| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Graphics.Barcode.Code128
Description
A library for generating barcodes in Code 128. Details of the encoding are available at http://en.wikipedia.org/wiki/Code_128. The width of the stripes and the height of the barcode are configurable. Two modes of operation are supported:
- Constructing a PDF directly in a
ByteString, and - Constructing an action in
HPDF'sDrawmonad, for composing the barcode with other information in a PDF.
- data BarcodeConfig = BarcodeConfig {}
- data Err = CantEncode Char
- barcodeSize :: BarcodeConfig -> [Char] -> Either Err (Double, Double)
- barcodePDF :: BarcodeConfig -> String -> IO ByteString
- drawBarcode :: BarcodeConfig -> String -> Point -> Either Err (Draw Point)
Documentation
data BarcodeConfig Source
Controls the size of the generated barcode. All units are in HPDF's internal sizing.
Constructors
| BarcodeConfig | |
Errors that can occur while constructing a barcode
Constructors
| CantEncode Char | The returned character cannot be encoded in Code 128 |
barcodeSize :: BarcodeConfig -> [Char] -> Either Err (Double, Double) Source
Determine the width and height of rendering a particular string as a barcode in a particular configuration.
barcodePDF :: BarcodeConfig -> String -> IO ByteString Source
Generate PDF data containing the barcode for a given string, with the tightest possible bounding box. If the string cannot be encoded in Code 128, an IOError is thrown.
Arguments
| :: BarcodeConfig | How to render the barcode |
| -> String | The string to encode |
| -> Point | The origin (lower left) of the barcode on the page |
| -> Either Err (Draw Point) |
Encode a string and construct an action in Draw that will
render it as a barcode. The action, if created successfully, will
return the opposite corner of the barcode. An error is returned if the string
could not be encoded as a Code128 barcode.