ui

README

UI

This package provides a simple interface with implementations for printing information in command-line applications. It supports various verbosity levels as well as formatting styles.

Quick Start

package main

import "github.com/gardenbed/charm/ui"

func main() {
  u := ui.New(ui.Info)
  u.Infof(ui.Green, "Hello, %s!", "World")
}

Documentation

Index

• Variables
• type ANSICode
• type Level
• type Style
  • func Bg256Color(code int) Style
  • func BgTrueColor(r, g, b int) Style
  • func Fg256Color(code int) Style
  • func FgTrueColor(r, g, b int) Style
• type UI
  • func New(level Level) UI
  • func NewNop() UI

Variables

var (
	Black   = Style{FgBlack}
	Red     = Style{FgRed}
	Green   = Style{FgGreen}
	Yellow  = Style{FgYellow}
	Blue    = Style{FgBlue}
	Magenta = Style{FgMagenta}
	Cyan    = Style{FgCyan}
	White   = Style{FgWhite}
)

ANSI Colors

Types

type ANSICode

type ANSICode int

const (
	Reset ANSICode = iota
	Bold
	Faint
	Italic
	Underline
	BlinkSlow
	BlinkRapid
	ReverseVideo
	Concealed
	CrossedOut
)

const (
	FgBlack ANSICode = iota + 30
	FgRed
	FgGreen
	FgYellow
	FgBlue
	FgMagenta
	FgCyan
	FgWhite
)

const (
	BgBlack ANSICode = iota + 40
	BgRed
	BgGreen
	BgYellow
	BgBlue
	BgMagenta
	BgCyan
	BgWhite
)

const (
	Fg256 ANSICode = 38
	Bg256 ANSICode = 48
)

type Level

type Level int

Level represents the verbosity level.

const (
	// Trace shows all messages.
	Trace Level = iota
	// Debug shows Debug, Info, Warn, and Error messages.
	Debug
	// Info shows Info, Warn, and Error messages.
	Info
	// Warn shows Warn and Error messages.
	Warn
	// Error shows only Error messages.
	Error
	// None does not show any messages.
	None
)

type Style

type Style []ANSICode

Style allows multiple ANSI codes.

func Bg256Color

func Bg256Color(code int) Style

Bg256Color creates a style for a 256-color background color.

func BgTrueColor

func BgTrueColor(r, g, b int) Style

BgTrueColor creates a style for a 24-bit background color.

func Fg256Color

func Fg256Color(code int) Style

Fg256Color creates a style for a 256-color foreground color.

func FgTrueColor

func FgTrueColor(r, g, b int) Style

FgTrueColor creates a style for a 24-bit foreground color.

type UI

type UI interface {
	// Output method independent of the verbosity level
	Printf(format string, a ...interface{})

	// Leveled output methods
	GetLevel() Level
	SetLevel(l Level)
	Tracef(s Style, format string, a ...interface{})
	Debugf(s Style, format string, a ...interface{})
	Infof(s Style, format string, a ...interface{})
	Warnf(s Style, format string, a ...interface{})
	Errorf(s Style, format string, a ...interface{})
}

UI is the interface for interacting with users in command-line applications.

func New

func New(level Level) UI

New creates a new user interface. This is a concurrent-safe UI and can be used across multiple Go routines.

func NewNop

func NewNop() UI

NewNop creates a nop user interface for testing purposes.