Tk::Reindex - change the base index of Text-like widgets |
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.
-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.
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.
Tk::Reindex - change the base index of Text-like widgets |