(by Mattias Werner, 1994-03-29)

This directory contains an example application, which can be connected
with the daVinci graph visualization system. Refer to the daVinci user
manual and the documented source code (application.c) for further details.

Use 'make' to compile this application. If you are not using a standard
OpenWindows installation (in /usr/openwin), you must edit the Makefile
to specify the correct include paths. In the directory there is a compiled 
binary of the application for Linux.

You can connect this application with daVinci by using two different
methods.  
    (1) Either you start the application from daVinci by specifying the 
	application name and full path in the menu 'Properties/Application...' 
	and then start it by using the menu 'File/Connect Application' or
    (2) you start daVinci from the application by pressing the button 
        'Connect daVinci...'. Then you must specify the name and full path 
        of daVinci and press 'Connect'.
    	
The application has two text subwindows. In the upper one you can edit 
messages which should be send to daVinci's application interface. After 
pressing 'Send Message' the whole text content of this subwindow is send 
to the visualization system. You can find some examples for commands in 
the file command_examples.txt in this directory. Further informations 
about daVinci's application interface can be found in the appendix B of 
the user manual. In the lower text area you can see the answers from 
daVinci. 

CAUTION: you can only send messages to daVinci which are conforming to the 
command grammar found in figure 4 (appendix B.3) of the user manual. Other
messages to the interface should be avoided. They are forcing an error 
message as answer:

	error_output_stream("syntax error in incoming message").
	
The reason is, that the interface can't be implemented in a fault tolerant 
way at the moment (see user manual for further details). A usual problem 
is a warning message from the application at startup like this linker 
warning (could this happen for Linux?):

	ld.so: warning: /usr/openwin/lib/libX11.so.4.3 has older revision 
	than expected 10
	
This message will be send to daVinci if you start it from here. Of course 
it is not an allowed command and the communication will fail. You have to 
make sure that the application is not reporting warnings or error messages. 
You can check this condition by calling the application from the shell. 
This restriction is of course very "unsightly" (sorry!). In one of the 
next releases we hope that the problem is solved.



