How to use EDITOR:PROCESS-CHARACTER?

Hi!

I'm trying to port my "Regex Coach" app[1] to Mac OS X. This basically
looked like a no-brainer but there's a serious timing problem related
to CAPI display updates. I searched around in the knowledgebase and in
old mailing list articles and I'm pretty sure this is the kind of
problem that has to be tackled with EDITOR:PROCESS-CHARACTER however I
fail to understand how this function should be applied properly.

I have specialized editor panes that are basically defined like this:

  (defclass editor-pane* (editor-pane))

  (defclass regex-editor-pane (editor-pane*) ())
  (defmethod capi:call-editor :after ((pane regex-editor-pane) command)
    (declare (ignore command))
    (ignore-errors
      (regex-editor-after-callback pane)))

In the REGEX-EDITOR-AFTER-CALLBACK function I call
X-HIGHLIGHT-WITH-FACE which is based on a function I once got from
Xanalys support:

  (defun x-highlight-with-face (pane start-index end-index face)
    (let ((buffer (capi:editor-pane-buffer pane)))
      (editor::buffer-save-excursion (buffer)
        (editor:with-point ((start (editor:buffers-start buffer))
                            (end (editor:buffers-start buffer)))
          (editor:increment-point start start-index)
          (editor:increment-point end end-index)
          (cond (face 
                 (editor::push-region-face face start end))
                (t
                 (editor:remove-text-properties start end
                                                (list 'editor::face t)))))))))

If I run this code (which works fine on Windows and Linux) unmodified
on OS X the editor panes only get updated with a delay of one key
pressed, i.e. the editor faces always reflect the state /before/ the
last key was pressed.

Now, where exactly do I use EDITOR:PROCESS-CHARACTER here? I tried to
wrap it around the whole BUFFER-SAVE-EXCURSION form but that didn't do
it. Then I wrapped it around PUSH-REGION-FACE and
REMOVE-TEXT-PROPERTIES respectively but that didn't help
either. Hmmm...

Thanks in advance,
Edi.

[1] <http://weitz.de/regex-coach/>

Re: How to use EDITOR:PROCESS-CHARACTER?

On Oct 19, 2004, at 6:29 PM, Edi Weitz wrote:

> Hi!
>
> I'm trying to port my "Regex Coach" app[1] to Mac OS X. This basically
> looked like a no-brainer but there's a serious timing problem related
> to CAPI display updates. I searched around in the knowledgebase and in
> old mailing list articles and I'm pretty sure this is the kind of
> problem that has to be tackled with EDITOR:PROCESS-CHARACTER however I
> fail to understand how this function should be applied properly.
>
>

Think of editor:process-character like capi:execute-with-interface. You 
basically want to call a function in the context of an editor pane. 
process-character can take a list and execute it like a function call. 
The name of the function does not exactly make this clear. So in your 
capi callback try

(editor:process-character (list 'x-highlight-with-face pane start-index 
end-index face) (capi:editor-window pane))

I use this function in my code to make things a little cleaner:

(defun editor-call (editor-pane function &rest args)
   (editor:process-character (cons function args) (capi:editor-window 
editor-pane)))

Best,

John DeSoi, Ph.D.

Re: How to use EDITOR:PROCESS-CHARACTER?

On Tue, 19 Oct 2004 19:34:54 -0400, John DeSoi <jd@icx.net> wrote:

> Think of editor:process-character like
> capi:execute-with-interface. You basically want to call a function
> in the context of an editor pane. process-character can take a list
> and execute it like a function call. The name of the function does
> not exactly make this clear.

Yes, that was my understanding of what I've read so far. It just
wasn't clear to me which operations have to wrapped by
PROCESS-CHARACTER and which haven't.

> So in your capi callback try
>
> (editor:process-character (list 'x-highlight-with-face pane
> start-index end-index face) (capi:editor-window pane))

Thanks for the hint but that one also doesn't work. :(

Hmmm...

Cheers,
Edi.

Re: How to use EDITOR:PROCESS-CHARACTER?

On Wed, 20 Oct 2004 10:24:48 -0400, John DeSoi <jd@icx.net> wrote:

> I'm not sure of another solution other than performing the command
> and highlighting in the same process-character call.

That was a good idea! I changed the relevant pieces of code from
something like

  (defmethod capi:call-editor :AFTER ((pane regex-editor-pane) command)
    (declare (ignore command))
    (regex-editor-after-callback pane))

to

  (defmethod capi:call-editor :AROUND ((pane regex-editor-pane) command)
    (declare (ignore command))
    (call-next-method)
    (ignore-errors
      (editor:process-character
       (list 'regex-editor-after-callback pane)
       (capi:editor-window pane))))

I was hesitant to do this because the Knowledgebase says that "you
should not perform CAPI operations using EDITOR:PROCESS-CHARACTER" but
it seems to work.

There are some minor problems left but the main obstacle seems to be
out of the way.

Thanks,
Edi.

Re: How to use EDITOR:PROCESS-CHARACTER?

On Fri, 22 Oct 2004 00:55:43 +0200, Edi Weitz <edi@agharta.de> wrote:

> I changed the relevant pieces of code from something like
>
>   (defmethod capi:call-editor :AFTER ((pane regex-editor-pane) command)
>     (declare (ignore command))
>     (regex-editor-after-callback pane))
>
> to
>
>   (defmethod capi:call-editor :AROUND ((pane regex-editor-pane) command)
>     (declare (ignore command))
>     (call-next-method)
>     (ignore-errors
>       (editor:process-character
>        (list 'regex-editor-after-callback pane)
>        (capi:editor-window pane))))
>
> I was hesitant to do this because the Knowledgebase says that "you
> should not perform CAPI operations using EDITOR:PROCESS-CHARACTER"
> but it seems to work.

Unfortunately it looks as if it was right to be hesitant. One part of
my app is a graph pane which is usually not shown. The contents of
this graph pane are updated from the function REGEX-EDITOR-CALLBACK
above.

Once I bring the graph pane to the foreground (even if I hide it again
afterwards) I get this error when I invoke a command in the editor
pane:

  Error: Trying to CREATE an element #<CL-PPCRE-INTERACTIVE::YELLOW-NODE-PANE "(a)bc" 10098F97>
   in a process #<MP:PROCESS Name "Editor Command Loop" Priority 60000000 State "Running">
   which is differet from the process #<MP:PROCESS Name "Cocoa Event Loop" Priority 60000000 State "Running">
   of the top level interface #<CL-PPCRE-INTERACTIVE::REGEX-INTERFACE "The Regex Coach" 1082D5B3>

So my question actually is the same one I had at the beginning: Which
functions should be wrapped with EDITOR:PROCESS-CHARACTER and which
not? What exactly does this function do?

Thanks,
Edi.

Re: How to use EDITOR:PROCESS-CHARACTER?

On Sat, 23 Oct 2004 09:32:20 -0400, John DeSoi <jd@icx.net> wrote:

> [...]
>
> I know this does not answer your question directly, but hopefully it
> provides some further insight into what you need to do.

Thanks for all your input. I've spend another couple of hours with
this problem last night and I'm now giving up officially. It turns out
that I'm either too dumb or that the way my "Regex Coach" app works
gets in the way of porting it cleanly to Mac OS X. I think I've
inserted calls to EDITOR:PROCESS-CHARACTER in all the right places and
I've played with various modifications but I always run into trouble
somehow.

I guess this is due to the fact that most of the action (including
CAPI calls, calls to editor functions and calls into CL-PPCRE) happens
in :BEFORE and :AFTER methods for CAPI:CALL-EDITOR. Changing this
would imply a complete rewrite of the whole application and I'm not
going to do that - this was supposed to be a fun project and I don't
earn any money with it.

Porting the "Regex Coach" from Win32 to Linux was a breeze with
CAPI. Porting to Mac OS X is obviously too hard for me. The fact that
I'm not familiar with OS X and always hit the wrong keys on my wife's
slow iBook doesn't make it easier.

Again, thanks for all your help.

Cheers,
Edi.