#!/usr/bin/perl --
use strict;
use warnings;

use Tk;

Main( @ARGV );
exit( 0 );

sub Main {
    tkgui(0, 'who appears selected ? (with exportselection only)');
    tkgui(1, 'who appears selected ? (with exportselection and callbacks)');
}

sub tkgui {
    my ( $bind_callbacks , $message ) = @_;
    my $exportselection = 0;
    my $mw = MainWindow->new;
    my $filename = $message;
    
    my $f = $mw->Frame->pack( -side => 'top', -fill => 'x' );
    my $e = $f->Entry(
        -textvariable => \$filename,
        -exportselection => $exportselection,
    )->pack(
        -side   => 'left',
        -anchor => 'w',
        -fill   => 'x',
        -expand => 1,
    );

    my $t = $mw->Scrolled(
        "Text",
        -exportselection => $exportselection,
    )->pack(
        -side   => 'bottom',
        -fill   => 'both',
        -expand => 1,
    );

    $t->insert(
        end => join "\n",
            qw' to hilite highlight selection without w/o focus
                tagAdd tagname @range
                tagConfigure foreground and background
            ',
            1 .. 10,
    );

    if( $bind_callbacks  ){
        $t->bind( '<<Selection>>', \&on_selection );
        $t->bind( '<FocusOut>', sub { my ($t) = @_; }, );
    }

    $mw->withdraw;
    $mw->deiconify;
    $mw->raise;
    $mw->focusForce;
    $mw->update;
    
    for( 1 .. 5 ){
        $filename = "$message [I HAVE FOCUS]";
        $e->selectionRange(0, length($filename) - 8 );
        $e->focus ;
        $e->update;
        $mw->update;
        warn 'focusCurrent? ', eval { $mw->focusCurrent } || 'none';
        sleep 1;
        $filename = "$message [I LOST FOCUS]";
        $t->selectAll;
        $t->focus;
        $t->update;
        $mw->update;
        warn 'focusCurrent? ', eval { $mw->focusCurrent } || 'none';
        sleep 1;
    }
    $mw->withdraw;
    return $mw;
}


sub on_selection {
    my( $t ) = @_;
    $t->tagDelete('ssel');
    if ( my (@range) = $t->tagRanges('sel') ) {
        $t->tagAdd( ssel => @range );
        for my $opt (qw' foreground background ') {
            $t->tagConfigure( ssel => "-$opt" => $t->cget("select$opt") );
        }
    }
    return;
}