ProgressBar.hs

module Test.Framework.Runners.Console.ProgressBar (
        Progress(..), progressBar
    ) where

import Text.PrettyPrint.ANSI.Leijen ( (<>), char, text, Doc )


data Progress = Progress Int Int

progressBar :: (Doc -> Doc) -> Int -> Progress -> Doc
progressBar color width (Progress count total) = char '[' <> progress_doc <> space_doc <> char ']'
  where
    -- The available width takes account of the enclosing brackets
    available_width = width - 2
    characters_per_tick = fromIntegral available_width / fromIntegral total :: Double
    progress_chars = round (characters_per_tick * fromIntegral count)
    space_chars = available_width - progress_chars
    progress_doc = color (text (reverse (take progress_chars ('>' : repeat '='))))
    space_doc = text (replicate space_chars ' ')