[reportlab-users] About a bug in barcodes

[Robin Becker]

On 02/09/2010 19:33, Germán M. Bravo wrote:

> Barcodes always show a stroke no matter what (even a very small one)

> ...that makes some printers print a nasty stoke that messes up the

> barcode. Rects built for barcodes should not have a stroke at all by

> default, but setting a StrokeColor makes reportlab drawing shapes add

> a stroke anyway.


strokeWidth==0 is not the same as no stroke being drawn. In all rational worlds 
it would be, but according to some person in postscript land zero means the 
smallest width possible. That's a bug in my opinion, but established by ancient 
convention, but just for PDF since line drawing in other universes has a 
different heritage.

I think this patch makes sense so I'll try and put it in today


>

> (In the eanbc.py for instance, around line 260), where it calls:

> Rect(..., strokeColor=barFillColor), it should call Rect(...,

> strokeColor=barStrokeColor) instead, and barStrokeColor should come

> from self.barStrokeColor that being None by default, instead of

> colors.black. That single bug makes my barcodes all messy. Below is a

> patch to fix eanbc.py.

>

> ------- PATCH FOLLOWS CUT HERE --------

> --- reportlab/graphics/barcode/eanbc.py	2010-08-08 10:37:45.000000000 -0500

> +++ reportlab/graphics/barcode/eanbc.py	2010-08-31 14:19:30.000000000 -0500

> @@ -179,7 +179,8 @@

>               }

>       fontSize = 8        #millimeters

>       fontName = 'Helvetica'

> -    textColor = barFillColor = barStrokeColor = colors.black

> +    textColor = barFillColor = colors.black

> +    barStrokeColor = None # Needs to be None for the render not to

> show any stroke at all

>       barStrokeWidth = 0

>       x = 0

>       y = 0

> @@ -243,6 +244,7 @@

>           fontSize = self.fontSize

>           barFillColor = self.barFillColor

>           barStrokeWidth = self.barStrokeWidth

> +        barStrokeColor = self.barStrokeColor

>

>           fth = fontSize*1.2

>           b = ''.join(b)

> @@ -255,7 +257,7 @@

>                   if lrect and lrect.y==yh:

>                       lrect.width += barWidth

>                   else:

> -                    lrect =

> Rect(x,yh,barWidth,barHeight-dh,fillColor=barFillColor,strokeWidth=barStrokeWidth,strokeColor=barFillColor)

> +                    lrect =

> Rect(x,yh,barWidth,barHeight-dh,fillColor=barFillColor,strokeWidth=barStrokeWidth,strokeColor=barStrokeColor)

>                       gAdd(lrect)

>               else:

>                   lrect = None

> ------- PATCH ENDS CUT HERE --------

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-- 
Robin Becker