RichEdit/xControls issues
Hi!
I did not stop rewriting a Syntax2.ew syntax control with bookmarks and text
folding, but I'm hitting a wall erected by Windows.
Because some text in the file shouldn't be displayed, as it relates to the
above features, I can't call the default processing for painting, as in the
current Syntax. This works, including painting the selected and [un]folded
areas.
The problem is that the RichEdit control, when responding to navigation keys,
displays the caret according to some internal info that is not updated when
changing font. Creating the caret with the right dimensions on w32HActivate or
w32HPaint doesn't help. Thus, for instance, the caret moves by 9 pixels up and
down even though the font size was set to 18 (characters entered display with
the right font however). Looks like this aspect remains stuck to default
parameters if the default painting is not used.
As I'm writing this post, I realize that calling the default processing to
paint on font change, then clear window and redraw my way might work, I have
to test this.
There are several options out, so I'm asking the (future) users of Syntax here:
1/ Use the CFM_HIDDEN attribute to hide unwanted text. That may be a bit slow,
and won't work with RichEdit v2.0 or less, which could be an issue on Win95/98
systems.
2/ Create a new control on font change, and route events so that win32lib
still believes the original id is alive. Drawback is that the undo stack is
lost in the process.
3/ Create the control from scratch, handling everything from selection to
undoing and stuff. This has some good aspects, as the RichEdit interface has
some backward compatible quirks I can get rid of. I started going that route,
but obviously it's a tremendous amount of work, so that the release date would
be quite later than expected.
None of the above is needed if the trick I mentioned works as expected, but
there's hardly any guarantee it does.
Whichever option is taken, the new control would have to include xControls.e
so as to register as a custom control. This approach would work for all of the
xControls collection, allowing them to be used independently; this change
avoids loading heaps of unused code, which is a factor in Eu2.5 (even though
the beta version improved things a lot).
win32lib does have an undocumented mechanism for registering custom controls,
but some of its routines are not coded to support custom controls known by
interface only. The days it fully works, Syntax2.ew can live without
xControls.e.
What do you think? Greg (or Don), you have a special vote to cast on this, of
course ...
CChris
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