File indexing completed on 2024-05-12 05:47:31

 /*
  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef KITEMLISTSMOOTHSCROLLER_H
 #define KITEMLISTSMOOTHSCROLLER_H
 
 #include "dolphin_export.h"
 
 #include <QAbstractAnimation>
 #include <QObject>
 
 class QPropertyAnimation;
 class QScrollBar;
 class QWheelEvent;
 
 /**
  * @brief Helper class for KItemListContainer to have a smooth
  *        scrolling when adjusting the scrollbars.
  */
 class DOLPHIN_EXPORT KItemListSmoothScroller : public QObject
 {
     Q_OBJECT
 
 public:
     explicit KItemListSmoothScroller(QScrollBar *scrollBar, QObject *parent = nullptr);
     ~KItemListSmoothScroller() override;
 
     void setScrollBar(QScrollBar *scrollBar);
     QScrollBar *scrollBar() const;
 
     void setTargetObject(QObject *target);
     QObject *targetObject() const;
 
     void setPropertyName(const QByteArray &propertyName);
     QByteArray propertyName() const;
 
     /**
      * Adjusts the position of the target by \p distance
      * pixels. Is invoked in the context of QAbstractScrollArea::scrollContentsBy()
      * where the scrollbars already have the new position but the content
      * has not been scrolled yet.
      */
     void scrollContentsBy(qreal distance);
 
     /**
      * Does a smooth-scrolling to the position \p position
      * on the target and also adjusts the corresponding scrollbar
      * to the new position.
      */
     void scrollTo(qreal position);
 
     /**
      * Must be invoked before the scrollbar should get updated to have a new
      * maximum. True is returned if the new maximum can be applied. If false
      * is returned the maximum has already been reached and the value will
      * be reached at the end of the animation.
      */
     // TODO: This interface is tricky to understand. Try to make this more
     // generic/readable if the corresponding code in KItemListContainer got
     // stable.
     bool requestScrollBarUpdate(int newMaximum);
 
     /**
      * Forwards wheel events to the scrollbar, ensuring smooth and proper scrolling
      */
     void handleWheelEvent(QWheelEvent *event);
 
 Q_SIGNALS:
     /**
      * Emitted when the scrolling animation has finished
      */
     void scrollingStopped();
 
 protected:
     bool eventFilter(QObject *obj, QEvent *event) override;
 
 private Q_SLOTS:
     void slotAnimationStateChanged(QAbstractAnimation::State newState, QAbstractAnimation::State oldState);
 
 private:
     bool m_scrollBarPressed;
     bool m_smoothScrolling;
     QScrollBar *m_scrollBar;
     QPropertyAnimation *m_animation;
 };
 
 #endif