Conference bulova::decw_jan-89_to_nov-90

436.0. "DECWindows/DECterm/DECforms application" by SRFSUP::EGGERT (Mary Eggert) Sun Mar 19 1989 16:18

I need help on the following DECwindows/DECterms application scenerio:

	_____________________________________________________________
	|		    |			|		    |
	|     DECforms	    |	  DECforms	|     DECforms	    |
	|     DECterm	    |	  DECterm	|     DECterm	    |
	|		    |			|		    |
	-------------------------------------------------------------
	|		    |			|		    |
	|     DECforms	    |	  DECforms	|     DECforms	    |
	|     DECterm	    |	  DECterm	|     DECterm	    |
	|		    |			|		    |
	-------------------------------------------------------------
	|							    |
	|							    |
	|							    |
	|	DECwindows dialog box				    |
	|							    |
	|							    |
	-------------------------------------------------------------

Some required capabilities for the above display:

1) Use the mouse in DECwindows dialog box (and pushbuttons) to select the
DECforms screen information to be displayed and the window to display it in.

2) Use the mouse to select a DECforms display to input screen data.

3) May want to swap the contents of two DECforms displays.

4) Need interrupt capability to service a high priority task.


Near as I can tell (after one week of looking at DECwindows documentation and
reading notes conferences), I have two options for creating the DECforms DECterm
sessions:

1) Use DECwTermPort to create the terminal port sessions.  Using some really
nice examples created by Dan D'Eramo and Dave Burleigh, I can do most of what
I want to do using the window id of the DECterms.  I don't believe (correct
me if I'm wrong) that I can detect which DECterm session a mouse has activated,
which is a real problem.

2) Use the DECterm widget.  From what I understand the DECterm widget would
be able to detect which DECterm session my mouse clicks, as well as allow me to
swap DECterm sessions.  I think I see how to use the DECterm widget if I were
directly controlling the information being displayed on the screen.  I'm
uncertain how I would get DECforms to interface with the DECterm widget:

DECforms uses the FORMS$ENABLE command to specify a device for the form and
returns a "session id" for use in future DECform commands, such as FORMS$SEND,
which sends information to the screen.  I assume I'd specify the pseudo device
(PYAxx) with the FORMS$ENABLE command.  Does anyone know whether my callback
routine could then display information using the DECforms FORMS$SEND command and
the session id (vs QIOs)? 


I am very open to general comments and suggestions, especially concerning
potential problems.  Can I do what I want to do?  Any examples using the DECterm
widget would also be appreciated (conference DECWINDOWS_PROGRAMMING note 33.4
was very useful).

Thanks in advance for any help,
--mary

>1) Use the mouse in DECwindows dialog box (and pushbuttons) to select the
>DECforms screen information to be displayed and the window to display it in.

DECforms V1.0 is character cell only, as such must be run in a terminal
emulator. It also does not use the ANSI mouse capabilities of the DECterm
and thus you are free to build a composite widget similar to the ones used
for Fileview which contain buttons, boxes, etc. You could then use DECforms 
to do the work in the terminal emulator.

>2) Use the mouse to select a DECforms display to input screen data.

If each of the DECterms that you create have an ability to provide a callback
for focus-in, then you could do this. The interaction would be that DECforms 
would always have a read outstanding to the DECterm, and the DECterm would
lose or gain focus depending upon where you pointed/clicked.

>3) May want to swap the contents of two DECforms displays.

Not enough information. More details please.

>4) Need interrupt capability to service a high priority task.

Also not enough information - define interrupt capability.

>DECforms uses the FORMS$ENABLE command to specify a device for the form and
>returns a "session id" for use in future DECform commands, such as FORMS$SEND,
>which sends information to the screen.  I assume I'd specify the pseudo device
>(PYAxx) with the FORMS$ENABLE command.  Does anyone know whether my callback
>routine could then display information using the DECforms FORMS$SEND command and
>the session id (vs QIOs)? 

In the FORMS$ENABLE request you would specify the device name as the TWAxx:
created by your call to create the DECterm. To update this display, you'd use
the FORMS$SEND, FORMS$RECIEVE and FORMS$DISABLE requests.

I think that you want to use the DECterm widget, but not being a DECterm
internals heavy, I'll defer that question to them.

Also, see the replies in the DECforms conference on DSSDEV::FORMS.

James
DECforms Dev.

I've gotten some really good information offline.  Thank you, James!

--mary