Jungfraujoch/viewer/image_viewer/JFJochImage.h

// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

#include <QGraphicsView>
#include <QMouseEvent>
#include <QTransform>
#include <QPointF>
#include "../../common/ColorScale.h"
#include "../../common/JFJochMessages.h"

// Q_DECLARE_METATYPE(ROIMessage)

class JFJochImage : public QGraphicsView {
    Q_OBJECT

    bool m_adjustForegroundWithWheel = false;

    // Viewport-lock support: guard prevents the emit<->apply ping-pong between
    // two linked views, and the helper broadcasts the current transform+center.
    bool m_applyingViewport = false;
    void emitViewportChanged();

    void DrawROI();
    virtual void addCustomOverlay();
    void updateROI();
    void writePixelLabels();
    void wheelEvent(QWheelEvent* event) override;
    void resizeEvent(QResizeEvent *event) override;
    void contextMenuEvent(QContextMenuEvent *event) override;

    void mousePressEvent(QMouseEvent *event) override;
    void mouseMoveEvent(QMouseEvent *event) override;
    void mouseReleaseEvent(QMouseEvent *event) override;

    ROIMessage accumulateROI(int64_t xmin, int64_t xmax, int64_t ymin, int64_t ymax,
                          const std::function<bool(int64_t,int64_t)>& inside);
protected:
    virtual void beforeOverlayCleared();

    bool show_saturation = false;

    bool auto_bg = false;
    bool auto_fg = false;
    bool hdr_mode = false;

    double scale_factor = 1.0;

    size_t W = 0, H = 0;
    size_t prev_W = 0, prev_H = 0;

    // Track initial fit state and last image size
    bool initial_fit_done_ = false;

    QColor feature_color = Qt::magenta;

    // Decimal places for non-integer per-pixel value labels. Float images are
    // unreadable with many decimals, so subclasses can lower this.
    int label_decimals_ = 3;

    float foreground = 10.0;
    float background = 0.0;
    ColorScale color_scale;
    std::vector<rgb> image_rgb;
    std::vector<float> image_fp;
    QPixmap pixmap;
    QImage qimg_buffer_;  // reusable image buffer — avoids 64MB alloc per frame

    // Persistent pixmap item — never destroyed/recreated on overlay update
    QGraphicsPixmapItem *pixmap_item_ = nullptr;
    // Overlay items managed separately
    QList<QGraphicsItem *> overlay_items_;

    // Helper: add an overlay item to the scene and track it for selective removal
    void addOverlayItem(QGraphicsItem *item);

    enum class MouseEventType {None, Panning, DrawingROI, MovingROI, ResizingROI, EditingExternalROI};
    MouseEventType mouse_event_type = MouseEventType::None;

    // Hooks for editing a named, persistent ROI drawn by a subclass (the base only
    // owns the mouse events; the subclass knows the loaded ROIs). roiEditPress returns
    // true to claim the gesture for ROI editing.
    virtual bool roiEditPress(const QPointF &scenePos) { return false; }
    virtual void roiEditMove(const QPointF &scenePos) {}
    virtual void roiEditRelease() {}
    virtual void roiScratchDrawn() {}   // a shift/ctrl-drag finished drawing a new box/circle
    QPoint lastMousePos;  // To track panning movement

    // Resizing which edge/corner
    enum class ResizeHandle { None, Left, Right, Top, Bottom, TopLeft, TopRight, BottomLeft, BottomRight, Inside };
    ResizeHandle active_handle_ = ResizeHandle::None;
    ResizeHandle hover_handle_ = ResizeHandle::None;

    enum class RoiType {RoiBox, RoiCircle};
    RoiType roi_type = RoiType::RoiBox;
    QPointF roiStartPos;
    QPointF roiEndPos;
    QRectF roiBox;

    static QPointF RoundPoint(const QPointF& p);
    virtual void mouseHover(QMouseEvent* event) = 0;

    ResizeHandle hitTestROIHandle(const QPointF& scenePos, qreal tol = 3.0) const;

    void updateOverlay();
    void GeneratePixmap();
    void Redraw();
    void CalcROI();

    // Invalidate pixmap_item_ and overlay tracking after scene()->clear()
    void resetScenePointers();

    // Perform initial fit-to-view (shorter direction), once per image size
    void fitToViewShorterSideOnce();
    QSize last_fit_viewport_ = {};

    void copyImageToClipboard();
    void copyImageWithOverlayToClipboard();
    void clearROIInternal();
signals:
    void autoForegroundChanged(bool input);
    void foregroundChanged(float v);
    void backgroundChanged(float v);
    void writeStatusBar(QString string, int timeout_ms = 0);
    void roiBoxUpdated(QRect box);
    void roiCircleUpdated(double x, double y, double radius);
    void roiCalculated(ROIMessage &output);
    void viewportChanged(QTransform transform, QPointF center);
    void hoverScenePos(QPointF scenePos);
private slots:
    void onScroll(int value);
public slots:
    void setFeatureColor(QColor input);
    void setColorMap(int color_map);
    virtual void changeForeground(float val);
    void changeBackground(float val);

    void SetROIBox(QRect box);
    void SetROICircle(double x, double y, double radius);

    void centerOnSpot(QPointF point);
    void applyViewport(QTransform transform, QPointF center);
    void fitToView();

    void adjustForeground(bool input);
    void setZoom(double input);
public:
    explicit JFJochImage(QWidget *parent = nullptr);
    double GetScaleFactor() const;
};