Development Guidelines

How your code should look like

• make sure the code is Java 7 compatible
• make sure there is no trailing white space
• don't use multiple consecutive empty lines
• JOSM uses 4 characters indentation and no tab stops (If you use Notepad++ you can change the default indentation in the "Preferences" -> "Tab Settings" -> check "Replace by spaces" (this is permanent) or with the "change indentation settings" button in the toolbar by removing the check at "use tabs" (this is a temopary setting).)
• Document your code thoroughly. Many people will thank you :)
• add curly brackets for each if, unless it is followed by return (or maybe throw)

How your javadoc should look like

• The ​Oracle Javadoc style guide is used as the base guide
• @since is used for public classes and methods (visible to plugin developers) with the JOSM revision that introduced the element. Example: @since 5408
  • @since is updated when a public method signature changes or if a class is renamed
  • @since can be omitted for public methods and fields introduced at the same time as the class, provided they do not have changed and the class is correctly documented.
• @throws is preferred to @exception

Configuring Eclipse

Internationalization

• make sure you use tr(...) for all localized strings

  import import static org.openstreetmap.josm.tools.I18n.tr;
  
  // use tr(...) for exception messages
  //
  throw new Exception(tr("error message always in tr()"));
  
  // use tr(...) for labels, title, tooltip texts and the like 
  //
  new JLabel(tr("Label always in tr()"));
  
  // etc.
  

• never assemble localized messages with +. Use format placeholders instead.

DONT new JLabel(tr("My Label " + labelId));

DO new JLabel(tr("My Label {0}",labelId));

Only exception: + can be used to break long lines of non-variable texts.

• When using apostrophe, the following rules apply:

For all tr the apostrophe is special. (Like backslash in C)
It needs to be escaped by another apostrophe:

new JButton(tr("Don''t press me more than {0} times!", n))

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