main.cpp Example File

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  #include <QtGui>

  #include "rasterwindow.h"

  class AnalogClockWindow : public RasterWindow
  {
  public:
      AnalogClockWindow();

  protected:
      void timerEvent(QTimerEvent *) override;
      void render(QPainter *p) override;

  private:
      int m_timerId;
  };

  AnalogClockWindow::AnalogClockWindow()
  {
      setTitle("Analog Clock");
      resize(200, 200);

      m_timerId = startTimer(1000);
  }

  void AnalogClockWindow::timerEvent(QTimerEvent *event)
  {
      if (event->timerId() == m_timerId)
          renderLater();
  }

  void AnalogClockWindow::render(QPainter *p)
  {
      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);

      p->setRenderHint(QPainter::Antialiasing);
      p->translate(width() / 2, height() / 2);

      int side = qMin(width(), height());
      p->scale(side / 200.0, side / 200.0);

      p->setPen(Qt::NoPen);
      p->setBrush(hourColor);

      QTime time = QTime::currentTime();

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

      p->setPen(hourColor);

      for (int i = 0; i < 12; ++i) {
          p->drawLine(88, 0, 96, 0);
          p->rotate(30.0);
      }
      p->setPen(Qt::NoPen);
      p->setBrush(minuteColor);

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

      p->setPen(minuteColor);

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

  int main(int argc, char **argv)
  {
      QGuiApplication app(argc, argv);

      AnalogClockWindow clock;
      clock.show();

      return app.exec();
  }