main.cpp Example File | Qt GUI 5.6

Qt 5.6 | Qt GUI | Analog Clock Window Example | main.cpp Example File

Qt 5.6.2 Reference Documentation

# main.cpp Example File

analogclock/main.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** You may use this file under the terms of the BSD license as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #include <QtGui>

      #include "rasterwindow.h"

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

      protected:
          void timerEvent(QTimerEvent *) Q_DECL_OVERRIDE;
          void render(QPainter *p) Q_DECL_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();
      }