Tk::Reindex - change the base index of Text-like widgets
use Tk::ReindexedText;
$t1=$w->ReindexedText(-linestart => 2);
use Tk::ReindexedROText;
$t2=$w->ReindexedROText(-linestart => 0);
Creates a new widget class based on Text-like widgets that can
redefine the line number base (normally Text widgets start line
numbers at 1), or possibly other manipulations on indexes.
The newly-defined widget takes all the same options as the base
widget, which defaults to Text.
- Name: lineStart
-
- Class: LineStart
-
- Switch: -linestart
-
Sets the line number of the first line in the Text widget. The
default -toindexcmd and -fromindexcmd use this configuration
option.
-item Name: toIndexCmd fromIndexCmd
-item Class: ToIndexCmd FromIndexCmd
-item Switch: -toindexcmd -fromindexcmd
These two options specify callbacks that are called with a list of
indexes and are responsible for translating them to/from indexes that
the base Text widget can understand. The callback is passed the
widget followed by a list of indexes, and should return a list of
translated indexes. -toindexcmd should translate from 'user'
indexes to 'native' Text-compatible indexes, and -fromindexcmd
should translate from 'native' indexes to 'user' indexes.
The default callbacks simply add/subtract the offset given by the
-linestart option for all indexes in 'line.character' format.
It would probably be prudent to make these functions inverses of each
other.
- import
-
To make new Reindex widgets, this function should be called via use
with the name of the Text-like base class that you are extending with
``Reindex'' capability. 'use base(Tk::Reindex Tk::nameofbasewidget)'
should also be specified for that widget.
I've used the word ``indexes'' instead of ``indices'' throughout the
documentation.
All the built-in perl code for widget bindings & methods will use the
new 'user' indexes. Which means all this index manipulation might
might break code that is trying to parse/manipulate indexes. Or even
assume that '1.0' is the beginning index. Tk::Text::Contents comes
to mind.
Andrew Allen <ada@fc.hp.com>
This code may be distributed under the same conditions as Perl.
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