QT 字幕滚动(左右滚动)

// 这里我就已一句话为例，如果存在什么换行之类的请参考 “QT 字幕滚动(上下滚动)” 进行处理
// 这里我就贴上代码，具体就不详细说明

----------------------------- HScrolllabel.h---------------------------------

#ifndef HSCROLLLABEL_H
#define HSCROLLLABEL_H
#include <QLabel>

class HScrollLabel : public QLabel
{
    Q_OBJECT
public:
    explicit HScrollLabel(QWidget *parent = 0, Qt::WindowFlags f=0);
    virtual ~HScrollLabel(){}

public slots:
    void setText(const QString &);

signals:
     void currentTextChanged();

protected:
    void showEvent(QShowEvent *);
    void paintEvent(QPaintEvent *);
    void timerEvent(QTimerEvent *);
    void hideEvent(QHideEvent *);

private slots:
    void metrics();
    void startScroll();

private:
    int getWidth();

private:
    int offset;
    int timerID;
    int textWidth;
    bool flag;
};


#endif // HSCOLLLABEL_H

----------------------------- HScrolllabel.cpp---------------------------------
#include "hscrolllabel.h"
#include <QPainter>
#include <QTimerEvent>
#include <QTimer>

HScrollLabel::HScrollLabel(QWidget *parent, Qt::WindowFlags f) :
  QLabel(parent,f)
{
flag = false;
offset = timerID = textWidth = 0;
connect(this, SIGNAL(currentTextChanged()), SLOT(metrics()));
}

void HScrollLabel::setText(const QString &curText)
{
if (text() != curText) {
QLabel::setText(curText);
QLabel::setAlignment(Qt::AlignCenter);
emit currentTextChanged();
}
}

void HScrollLabel::startScroll()
{
        timerID = startTimer(50);
}

void HScrollLabel::metrics()
{ 
flag = false;
offset = 0;
  textWidth = 0;

        if(getWidth() < width())
return;

flag = true;
         textWidth = getWidth() +width();
QTimer::singleShot(500, this, SLOT(startScroll()));
}

int HScrollLabel::getWidth()
{
    int fm_width = fontMetrics().width(text());
return  fm_width;
}

void HScrollLabel::showEvent(QShowEvent *)
{
         metrics();
}

void HScrollLabel::paintEvent(QPaintEvent *event)
{
QPainter painter(this);
//if (textWidth < 1) return;

if(!flag)
{
painter.drawText(0, 0, width(), height() ,
  Qt::AlignHCenter | Qt::AlignVCenter, text());
return;
}

int x = -offset ;
while (x < width()) {
painter.drawText(x, 0, textWidth, height() ,
Qt::AlignHCenter | Qt::AlignVCenter, text());
x += textWidth;
}
}

void HScrollLabel::timerEvent(QTimerEvent *event)
{
if (event->timerId() == timerID) {
++offset;
if (offset >= textWidth) 
offset = 0;
scroll(-3, 0);            // 这里是从右向左滚动
} else {
QWidget::timerEvent(event);
}
}

void HScrollLabel::hideEvent(QHideEvent *)
{
offset = 0;
if (timerID) killTimer(timerID);

}