imagewidget.h

/***********************************************************************
* FILENAME :    imagewidget.h
*
* LICENSE:
*       qcvTouchUp provides an image processing toolset for editing
*       photographs, purposed and packaged for use in a desktop application 
*       user environment. Copyright (C) 2018,  Matthew R. Miller
*
*       This program is free software: you can redistribute it and/or modify
*       it under the terms of the GNU General Public License as published by 
*       the Free Software Foundation (version 3 of the License) and the 
*       3-clause BSD License as agreed upon through the use of the Qt toolkit
*       and OpenCV libraries in qcvTouchUp development, respectively. Copies
*       of the appropriate license files for qcvTouchup, and its source code,
*       can be found in LICENSE.Qt.txt and LICENSE.CV.txt.
*
*       This program is distributed in the hope that it will be useful,
*       but WITHOUT ANY WARRANTY; without even the implied warranty of
*       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*       GNU General Public License for more details.
*
*       You should have received a copy of the GNU General Public License and
*       3-clause BSD License along with this program.  If not, please see 
*       <http://www.gnu.org/licenses/> and <https://opencv.org/license.html>.
*    
*       If you wish to contact the developer about this project, please do so
*       through their account at <https://github.com/mattrussmill>
*
* DESCRIPTION :
*       This widget creates a scrollable area in which a QImage can be
*       viewed and resized without distortion. The area can also return
*       a selected point from within the image (scaled appropriately)
*       to be used in selecting colors within the displayed image.
*
* NOTES :
*       QWidget was subclassed to ImageWidget instead of QScrollArea so
*       that most of the QScrollArea members remain encapsulated and
*       private.
*
* AUTHOR :  Matthew R. Miller       START DATE :    January 7, 2018
*
* CHANGES : N/A - N/A
*
* VERSION       DATE            WHO                     DETAIL
* 0.1           01/22/2018      Matthew R. Miller       Initial Rev
* 0.2           06/23/2018      Matthew R. Miller       Drag and Drop Open
* 0.3           10/26/2018      Matthew R. Miller       Pixel Selection Added
* 0.4           12/17/2018      Matthew R. Miller       ROI Selection Added
************************************************************************/

#ifndef IMAGEWIDGET_H
#define IMAGEWIDGET_H

#include <QWidget>
#include <opencv2/core/core.hpp>
class QLabel;
class QScrollArea;
class QImage;
class QMenu;
class QPoint;
class QMutex;
class QRect;
class QPaintEvent;
class QPixmap;

class ImageWidget : public QWidget
{
    Q_OBJECT

public:
    ImageWidget(QWidget *parent = nullptr);
    enum CoordinateMode
    {
        NoClick        = 0x0,
        SingleClick    = 0x1,
        SingleUnclick  = 0x2,
        ClickUnclick   = 0x4,
        ClickDrag      = 0x8,
        RectROI        = 0x10,
        DragROI        = 0x20,
        BrushImage     = 0x40
    };
    Qt::ScrollBarPolicy verticalScrollBarPolicy() const;
    Qt::ScrollBarPolicy horizontalScrollBarPolicy() const;
    void setVerticalScrollBarPolicy(Qt::ScrollBarPolicy sbp = Qt::ScrollBarAsNeeded);
    void setHorizontalScrollBarPolicy(Qt::ScrollBarPolicy sbp = Qt::ScrollBarAsNeeded);
    void setFillWidget(bool fill = true);
    uint getRetrieveCoordinateMode() const; //change to RetrieveCoordinateMode
    double currentScale() const;
    bool imageAttached() const;
    bool fillWidgetStatus() const;
    const QImage* displayedImage();
    void setMutex(QMutex &m);

signals:
    void imageSet();
    void imageCleared();
    void imageNull();
    void imagePointSelected(QPoint selectedPoint);
    void imageRectRegionSelected(QRect roi);
    void fillWidgetChanged(bool fillScrollArea);
    void droppedImagePath(QString imagePath);
    void droppedImageError();

public slots:
    void setImage(const QImage *image);
    void clearImage();
    void zoomIn();
    void zoomOut();
    void zoomFit();
    void zoomActual();
    void updateDisplayedImage();
    void setRetrieveCoordinateMode(uint mode);
    void setRectRegionSelected(QRect roi);

protected:
    virtual void resizeEvent(QResizeEvent *event) override;
    virtual void mouseReleaseEvent(QMouseEvent *event) override;
    virtual void mousePressEvent(QMouseEvent *event) override;
    virtual void mouseMoveEvent(QMouseEvent *event) override;
    virtual void wheelEvent(QWheelEvent *event) override;
    virtual void contextMenuEvent(QContextMenuEvent *event) override;
    virtual void dragEnterEvent(QDragEnterEvent *event) override;
    virtual void dragLeaveEvent(QDragLeaveEvent *event) override;
    virtual void dropEvent(QDropEvent *event) override;
    QMutex *mutex_m = nullptr;

private:
    void selectRegionOnPixmap();
    void displayBrushOnPixmap();
    void initializePaintMembers();
    void zoomAgain();
    QPoint getPointInImage();
    QRect getAdjustedRegion();
    QAction *zoomInAction_m;
    QAction *zoomOutAction_m;
    QAction *zoomFitAction_m;
    QAction *zoomActualAction_m;
    QLabel *imageLabel_m;
    QPixmap painterBuffer_m;
    QScrollArea *scrollArea_m;
    QRect region_m;
    QPoint dragStart_m;
    uchar brushRadius_m;
    const QImage *attachedImage_m = nullptr;
    uint retrieveCoordinateMode_m = NoClick;
    float scalar_m;
    bool fillScrollArea_m = true;
};

#endif // IMAGEWIDGET_H