String class extension functions to help with adding colour (color) to terminal / console output using ANSI escape codes: https://en.wikipedia.org/wiki/ANSI_escape_code. Created for students in my coding classes to use.
Provides functions to specify foreground and background colour using...
- colour names
- RGB colour
- HSV colour
- Hex colour codes
Just add Kolour.kt to your project and you should be good to go.
Main.kt includes a colourTest() function that should produce this output, so you can check the compatability of your terminal / IDE:
A limited set of named colours (compatible with most terminals) is included. (Note that the colours shown are representative of my IDE's colour config - your's will likely look different.)
"Hello World!".red()
"Hello World!".yellow().bgRed()
"Hello World!".bold().black().bgYellow()
A list of the colour functions for standard colours (see notes at end re. bright colours, etc.), both foreground and backgrond:
.normal()and.bgNone().black()and.bgBlack().white()or.grey()and.bgGrey().red()and.bgRed().yellow()and.bgYellow().green()and.bgGreen().cyan()and.bgCyan().blue()and.bgBlue().magenta()and.bgMagenta()
Additional styling:
.bold().italic().underline()
On termnals that support 24-Bit colour, there are a number of functions that allow you to define colours in various, convenient ways:
.col(r, g, b).bgCol(r, g, b)
Where r, g and b are Ints in the range 0 to 255
"Hello World!".col(255, 255, 255).bgCol(50, 75, 100)
.col(hue, saturation, value).bgCol(hue, saturation, value)
Where hue, saturation and value are Doubles in the range 0.0 to 1.0
"Hello World!".col(0.9, 1.0, 1.0).bgCol(0.9, 1.0, 0.2)
.col(hex).bgCol(hex)
Where hex is a String of the fomat "#rrggbb" or "#rgb"
"Hello World!".col("#ff0").bgCol("#33691e")
Since the escape sequences used to colour the text add characters to a string, the length of the resulting string is far longer than the visible characters displayed in the terminal.
e.g. "Hello".length is 5, but "Hello".red().bgYellow().length is 23!
So a utility function, length() is provided which will return the length of a string, less any escape sequences
e.g. "Hello".red().bgYellow().length() correctly returns 5, even though the string with its added escape sequences is far longer.
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I haven't bothered with the 'bright' colours as they're rendered so inconsistently by different terminal / IDEs, depending on the config: in some cases the colours are different, others not; sometimes the font is made bold; etc. I've never found the bright colours particularly useful. Easy enough to add them in if you need them.
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I've called the colour which is normally refered to as 'white', 'grey' since it's clearly not white! Likewise for the 'white' background, it's called 'bgGrey'.