On Apr 29, 2008, at 9:48 AM, Gabor Szabo wrote:
> I must be missing something:
>
> I am trying to get an iter on a line.
>
> Sometimes the offset is too big so the below function throws
> an exception:
>
> $end_iter= $buffer->get_iter_at_line_offset($line, $end);
>
> Gtk-ERROR **: Char offset 24 is off the end of the line at ....
>
> The problem is that even if I put the expression in eval it does not
> catch it.
When it says "$somename-ERROR" like that, it's not really an
exception, but somebody calling g_error() down inside the C code.
These are considered fatal error conditions.
Sure enough:
$ grep "is off the end of the line" gtk+/gtk/*.c
gtk+/gtk/gtktextiter.c: g_error ("Byte index %d is off the end of
the line",
gtk+/gtk/gtktextiter.c: g_error ("Char offset %d is off the end of
the line",
Those are in the functions iter_set_from_byte_offset() and
iter_set_from_char_offset().
The docs for gtk_text_buffer_get_iter_at_line_offset() say:
* Obtains an iterator pointing to @char_offset within the given
* line. The @char_offset must exist, offsets off the end of the line
* are not allowed. Note <emphasis>characters</emphasis>, not bytes;
* UTF-8 may encode one character as multiple bytes.
> Can I catch this exception somehow?
With some work, yes, you can trap it with a perl handler. This is not
really generic, though, and is not a proper solution to your problem.
#!/usr/bin/perl
use strict;
use Glib;
Glib::Log->set_handler ("Foo", [qw/fatal error critical warning/], sub {
my ($domain, $flags, $message) = @_;
use Carp;
die Carp::longmess("$domain: $message");
});
eval {
Glib->error ("Foo", "holy crap!");
};
if ($@) {
print "We trapped a g_error() call, whose message was:\n"
. " \"[EMAIL PROTECTED]"\n";
}
__END__
> As a workaround, can I get the length of a row from the Text::Buffer?
/**
* gtk_text_iter_get_chars_in_line:
* @iter: an iterator
*
* Returns the number of characters in the line containing @iter,
* including the paragraph delimiters.
*
* Return value: number of characters in the line
**/
Looks like your best bet will be
$iter = $buffer->get_iter_at_line ($line_index);
$chars_in_line = $iter->get_chars_in_line ();
if ($chars > $chars_in_line) {
$chars = $chars_in_line;
}
$iter->forward_chars ($chars);
--
So this new album took us quite a while, to get it together, to find a
title and things like that - and we were travelling quite a bit - we
made a few sort of gestures in the East, and a few gestures in the
West, and then we got thrown out because of our gestures - this is
something that we decided was an apt title for a thing that's called
'The Song Remains The Same'.
-- Robert Plant, rambling to introduce a song
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