Paul Breneman wrote:
Mark Morgan Lloyd wrote:
Does anybody have any suggestions for a component to display status or
terminal text that will allow limited enhancement (colour, possibly
underline etc.)?
Over the last few weeks I've been tinkering with an emulator for an
obsolete mechanical terminal (IBM 2741), including support for the APL
character set. I started off using a listbox for simple output, noting
that this didn't have provision for multiple colours or marking the
insertion point. I moved on to stuffing characters into a memo, this
allowed me to force a current-position marker but still had no colour.
Looking at the CmdLine component, it appears OK as a command window
(i.e. accepting keyboard input etc.) but isn't so hot when the
principal requirement is to display text pushed into the underlying
strings storage from elsewhere: in particular, there isn't a way to
force the insertion point marker to the end of what's just been output.
I'm sure I'm not the only person who wants to do this sort of thing:
does anybody have any recommendations?
Mark,
I don't have any recommendations but I'm following this message thread
with much interest. Last fall I wrote a "serial debug terminal" with
Free Pascal and fpGUI and that program has proved to be one of the most
useful simple programs I've written in a long time. I've customized it
a few times already for real work projects and I also have some other
projects planned. If you want to see how simple the present code is see
the "DbgTerm.pas" program at this page:
http://www.turbocontrol.com/easyfpgui.htm
I think that almost everybody who has to deal with non-modem equipment
or who has demanding modem requirements (e.g. accommodate a mix of
incoming and outgoing calls and/or obscure protocols) ends up doing the
same. Something that's particularly badly handled in off-the-shelf
software is control-line handling (DTR, CD etc.).
Right now you can't put the cursor in the terminal and send characters
by typing them, but rather there are separate SendEdit and SendButton
components. I'd like to implement a more standard "terminal" operation
so what you are discussing here applies to that.
In my case, I'm collecting keydown events from whatever the visible
control is, converting them to an internal code (derived from the
mechanics of the original 2741 terminal), (local echo done here),
converting that to characters for the serial interface, and finally
sending those to a serial line or telnet connection. Received data
(which might be coded differently from what was transmitted) is
converted to the internal code, written to the same queue that got the
local echo, the content of which is finally converted to Unicode using a
table that mimics an IBM golfball and stuffed into the stringlist that
underlies the listbox or memo control.
A listbox does not have a caret marking the insertion point. A memo
does, and I can generally force that to indicate the position the next
keypress will appear after each character is output. Obviously that can
be confused by a mouse click, but since I'm not using the control's own
keyboard handler the next output character will always appear in the
right place.
I'm sure all this isn't very efficient, but I am, after all, emulating
the terminal that gave the World 134.5 Baud operation :-)
I'd like to keep the present DbgTerm as a very simple example of serial
communications code but I will consider having a more complex terminal
program too. I've run into many people who need a replacement for
HyperTerminal since it has been gone from Vista and later Windows editions.
For Windows I'd point you at Teraterm, of which v1 was Pascal if you
think you need to tinker. For Linux gtkterm.
--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk
[Opinions above are the author's, not those of his employers or colleagues]
--
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