KuntalBhusan has asked for the wisdom of the Perl Monks concerning the following question:

Dear Monks, I want to write a subroutine for Tk::Canvas so that when it is called it will enable the user to view all elements of a Tk ::Canvas which would be something like the ViewAll() function of Tk::AbstractCanvas or something better (I don't want to use Tk::AbstractCanvas for some reasons...). The code I have written is something like this : 

sub fit_to_canvas
{
my ($xt0,$yt0,$xt1,$yt1) = $_canvas{0}->bbox('all'); 

if($xt0 != "")
{
my ($x0,$y0,$x1,$y1) = $_canvas{0}->bbox('all'); 

$_canvas{0}->xviewMoveto($x0);
$_canvas{0}->yviewMoveto($y1);

$_canvas{0}->configure(-scrollregion => [$x0,$y0,$x1,$y1]);

}## end of if not empty canvas

}

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But it does not seen to work properly and do what I need.... Any help will be highly appreciated in this regard.. Thanks, Kuntal
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Re: Help needed regarding creating a subroutine to fit and view all items in a Tk::Canvas
by zentara (Cardinal) on Nov 01, 2012 at 16:15 UTC
    Try something like in this example code. After getting your bbox('all'), do your configure, then adjust the scrollbars. 
    # add these lines to force scroll to the ends
my @bbox = $can->bbox( 'img'  );
$can->configure(-scrollregion => [@bbox] );
$can->xviewMoveto(1);
$can->yviewMoveto(1);

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    See example code in Tk photo pixel colors
    I'm not really a human, but I play one on earth.
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