paintwidget.h

#ifndef PAINTWIDGET_H
#define PAINTWIDGET_H

#include <QWidget>

class PaintWidget : public QWidget {
  Q_OBJECT

 public:
  PaintWidget(QWidget *parent = nullptr);
  ~PaintWidget();

 private slots:
  void ShowMessage();
  void UpdateEllipsePosition();

 protected:
  virtual void mousePressEvent(QMouseEvent *event);
  virtual void paintEvent(QPaintEvent *event);
  virtual void mouseMoveEvent(QMouseEvent *event);
  virtual void mouseReleaseEvent(QMouseEvent *event);
  virtual void resizeEvent(QResizeEvent *event);
  virtual void keyPressEvent(QKeyEvent *event);

 private:
  void DrawWeb(QPainter *painter);
  void DrawEllipse(QPainter *painter);
  void AddToTimerInterval(int milliseconds);
  void DrawSpider(QPainter *painter);
  void ShowMousePosition();

 private:
  QTimer *ellipseMoveTimer_;
  QRect windowRect_;

  QPoint cursorPosition_;
  QPoint ellipsePosition_;

  bool isDrawingWeb_;
  int timeInterval_;
};
#endif  // PAINTWIDGET_H