README.developer

README.developer - Notes and current status of 2016 JSettlers development
	(version 2.0.xx, beta server running at nand.net)
	http://nand.net/jsettlers/devel/
	https://github.com/jdmonin/JSettlers2

Scroll down a bit for the current TODO list.
See VERSIONS.txt for recent changes.

CONTENTS
--------
- Overall structure of the code and project
- Tips for debugging
- Setup instructions for JSettlers as an Eclipse project
	(although you may use any IDE you want)
- Recommended debug/run configurations for testing
- If you want to configure a sqlite database for testing
- Build setup and results
- Current partially-done work
- Current TODO list
- Developing with a database (JDBC)
- Internationalization (I18N)
- Robots (AI)
- Coding Style
- github usage


Overall Structure
-----------------
The main server class is soc.server.SOCServer.
The client communication is soc.client.SOCPlayerClient, and in-game interface is in soc.client.SOCPlayerInterface.
Game state is held at the server in soc.game.SOCGame and its fields.  Partial game state is known at clients.
Communication is described in soc.message.SOCMessage.
Robots talk with the server like normal human clients.
Most robot messages are per-game; instead of being handled in SOCRobotClient,
these are handled in a loop in SOCRobotBrain.run().
Game options and scenario rules are controlled through SOCGameOption; see initAllOptions javadoc for a list.
Options have flags for their properties ("hidden internal option", "drop if not set", etc).
All scenario-related game option keynames start with "_SC_", and provide special rules for the scenario.

Coding is done in Java 1.5, but should compile cleanly in newer JDKs.
(Before v2.0, we restricted ourselves to 1.4 for backwards compatibility.)
The build system is Ant, which is natively understood by Eclipse.  Use any IDE you want, including vi.
Use spaces, not tabs.  Please try to keep the other conventions of the code already there.
(See "Coding Style" below for more details.)

When adding new methods or fields, describe them in javadoc, including the @since marker
and the one-sentence summary (even though some old methods don't have that summary).

When submitting patches, please use unified diff (-ur) format.

For more information about the AI, please see the "Robots (AI)" section
and Robert S Thomas' dissertation.

For more information about the board coordinates, see the dissertation appendix A,
or javadocs in soc.game.SOCBoard, and src/docs/hexcoord.gif and hexcoord-6player.gif.
To show piece coordinates in the board's tooltips, in the game window chat box type: =*= showcoords
To no longer show those coordinates, type: =*= hidecoords

The client's structure was refactored in 2.0 by Paul Bilnoski.  Paul's description of this work:
Added two major new pieces of API: PlayerClientListener and GameDisplay. These are spliced between the
SOCPlayerClient and AWT UI code, primarily found in SOCPlayerInterface. The APIs are used by the player client
abstract network communication away from the UI - to communicate with the UI about network events received and
receive events to send to the server. Some of it is done using inner classes and interfaces which should be
split out into an improved package structure.


Tips for Debugging
------------------
You can use debug commands in any practice game, by typing into the game chat
textfield.  Type *help* for a list of commands.
(If you need to use debug commands over a network connection, start that server
 with -Djsettlers.allow.debug=Y and connect with username debug.  For security,
 please use sqlite or another database, and make a "debug" account with a password.
 See README.txt section "Database Setup".)

If you want to inspect the game object state at the server or robot:
	Set a breakpoint at SOCServer.processDebugCommand, or at "case SOCMessage.GAMETEXTMSG"
	  send a text msg from a client (the chat textfield), and inspect the game obj at that point
	To inspect game state at robot, breakpoint robotcli.treat and send a text msg like *BOTLIST* or robot2:current-plans
	On Linux/Unix JVMs, you can print a stack trace / thread dump at the server by sending SIGQUIT
	  (kill -QUIT pidnumber). In deadlocks the thread dump won't show what has an object locked,
	  but may show what's waiting on the object.

Some game options are meant to be set by the server during game creation,
not requested by the client.  Their option keynames all start with '_'.
(These are used for game scenario rules.)  The New Game Options frame normally
hides them during game setup.  If you want to show them:
	Launch the client
	Start a Server, or Join a Server
	In the Nickname field, type: debug
	Click Practice or New Game
The values you set may still be overridden by the server in SOCGameOption.adjustOptionsToKnown.

To use the "Free Placement" debug mode, type this debug command on your turn:
	*FREEPLACE* 1
You can now build and place pieces without consuming resources, by clicking
or right-clicking on the board.  (Don't use the "Buy" buttons for Free Placement.)
The placements must follow game rules, except that they cost no resources.
To place for another player, click their face icon.  You cannot remove a piece
once it is placed.

The placed pieces accumulate victory points for their players as normal, and
Longest Road is tracked.  If a player gets 10 VP total, the game will be over
when their turn arrives; your own player would win the game immediately.

To exit Free Placement mode, either click "Done" (which will end your turn) or
type this debug command:
	*FREEPLACE* 0
When exiting Free Placement mode during initial placement, all players must have
either 1 settlement and road, or at least 2 settlements and roads.  This allows
the game setup routines to work properly during this debug mode.  The current
player will be set to the first player (if 2+ settlements/roads placed) or the
last player (1 settlement placed).

In Eclipse, increase the console buffer size before long test runs, so you can
scroll up to see the entire game's debug output.  Go to Eclipse Preferences ->
Run/Debug -> Console, and either un-check "Limit console output", or set it to
a size larger than the default 80000 characters.  Robots and network messages
can create a lot of output, so can javadoc generation.

These debug commands are used at the client to help show the board's status:
	=*= showcoords or =*= hidecoords
		show or hide coordinates of the playing piece, hex, etc
		currently at the mouse pointer's location
	=*= show: all or =*= hide: all
		show or hide potential and legal piece placements which are
		currently valid for player 0 (sits in the upper-left corner);
		available only for the sea board layout, not the classic 4- or
		6-player boards.  To show only some piece types' legals and
		potentials, instead of 'all' use an index number from
		SOCBoardPanel.debugShowPotentials javadoc.

If you want the robots to play a few games without any humans, set this
property on the command line when starting the server:
	-Djsettlers.bots.botgames.total=5
As each game finishes, a new bot-only game will be started until 5 have been
played. You can optionally use the client to observe a bot-only game. Also if
jsettlers.bots.botgames.total != 0, at any time the client can create a new game
and start it as bots-only using the debug command *STARTBOTGAME* [maxBots].
See the "Robots (AI)" section for more details on bot testing.

Setup instructions for JSettlers as an Eclipse project
------------------------------------------------------
  (written for Eclipse 3.6, should be applicable to other versions with minor changes)

- choose File -> New -> Project... -> Java Project from Existing Ant Buildfile.
- Browse to jsettlers-1.1.xx-src/build.xml, select the "javac" task in target "compile".
  Check "Link to the buildfile in the file system", hit Finish.
- Project -> Properties: Resource: Text file encoding: UTF-8
- You'll need to build once before you run it, to create version.info from resources/version.info.in.

Continue reading to see how to set up the builds and the coding style in Eclipse.


Build Setup and Results
-----------------------
Before building, make sure you have the Java Development Kit version 5 or later.
If you simply want to run the client or server, you only need the Java Runtime (JRE).
If you wish to maintain a user database for your server, you need MySQL or PostgreSQL
installed and configured, or the sqlite jdbc driver for a file-based local database.

This package was designed to build with eclipse, or with the ANT tool available
from http://ant.apache.org/ .

Check the "build.properties" file. There may be build variables you
may want to change locally. These can also be changed from the command
line if calling ant that way, by passing a "-Dname=value" parameter to ant.

There are several build targets, here are the most useful ones:

 build      Create project jar files. (default)
 clean      Cleans the project of all generated files
 compile    Compile class files into "target/classes"
 dist       Build distribution tarballs and zips.
 javadoc    Creates JavaDoc files in "target/docs/api"
 src        Create a tarball of the source tree
 build-i18neditor  Create PTE.jar for maintaining i18n translations (not built by default)

All files created by building are in the "target" directory, including
JARs, Java .class files, and JavaDoc files. Distribution tarballs, zip
files, and installation files are placed in "dist".


Recommended debug/run configurations for testing
------------------------------------------------
  In my Eclipse project, I've created these debug/run configurations:

Java applet: soc.client.SOCApplet
   width 700, height 500
   parameters: PORT = 8880

Java applications:
  cli-noargs  soc.client.SOCPlayerClient
  socserver   soc.server.SOCServer
     arguments: -o N7=t7 -o RD=y -Djsettlers.startrobots=7
                -Djsettlers.allow.debug=Y 8880 20 dbuser dbpass
  socserver-sqlite  soc.server.SOCServer
     arguments: -o N7=t7 -o RD=y -Djsettlers.db.url=jdbc:sqlite:jsettlers.sqlite  -Djsettlers.startrobots=7
                -Djsettlers.allow.debug=Y 8880 20 dbuser dbpass

  The server will start 7 bots with the above configuration.  If you need to stop and start your
  own bots, then add
		-Djsettlers.bots.cookie=cook
  to the server configuration arguments, and create these Java application configs:
  robot1      soc.robot.SOCRobotClient
     arguments: localhost 8880 robot1 r1 cook
  robot2      soc.robot.SOCRobotClient
     arguments: localhost 8880 robot2 r2 cook


If you want to configure a sqlite database for testing
------------------------------------------------------
  These instructions are written for Eclipse 3.6.
  See also the "Developing with a database (JDBC)" section of this readme.
  JSettlers+sqlite works with standard Eclipse; the j2ee eclipse also has a convenient data browser.
  Note that README.txt mentions a command-line option -Djsettlers.db.jar=driverfile.jar ; that's
  needed only while running the jsettlers JAR from the command line, not running inside eclipse.

  - See the "socserver-sqlite" line just above for the server command line;
	this is an eclipse Run Configuration for a jsettlers server which
	includes the sqlite database you're about to configure.

  - Download the driver from https://bitbucket.org/xerial/sqlite-jdbc

  - Eclipse menu -> prefs -> data mgmt -> connectivity -> driver definitions -> add
	  [this menu path will be available only under eclipse j2ee, not the basic eclipse]
	  select SQLite JDBC Driver
	  jar list -> edit (or add,if empty) -> navigate to sqlite-jdbc-3.7.2.jar -> OK

  - Project build path: libraries: include sqlite-jdbc-3.7.2.jar here too

  - Build the project (from build.xml; creates target/classes/resources/version.info)

  - Run socserver once to create the db file and exit cleanly:
	run configurations
	  main class: soc.server.SOCServer
	  program arguments: -Djsettlers.db.url=jdbc:sqlite:jsettlers.sqlite  -Djsettlers.db.script.setup=../src/bin/sql/jsettlers-tables.sql
	  working directory: filesystem: JSettlers2/target
	If sqlite crashes on launch, retry with -Dsqlite.purejava=true
	This line should appear in the console:
	Setup script was successful. Exiting now.

  - Add the database to eclipse j2ee, so you can add tables and query it:
	[skip this if your eclipse is not j2ee]
	Window -> show view -> other... -> data mgmt -> data source explorer
	Right-click Database Connections, choose New
	  Type: SQLite ; give a description and click Next
	  Browse to jsettlers.sqlite
		(it's most likely in your workspace, or the server's working directory)
	  Click "Test Connection"
	  Click Finish

  - Run the "socserver-sqlite" configuration
	  main class: soc.server.SOCServer
	  program arguments: -Djsettlers.db.url=jdbc:sqlite:jsettlers.sqlite  8880 20 dbs dbp
	  working directory: filesystem: JSettlers2/target
	This line should appear in the console:
	User database initialized.

  - The database is now ready for use, development, and debugging.
	To create player users, see README.txt and use SOCAccountClient.


Current partially-done work
---------------------------
	- Refactor SOCMessage classes to use templates
	- Some SOCMessage classes (SOCGames, SOCJoinGameRequest) accept objects like SOCGame and parse/create them;
	    over-the-network communication will always be strings only.


Current TODO list
-----------------
	Work on these possible roadmap items has not yet begun.
	This list is ranked from easier, to more difficult.
	You can also search the source for TODO for ideas.

	- Visual reminder to player when they've made a trade offer
	- Show # VP when choosing where to sit, if game is in progress
	- Keyboard shortcuts for "roll", "done" buttons
	- Search the source for /*18N*/ and externalize those strings; see "I18N" section below
	- Occasionally an image does not re-scale when board is stretched.
		Instead of giving up (SOCBoardPanel.scaledHexFail, etc),
		try re-scaling again, but increase width or height by 1 pixel.
	- Kick robots if inactive but current player in game, assume they're buggy (use forceEndTurn)
	- Control the speed of robots in practice games
		Adjust SOCRobotBrain.pause, ROBOT_FORCE_ENDTURN_TRADEOFFER_SECONDS, etc
	- Sound effects
	- Possible: Auto-add robots when needed as server runs, with server active-game count
		only do it if jsettlers.startrobots property is set
	- Docker (dockerfile in git) or other containerization, including sqlite jdbc and a jsserver.properties using sqlite
		related bootstrapping issue: admin doc reminder to create admin acct right away, name that admin in jsserver.properties
	- User documentation is out of date; unsure if any user ever reads it anyway
	- refactor: ga.getPlayer(ga.getCurrentPlayer()) or getClient().getClientManager()
	- Refactor SOCRobotClient: Move simple handle-methods which don't
		put the message into brainQ, but only update game fields/
		methods, into SOCDisplayless if possible.
	- Refactor: SOCGameOption static methods to check and change values within a set
	- refactor: name of dev-cards consolidate
	- refactor: resource-type constants consolidate somewhere (Clay, Wheat, etc)
		current SOCResourceConstants.CLAY vs SOCPlayerElement.CLAY
	- Refactor: combine the cli/displayless/robot endturn-like methods
		ex. search for ga.setCurrentDice(0), or newToOld, or ga.resetVoteClear
	- At board reset, game observers not currently handled properly
	- Property for read-only database use without errors
	- Game "owner" with extra powers (kick out player, etc)
		What happens if owner loses connection?
	- Customize bot names (txt file or startup property) in srv.setupLocalRobots
	- "Hot seat" mode (multiple human players sharing a screen on 1 client)
	- Monitoring: Command line utility or html-based dashboard: Uptime, health of bots,
		currently active/total games from *STATS* cmd, client versions, any errors, etc
	- Per-game thread/message queue at server (use SOCMessageForGame.getGame)
	- HTML5 client
	- Cities & Knights support
		- UI mock-ups
		- state change / network message plans
		- robot support


Developing with a database (JDBC)
---------------------------------
JSettlers can optionally use a database to store users and passwords, game score history,
and robot parameters.  If databases interest you, the project welcomes contributions.
Please keep these things in mind:

- The DB is an optional part of jsettlers, other functions can't rely on it.
- DB code should be vendor-neutral and run on mysql, postgres, sqlite, oracle, etc.
  Please test against sqlite and at least one other db type before sending a pull request.
- See README.txt for JDBC driver download sites, URL syntax, and server command-line arguments.
- For test runs inside Eclipse, add the JDBC driver to the project's build path -> Libraries -> Add External JAR,
  or add it to the classpath tab of SOCServer's eclipse Run Configuration; that option is
  useful when testing against multiple database types.
- See also the "If you want to configure a sqlite database for testing" section of this readme.


Internationalization (I18N)
---------------------------
An internationalization framework has just been put into place for v2.0.00,
and not yet fully used, so you won't see it used in every server and client class.
Some work in progress is surrounded by marker comments: /*I*/"{0} has won the game with {1} points."/*18N*/

When building strings that the user will see, don't use + to build the strings;
use strings.get or strings.getSpecial with parameter placeholders such as {0}.
(At the server, use messageToPlayerKeyed, messageToPlayerKeyedSpecial, messageToGameKeyed, etc.)
The client strings live in soc/client/strings/data*.properties.  An example commit is 68c3972.
The server strings live in soc/server/strings/*.properties.  An example commit is 3e062b7.
See the comments at the top of any *.properties file for format details.

If an i18n string lookup's english text isn't obvious from the key, add it as a
comment to make searching the source for strings easier:
	setTooltipText(strings.get("hpan.points.total.yours"));  // "Your victory point total"

Note that all java properties files use ISO-8859-1, not UTF-8, as their encoding.
Make sure your editor or IDE honors this encoding format.  Unfortunately you must use \uXXXX
for characters outside that 8-bit encoding's range, directly or with the native2ascii utility:
	native2ascii -encoding utf8 examplefile.utf8 examplefile.properties

You can use the included editor net.nand.util.i18n.gui.PTEMain to edit localized strings
for two locales side by side; this editor has unicode support and color hilighting, and
will convert to ISO-8859-1 (with unicode escapes) automatically when saving.
See src/java/net/nand/util/i18n/README.txt for more details.

Before running PTEMain for the first time, you must build the JSettlers build target
(using ant or eclipse) so that the editor's own externalized strings will be available.

When starting the editor this message is harmless, because preferences are stored per-user:
	Dec 6, 2013 3:59:16 PM java.util.prefs.WindowsPreferences <init>
	WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.

To override system locales for testing, launch the client with vm argument -Djsettlers.locale=es
(this goes before -jar if using the command line).

Pseudolocalization for testing (en_AA locale) uses StringUtil from the JBoss Ant-Gettext utilities.
See command-line utility net.nand.util.i18n.PropsFilePseudoLocalizer.

Thanks to Luis A. Ramirez for building the initial client i18n framework and advocating i18n-friendly
programming practices throughout the code base with helpful specific suggestions.


Robots (AI)
-----------
If you're interested in experimental changes to the jsettlers robots, or writing a "third-party"
robot to connect to jsettlers, read this section.

The project was originally started as Robert S Thomas' PhD dissertation about AI agents, so there's
some instrumentation for the bots but it's not entirely documented.  For a technical overview of
how the bots plan their actions, start at the SOCRobotBrain class javadoc.

There are a few bot debugging commands, such as print-vars and stats. To send them, type
botname:command into the chat textbox while playing or observing a game with bots:
	robot 7:stats
See SOCRobotClient.handleGAMETEXTMSG_debug for more details.

If you're looking to make minor changes, it's probably best to fork the soc.robot package and go
from the classes and javadocs there.  For a larger change, some parts of soc.robot might still be
useful to talk with the server and track the game's other players.  Robert S Thomas' dissertation
also has some discussion on those structures.

Right now bots are instantiated within the server for security; for a 3rd-party bot, start with the
soc.robot.SOCRobotClient class.  You can start a bot separately from the server through the
SOCRobotClient constructor or main method.

The server generates a security cookie that bots must send at connect. You can view the cookie by
starting the server with
      -Djsettlers.bots.showcookie=Y
or override it with something like
      -Djsettlers.bots.cookie=foo

For bot testing and statistics, you can have the server run some robot-only games (no human players)
with the jsettlers.bots.botgames.total property. To run 7 robot-only games in a row, with each game
randomly choosing from 10 robot players, you could start the server with:
      -Djsettlers.startrobots=10 -Djsettlers.bots.botgames.total=7
The robot-only games run at a quick pace, about 2 minutes for a 4-player game. You can use the
jsettlers client to observe a bot game as it plays.

If jsettlers.bots.botgames.total != 0 (including < 0), at any time the client can create a new game,
join but not sit down at a seat, and start that game as bots-only using the debug command
*STARTBOTGAME* [maxBots] to test the bots with any given combination of game options and scenarios.


Coding Style
------------
Scroll down a bit if you just want to see how to set up the style in Eclipse.

This is the project's coding style, based on the original authors' style.
This section has more detail than you need to know, but it's here if you're interested.
Although we may not agree with every detail of it, for consistency's sake,
please keep the conventions of the code that's already there.

Use spaces, not tabs.  The basic indent is 4.  Place braces on their own line.
Lines should be less than about 120 characters long; if you have to indent too
much, consider refactoring into a new method.

Use 1 blank line between methods.  If you have nested classes, use 3 blank 
lines between them, and comment each one's closing brace with the class name.
If you have a long method whose work can be divided into "sections",
preface each section with a /** javadoc-style */ multi-line comment.

If a declaration line is getting too long (about 120 characters), break it
and indent it slightly from the first line, not aligned with the method name.
Throws declarations are also always indented on the next line:
    public SOCGameOption(String key, int minVers, int lastModVers,
        boolean defaultValue, boolean dropIfUnused, String desc)
        throws IllegalArgumentException
If related methods have the same name but different sets of arguments, indent
all their declarations the same way for easier comparison.

Some methods return in the middle of their body, depending on conditions.
That kind of early return should be marked with a prominent comment such as:
	return;   // <--- Early return: Temporary piece ---

If an i18n string lookup's english text isn't obvious from the key, add it as a
comment to make searching the source for strings easier:
	setTooltipText(strings.get("hpan.points.total.yours"));  // "Your victory point total"

Use parentheses around all boolean expressions, to make them easier to see as such:
	flagvalue = (state == xyz);
	somevar = (testflag) ? a : b;

Some methods end with this style of code:
	if (x)
	    return y;
	else
	    return z;
In those cases, the return is part of the logical flow of the if-statement:
Both y and z are normal and valid, and deserve equal "visual weight" and indenting.
That section of code should not be reformatted to something like:
	if (x)
	    return y;
	return z;
because conventionally in jsettlers, that would mean z is the usual case
and y is less common or is an edge condition.

In emacs, you can place this in your .emacs file to use spaces instead of tabs:
(setq-default c-basic-offset 4)
(setq indent-tabs-mode nil)
	[ courtesy http://www.jwz.org/doc/tabs-vs-spaces.html, which also mentions vi ]
You will also want this to have this, which disables auto-reindenting:
(setq-default c-electric-flag nil)


Here's how to set up the coding style in Eclipse:

	preferences -> general -> editors -> text editors:
	[x] insert spaces for tabs
	displayed tab width: 8
	[x] show print margin
	print margin column: 120
	[x] show whitespace characters
		configure visibility -> trailing space, trailing ideographic space, trailing tab

	project properties -> java compiler -> configure workspace settings
	  compiler compliance level: 1.5

	prefs -> java -> code style -> formatter
		Click "Enable Project Specific Settings", then New
		{
		Profile name: 'jsettlers'
		"based on Eclipse built-in standard"
		[X] Open the edit dialog now

		(Indentation)
		Tab policy: Spaces only
		Indentation: 4
		Tab size: 8
		confirm is unchecked: [ ] Indent empty lines

		(Brace positions)
		All 'next line' except:
		Blocks in case stmt: Next line indented
		Array init: Next line indented
		[X] Keep empty array initializer on one line

		(Control Statements)
		[X] New line before else in if
		[X] New line before catch in try
		[X] New line before finally in try
		[ ] New line before while in do
		[X] Keep 'else if' on one line
		[ ] (all other options)

		(All other tabs)
		Take defaults

		}

		Hit OK
		Make sure the formatter "active profile" is jsettlers
		restart eclipse

		go to prefs -> java -> code style -> formatter
		  if it's not active: set active profile to jsettlers & restart eclipse

		prefs -> java -> editor -> typing
			Verify tab 8 spaces, indent 4 spaces:
	   [x] Tab key adjusts indentation of current line
	   "The tab display value (currently 8) and whether spaces are used to indent lines
	    are configured on the formatter preference page.  The current indentation size
	    is 4, using spaces."

When you hit enter twice to skip a line in Eclipse, watch for unwanted whitespace because
Eclipse will add whitespace to each blank line to match the current indent.

If desired, in Eclipse preferences, you can bind a key combination to Remove Trailing Whitespace.
This will trim it from the entire file when the key is pressed.

To manually clean up trailing whitespace:
Eclipse preferences -> general -> editors -> text editors -> [x] Show whitespace characters
Find/Replace: Regular expressions: Find [\t ]+$

The rotated 3:1 port hexes' font is Optima Bold, 21 pt.


github
------
The project code lives at https://github.com/jdmonin/JSettlers2 .
Patches can be sent by email or by pull request.
Please make sure your patch follows the project coding style.

The master branch receives new features and enhancements for the next 'minor'
release.  As soon as a bug is fixed or a feature's design is fairly stable, it
should be committed to master.

The master branch has new 2.0.xx development.  Until 2.0.00 is ready,
there's an old-1.1.xx branch in case of urgent bugfixes, so we can release
new stable versions.  Most work on 1.1.xx is backported from 2.0; changeset
comments often mention a hash from a master commit.  Version 2.0.00 was
split off right after releasing version 1.1.13.

Once 2.0.00 is out, we'll follow the usual jsettlers model:
There are no branches, because jsettlers2 is mature at this point.
Each minor release is a stable release, there is no experimental branch.

Each release's files are tagged for the release ("release-1.1.14").
The last commit for the release updates VERSIONS.txt with the final build number,
with a commit message like: Version 1.1.14 is build OV20120930
Then: git tag -a release-1.1.14 -m 'Version 1.1.14 is build OV20120930'

You can also see an overview of commit comments in the git log
histories of src/java/resources/version.info.in and VERSIONS.txt.

The github repo includes the full JSettlers2 CVS history formerly hosted at
http://sourceforge.net/projects/jsettlers2/ through 2012-09-28.
The old old source history from Robert S Thomas (2004-2005) can be found at
http://sourceforge.net/projects/jsettlers/ .