- Qt 5.5
- Qt Widgets
- Shaped Clock Example
- shapedclock.cpp Example File
- Qt 5.5.1 Reference Documentation

# shapedclock.cpp Example File

widgets/shapedclock/shapedclock.cpp

    /****************************************************************************
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    ** This file is part of the examples of the Qt Toolkit.
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    ** $QT_BEGIN_LICENSE:BSD$
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    #include <QtWidgets>

    #include "shapedclock.h"

    ShapedClock::ShapedClock(QWidget *parent)
        : QWidget(parent, Qt::FramelessWindowHint | Qt::WindowSystemMenuHint)
    {
        QTimer *timer = new QTimer(this);
        connect(timer, SIGNAL(timeout()), this, SLOT(update()));
        timer->start(1000);

        QAction *quitAction = new QAction(tr("E&xit"), this);
        quitAction->setShortcut(tr("Ctrl+Q"));
        connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
        addAction(quitAction);

        setContextMenuPolicy(Qt::ActionsContextMenu);
        setToolTip(tr("Drag the clock with the left mouse button.\n"
                      "Use the right mouse button to open a context menu."));
        setWindowTitle(tr("Shaped Analog Clock"));
    }

    void ShapedClock::mousePressEvent(QMouseEvent *event)
    {
        if (event->button() == Qt::LeftButton) {
            dragPosition = event->globalPos() - frameGeometry().topLeft();
            event->accept();
        }
    }

    void ShapedClock::mouseMoveEvent(QMouseEvent *event)
    {
        if (event->buttons() & Qt::LeftButton) {
            move(event->globalPos() - dragPosition);
            event->accept();
        }
    }

    void ShapedClock::paintEvent(QPaintEvent *)
    {
        static const QPoint hourHand[3] = {
            QPoint(7, 8),
            QPoint(-7, 8),
            QPoint(0, -40)
        };
        static const QPoint minuteHand[3] = {
            QPoint(7, 8),
            QPoint(-7, 8),
            QPoint(0, -70)
        };

        QColor hourColor(127, 0, 127);
        QColor minuteColor(0, 127, 127, 191);

        int side = qMin(width(), height());
        QTime time = QTime::currentTime();

        QPainter painter(this);
        painter.setRenderHint(QPainter::Antialiasing);
        painter.translate(width() / 2, height() / 2);
        painter.scale(side / 200.0, side / 200.0);

        painter.setPen(Qt::NoPen);
        painter.setBrush(hourColor);

        painter.save();
        painter.rotate(30.0 * ((time.hour() + time.minute() / 60.0)));
        painter.drawConvexPolygon(hourHand, 3);
        painter.restore();

        painter.setPen(hourColor);

        for (int i = 0; i < 12; ++i) {
            painter.drawLine(88, 0, 96, 0);
            painter.rotate(30.0);
        }

        painter.setPen(Qt::NoPen);
        painter.setBrush(minuteColor);

        painter.save();
        painter.rotate(6.0 * (time.minute() + time.second() / 60.0));
        painter.drawConvexPolygon(minuteHand, 3);
        painter.restore();

        painter.setPen(minuteColor);

        for (int j = 0; j < 60; ++j) {
            if ((j % 5) != 0)
                painter.drawLine(92, 0, 96, 0);
            painter.rotate(6.0);
        }
    }

    void ShapedClock::resizeEvent(QResizeEvent * /* event */)
    {
        int side = qMin(width(), height());
        QRegion maskedRegion(width() / 2 - side / 2, height() / 2 - side / 2, side,
                             side, QRegion::Ellipse);
        setMask(maskedRegion);
    }

    QSize ShapedClock::sizeHint() const
    {
        return QSize(100, 100);
    }