A Stopwatch in qt GUI ?

[Santosh Reddy]

Did you take the corrected code from my previous post.

Anyway here it is again

class StopWatch : public QWidget
{
    Q_OBJECT
public:
    explicit StopWatch(QWidget * parent = 0)
        : QWidget(parent)
        , mRunning(false)
        , mStartTime()
        , mLabel(new QLabel("00:00:00,000"))
        , mTotalTime(0)
        , mStart(new QPushButton("Start"))
        , mPause(new QPushButton("Pause"))
        , mStop(new QPushButton("Stop"))
    {
        QGridLayout * gridLayout = new QGridLayout(this);
 
        gridLayout->addWidget(mLabel,   0, 0, 1, 3);
        gridLayout->addWidget(mStart,   1, 0, 1, 1);
        gridLayout->addWidget(mPause,   1, 1, 1, 1);
        gridLayout->addWidget(mStop,    1, 2, 1, 1);
 
        connect(mStart, SIGNAL(clicked()), SLOT(start()));
        connect(mPause, SIGNAL(clicked()), SLOT(pause()));
        connect(mStop, SIGNAL(clicked()), SLOT(stop()));
 
        QFont font("Arial", 24, QFont::Bold);
        QPalette palette = mLabel->palette();
        palette.setColor(QPalette::WindowText, Qt::blue);
        mLabel->setPalette(palette);
        mLabel->setFont(font);
        gridLayout->setAlignment(mLabel, Qt::AlignCenter);
 
        mStart->setEnabled(true);
        mPause->setEnabled(false);
        mStop->setEnabled(false);
 
        startTimer(0);
    }
 
public slots:
    void start(void)
    {
        mStartTime = QDateTime::currentDateTime();
        mRunning = true;
        mStart->setEnabled(false);
        mPause->setEnabled(true);
        mStop->setEnabled(true);
    }
 
    void pause(void)
    {
        mStart->setEnabled(true);
        mPause->setEnabled(false);
        mStop->setEnabled(true);
        timerEvent(new QTimerEvent(0));
        mTotalTime += mSessionTime;
        mRunning = false;
    }
 
    void stop(void)
    {
        mStart->setEnabled(true);
        mPause->setEnabled(false);
        mStop->setEnabled(false);
        mTotalTime = 0;
        mRunning = false;
    }
 
protected:
    void timerEvent(QTimerEvent *)
    {
        if(mRunning)
        {
            mSessionTime = mStartTime.msecsTo(QDateTime::currentDateTime());
            qint64 time = mTotalTime + mSessionTime;
            time *= 111;
            unsigned int h = time / 1000 / 60 / 60;
            unsigned int m = (time / 1000 / 60) - (h * 60);
            unsigned int s = (time / 1000) - ((m + (h * 60))* 60);
            unsigned int ms = time - (s + ((m + (h * 60))* 60)) * 1000;
            const QString diff = QString("%1:%2:%3,%4")
                                    .arg(h,  2, 10, QChar('0'))
                                    .arg(m,  2, 10, QChar('0'))
                                    .arg(s,  2, 10, QChar('0'))
                                    .arg(ms, 3, 10, QChar('0'));
            mLabel->setText(diff);
        }
    }
 
private:
    bool        mRunning;
    QDateTime   mStartTime;
    QLabel *    mLabel;
    qint64      mTotalTime;
    qint64      mSessionTime;
 
    QPushButton * mStart;
    QPushButton * mPause;
    QPushButton * mStop;
};

class StopWatch : public QWidget
{
    Q_OBJECT
public:
    explicit StopWatch(QWidget * parent = 0)
        : QWidget(parent)
        , mRunning(false)
        , mStartTime()
        , mLabel(new QLabel("00:00:00,000"))
        , mTotalTime(0)
        , mStart(new QPushButton("Start"))
        , mPause(new QPushButton("Pause"))
        , mStop(new QPushButton("Stop"))
    {
        QGridLayout * gridLayout = new QGridLayout(this);

        gridLayout->addWidget(mLabel,   0, 0, 1, 3);
        gridLayout->addWidget(mStart,   1, 0, 1, 1);
        gridLayout->addWidget(mPause,   1, 1, 1, 1);
        gridLayout->addWidget(mStop,    1, 2, 1, 1);

        connect(mStart, SIGNAL(clicked()), SLOT(start()));
        connect(mPause, SIGNAL(clicked()), SLOT(pause()));
        connect(mStop, SIGNAL(clicked()), SLOT(stop()));

        QFont font("Arial", 24, QFont::Bold);
        QPalette palette = mLabel->palette();
        palette.setColor(QPalette::WindowText, Qt::blue);
        mLabel->setPalette(palette);
        mLabel->setFont(font);
        gridLayout->setAlignment(mLabel, Qt::AlignCenter);

        mStart->setEnabled(true);
        mPause->setEnabled(false);
        mStop->setEnabled(false);

        startTimer(0);
    }

public slots:
    void start(void)
    {
        mStartTime = QDateTime::currentDateTime();
        mRunning = true;
        mStart->setEnabled(false);
        mPause->setEnabled(true);
        mStop->setEnabled(true);
    }

    void pause(void)
    {
        mStart->setEnabled(true);
        mPause->setEnabled(false);
        mStop->setEnabled(true);
        timerEvent(new QTimerEvent(0));
        mTotalTime += mSessionTime;
        mRunning = false;
    }

    void stop(void)
    {
        mStart->setEnabled(true);
        mPause->setEnabled(false);
        mStop->setEnabled(false);
        mTotalTime = 0;
        mRunning = false;
    }

protected:
    void timerEvent(QTimerEvent *)
    {
        if(mRunning)
        {
            mSessionTime = mStartTime.msecsTo(QDateTime::currentDateTime());
            qint64 time = mTotalTime + mSessionTime;
            time *= 111;
            unsigned int h = time / 1000 / 60 / 60;
            unsigned int m = (time / 1000 / 60) - (h * 60);
            unsigned int s = (time / 1000) - ((m + (h * 60))* 60);
            unsigned int ms = time - (s + ((m + (h * 60))* 60)) * 1000;
            const QString diff = QString("%1:%2:%3,%4")
                                    .arg(h,  2, 10, QChar('0'))
                                    .arg(m,  2, 10, QChar('0'))
                                    .arg(s,  2, 10, QChar('0'))
                                    .arg(ms, 3, 10, QChar('0'));
            mLabel->setText(diff);
        }
    }

private:
    bool        mRunning;
    QDateTime   mStartTime;
    QLabel *    mLabel;
    qint64      mTotalTime;
    qint64      mSessionTime;

    QPushButton * mStart;
    QPushButton * mPause;
    QPushButton * mStop;
};

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[020394]

Yea i followed the way you did it , just took away the adding of widget and the ms part . As i am using qt designer to add the buttons . The stopwatch is working perfectly fine just after the 1 hr 30min mark , something went wrong . I will counter check the code . Will update this post if there are still errors

[020394]

Ok , the problem is soved already , It seems that i did not copy the unsigned h part correctly . Thank you so much for the help Santoshb Reddy

[CUTEE]

Hello, Santosh,

sorry to ask this, but how exactly can I get this code to run? I get lots of errors.

I know my question exposes huge deficit in most basic knowledge of the QT environment, however I need a cutom stopwatch next week So I was just googling for some code and found this.

I downloaded QT Creator and made a new project with the wizard, which generated three files: main.cpp, mainwindow.cpp and mainwindow.h

Where do I have to put your code to be able to run it?

Sorry for my ignorance, I will certainly dig deeper in near future, but I need a quick start right now. Yes, I understand what QT is, but I do not have experience in C++ - I speak some C, PHP, Python and web related things, so this is mainly about not understanding the formalities of the environment, I do indeed understand what your code does, but I have no clue how to accomodate the QT Creator to make it executable.

Thanks for your attention!
John