root.bnl Valeri Fine (BNL, STAR)

1. Using the Qt framework to create GUI for the complex interactive HENP applications Whether it is feasible to benefit just from the two best technologies http://root.bnl.gov Valeri Fine (BNL, STAR)

2. Abstract This talk presents the overview of the main components of the unique technology creating the complex data-analysis and the computer simulation interactive software packages and problem-oriented applications based on Qt and ROOT frameworks. The system has been under development for last 4 years. It is developed mainly within STAR (and at some point it was supported by US Atlas) and it is included in the regular distribution of the ROOT package. The later is a “de facto” standard of the HENP OO frameworks for the modern HENP experiments BNL technology meeting fine@bnl.gov

3. Batch and interactive stages • GUI is not the first concern of the HENP frameworks. We worry whether we are capable to collect, preserve, re-distribute our hard-earned TBytes. • However the final stages of the job are mainly interactive. • The very first steps of the data-taking in the “control rooms” are interactive also BNL technology meeting fine@bnl.gov

4. Operating system “model” for HENP cross-platform applications“pro” It is not unusual when the life cycle of the major HENP applications last for dozens years. In other words it is much more then the life cycle of any known “system components” like operating system, file system, GUI etc. and hardware as well. To survive the sophisticated and expansive HENP applications must be in possession of some (tiny) layer to separate the HENP applications and the concrete system environment evolvement. It is possible by introducing some sort of the “virtual operating system model” the applications rely on; and providing the implementation of that model as soon as operating environment evolves. BNL technology meeting fine@bnl.gov

5. Operating system “model” for HENP cross-platform applications “cons” Even though it does allow to prolong the life cycle of the software package that comes for the price. • One is still required to learn and maintain the specific pieces of the code for many different platforms, • and the different versions of one and the same platform for the entire application life. • That sometimes entails the narrowing the number of different platforms the package is available for. • On the other hand many features one has to deal with are not application specific. • This implies that the good layer can be ''borrowed'' from some third party dedicated packag BNL technology meeting fine@bnl.gov

6. ROOT low level GUI interface ROOT (TVirtualPad) ROOT (TG<family> 3 different implementations to develop and support TVirtualX TGWIN32 TGX11 TGWin32GDK BNL technology meeting fine@bnl.gov

7. Why Qt? The present model has been serving ROOT and ROOT users very well for 9 years soon. On the other hand, most tasks to be performed and implement have no ROOT specific and have been successfully solved by other packages. • Qt package from TrollTech AS was especially attractive not only due to its superior quality and high level technical support but because it comes with the source code and tools to build it in place (including a commercial version for Windows). • The rich set of Qt documentation can be found on Web and available from the leading publishers as well. • Qt is a multi-platform C++ application framework that developers can use to write single-source applications that run-natively-on Windows, Linux, Unix, Mac OS X and embedded Linux. • Qt has been used to build thousands of successful commercial applications worldwide, • and is the basis of the open source KDE desktop environment. BNL technology meeting fine@bnl.gov

8. Why Qt (cont.) • Cross platforms • Documentation • Open Source (including Win32) • The “native” development tool integration • “Native” GUI (Win32, Mac) integration • Free (for x11 and Mac) • “non-commercial” for Win32 • Microsoft Foundation classes migration • Motif migration • Embedded platform High quality The review http://www.geocities.com/SiliconValley/Vista/7184/guitool.htmlof the more then 100 different GUI packages named Qt “the best GUI packages” BNL technology meeting fine@bnl.gov

9. Qt – “softgate” to 3d party applications • Qt – rich itself, but there is nothing up with that. All modern GUI system (GDK, MFC, Motif etc) are in possession more/less the same functionality. • Qt authors addressed many hot issues and the main one is how to connect the different packages within one application seamlessly? BNL technology meeting fine@bnl.gov

10. Qt cornerstones • Signal / Slot C++ object communication mechanism • OO model: Qt uses the named generic container of the named generic containers. In other words Qt basic OO model is a the tree-like structure These allow significantly simply the 3d-party interactive libraries integration. They made it possible at last! BNL technology meeting fine@bnl.gov

11. 1994: Trolltech founded in Oslo, Norway 1996: First sale of Qt (to European Space Agency) 1998: Created the KDE Free Qt Foundation 1998: Released Qt/X11 under the QPL 1999: Qt 2 released 1999: Opened Australian office 1999: Received first-round funding 2000: Released Qt/Embedded 2000: Opened US office 2000: Released Qt/X11 under the GPL 2001: First Qtopia adoption (by Sharp Electronics) 2001: Qt 3 released 2002: Teambuilder released 2003: QSA released 2003: Released Qt/Mac under the GPL 2003: Introduces Qt Solutions 2004: Released Qtopia Phone Edition http://www.trolltech.com/company/history.html Jan 95: Thinking/writing/rewriting/??? November 95: Public seminar, show Root 0.5 Spring 96: decision to use CINT Jan 97: Root version 1.0 Jan 98: Root version 2.0 – STAR ROOT-based offline framework Mar 99: Root version 2.21/08 (1st Root workshop FNAL) Feb 00: Root version 2.23/12 (2nd Root workshop CERN) Mar 01: Root version 3.00/06 Jun 01: Root version 3.01/05 (3rd Root workshop FNAL) Jan 02: Root version 3.02/07 (LCG project starts: RTAGs) Oct 02: Root version 3.03/09 (4th Root workshop CERN) Dec 03: Root version 3.10/02 (last PRO release) Feb 04: Towards version 4.00 (5th Root workshop SLAC) http://www.slac.stanford.edu/BFROOT/www/Computing/Distributed/ROOT2004/files/brun.ppt Why now?Qt and ROOT timeline BNL technology meeting fine@bnl.gov

12. Approaching Qt • Goals: • Immediate man-power conservation – “experiment target” • Insure the package long healthy life (25 years?) – “developer target” • Qt “alone” - LHC++ (CERN) • Qt “outside” - GO4 approach (GSI) • Qt “just inside” - Acat2002 (STAR) • Qt “side by side” - Qt CINT approach (Masa Goto, HP Japan) • Qt “deep inside” - Acat2003 (STAR) BNL technology meeting fine@bnl.gov

13. LHC++ about QT BNL technology meeting fine@bnl.gov

14. ROOT Qt-based GUI interface ROOT ROOT TVirtualX only one (!) implementation TGQt BNL technology meeting fine@bnl.gov

15. ROOT GUI class library and Qt layer • The above Qt layer first was present last year on Acat2002 @ Moscow and has the significant drawback. • Event though it solves the problem of combining the ROOT Canvas and Qt widgets within one single application it was not compatible with the ROOT GUI class library and the compatibility with the conventional ROOT development. BNL technology meeting fine@bnl.gov

16. TGQt TQtWidget TQtClientFilter TVirtualX QWidget QObject TQtClientWidget QFrame QWidget Transformation the QEvent Q-object into the ROOT Event_t structure • “Clear boxes” show the overloaded methods • of the TVirtualX interface TGClient::ProcessOneEvent method • “Gray boxes” show the Classes inheritance diagram Event_t QEvent Class name TGQt::NextEvent() QPtrQueue<Event_t> fRootEventQueue TGQt::Init(…) TGQt::CreateWindow(…) TGQt::InitWindow(…) QWidget::installEventFilter

17. ROOT Qt-based GUI interface ROOT ROOT TVirtualX ROOT Gui class library TCanvas/TPad TGQt BNL technology meeting fine@bnl.gov

18. To run ROOT Create TApplication Enter ROOT event loop TApplication::Run To run Qt Create QApplication Enter Qt event loop QApplication::exec() ROOT vs Qt This implementation: TApplication QApplication QApplication::exec() TApplication::Run() Bottom line:No need to deal with QApplication! BNL technology meeting fine@bnl.gov

19. Qt Root “Hello Word” 1. Qt “Hello Word” source file #include <qapplication.h> #include <qpushbutton.h> int main( int argc, char **argv ) { QApplication a( argc, argv );// to be replaced QPushButton hello( "Hello world!", 0 ); hello.resize( 100, 30 ); a.setMainWidget( &hello ); // to be removed hello.show(); return a.exec(); // to be replaced } 2. QtROOT “Hello Word” source file #include <TRint.h> #include <qpushbutton.h> int main( int argc, char **argv ) { // Create an interactive ROOT application TRint *theApp = new TRint("Rint", &argc, argv); QPushButton hello( "Hello world!", 0 ); hello.resize( 100, 30 ); hello.show(); theApp->Run(); // and enter the event loop... } BNL technology meeting fine@bnl.gov

20. How to make ROOT application Qt-aware Copy the custom version of ".rootrc" file into your working directory Unix: Gui.Backend: qt Gui.Factory: qtgui Plugin.TGuiFactory: qtgui TQtGUIFactory QtGui "TQtGUIFactory()" Gui.Backend: qt Gui.Factory: qt Windows: Gui.Backend: qtwin32 Gui.Factory: qtguiwin32 No correction of the user code! BNL technology meeting fine@bnl.gov

21. Additional resource parameters Qt-base “Pad” Editor Plugin.TVirtualPadEditor: Ged TQtGedEditor QtGed "TQtGedEditor(TCanvas*)" TImage class Qt-based implementation Plugin.TPaletteEditor: * TQtPaletteEditor QtImage "TQtPaletteEditor(TAttImage*,UInt_t,UInt_t)“ Plugin.TImage: * TQtImage QtImage "TQtImage()" Customize “look and fell” # GUI specific settings Gui.Style: windows BNL technology meeting fine@bnl.gov

22. Benefits One can include Qt-based GUI components and packages into ROOT based applications Qwt Coin3D GO4 QGLViewer BNL technology meeting fine@bnl.gov

23. A test application to combine ROOT and Qt Widget BNL technology meeting fine@bnl.gov

24. ROOT QtGLWidget A fragment of STAR “Event Display” QtGLViewer class based viewer see: http://www.rhic.bnl.gov/~fine/EventDisplay ) BNL technology meeting fine@bnl.gov

25. High resolution OpenGL pictures(fragment STAR detector at RHIC BNL technology meeting fine@bnl.gov

26. Qt-based ROOT geometry browser BNL technology meeting fine@bnl.gov

27. STAR reconstructed events It is also possible to use the Coin3D package to visualize ROOT objects STAR Detector with real tracks BNL technology meeting fine@bnl.gov

28. How to make Qt application ROOT-aware • That’s easy!!! • One needs a few standard and well defined by Qt documentation steps, namely: • Launch the Qt “designer” • Load the TQtWidget.cw file which is a Qt designer definition of the “custom widget” • Add the list of ROOT libraries and header file to your Qt project • That’s all • Use Qt desinger the why Qt prescribes http://doc.trolltech.com/3.3/designer-manual-2.html No correction of the Qt documentation BNL technology meeting fine@bnl.gov

29. http://root.bnl.gov/QtRoot/root/qtExamples/ex1/README • wget http://root.bnl.gov/QtRoot/downloads/qtRootProject.tar.gz" • qmake tqrootexample.pro • make • tqrootexample [-style=windows | platinum | motif ] BNL technology meeting fine@bnl.gov

30. How to make ROOT application Qt-aware That’s simple nowadays!!! • Install the ROOT with the Qt layer. • Use any Qt widgets as prescribed. No need to worry about Qt initilization and qt event loop. ROOT Qt layer takes carre about this. BNL technology meeting fine@bnl.gov

31. Where to get Qt-ROOT from? BNL technology meeting fine@bnl.gov

32. Qt-ROOT FAQ BNL technology meeting fine@bnl.gov

33. How to install BNL technology meeting fine@bnl.gov

34. Conclusion There are enough evidences the present approach allows the ROOT developers as well as ROOT users to work with code that has no X11 / WIN32 graphics subsystem dependencies and at the same time opens unrestricted access to a rich set of ready-to-use commercial and free GUI Qt-based widgets and interactive applications. Qt layer is provided as the standard ROOT “plug-in” share library. That allows user to turn the layer on/off at run time with no change of recompilation of the user’s code. At the moment the project consists of two large pieces. The core part called “Root Qt layer” had been adopted by ROOT team and it is included since ROOT release 4.00.08 in the standard ROOT CERN distribution and available from ROOT CVS repository @ CERN. The second part is a set of the Qt-based application built on the top of the “Qt layer”. It is called “ROOT Qt extensions” and available from BNL CVS repository (provided by ITD@BNL) Information about progress can be found on BNL Web site: http://root.bnl.gov BNL technology meeting fine@bnl.gov

35. Qt framework + Qt GUI + ROOT Data-Analysis and Visualization facility = New generation of the powerful interactive applications BNL technology meeting fine@bnl.gov

36. References • CINT status, Masa Goto http://www.slac.stanford.edu/BFROOT/www/Computing/Distributed/ROOT2004/files/goto.ppt • Cross-platform approach to create the interactive application based on ROOT and Qt GUI libraries. http://www-conf.kek.jp/acat03/prog/presen/id0112.ppt • ROOT in GO4, Joern Adamczewski http://www.slac.stanford.edu/BFROOT/www/Computing/Distributed/ROOT2004/files/adamczewski.ppt • Cross-platform Qt-based implementation of low level GUI layer of ROOT http://acat02.sinp.msu.ru/presentations/fine/Acat2002.ppt • Cross-platform approach to create the interactive application based on ROOT and Qt GUI libraries http://www-conf.kek.jp/acat03/prog/presen/id0112.ppt • Visualization of the ROOT 3D class objects with Open Inventor-like viewers http://www-conf.kek.jp/acat03/prog/presen/id0113.ppt • C++ GUI Programming with Qt3 http://phptr.com/content/images/0131240722/downloads/blanchette_book.pdf BNL technology meeting fine@bnl.gov