to next item
                            MoveNextLineEdit(i);
                        }
                        break;

                    case Qt::Key_0:
                        if ( pEdit->text().isEmpty() || pEdit->text() == "0" )
                        {
                            pEdit->setText("0");
                            // user wants to move to next item
                            MoveNextLineEdit(i);
                        }
                        emit signalTextChanged( pEdit );
                        break;

                    case Qt::Key_Backspace:
                        if ( pEdit->text().isEmpty() || pEdit->cursorPosition() == 0)
                        {
                            // user wants to move to previous item
                            MovePrevLineEdit(i);
                        }
                        break;

                    case Qt::Key_Comma:
                    case Qt::Key_Period:
                        MoveNextLineEdit(i);
                        break;

                    default:
                        emit signalTextChanged( pEdit );
                        break;

                    }
                }
            }
        }
    }

    return bRes;
}

void IPCtrl::MoveNextLineEdit(int i)
{
    if ( i+1 != QTUTL_IP_SIZE )
    {
        m_pLineEdit[i+1]->setFocus();
        m_pLineEdit[i+1]->setCursorPosition( 0 );
        m_pLineEdit[i+1]->selectAll();
    }
}

void IPCtrl::MovePrevLineEdit(int i)
{
    if ( i != 0 )
    {
        m_pLineEdit[i-1]->setFocus();
        m_pLineEdit[i-1]->setCursorPosition( m_pLineEdit[i-1]->text().size() );
    }
}

bool IPCtrl::getIP(QHostAddress *haddr)
{
    QString ip_str;
    ip_str.clear();
    for(int i=0;i<QTUTL_IP_SIZE;i++)
    {
        if(i!=0)
            ip_str.append(".");
        if(m_pLineEdit[i]->text().isEmpty())
        {
           QMessageBox::warning(NULL, tr("warning"), tr("IP setting error"));
           return false;
        }

        ip_str.append(m_pLineEdit[i]->text());
    }
    qDebug()<<ip_str;
    *haddr=QHostAddress(ip_str);
    return true;
}