Writing Extension Modules (Plugins) for JAS 3 Mark Donszelmann Tony Johnson Victor Serbo Max Turri CHEP2004, 27 september-1 october 2004, Interlaken, Switzerland.

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland2 Content JAS 3 and the FreeHEP Application Framework Plugins Management Menus, Command Processing and Pages Communication, Services Tree Comparison to Other Frameworks Simple Event Display plugin Conclusions

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland3 JAS 3 Based on the FreeHEP Application Framework, Empty Framework into which extension modules (plugins) can be loaded. JAS3 IS just a set of built-in plugin modules Provides General functionality: Top-level GUI: windows, menus, status bar, etc… Help System Storage/retrieval of user preferences Customizable by adding, removing or replacing plugin modules. Plugins Data Analysis and other functionality is provided by a set of plugins. Plugins are (in general) only loosely coupled. Provide a set of services and events  available to JAS  and extensible by new plugin modules. Communication  restricted to service interfaces and notification events. Can be added, removed, upgraded independently Present seamless interface to user, for instance by merging functionality into existing menus

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland4 Example Plugin: BaBar’s Ambient Data Explorer

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland5 Example Plugin: FermiLab’s Accelerator Control

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland6 Management of Plugin Modules Plugin Types: Built-in modules (cannot be removed) System modules (come standard with JAS) User modules (individual or group based) PluginManager in JAS to handle installation and removal Semi-Automatic download of updated plugins based on version numbers Plugins can be published on the Web as jar files with an embedded XML description file Dependencies and versions can be specified

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland7 Built-in and System modules Built-in modules Console Data Source File Opener Plotter Plugin Manager Preferences Save/Restore Status Bar Tree Web Browser System modules AIDA Compiler Excel Jython PAW for AIDA Pnuts Record Loop Root for AIDA Simple Editor SpreadSheet Tuple Explorer

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland8 Instantiation and Initialization Plugins inherit from the Plugin class. Plugins are constructed after which the init() and postInit() methods are called. Plugins may implement a set of standard or plugin defined services. Plugins make themselves known to the system in the init() method. Plugins should look for other plugins in the postInit() method or afterwards.

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland9 Menu and ToolBar Plugins can add their own menus to the Menubar in any position to any submenus in any position Plugins can add their own toolbars to the general toolbar toolbars automatically hide themselves if functionality is temporarily unavailable Menus and Toolbars can be added statically, using an XML description file dynamically by the plugin at runtime

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland10 Command Processing Actions from menus and toolbars hook up to a command processor Handles enabling and disabling of menu/toolbar buttons Handles state of checkbox or radio buttons Handles the dispatching of actions to multiple listeners

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland11 Pages Pages can be used by plugins to display any content (Histograms, Events, …) PageManager handles the display of pages. as tabbed pages as internal windows ManagedPage service allows you to handle page notifications page displayed page selected page iconized …

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland12 Find others and be found Lookup system Lookup services by class or interface Lookup services by name Publish Register by class and name

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland13 Services Standard services FileHandler / URLHandler DataSource ManagedPage PreferencesManager … Plugin-defined for others to look up and use

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland14 Tree - a point of contact Plugins can add/remove nodes on the tree A node is defined by a type (java Class) and can contain multiple objects Any plugin can attach objects to a given node Plugins can add behavior to any type of node A node’s behavior is defined by its type (by inheritance) Node adapters are registered with the tree for a given type and with a given priority A node adapter controls: Single and Double click Popup menu Icon Text Drag & Drop … Plugins modify the tree by sending it Notifications The trees feedback to the plugins is sent via Events Plugins can modify behaviour of nodes created by other plugins

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland15 Via the Root plugin we open a root file The content of the root file is presented in the tree by the AIDA plugin: histograms and tuples are shown The TupleExplorer plugin modifies the appearance and behavior of a tuple by adding extra functionality: the internal structure is displayed. Ex.: the tooltip text is modified. Tree - Root Example

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland16 Comparison to other Frameworks Other similar framework available for Java IDEs Netbeans JAS uses some utilities from netbeans and will likely adopt other modules (editor, window manager) in future Eclipse Newer plugin architecture, architected for fast startup (e.g. plugins not loaded until used) Eclipse is SWT based (not Swing like Netbeans, JAS) Open source Java Plugin Framework Encapsulates feature of eclipse plugins without SWT Maybe useful for future release of JAS JAS is a much lighter framework than full IDE JAS base plugins provide plotting, data analysis capabilities.

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland17 Simple Event Display (real life example) Suppose you want to read a file with an event per line format like this: eventLabel run#.event# weight Ecm[GeV] zVertex[cm] objectType1 (mass)[GeV] pT[GeV] eta phi[degrees] … mad_ttbar-e+vemu-vm-b-b e mu j j uncl ; and display the events in WIRED 4, with all its functionality:

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland18 Simple Event Display Plugin Give the file an extension Create a FileHandler for it Parse the file and provides its lines as Records in a RecordSource Each Record needs to be converted (on the fly) into a HepRep Provide to WIRED 4. Green = Part of JAS/FreeHEP Pink = Provided by plugin implementer

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland19 Conclusion JAS 3 is a configuration of plugin modules used in the lightweight FreeHEP Application Framework. It can be easily extended by writing fairly independent plugin modules Plugin modules can communicate with JAS and other modules via services and events.

30 September 2004Mark Donszelmann, CHEP 2004, Interlaken, Switzerland20 References JAS 3 – Documentation on JAS 3 and how to write extension modules. Forums – Discussions on JAS 3, FreeHEP and WIRED 4.