gocolor

Go Color

I love the way fatih/color work and the power of BurntSushi/termcolor.

Installation

go get github.com/Nguyen-Hoang-Nam/go-color

Usage

First you need to create new instance with New function then you can use this instance to run function like fmt package. (Currently this library only support Println function)

warning := gocolor.New(gocolor.AnsiEscape(gocolor.FgRed))
warning.Println("Some warning")

One more thing, New function is actually variadic function so you can add as many parameters as you like.

warning := gocolor.New(gocolor.AnsiEscape(gocolor.FgRed), gocolor.AnsiEscape(gocolor.FgYellow))
warning.Println("Some warning")

Add

Sometime, you may want to add or change color then this function is for you

warning := gocolor.New(gocolor.AnsiEscape(gocolor.FgRed)).Add(gocolor.AnsiEscape(gocolor.BgYellow))
warning.Println("Some warning")

RGB

RGB color is the reason why I create this package

warning := gocolor.New(gocolor.FgRGB(255, 0, 0))
warning.Println("Some warning")

In case, your terminal is not support RGB color then I will try to fallback to 256 colors or ansi color base on your flag.

I also support HSV, too. (Thanks to go-colorful)

warning := gocolor.New(gocolor.FgHSV(120, 1, 0.5))
warning.Println("Some warning")

Flags

This topic is quite complicated, there are 5 flags you can set:

• TrueColor (Only work with true color terminal, otherwise weird character will print in screen)
• Color256 (Only work with terminal support 256 colors)
• Ansi (Work in most terminal event Window but look really ugly)
• NoColor (Really, why use this package with this flag :v)
• Auto (Default options, try to guest with flag should be use by checking $COLORTERM, $TERM, $NO_COLOR)

truecolor := gocolor.New(gocolor.FgRBG(255, 0, 255)).setFlag(gocolor.TrueColor)

There is one caution, most terminal emulator supports users to customize Ansi color (16 colors). This library simply can not get these customizable colors so I choose default 16 colors of XTerm as fallback colors.

Color256

Yes, this function allows you to choose between 256 colors.

color256 := gocolor.New(gocolor.FgColor256(50))

Ansi

This is quite madness, so you may want to read more in wiki

There are 8 colors, you can combine with 4 prefix (Fg-, Bg-, FgBright-, BgBright-)

• Black
• Red
• Green
• Yellow
• Blue
• Magenta
• Cyan
• White

ansiColor := gocolor.New(gocolor.AnsiEscape(gocolor.FgRed))

I create some constants so that you don't need to remember their codes.

• Reset
• Bold
• Dim
• Italic
• Underline
• Reverse

ansiColor := gocolor.New(gocolor.AnsiEscape(gocolor.FgRed), gocolor.AnsiEscape(gocolor.Underline))

Distance

This is also a tough topic, when I try to fallback RGB aka true color to support 256 color or Ansi color terminal. I might need some way to find the color which is the nearest to original color.

• DistanceRgb (default)
• DistanceLab
• DistanceLuv
• DistanceCIE94
• DistanceCIEDE2000

distanceLab := gocolor.New(gocolor.FgRBG(255, 0, 255)).SetDistance(gocolor.DistanceLab)

Each distances may give you a completely difference fallback color which is unsurprising

Complementary

Sometime you may want to make background or foreground to the complementary color to make a high contrast message.

complementary := gocolor.New(gocolor.FgRBG(255, 0, 255)).AddComplementary()

Fallback

If you want to change default fallback colors. You can use SetFallback or SetFallbackFromPath function.

fallback := gocolor.New().SetFallbackFromPath("./configuration.json").Add(gocolor.FgColor256(24))

TODO

• Pipeline
• Add image to README
• Support change default Ansi color
• Add github CI
• Improve test cases

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT