chore: adjusted the project directory structure

app/mainwindow.h

@@ -0,0 +1,83 @@
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QParallelAnimationGroup>
+#include <QPropertyAnimation>
+#include <QPushButton>
+
+QT_BEGIN_NAMESPACE
+class QGraphicsOpacityEffect;
+class QGraphicsView;
+QT_END_NAMESPACE
+
+class ToolButton;
+class GraphicsView;
+class NavigatorView;
+class BottomButtonGroup;
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    explicit MainWindow(QWidget *parent = nullptr);
+    ~MainWindow() override;
+
+    void showUrls(const QList<QUrl> &urls);
+    void adjustWindowSizeBySceneRect();
+    QUrl currentImageFileUrl() const;
+
+    void clearGallery();
+    void loadGalleryBySingleLocalFile(const QString &path);
+    void galleryPrev();
+    void galleryNext();
+    bool isGalleryAvailable();
+
+signals:
+    void galleryLoaded();
+
+protected slots:
+    void showEvent(QShowEvent *event) override;
+    void enterEvent(QEvent *event) override;
+    void leaveEvent(QEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
+    void mouseDoubleClickEvent(QMouseEvent *event) override;
+    void wheelEvent(QWheelEvent *event) override;
+    void resizeEvent(QResizeEvent *event) override;
+    void contextMenuEvent(QContextMenuEvent *event) override;
+
+    bool nativeEvent(const QByteArray& eventType, void* message, long* result) override;
+
+    QSize sizeHint() const override;
+
+    void centerWindow();
+    void closeWindow();
+    void updateWidgetsPosition();
+    void toggleProtectedMode();
+    void toggleStayOnTop();
+    bool stayOnTop();
+    void quitAppAction(bool force = false);
+    void toggleFullscreen();
+    void toggleMaximize();
+
+private:
+    QPoint m_oldMousePos;
+    QPropertyAnimation *m_fadeOutAnimation;
+    QPropertyAnimation *m_floatUpAnimation;
+    QParallelAnimationGroup *m_exitAnimationGroup;
+    ToolButton *m_closeButton;
+    ToolButton *m_prevButton;
+    ToolButton *m_nextButton;
+    GraphicsView *m_graphicsView;
+    NavigatorView *m_gv;
+    BottomButtonGroup *m_bottomButtonGroup;
+    bool m_protectedMode = false;
+    bool m_clickedOnWindow = false;
+
+    QList<QUrl> m_files;
+    int m_currentFileIndex = -1;
+};
+
+#endif // MAINWINDOW_H