Writing Extension Modules (Plugins) for

JAS 3

Mark Donszelmann Tony Johnson

Victor SerboMax Turri

CHEP2004, 27 september-1 october 2004,Interlaken, Switzerland.

30 September 2004 Mark Donszelmann, CHEP 2004, Interlaken, Switzerland 2

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 2004 Mark Donszelmann, CHEP 2004, Interlaken, Switzerland 3

JAS 3 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

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Example Plugin:BaBar’s Ambient Data Explorer

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Example Plugin:FermiLab’s Accelerator Control

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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

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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

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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 2004 Mark Donszelmann, CHEP 2004, Interlaken, Switzerland 9

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

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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

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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 …

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Find others and be found

Lookup system Lookup services by class or interface Lookup services by name

Publish Register by class and name

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Services

Standard services FileHandler / URLHandler DataSource ManagedPage PreferencesManager …

Plugin-defined for others to look up and use

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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

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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

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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

http://jpf.sourceforge.net/ 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.

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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  151435.538095  0.05  1960.  -10.21 e+  55.5416 -1.17836 89.2775  mu-  26.8907 -0.236785 -82.8115  j  9.03099 104.635 0.22464 -120.258  j  4.31111 25.401 -0.992276 21.7658  uncl 0 12.9285 056.8782;

and display the events in WIRED 4, with all itsfunctionality:

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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

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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.

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References

JAS 3 – http://jas.freehep.org/jas3 Documentation on JAS 3 and how to write

extension modules. Forums – http://forum.freehep.org

Discussions on JAS 3, FreeHEP and WIRED 4.