Qt 5.11 | Qt Widgets | Easing Curves Example | animation.h Example File

Qt 5.11.3 Reference Documentation

# animation.h Example File

animation/easing/animation.h

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      #ifndef ANIMATION_H
      #define ANIMATION_H

      #include <QtWidgets>

      #include <QtCore/qpropertyanimation.h>

      class Animation : public QPropertyAnimation {
      public:
          enum PathType {
              LinearPath,
              CirclePath,
              NPathTypes
          };
          Animation(QObject *target, const QByteArray &prop)
              : QPropertyAnimation(target, prop)
          {
              setPathType(LinearPath);
          }

          void setPathType(PathType pathType)
          {
              if (pathType >= NPathTypes)
                  qWarning("Unknown pathType %d", pathType);

              m_pathType = pathType;
              m_path = QPainterPath();
          }

          void updateCurrentTime(int currentTime) override
          {
              if (m_pathType == CirclePath) {
                  if (m_path.isEmpty()) {
                      QPointF to = endValue().toPointF();
                      QPointF from = startValue().toPointF();
                      m_path.moveTo(from);
                      m_path.addEllipse(QRectF(from, to));
                  }
                  int dura = duration();
                  const qreal progress = ((dura == 0) ? 1 : ((((currentTime - 1) % dura) + 1) / qreal(dura)));

                  qreal easedProgress = easingCurve().valueForProgress(progress);
                  if (easedProgress > 1.0) {
                      easedProgress -= 1.0;
                  } else if (easedProgress < 0) {
                      easedProgress += 1.0;
                  }
                  QPointF pt = m_path.pointAtPercent(easedProgress);
                  updateCurrentValue(pt);
                  emit valueChanged(pt);
              } else {
                  QPropertyAnimation::updateCurrentTime(currentTime);
              }
          }

          QPainterPath m_path;
          PathType m_pathType;
      };

      #endif // ANIMATION_H