cosmetic to MainWindow,

drop does not work for widget,
fixed offset problem,
add esc key

QtMeshViewer/Header/GeometryEngine.h

@@ -25,10 +25,10 @@ private:
 	QVector<QOpenGLTexture*> m_textures;
 	QVector<DrawInformation> m_drawList;
 
-	void loadFile(const char* filePath);
 	void loadTexture(const char* filePath);
 
 public:
+	void loadFile(const char* filePath);
 	void drawGeometry(QOpenGLShaderProgram *program);
 };