/*
 * @RDE_HEADER@
 * graphicsview widget to resize qpixmaps/qimages with mouse drag and mwheel
 * $Id$
 * $HeadURL$
 * $Author$
 * Created by Jens Heilmann, SLTE, 2020-10-14
 */

#pragma once

#include "lts_widgets_export.h"
#include <QGraphicsView>

namespace LtsWidgets
{

/**
 * @brief The ImageCropper class provides a graphicsview widget to crop images with mouse drag and mwheel scroll.
 *        avatar() returns a pixmap of the current view (the cropped image).
 */
class LTSWIDGETS_EXPORT LtsImageCropper : public QGraphicsView
{

  Q_OBJECT

  Q_PROPERTY(QPixmap  pixMap     READ pixmap     WRITE setPixmap)
  Q_PROPERTY(double   multiplier READ multiplier WRITE setMultiplier)
  Q_PROPERTY(double   maxZoom    READ maxZoom    WRITE setMaxZoom)

public:
  /**
    * @brief ImageCropper
    * @param parent
    * @param size specifies the size of the graphicsview widget, aswell as the size of the cropped image.
    * @param image to crop
    */
  LtsImageCropper(QWidget *parent = nullptr, const QSize &size = {} , const QPixmap &pixmap = {});
  ~LtsImageCropper();

  /**
   * @brief setter for image
   * @param image
   */
  void setPixmap(const QPixmap &pixmap);

  /**
   * @brief setter for image
   * @param image
   */
  void setImage(const QImage &image);

  /**
   * @brief set the zoom mutliplier for mwheel scaling e.g. 1.03.
   * @param multiplier
   */
  void setMultiplier(double multiplier);

  /**
   * @brief set the maximum zoom in scale e.g. 2.0 = 200% zoom in.
   * @param maxZoom
   */
  void setMaxZoom(double maxZoom) { m_maxScale = maxZoom; }

  /**
   * @brief returns the current graphicsview view as a pixmap.
   * @return qpixmap
   */
  QPixmap pixmap() { return grab(); }

  /**
   * @brief returns the current graphicsview view as qimage.
   * @return qimage
   */
  QImage  image();

  /**
   * @brief returns the current multiplier
   * @return double
   */
  double multiplier() const { return m_multiplier; }

  /**
   * @brief returns the current max zoom value
   * @return double
   */
  double maxZoom() const { return m_maxScale; }

private:
  QGraphicsScene      *m_scene = nullptr;
  QGraphicsPixmapItem *m_pixmapItem = nullptr;

  double m_currentZoom;
  double m_minScale;
  double m_maxScale;
  double m_stepScale;
  double m_multiplier;

  void calculateScaleStep();

protected:
  void wheelEvent(QWheelEvent *event) override;
  void mousePressEvent(QMouseEvent *event) override;
  void mouseReleaseEvent(QMouseEvent *event) override;

};

} // namespace LtsWidgets