main.cpp Example File

  /****************************************************************************
  **
  ** 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 <QGuiApplication>
  #include <QQmlApplicationEngine>
  #include <QQmlContext>
  #include <QObject>
  #include <QTime>
  #include <QBasicTimer>
  #include <QDebug>
  #include <QEasingCurve>
  #include <QGeoCoordinate>
  #include <QtPositioning/private/qgeoprojection_p.h>

  #define ANIMATION_DURATION 4000

  class PlaneController: public QObject
  {
      Q_OBJECT
      Q_PROPERTY(QGeoCoordinate position READ position WRITE setPosition NOTIFY positionChanged)
      Q_PROPERTY(QGeoCoordinate from READ from WRITE setFrom NOTIFY fromChanged)
      Q_PROPERTY(QGeoCoordinate to READ to WRITE setTo NOTIFY toChanged)

  public:
      PlaneController()
      {
          easingCurve.setType(QEasingCurve::InOutQuad);
          easingCurve.setPeriod(ANIMATION_DURATION);
      }

      void setFrom(const QGeoCoordinate& from)
      {
          fromCoordinate = from;
      }

      QGeoCoordinate from() const
      {
          return fromCoordinate;
      }

      void setTo(const QGeoCoordinate& to)
      {
          toCoordinate = to;
      }

      QGeoCoordinate to() const
      {
          return toCoordinate;
      }

      void setPosition(const QGeoCoordinate &c) {
          if (currentPosition == c)
              return;

          currentPosition = c;
          emit positionChanged();
      }

      QGeoCoordinate position() const
      {
          return currentPosition;
      }

      Q_INVOKABLE bool isFlying() const {
          return timer.isActive();
      }

  public slots:
      void startFlight()
      {
          if (timer.isActive())
              return;

          startTime = QTime::currentTime();
          finishTime = startTime.addMSecs(ANIMATION_DURATION);

          timer.start(15, this);
          emit departed();
      }

      void swapDestinations() {
          if (currentPosition == toCoordinate) {
              // swap destinations
              toCoordinate = fromCoordinate;
              fromCoordinate = currentPosition;
          }
      }

  signals:
      void positionChanged();
      void arrived();
      void departed();
      void toChanged();
      void fromChanged();

  protected:
      void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE
      {
          if (!event)
              return;

          if (event->timerId() == timer.timerId())
              updatePosition();
          else
              QObject::timerEvent(event);
      }

  private:
      void updatePosition()
      {
          // simple progress animation
          qreal progress;
          QTime current = QTime::currentTime();
          if (current >= finishTime) {
              progress = 1.0;
              timer.stop();
          } else {
              progress = ((qreal)startTime.msecsTo(current) / ANIMATION_DURATION);
          }

          setPosition(QGeoProjection::coordinateInterpolation(
                            fromCoordinate, toCoordinate, easingCurve.valueForProgress(progress)));

          if (!timer.isActive())
              emit arrived();
      }

  private:
      QGeoCoordinate currentPosition;
      QGeoCoordinate fromCoordinate, toCoordinate;
      QBasicTimer timer;
      QTime startTime, finishTime;
      QEasingCurve easingCurve;
      // ...
  };

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

      PlaneController oslo2berlin;
      PlaneController berlin2london;

      QQmlApplicationEngine engine;
      engine.rootContext()->setContextProperty("oslo2Berlin", &oslo2berlin);
      engine.rootContext()->setContextProperty("berlin2London", &berlin2london);
      engine.load(QUrl(QStringLiteral("qrc:/planespotter.qml")));

      return app.exec();
  }

  #include "main.moc"