Help for MAJA

FAQ

You need Netscape 4.04/5 with the JDK 1.1-patch, Netscape 4.06-8 or 4.5! Any previous version will definitely fail, since MAJA uses the new JDK 1.1 event-model, which is not supported by previous versions.
The Microsoft Internet Explorer 4.x can be used as well.
If you have older versions without support for JDK 1.1, then use the plug-in versions. The Java plug-in (previously called Activator) is available from Sun Microsystems. If you do not have it installed, then loading the respective version will offer you to download it. Versions for Netscape for Solaris and MS Windows and the MS Internet Explorer are available.
Security Exceptions may occur when Ctrl-C is pressed or when the application is terminated with the escape-key. These can be ignored.
If the applet does not respond to your key-presses, try to click onto the applet first. To use shortcuts for Netscape again, click into a window of Netscape outside the applet.
Huge images often make problems, especially JPEG encoded ones. MAJA aborts an image, if more than eight errors occur while loading it.
HotJava has some real problems with JPEG images. Under some weird circumstances it fails to load them.

PNG is still not supported as graphic format. Netscape and Microsoft will include it someday, I hope.
This format can be included by using an external image-handler. The handler-class must be provided as applet-parameter:
<param name="image.<ext>" value=<class>>
<ext> is the extension of the image-format and <class> is the handler, which has to implement java.awt.image.ImageProducer and which must have a constructor with java.net.URL as parameter. An example for PNG would be:
<PARAM name="image.png" value="com.sixlegs.image.png.PngImage"> (see Six-Legged Software; note that this handler is NOT provided with MAJA and the examples do not use PNG images).
MAJA only understands the MHEG-5 text-notation. ASN.1 is not supported and there are no plans to support it in the near future.
MAJA is not fully DTG-compliant. There are some features missing: ASN.1, PNG, audio from memory, several resident programs. We are working on it.
It runs on JDK 1.2. In beta 4 is a bug, which results in incorrect font-metrics. So text may be layed-out incorrectly. This is fixed in rc1/2.
Where are the plug-ins? - The public version of MAJA no longer supports video-streams. Only simple audio-streams are supported. The normal version supports the Java Media Framework from Sun Microsystems and Intel. It also supports the Netscape plug-in and can access local players, when run as application.
MAJA can be run as application. In this case start it like this:
java maja <file or URL to scene> [<parameter-name>=<value> ...]
You should use JDK 1.1.5 or above. I usually provide the following options to the java-interpreter/-jit: -ms16m -mx64m -ss4m
OK, can I get the normal version? - Please contact us. Maybe we can sort something out.
WOW! The IS version seems to be much faster than the DIS version! - The IS engine is now completely implemented in Java. So there is no need anymore to contact a remote engine via CORBA (this is still supported). A list of implemented objects and actions can be found here.

For further questions you can ask the following people:

Klaus Hofrichter (hofrichter@fokus.gmd.de): He is the leader of the GLUE-project, in which the MHEG-engine is being developed.
Andreas Zisowsky (zisowsky@fokus.gmd.de): He developed the MAJA-applet.

Special keys

Some browsers on some platforms do not provide all pressed/released keys to the applet. Therefore some extra keys are used to simulate the non-provided key-presses. As far as possible, the keys of Vi and Emacs are used.

Key-mappings for all objects except EntryFields
default	alt. 1	alt. 2	meaning
Cursor-up	k	Ctrl-p	up
Cursor-down	j	Ctrl-n	down
Cursor-left	h	Ctrl-b	left
Cursor-right	l	Ctrl-f	right
Page-Up	-	Ctrl-u	previous page
Page-Down	+	Ctrl-d	next page
ENTER	SPACE		select (SPACE only non-DTG mode)
SPACE			Text-key (DTG mode)
F1	Ctrl-1	? or Ctrl-h	help
F5	Ctrl-5	r	red on remote-control
F6	Ctrl-6	g	green on remote-control
F7	Ctrl-7	y	yellow on remote-control
F8	Ctrl-8	b	blue on remote-control
Mappings for EntryFields
Cursor-left	Ctrl-b		left
Cursor-right	Ctrl-f		right
Backspace	Ctrl-h		remove previous character
Del			remove current character
Tab			enter four spaces
Escape			terminate input
Additional keys
Ctrl-C	(Escape)		Abort and destroy Applet
Ctrl-L			Repaint all
Ctrl-R			Restart from the beginning
Keys in non-obfuscated version
Ctrl-D			Toggle debug-mode
Ctrl-V			Print debug-info of active Visibles under mouse-cursor
Ctrl-O			Print debug-info of Application, Scene and Ingredients

Applet-Parameters

Name	Value	Description
scene	URL to MHEG-Application	URL to the file containing the MHEG-application (usually "appdir/startup"). This can be relative, if the parameter scenebase is provided. If MAJA is run as application and not as applet, then this must be the first parameter without the prefix scene=.
scenebase	URL to application-root	URL to the directory, which contains the application-directories. MAJA tries to find that automatically from the startup-scene and the group-identifier of the first application. But this may not work, if that identifier is incorrect or uses some of the weird shorthand-notations of DTG/DAVIC.
image.<ext>	class	Image-handler for the specified extension, if it is not supported by the browser. The class must implement java.awt.image.ImageProducer and must have an constructer with the parameter java.net.URL.
dtg	true	This value is usually derived from the InputEventRegister of the scenes. It must be provided, if some specific DTG default-values in the application are required, before the scene is loaded.
text	html	Specifies that all texts should be processed in HTML-mode, regardless if they contain any html- or body-tags.
store	file:<path> server:[host][:port]	The file, where to store persistent information. It is also possible to access a remote persistent store-server. A really simple implementation is available upon request.
orm	URL	URL to a file containing the IOR of the DSM-CC server. scene or scenebase must have the protocol "dsmcc" in that case. The protocol-handler is available upon request (requires Inprise's VisiBroker 3.x).
Non-obfuscated version
debug	on \| off \| engine	Since MAJA is perfect, you will never need this... ;-)
engine	class	Class, which parses MHEG-5 or which connects to an external engine.
server	host	Specifies the location of an external server to start.
IOR	IOR	IOR of already running external server.

You would like to have more help or you have comments? Send mail to: zisowsky@fokus.gmd.de

Last modified: 10. February 1999