= Developers Guide =

This page explains how to create a patch, modify the core JOSM application or existing plugins.

At least basic Java programming skills are necessary. See [WikiStart#Contribute WikiStart] how you could improve JOSM without Java skills.

== Source code and JOSM builds ==

* [wiki:InstallNotes Installing and Running JOSM]
* [[Source code#Getthesource]]
* [[Source code#CompilingusingAnt]]
* [wiki:DevelopersGuide/Compiling Compiling JOSM using IDE]
 * [wiki:DevelopersGuide/CreateBuild How to create a JOSM build]

== Developer guidelines ==

* [wiki:DevelopersGuide/StyleGuide Development Guidelines] (Coding style and Internationalization)
* [wiki:DevelopersGuide/DefaultPresets Default Presets] (about new osm-tags and icons in JOSM)
* [wiki:DevelopersGuide/PatchGuide Patch Guidelines] (How to submit a patch)
* [wiki:DevelopersGuide/Schedule Track the state of development] (Release Schedule)
* [wiki:DevelopersGuide/Releasing Releasing]
* [wiki:Releases Releases]

=== Eclipse ===

* [wiki:DevelopersGuide/EclipseTips Various Eclipse tips]
* [http://www.youtube.com/watch?v=-LoWGf-hqiQ Video: how to checkout JOSM into Eclipse]
* [http://www.youtube.com/watch?v=Z3OjG3nDvzA Video: how to checkout a JOSM plugin into Eclipse]

=== VisualVM ===
VisualVM may be used to find memory leaks or generate heap dumps from a josm instance running concurrently. Heap dumps can be structurally examined. VisualVM organizes them e.g. by number and type of objects, memory used and cpu time consumed in an explorable tree view. Heap dump and garbage collection of the target instance is requestable using button clicks.
* [http://visualvm.github.io VisualVM]

If an autonomous instance of josm should be debuggable from within eclipse at the same time, command line parameters must be supplied to open a transport socket that the debugger can connect to:
{{{
  #!bash
  # run JOSM with remote debug options; let VisualVM connect to 127.0.0.1 and port 9988; see the vm working
  java -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:9988,server=y,suspend=n -Xmx1200m -jar josm-latest.jar
}}}

This is not necessary if the internals of JOSM are to be explored by VisualVM exclusively (tested with the yet to be released, but available, version 1.4).


== JOSM core ==

* [/doc JavaDoc class documentation] (for JOSM and JMapViewer)
* [[JavaBugs]] - you may encounter one of them

== JOSM plugins ==
* [wiki:DevelopersGuide/DevelopingPlugins Develop Plugins]
 * [wiki:DevelopersGuide/DevelopingPlugins#Publishingthenewplugin Plugin publication steps]
* [wiki:DevelopersGuide/PluginInstallationWithoutRestart Plugin installation without restart]


== SVN ==
* [wiki:DevelopersGuide/SVN_Account How to use your JOSM SVN account]

== JOSM Help System ==
* [wiki:/DevelopersGuide/HelpSystem Context-sensitive help]
* [wiki:/DevelopersGuide/HelpSystem/HelpTopicsList Current list] of context-sensitive help topics 

== Shortcuts ==
* [wiki:/DevelopersGuide/ShortcutsList Current list of used shortcuts]

== Translation ==
* see [wiki:Translations], [wiki:Translations/Wiki] and [wiki:TaggingPresets#Translation TaggingPresets#Translation]

== Developers ==
Dirk Stöcker is currently the lead maintainer of JOSM. Developers of JOSM with SVN commit privileges active in the past several months include:
||=Trac username=||=Name=||
||akks || Alexei Kasatkin ||
||bastiK || Paul Hartmann ||
||Don-vip || Vincent Privat ||
||Klumbumbus || Stefan Volke ||
||michael2402 || Michael Zangl ||
||simon04 || Simon Legner ||
||stoecker || Dirk Stöcker ||
||wiktorn || Wiktor Niesiobędzki ||

Immanuel Scholz was the original creator of JOSM, and previous maintainers include Frederik Ramm.

Previous developers include Frederik Ramm (framm) and Jiri Klement (jttt).

Many others have contributed through bug reports, patches, translations, and documentation work.