--- Marco Cimarosti <marco.cimarosti@...>
wrote:

> Andrew Dunbar wrote:
> > > I meant, that "part" ("piece", "chunk",
> > > whatever) of software which handles cursor
> > > movements and editing actions, [...]
> >
> > Well there is no such thing.
>
> You wouldn't be able to type, if there wasn't such a
> thing, somewhere.

What I'm trying to clarify is that there is no module,
no part of the OS, no central place.

> > Certainly no part of the OS. The keyboard map is
> > part of the OS. Input methods are part of the OS.
> > Rendering is part of the OS. And all of these are
> > modular.
>
> No centralized code for handling of arrow or delete
> keys? So every programmer should reinvent the wheel
> at every other application?

I don't know if it's still such a good idea that they
*should* but the fact is that they *do*. Most program-
mers still only think of English or other languages
where one letter = one codepoint.

> > There is no central place which handles deleting
> > etc.
> > For widgest/gadgets/controls (whatever each OS
> > calls them) there may be OS code which treats

these

> > events in a uniform way.
>
> Which is exactly what you said did not exist...

I said there *may* be and I said only for controls.
Most applications are not an OS control. Windows's
Notepad and OSX's text editor may be but I can't be
sure. Some OSes may have various single-line string
input controls, a plain text multi-line text box
control, and sometimes a formatted multi-line text box
control. Outside these it is every programmer for
himself. I am not saying this is a good thing.

> > Outside these, in the main window of an editor or
> > anything else which is not a standard control,
>
> Can't the main window of an editor be a standard
> control? E.g., the main window of Windows' Notepad
> is a standard text box.

Only very simple ones. The text box I'm typing into
now
is another such case (but on Mozilla it probably would
not be). Any word processor, programmer's editor, etc
is not. Most software that most users of this list use
for their serious language-specific stuff are not.

> A simple editor of that kind is only interested in
> intercepting applicative events such as menu
> selections: it doesn't care what's going on in the
> text windows, as long as it can rely on the fact
> that the text control will handle all the usual
> stuff.

Yes.

> > there are only events which are passed to
> > the application. Every application can do whatever
> > it wants.
>
> GUI applications do receive an event for every key
> press, but they normally ignore it, so that
> the "system" (i.e., the text control, which is an
> DLL or OCX belonging to the OS) already implements
> default text editing.

Unless the application is a text editor or the
programmer wants to do something the standard control
cannot do.

> Most GUI applications are only interested in
> handling higher-level events, such as the
> notification that an editing operation in a certain
> box has completed, so that they can check the
> validity of the entered/edited data.

I don't agree with "most". Especially when we narrow
the field to text editing applications.

> > > Of course, this "module" can just be a piece of
> > > an applicative program (also the display module
> > > can:
> > > not all applications use Uniscribe or similar
> > > system-level facilities), but most typically it
> > > is a service supplied by the system.
> >
> > Well there are very few Windows applications which
> > don't use Uniscribe at all.
>
> And very few Windows applications implement their
> special handling of arrows or delete keys.

I disagree. I'd have a hard time thinking of any GUI
softwaer I've ever worked on which didn't handle
keypresses.

> In any case, I was describing what each "logical
> module" does during an editing session, because
> Susan was after the wrong impression that the
> display module (Uniscribe, in Windows) handled
> things like the delete keys.

Well describing it as modular is very innacurate. It
gives people the wrong impression that when the OS is
upgraded, the majority of applications will receive an
upgraded ability. The code I'm aware of which treats
combining characters and indic syllables in the way
we're talking about uses the Unicode tables directly
and not some modular part of the OS.

> Discussing the precise software tier in which each
> one these modules sits in *Windows* was quite out of
> the scope of my discussion, and quite OT for this
> forum, I think.

Not at all. I want people to understand why different
software works differently. Even with the newest
versions and the newest OSes. Just last night I was
trying to edit some Hebrew with vowel points - which
is easier than Indic languages. And every application
I used worked differently. I was using Notepad, MS
Word
2000, Internet Explorer, and Vim. It's very annoying
and I understand why it is this way. I expected that
some people on this list are similarly annoyed and
would also wonder why it is this way. I think trying
to explain the haphazard nature of text editing today
is within the scope of this list.

Andrew.

> --
> Marco
>
>

=====
http://linguaphile.sf.net/cgi-bin/translator.pl http://www.abisource.com





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