Applets, user's manual

Applet archive in jar format   Applet archive in zip format   Programmer's manual

Introduction

The new version of the applets used in the present web site are available.

They are bases on a same set of JAVA classes which have been rewritten.

Here are the main improvements :

• an interactive text zone which allows to update the position in cliking on a move,
• a text zone scrolling which automatically shows the move corresponding to the position on the chess board,
• a drawing of small pictures in place of usual piece symbols,
• a commented zone which allows you to to improve your comments thanks to special commands :
  • setting colors ( &red &green &blue &black )
  • changing symbols into figures ( ^P^N ^B ^R ^Q ^K )
  • modifying the font from roman to italic or bold face ( &rm &it &bf )
• a commented zone already colorized by default even if you haven't put special command within your comments,
• games put outside HTML pages, within independent files in PGN format,
• exercises which initial position can be provided in the FEN format.

The set of applets, including piece pictures, needs 80 kb, about the size of a 640x480 picture in JPEG format.

Downloading applets

Applets are stored within a unique file chess.jar you can download in clicking on the this link. Save this file on your computer.

chess.jar is a java archive which contains all classes and pictures the applets need.

To use these applets in your web site, you must :

• install the file "chess.jar"
• install in parallel the directory "chess" equivalent to the archive. This seems a little bit strange but internet navigators are not always able to take advantage of a java archive directly.

To implement an applet in an html page, you have to follow the following syntax :

  <applet codebase="path to reach the directory containing chess.jar and the sub-directory chess"
          code="chess.applet_name"
          archive="full_file_name_of_chess.jar" width=500 height=450>
    ... paremetars of the selected applet ...
  </applet>

The parameter codebase is faculattive if the sub-directory chess est stored in the same directory as your HTML pages (a good practice). Moreover all PGN file you want to publich must be obligatorily located within the directory codebase or in a sub-directory, otherwise the applets will not be abel to access them (strong limitation of navigators due to security reasons).

Installing the directory "chess" on your computer is not difficult if you have a java compiler. The following instruction will deflate the archive :

   jar xvf chess.jar

No panic if you don't have any java compiler : I have also prepared a Zip archive (I hope you have at least WinZip, unzip or pkunzip ...) : chess.zip

Now, take care about capital and small letters because Bill Gates is there, just behind you, in your shadow (Dear Bill, we would be bored without him istn't it ?). Indeed, Windows likes to translate small letters into capital letters and neither Internet, nor Java do not like that. For files "*.class", there is usually no problem because these files do not follow the old DOS syntax (too long suffix) and Windows does not translate them. But for the other files, especially directories and pictures, be careful : they must appear in small letters in the Windows Explorer. Here is the normal organisation of the chess directory :

  chess -> *.class
        -> images -> *.gif

If you see for instance "Chess" instead of "chess" of "Pieces25.gif" instead of "pieces25.gif" then it is time to replace capital letters by small letters !

Available applets

Four applets are presently available :

• chess.replay replace the old replay : it allows you to replay games entered within HTML pages as applet parameters.
• chess.exo replace the old exo : it allows to show manay small chess boards, each of then repesenting an exercise to solve. Thes erercises, are defineds as applet parameters withing the HTML page.
• chess.database enables you to replay games saved in independent PGN files. Caution : each file must contain one and only one game. However, thes files can be organised in packages thanks to special files decribing menus. This applet displays two menus ; the menu managing packages and the menu of the current package.
• chess.exobase allows you to solve exercises (or te replay games) saved in PGN files. A same file may contain many exercises (or games). nevertheless, take care about the time needed to download such a file. This is the reason why this applet is mainly used to display exercices rathar than games : exercises, even commented, always keep a reasonable size.

The two last applets are new and allow you to publish games or studies directly produced by softwares like ChessBase or ChessAssistant. ChessBase offers a similar solution in its version 7 (via a JavaScript program) but the result is quite rigid and not enough interactive.

Playing your own variants

To move a piece you must :

• click on the piece to move
• click on the arrival cell

These variants are not taken into account in the game : they are only displayed. This is the reseon why you cannot come back within such a variant (you come back to the initial position).

Moreover, only the queen promotion is understood for the moment.

Additional informations

If you want to get the source files of the applets, then send me a message either to my professional or to my personal address. All suggestions to improve them will be welcome.

If you prefer to make more complete some topics in the present web site, then do not hesitate and send me you commented games or studies in PGN format. I will publish them for you without forgetting to precise the author name.