Qt-LCD电子时钟

#ifndef DIGICLOCK_H
#define DIGICLOCK_H
#include <QObject>
#include <QLCDNumber>
class DigiClock : public QLCDNumber
{
    Q_OBJECT
public:
    DigiClock(QWidget *parent = 0);
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
private slots:
    void showTime();
private:
    QPoint dragPosition;
    bool showColon;
};
#endif // DIGICLOCK_H

#include "digiclock.h"
#include <QTime>
#include <QTimer>
#include <QMouseEvent>
#include <QString>
DigiClock::DigiClock(QWidget *parent) : QLCDNumber(parent)
{
    QPalette p = palette();
    p.setColor(QPalette::Window,Qt::blue);
    setPalette(p);
    setWindowFlags(Qt::FramelessWindowHint);
    setWindowOpacity(0.5);
    QTimer *timer = new QTimer(this);
    connect(timer,SIGNAL(timeout()),this,SLOT(showTime()));
    timer->start(1000);
    showTime();
    resize(150,60);
    showColon = true;
}
void DigiClock::mousePressEvent(QMouseEvent *event)
{
    if(event->button() == Qt::LeftButton)
    {
        dragPosition = event->globalPos()-frameGeometry().topLeft();
        event->accept();
    }
    if(event->button() == Qt::RightButton)
    {
        close();
    }
}
void DigiClock::mouseMoveEvent(QMouseEvent *event)
{
    if(event->buttons() & Qt::LeftButton)
    {
        move(event->globalPos() - dragPosition);
        event->accept();
    }
}
void DigiClock::showTime()
{
    QTime time = QTime::currentTime();
    QString text = time.toString("hh:mm");
    if(showColon)
    {
        text[2] = ':';
        showColon = false;
    }
    else
    {
        text[2] = ' ';
        showColon = true;
    }
    display(text);
}