kis_zoom_scrollbar.h

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/*
 *  SPDX-FileCopyrightText: 2020 Eoin O 'Neill <eoinoneill1991@gmail.com>
 *  SPDX-FileCopyrightText: 2020 Emmet O 'Neill <emmetoneill.pdx@gmail.com>
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 
#ifndef KIS_ZOOM_SCROLLBAR_H
#define KIS_ZOOM_SCROLLBAR_H
 
#include <QScrollBar>
#include <QVector2D>
 
#include <kritaui_export.h>
 
class KRITAUI_EXPORT KisZoomableScrollBar : public QScrollBar
{
    Q_OBJECT
 
public:
    KisZoomableScrollBar(QWidget* parent = 0);
    KisZoomableScrollBar(Qt::Orientation orientation, QWidget * parent = 0);
    ~KisZoomableScrollBar();
 
    QPoint barPosition();
 
    //Catch for teleportation from one side of the screen to the other.
    bool catchTeleports(QMouseEvent* event);
 
    //Window-space wrapping for mouse dragging. Allows for blender-like
    //infinite mouse scrolls.
    void handleWrap(const QPoint &accel, const QPoint &globalMouseCoord);
 
    //Scroll based on a mouse acceleration value.
    void handleScroll(const QPoint &accel);
 
    void tabletEvent(QTabletEvent *event) override;
    virtual void mousePressEvent(QMouseEvent *event) override;
    virtual void mouseMoveEvent(QMouseEvent *event) override;
    virtual void mouseReleaseEvent(QMouseEvent *event) override;
 
    virtual void wheelEvent(QWheelEvent *event) override;
 
    void setZoomDeadzone(float value);
    void setWheelOverscrollSensitivity(float sensitivity);
 
Q_SIGNALS:
    void zoom(qreal delta);
    void overscroll(qreal delta);
 
private:
    QPoint initialPositionRelativeToBar;
    QPoint lastKnownPosition;
    QVector2D accelerationAccumulator;
    qreal scrollSubPixelAccumulator;
    qreal zoomThreshold;
    qreal wheelOverscrollSensitivity;
    bool catchTeleportCorrection = false;
    bool zoomEnabled = true;
};
 
#endif // KIS_ZOOM_SCROLLBAR_H