Re: [perl-win32-gui-users] EOL control in scintilla

[Sean H. <jal...@ho...>]

I tracked down the extra spaces problem. It turned out to be a space at =
 =

the end of the line (after the EOL character(s)), not at the beginning, =
 =

which is why it doesn't show up on the first line.

Here's the cause of the problem:
# How many characters are on a line, not including end of line character=
s?
sub LineLength {
  my ($self, $line) =3D @_;
  return $self->SendMessage (2350, $line, 0);
}

Scintilla's documentation says:
SCI_LINELENGTH(int line)
This returns the length of the line, including any line end characters. =
If  =

line is negative or beyond the last line in the document, the result is =
0.  =

If you want the length of the line not including any end of line  =

characters, use SCI_GETLINEENDPOSITION(line) - SCI_POSITIONFROMLINE(line=
).

Laurent's code makes an incorrect assumption about EOL markers and  =

SCI_LINELENGTH. (Although it may have been correct when it was coded, an=
d  =

Scintilla later changed.) Everywhere Laurent has used LineLength to get =
 =

the text at a line, he has done the following:
my $lenght =3D $self->LineLength($line);
my $text   =3D " " x ($lenght + 1);
$self->SendMessageNP (2153, $line, $text);

He has to create the buffer first, because SendMessage requires the memo=
ry  =

to be already allocated, so he creates a buffer of spaces. But he create=
s  =

it one byte too long, so there's a trailing space in the returned text.

(SendMessageNP is an alias for SendMessage with the second parameter as =
a  =

pointer. There is also SendMessage PN for the first parameter as a point=
er  =

and SendMessagePP for both parameters as pointers. It would probably be =
 =

better to have a single SendMessage function, and use references when yo=
u  =

want a parameter to be a pointer, but I don't currently have a compiler,=
  =

so I can't mess with the C code. We'd have to leave the extra methods in=
  =

for a couple versions anyway, to prevent older code from breaking.)

The intermediate solution is to go to line 196 in Scintilla.pm (in the  =

GetLine() sub) and take out the '+1'. Then when SaveFile calls GetLine, =
 =

you won't get a trailing space.

The long-term solution is to find every place Laurent has used LineLengt=
h,  =

and fix it. I am willing to do this and email the fixed file to someone =
 =

with CVS access, so it will be correct in the next version. I'll test it=
  =

via SaveFile, with differrent combinations of EOL markers in source and =
 =

destination files, to make sure it really works. (I'll also fix that  =

annoying little misspelling in the local variable while I'm at it.)