hled.cpp Example File

    #include <QtGui>
    #include "hled.h"

    struct HLed::Private
    {
    public:
        Private()
            : darkerFactor(300), color(Qt::green), isOn(true)
        { }

        int darkerFactor;
        QColor color;
        bool isOn;
    };

    HLed::HLed(QWidget *parent)
        :QWidget(parent), m_d(new Private)
    {
    }

    HLed::~HLed()
    {
        delete m_d;
    }

    QColor HLed::color() const
    {
        return m_d->color;
    }

    void HLed::setColor(const QColor &color)
    {
        if (m_d->color == color)
            return;
        update();
    }

    QSize HLed::sizeHint() const
    {
        return QSize(20, 20);
    }

    QSize HLed::minimumSizeHint() const
    {
        return QSize(16, 16);
    }

    void HLed::toggle()
    {
        m_d->isOn = !m_d->isOn;
        update();
    }

    void HLed::turnOn(bool on)
    {
        m_d->isOn = on;
        update();
    }

    void HLed::turnOff(bool off)
    {
        turnOn(!off);
    }

    void HLed::paintEvent(QPaintEvent * /*event*/)
    {
        int width = ledWidth();

        QPainter painter(this);
        painter.setRenderHint(QPainter::Antialiasing);

        QColor color = m_d->isOn ? m_d->color
                                 : m_d->color.darker(m_d->darkerFactor);

        QBrush brush;
        brush.setStyle(Qt::SolidPattern);
        brush.setColor(color);
        painter.setBrush(brush);
        // draw plain
        painter.drawEllipse(1, 1, width-1, width-1);

        QPen pen;
        pen.setWidth(2);

        int pos = width / 5 + 1;
        int lightWidth = width * 2 / 3;
        int lightQuote = 130 * 2 / (lightWidth ? lightWidth : 1) + 100;

        // draw bright spot
        while (lightWidth) {
            color = color.lighter(lightQuote);
            pen.setColor(color);
            painter.setPen(pen);
            painter.drawEllipse(pos, pos, lightWidth, lightWidth);
            lightWidth--;

            if (!lightWidth)
                break;

            painter.drawEllipse(pos, pos, lightWidth, lightWidth);
            lightWidth--;

            if (!lightWidth)
                break;

            painter.drawEllipse(pos, pos, lightWidth, lightWidth);
            pos++;
            lightWidth--;
        }

        //draw border
        painter.setBrush(Qt::NoBrush);

        int angle = -720;
        color = palette().color(QPalette::Light);

        for (int arc=120; arc<2880; arc+=240) {
            pen.setColor(color);
            painter.setPen(pen);
            int w = width - pen.width()/2;
            painter.drawArc(pen.width()/2, pen.width()/2, w, w, angle+arc, 240);
            painter.drawArc(pen.width()/2, pen.width()/2, w, w, angle-arc, 240);
            color = color.darker(110);
        }
    }

    int HLed::ledWidth() const
    {
        int width = qMin(this->width(), this->height());
        width -= 2;
        return width > 0 ? width : 0;
    }