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

Hi all. I'm having a bit of a problem in creating a ps. Each time I try to create a postscript the tops or sides of my canvas get trimmed while using the code below: 
    my @dim = $canvas->bbox("all");
    my $width = ($dim[2]-$dim[0]);
    my $height = ($dim[3]-$dim[1]); 
    
    my $ps = $canvas->
    postscript(  '-pagewidth'  => "8 i",
              '-pageanchor' => "center",
             '-width' => $width,
             '-height' =>$height
                      );

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I'm guessing I either have to define a -pagex, -pagey and then anchor on "center" or set the -x and -y. The problem is how do I determine what these values are? I've used $canvas->bbox("all") to capture the dimensions of my canvas. This allowed me to set my width and height but I could not set -x,-y or the -pagex,-pagey as the dimension values are are off by some factor. below is a snip of what I have tried but it jsut makes things worse: 
    my @dim = $canvas->bbox("all");
    my $width = ($dim[2]-$dim[0]);
    my $height = ($dim[3]-$dim[1]); 
    my $pagex = ($dim[0]+$dim[2])/2;
    my $pagey = ($dim[1]+$dim[3])/2;
    
    my $ps = $canvas->
    postscript(  '-pagewidth'  => "8 i",
              '-pageanchor' => "center",
              '-pagex' => $pagex,
              '-pagey' => $pagey,
#              '-x' => $dim[0],
#              '-y' => $dim[1],
             '-width' => $width,
             '-height' =>$height
                      );

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Does anyone know how tho convert the dim values so that I can use them in the -x,-y or -pagex,-pagey? Thanks in advance.

Replies are listed 'Best First'.
Re: Dumping Tk canvas to postscript
by tachyon (Chancellor) on Mar 12, 2004 at 23:53 UTC

    The defaults for -height and -width are the full hw size of the canvas widget so you should just be able to: 

    my $ps = $canvas->postscript(  '-pagewidth'  => "8 i" );

    [download]

    and it will x:y symetrical scale to give a result 8 inches wide and X high. I presume you have tried this? The bbox (bounding box) co-ords are noted in the docs to be *approximate* ie (Returns a list with four elements giving an approximate bounding box for all the items named by the tagOrId arguments) which appears to be what you are seeing.

    cheers

    tachyon

[reply]
[d/l]
      Hey there hmmm sorry but I think I've mislead you a bit. The canvas is a scrolled canvas: 
       $c = $main_window 
    -> Scrolled("Canvas")-> pack();
  $canvas = $c->Subwidget("canvas");

      [download]
      What you suggested works great for printing out the visible portion but I want to print out the whole canvas (all the objects) hence the bbox.
      Any ideas?

      Thanks,
      toonewbie
[reply]
[d/l]
        I think this bit from the Tk::Canvas documentation:
        Note: by default Postscript is only generated for information that appears in the canvas's window on the screen.
        may be interpreted that only the visible part could be dumped.
[reply]

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