Curses::UI::Searchable(3) Add 'less'-like search abilities to a widget


 Curses::UI::Searchable - base class


package MyWidget;
use Curses::UI::Searchable;
use vars qw(@ISA);
@ISA = qw(Curses::UI::Searchable);
sub new () {
# Create class instance $this.
$this->set_routine('search-forward', \&search_forward);
$this->set_binding('search-forward', '/');
$this->set_routine('search-backward', \&search_backward);
$this->set_binding('search-backward', '?');
sub layout_content() {
my $this = shift;
# Layout your widget's content.
return $this;
sub number_of_lines() {
my $this = shift;
# Return the number of lines in
# the widget's content.
return ....
sub getline_at_ypos($;) {
my $this = shift;
my $ypos = shift;
# Return the content on the line
# where ypos = $ypos
return ....


Using Curses::UI::Searchable, you can add 'less'-like search capabilities to your widget.

To make your widget searchable using this class, your widget should meet the following requirements:

  • make it a descendant of Curses::UI::Searchable

    All methods for searching are in Curses::UI::Searchable. By making your class a descendant of this class, these methods are automatically inherited.

  • -ypos data member

    The current vertical position in the widget should be identified by $this->{-ypos}. This y-position is the index of the line of content. Here's an example for a Listbox widget.

       0   |One   |
       1   |Two   |
       2   |Three |
  • method: number_of_lines ( )

    Your widget class should have a method number_of_lines, which returns the total number of lines in the widget's content. So in the example above, this method would return the value 3.

  • method: getline_at_ypos ( YPOS )

    Your widget class should have a method getline_at_ypos, which returns the line of content at -ypos YPOS. So in the example above, this method would return the value ``Two'' for YPOS = 1.

  • method: layout_content ( )

    The search routines will set the -ypos of your widget if a match is found for the given search string. Your layout_content routine should make sure that the line of content at -ypos will be made visible if the draw method is called.

  • method: draw ( )

    If the search routines find a match, $this->{-search_highlight} will be set to the -ypos for the line on which the match was found. If no match was found $this->{-search_highlight} will be undefined. If you want a matching line to be highlighted, in your widget, you can use this data member to do so (an example of a widget that uses this option is the Curses::UI::TextViewer widget).

  • bindings for searchroutines

    There are two search routines. These are search_forward and search_backward. These have to be called in order to display the search prompt. The best way to do this is by creating bindings for them. Here's an example which will make '/' a forward search and '?' a backward search:

        $this->set_routine('search-forward'  , \&search_forward);
        $this->set_binding('search-forward'  , '/');
        $this->set_routine('search-backward' , \&search_backward);
        $this->set_binding('search-backward' , '?');


Copyright (c) 2001-2002 Maurice Makaay. All rights reserved.

Maintained by Marcus Thiesen ([email protected])

This package is free software and is provided ``as is'' without express or implied warranty. It may be used, redistributed and/or modified under the same terms as perl itself.