+ void paintEvent(QPaintEvent *event);
+
+private:
+ void mousePressEvent(QMouseEvent *event);
+ void mouseMoveEvent(QMouseEvent *event);
+ void mouseReleaseEvent(QMouseEvent *event);
+ void wheelEvent(QWheelEvent *event);
+
+private:
+ void setup_viewport(int width, int height);
+
+ void paint_ruler(QPainter &p);
+
+ void zoom(double steps, int offset);