File indexing completed on 2025-04-27 03:58:24

 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 2010-04-30
  * Description : Image zoom settings
  *
  * SPDX-FileCopyrightText: 2010-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 #ifndef DIGIKAM_IMAGE_ZOOM_SETTINGS_H
 #define DIGIKAM_IMAGE_ZOOM_SETTINGS_H
 
 // Qt includes
 
 #include <QSizeF>
 #include <QRectF>
 #include <QPointF>
 #include <QWidget>
 
 // Local includes
 
 #include "digikam_export.h"
 
 namespace Digikam
 {
 
 class DIGIKAM_EXPORT ImageZoomSettings
 {
 
 public:
 
     enum FitToSizeMode
     {
         AlwaysFit,
         OnlyScaleDown
     };
 
 public:
 
     ImageZoomSettings();
     explicit ImageZoomSettings(const QSize& imageSize, const QSize& originalSize = QSize());
 
     /**
      * Sets the size of the (available) image data.
      * Optionally, you can specify an original size, if the available image
      * data is a scaled-down version. In this case, zoom factors will refer
      * to the original size.
      * The zoom factor is unchanged, you need to call fitToSize again.
      */
     void setImageSize(const QSize& size, const QSize& originalSize = QSize());
 
     /**
      * Set the graphics view widget to track the device pixel ratio.
      */
     void setDisplayWidget(QWidget* const widget);
 
     /**
      * Return the currently set zoom factor
      */
     double zoomFactor()                                                             const;
 
     /**
      * Return the real zoom factor dependent on device pixel ratio
      */
     double realZoomFactor()                                                         const;
 
     /**
      * Returns the (available) image size
      */
     QSizeF imageSize()                                                              const;
 
     /**
      * Return the original image size. Can be identical to size().
      */
     QSizeF originalImageSize()                                                      const;
 
     /**
      * Return the size of the image when the current zoom factor is applied.
      * This is the size the image should be displayed at.
      */
     QSizeF zoomedSize()                                                             const;
 
     bool isFitToSize(const QSizeF& frameSize)                                       const;
 
     /**
      * Sets the current zoom factor, relative to (original) size.
      */
     void setZoomFactor(double zoom);
 
     /**
      * Sets the current zoom factor to the factor needed to fit
      * the current (original) image size into the given view size.
      * Aspect ratio will be respected, that means the frameSize may not be
      * completely filled in one dimension, and zoomedSize()
      * can differ from frameSize in one dimension.
      */
     void fitToSize(const QSizeF& frameSize, FitToSizeMode = AlwaysFit);
 
     /**
      * For a given rectangle contained in ((0,0), zoomedSize())
      * returns the corresponding rectangle in (0,0),imageSize().
      */
     QRectF sourceRect(const QRectF& imageRect)                                      const;
 
     QRectF mapZoomToImage(const QRectF& imageRect)                                  const;
 
     /**
      * For a given rect contained in ((0,0), imageSize())
      * returns the corresponding rectangle in (0,0),zoomedSize().
      */
     QRectF mapImageToZoom(const QRectF& imagePoint)                                 const;
 
     /**
      * For a given point (in (0,0), zoomedSize())
      * returns the corresponding point in (0,0),imageSize().
      */
     QPointF mapZoomToImage(const QPointF& zoomedPoint)                              const;
 
     /**
      * For a given point (in (0,0), imageSize())
      * returns the corresponding point in (0,0),zoomedSize().
      */
     QPointF mapImageToZoom(const QPointF& imagePoint)                               const;
 
     /**
      * Returns the zoom factor that would be used by fitToSize()
      * called with the given frameSize.
      */
     double fitToSizeZoomFactor(const QSizeF& frameSize, FitToSizeMode = AlwaysFit)  const;
 
     /**
      * When changing the zoom from current zoom to given nextZoom,
      * sometimes a special value may be crossed, and this could then be used
      * instead of nextZoom. Returns this special zoom, or nextZoom if not applicable.
      */
     double snappedZoomStep(double nextZoom, const QSizeF& frameSize)                const;
 
     /**
      * When setting a new zoom factor (absolute value), the new value may be
      * very close to a special value. Returns this special value if this is the case,
      * returns newZoom if not applicable.
      */
     double snappedZoomFactor(double newZoom, const QSizeF& frameSize)               const;
 
 private:
 
     double displayRatio()                                                           const;
 
 protected:
 
     QSizeF   m_size;
     double   m_zoom;
     double   m_zoomConst;
 
     QWidget* m_displayWidget;
 };
 
 } // namespace Digikam
 
 #endif // DIGIKAM_IMAGE_ZOOM_SETTINGS_H