[kowainik#51] implemented rgb and rgbMessage function

dariodsa · Apr 3, 2021 · 40bc041 · 40bc041
1 parent c3d994f
commit 40bc041
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diff --git a/src/Colourista/IO.hs b/src/Colourista/IO.hs
@@ -19,6 +19,7 @@ module Colourista.IO
     , whiteMessage
     , magentaMessage
     , cyanMessage
+    , rgbMessage
       -- ** Aliases with unicode indicators
     , successMessage
     , infoMessage
@@ -35,7 +36,8 @@ module Colourista.IO
 #if __GLASGOW_HASKELL__ < 804
 import Data.Semigroup (Semigroup (..))
 #endif
-import Data.Text (Text)
+import Data.Maybe (fromJust, isNothing)
+import Data.Text (pack, Text)
 
 import Colourista.Mode (HasColourMode)
 
@@ -47,6 +49,12 @@ import qualified Colourista.Pure as Colourista
 -- Direct IO functions
 ----------------------------------------------------------------------------
 
+-- | Print 'Text' coloured in specified RGB notaion
+rgbMessage :: HasColourMode => String -> Text -> IO ()
+rgbMessage  colour text | isNothing res  = errorMessage $ pack $ "Invalid hex value - " ++ colour
+                        | otherwise      = formattedMessage [ fromJust res] text
+  where res = Colourista.rgb colour
+
 -- | Print 'Text' coloured in 'Colourista.red'.
 redMessage :: HasColourMode => Text -> IO ()
 redMessage = formattedMessage [Colourista.red]

diff --git a/src/Colourista/Pure.hs b/src/Colourista/Pure.hs
@@ -18,6 +18,7 @@ module Colourista.Pure
     , white
     , magenta
     , cyan
+    , rgb
 
       -- * Background
     , redBg
@@ -42,14 +43,18 @@ module Colourista.Pure
     ) where
 
 import Data.ByteString (ByteString)
+import Data.Foldable (foldl')
+import Data.Int (Int8)
 import Data.List.NonEmpty (NonEmpty (..))
+import Data.Maybe (fromJust, isNothing, mapMaybe)
 import Data.Semigroup (Semigroup (..))
 import Data.String (IsString (..))
 import Data.Text (Text)
 import System.Console.ANSI (Color (..), ColorIntensity (Vivid), ConsoleIntensity (BoldIntensity),
                             ConsoleLayer (Background, Foreground), SGR (..), Underlining (..),
                             setSGRCode)
 
+import Data.Colour.SRGB (sRGB24)
 import Colourista.Mode (HasColourMode, withColourMode)
 
 
@@ -142,6 +147,51 @@ cyan = withColourMode $ fromString $ setSGRCode [SetColor Foreground Vivid Cyan]
 {-# SPECIALIZE cyan :: HasColourMode => Text       #-}
 {-# SPECIALIZE cyan :: HasColourMode => ByteString #-}
 
+-- | Code to apply any arbitrary hex color for the terminal output.
+rgb :: (HasColourMode, IsString str) => String -> Maybe str
+rgb hex | length hex > 6        = Nothing
+        | length rgbValues /= 3 = Nothing
+        | otherwise             =  Just $ withColourMode $ fromString $ setSGRCode [SetRGBColor Foreground (sRGB24 redComponent greenComponent blueComponent)]
+  where
+    hexVal = replicate (6 - length hex) '0' ++ hex
+    rgbValues  = map fromIntegral $ mapMaybe hexToInt [ (hexVal !! 0) : [hexVal !! 1]
+                                                      , (hexVal !! 2) : [hexVal !! 3]
+                                                      , (hexVal !! 4) : [hexVal !! 5]]
+
+    redComponent   = rgbValues !! 0
+    greenComponent = rgbValues !! 1
+    blueComponent  = rgbValues !! 2
+    hexToInt :: String -> Maybe Int
+    hexToInt [] = Just 0
+    hexToInt val | isNothing z || isNothing other  = Nothing
+                 | otherwise = Just $ fromJust z + 16 * fromJust other
+      where
+        other = hexToInt (init val)
+        z = case last val of
+              '0' -> Just 0
+              '1' -> Just 1
+              '2' -> Just 2
+              '3' -> Just 3
+              '4' -> Just 4
+              '5' -> Just 5
+              '6' -> Just 6
+              '7' -> Just 7
+              '8' -> Just 8
+              '9' -> Just 9
+              'a' -> Just 10
+              'b' -> Just 11
+              'c' -> Just 12
+              'd' -> Just 13
+              'e' -> Just 14
+              'f' -> Just 15
+              'A' -> Just 10
+              'B' -> Just 11
+              'C' -> Just 12
+              'D' -> Just 13
+              'E' -> Just 14
+              'F' -> Just 15
+              _   -> Nothing
+
 ----------------------------------------------------------------------------
 -- Background
 ----------------------------------------------------------------------------