chore: adjusted the project directory structure

app/graphicsview.h

@@ -0,0 +1,66 @@
+#ifndef GRAPHICSVIEW_H
+#define GRAPHICSVIEW_H
+
+#include <QGraphicsView>
+#include <QUrl>
+
+class GraphicsScene;
+class GraphicsView : public QGraphicsView
+{
+    Q_OBJECT
+public:
+    GraphicsView(QWidget *parent = nullptr);
+
+    void showFileFromUrl(const QUrl &url, bool requestGallery = false);
+
+    void showImage(const QPixmap &pixmap);
+    void showImage(const QImage &image);
+    void showText(const QString &text);
+    void showSvg(const QString &filepath);
+    void showGif(const QString &filepath);
+
+    GraphicsScene * scene() const;
+    void setScene(GraphicsScene *scene);
+
+    qreal scaleFactor() const;
+
+    void resetTransform();
+    void zoomView(qreal scaleFactor);
+    void resetScale();
+    void rotateView(qreal rotateAngel);
+    void fitInView(const QRectF &rect, Qt::AspectRatioMode aspectRadioMode = Qt::IgnoreAspectRatio);
+
+    void checkAndDoFitInView(bool markItOnAnyway = true);
+
+signals:
+    void navigatorViewRequired(bool required, qreal angle);
+    void viewportRectChanged();
+    void requestGallery(const QString &filePath);
+
+public slots:
+    void toggleCheckerboard();
+
+private:
+    void mousePressEvent(QMouseEvent * event) override;
+    void mouseMoveEvent(QMouseEvent * event) override;
+    void mouseReleaseEvent(QMouseEvent * event) override;
+    void wheelEvent(QWheelEvent *event) override;
+    void resizeEvent(QResizeEvent *event) override;
+
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dragMoveEvent(QDragMoveEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+
+    bool isThingSmallerThanWindowWith(const QTransform &transform) const;
+    bool shouldIgnoreMousePressMoveEvent(const QMouseEvent *event) const;
+    void setCheckerboardEnabled(bool enabled);
+    void applyTransformationModeByScaleFactor();
+
+    void resetWithScaleAndRotate(qreal scaleFactor, qreal rotateAngle);
+
+    bool m_enableFitInView = false;
+    bool m_checkerboardEnabled = false;
+    qreal m_rotateAngle = 0;
+};
+
+#endif // GRAPHICSVIEW_H