File indexing completed on 2024-04-21 05:51:27

 /*
     SPDX-FileCopyrightText: 2015 Lindsay Roberts <os@lindsayr.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #ifndef SCROLLSTATE_H
 #define SCROLLSTATE_H
 
 class QWheelEvent;
 
 namespace Konsole
 {
 /**
  * Represents accumulation of wheel scroll from scroll events.
  *
  * Modern high precision scroll events supply many smaller events
  * that may or may not translate into a UI action to support smooth
  * pixel level scrolling. Builtin classes such as QScrollBar
  * support these events under Qt5, but custom code
  * written to handle scroll events in other ways must be modified
  * to accumulate small deltas and act when suitable thresholds have
  * been reached (ideally 1 for pixel scroll values towards any action
  * that can be mapped to a pixel movement).
  */
 struct ScrollState {
     enum {
         DEFAULT_ANGLE_SCROLL_LINE = 120,
     };
     enum {
         DEGREES_PER_ANGLE_UNIT = 8,
     };
     static inline int degreesToAngle(const int angle)
     {
         return angle * DEGREES_PER_ANGLE_UNIT;
     }
 
     int angle() const
     {
         return _remainingScrollAngle;
     }
 
     int pixel() const
     {
         return _remainingScrollPixel;
     }
 
     /** Add scroll values from a QWheelEvent to the accumulated totals */
     void addWheelEvent(const QWheelEvent *wheel);
 
     /** Clear all - used when scroll is consumed by another class like QScrollBar */
     void clearAll();
     /** Return the (signed) multiple of @p stepsize available and subtract it from
      * accumulated totals. Also clears accumulated pixel scroll. */
     int consumeLegacySteps(int stepsize);
     /** Return the (signed) multiple of @p pixelStepSize if any pixel scroll is
      * available - that is, if pixel scroll is being supplied, or the same from
      * the @p angleStepSize else. The corresponding value is subtracted from
      * the accumulated total. The other scroll style value is cleared. */
     int consumeSteps(int pixelStepSize, int angleStepSize);
 
     ScrollState()
         : _remainingScrollAngle(0)
         , _remainingScrollPixel(0)
     {
     }
 
     int _remainingScrollAngle;
     int _remainingScrollPixel;
 };
 }
 
 #endif // SCROLLSTATE_H