Problems with creating my own syntax highlighter

Desktop wxRuby
1

Well, I wanted to make my own syntax highlighter using
Wx::StyledTextCtrl.
The easiest way to do it seemed to parse the text contents in a
content-changed-event. But it doesn’t seem to work…

I tried to edit the scintilla sample and added this event(@sci is the
StyledTextCtrl):

@sci.evt_stc_change(@sci.get_id)  do
    @sci.clear_document_style
    @sci.start_styling(1,31)
    @sci.style_set_font_attr(10, 10, "Courier", true, true, true)
    @sci.set_styling(2,10)
    puts 1
end

This prints out “1” when you edit the text(twice actually, which i do
not
understand), but doesn’t change the text layout. But if I put it in an
event
triggered by a button, it will work(onEOL is triggered by clicking the
“show
end of line” button in the scintilla sample):

def onEOL
@sci.clear_document_style
@sci.start_styling(1,31)
@sci.style_set_font_attr(10, 10, “Courier”, true, true, true)
@sci.set_styling(2,10)
puts 1
end

As soon as I click the button, the second and third character get
styled. I
don’t get why it doesn’t work in the text content changed event. What
happens there, is it intended not to work? What is the best way to get
it to
work?

2

Christian Bielert wrote:

Well, I wanted to make my own syntax highlighter using
Wx::StyledTextCtrl. The easiest way to do it seemed to parse the text
contents in a content-changed-event. But it doesn’t seem to work…
I would have expected the code you posted to work too, but the following
seems to work for me (Linux/GTK), hooking into evt_stc_updateui

@sci.style_set_font_attr(10, 10, "Courier", true, true, true)
@sci.evt_stc_updateui(@sci) do | e |
  @sci.clear_document_style
  @sci.start_styling(2,31)
  @sci.set_styling(5,10)
  @sci.set_save_point
end

style_set_xxx only needs to be called once per style, per control. It
seems to be a reasonably expensive call so putting it outside the loop
got rid of any lag for me.

There are a few odd things going on with StyledTextEvent - from the
Scintilla docs evt_stc_change should only get called when the text is
modifed, but it seems to be getting called repeatedly. And
StyledTextEvent should inherit from Wx::Event, but it currently inherits
from Wx::Control (!). I’ll look into those and hopefully fix something
up for the next release.

Thanks for the report.

cheers
alex