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starlog/color.go

604 lines
18 KiB
Go

package starlog
import (
"fmt"
"io"
"os"
"strconv"
"strings"
"sync"
"github.com/mattn/go-colorable"
"github.com/mattn/go-isatty"
)
var (
// NoColor defines if the output is colorized or not. It's dynamically set to
// false or true based on the stdout's file descriptor referring to a terminal
// or not. This is a global option and affects all colors. For more control
// over each color block use the methods DisableColor() individually.
NoColor = os.Getenv("TERM") == "dumb" ||
(!isatty.IsTerminal(os.Stdout.Fd()) && !isatty.IsCygwinTerminal(os.Stdout.Fd()))
// Output defines the standard output of the print functions. By default
// os.Stdout is used.
Output = colorable.NewColorableStdout()
// Error defines a color supporting writer for os.Stderr.
Errors = colorable.NewColorableStderr()
// colorsCache is used to reduce the count of created Color objects and
// allows to reuse already created objects with required Attr.
colorsCache = make(map[Attr]*Color)
colorsCacheMu sync.Mutex // protects colorsCache
)
// Color defines a custom color object which is defined by SGR parameters.
type Color struct {
params []Attr
noColor *bool
}
// Attr defines a single SGR Code
type Attr int
const escape = "\x1b"
// Base attributes
const (
Reset Attr = iota
Bold
Faint
Italic
Underline
BlinkSlow
BlinkRapid
ReverseVideo
Concealed
CrossedOut
)
// Foreground text colors
const (
FgBlack Attr = iota + 30
FgRed
FgGreen
FgYellow
FgBlue
FgMagenta
FgCyan
FgWhite
)
// Foreground Hi-Intensity text colors
const (
FgHiBlack Attr = iota + 90
FgHiRed
FgHiGreen
FgHiYellow
FgHiBlue
FgHiMagenta
FgHiCyan
FgHiWhite
)
// Background text colors
const (
BgBlack Attr = iota + 40
BgRed
BgGreen
BgYellow
BgBlue
BgMagenta
BgCyan
BgWhite
)
// Background Hi-Intensity text colors
const (
BgHiBlack Attr = iota + 100
BgHiRed
BgHiGreen
BgHiYellow
BgHiBlue
BgHiMagenta
BgHiCyan
BgHiWhite
)
// New returns a newly created color object.
func NewColor(value ...Attr) *Color {
c := &Color{params: make([]Attr, 0)}
c.Add(value...)
return c
}
// Set sets the given parameters immediately. It will change the color of
// output with the given SGR parameters until color.Unset() is called.
func Set(p ...Attr) *Color {
c := NewColor(p...)
c.Set()
return c
}
// Unset resets all escape attributes and clears the output. Usually should
// be called after Set().
func Unset() {
if NoColor {
return
}
fmt.Fprintf(Output, "%s[%dm", escape, Reset)
}
// Set sets the SGR sequence.
func (c *Color) Set() *Color {
if c.isNoColorSet() {
return c
}
fmt.Fprintf(Output, c.format())
return c
}
func (c *Color) unset() {
if c.isNoColorSet() {
return
}
Unset()
}
func (c *Color) setWriter(w io.Writer) *Color {
if c.isNoColorSet() {
return c
}
fmt.Fprintf(w, c.format())
return c
}
func (c *Color) unsetWriter(w io.Writer) {
if c.isNoColorSet() {
return
}
if NoColor {
return
}
fmt.Fprintf(w, "%s[%dm", escape, Reset)
}
// Add is used to chain SGR parameters. Use as many as parameters to combine
// and create custom color objects. Example: Add(color.FgRed, color.Underline).
func (c *Color) Add(value ...Attr) *Color {
c.params = append(c.params, value...)
return c
}
func (c *Color) prepend(value Attr) {
c.params = append(c.params, 0)
copy(c.params[1:], c.params[0:])
c.params[0] = value
}
// Fprint formats using the default formats for its operands and writes to w.
// Spaces are added between operands when neither is a string.
// It returns the number of bytes written and any write error encountered.
// On Windows, users should wrap w with colorable.NewColorable() if w is of
// type *os.File.
func (c *Color) Fprint(w io.Writer, a ...interface{}) (n int, err error) {
c.setWriter(w)
defer c.unsetWriter(w)
return fmt.Fprint(w, a...)
}
// Print formats using the default formats for its operands and writes to
// standard output. Spaces are added between operands when neither is a
// string. It returns the number of bytes written and any write error
// encountered. This is the standard fmt.Print() method wrapped with the given
// color.
func (c *Color) Print(a ...interface{}) (n int, err error) {
c.Set()
defer c.unset()
return fmt.Fprint(Output, a...)
}
// Fprintf formats according to a format specifier and writes to w.
// It returns the number of bytes written and any write error encountered.
// On Windows, users should wrap w with colorable.NewColorable() if w is of
// type *os.File.
func (c *Color) Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
c.setWriter(w)
defer c.unsetWriter(w)
return fmt.Fprintf(w, format, a...)
}
// Printf formats according to a format specifier and writes to standard output.
// It returns the number of bytes written and any write error encountered.
// This is the standard fmt.Printf() method wrapped with the given color.
func (c *Color) Printf(format string, a ...interface{}) (n int, err error) {
c.Set()
defer c.unset()
return fmt.Fprintf(Output, format, a...)
}
// Fprintln formats using the default formats for its operands and writes to w.
// Spaces are always added between operands and a newline is appended.
// On Windows, users should wrap w with colorable.NewColorable() if w is of
// type *os.File.
func (c *Color) Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
c.setWriter(w)
defer c.unsetWriter(w)
return fmt.Fprintln(w, a...)
}
// Println formats using the default formats for its operands and writes to
// standard output. Spaces are always added between operands and a newline is
// appended. It returns the number of bytes written and any write error
// encountered. This is the standard fmt.Print() method wrapped with the given
// color.
func (c *Color) Println(a ...interface{}) (n int, err error) {
c.Set()
defer c.unset()
return fmt.Fprintln(Output, a...)
}
// Sprint is just like Print, but returns a string instead of printing it.
func (c *Color) Sprint(a ...interface{}) string {
return c.wrap(fmt.Sprint(a...))
}
// Sprintln is just like Println, but returns a string instead of printing it.
func (c *Color) Sprintln(a ...interface{}) string {
return c.wrap(fmt.Sprintln(a...))
}
// Sprintf is just like Printf, but returns a string instead of printing it.
func (c *Color) Sprintf(format string, a ...interface{}) string {
return c.wrap(fmt.Sprintf(format, a...))
}
// FprintFunc returns a new function that prints the passed arguments as
// colorized with color.Fprint().
func (c *Color) FprintFunc() func(w io.Writer, a ...interface{}) {
return func(w io.Writer, a ...interface{}) {
c.Fprint(w, a...)
}
}
// PrintFunc returns a new function that prints the passed arguments as
// colorized with color.Print().
func (c *Color) PrintFunc() func(a ...interface{}) {
return func(a ...interface{}) {
c.Print(a...)
}
}
// FprintfFunc returns a new function that prints the passed arguments as
// colorized with color.Fprintf().
func (c *Color) FprintfFunc() func(w io.Writer, format string, a ...interface{}) {
return func(w io.Writer, format string, a ...interface{}) {
c.Fprintf(w, format, a...)
}
}
// PrintfFunc returns a new function that prints the passed arguments as
// colorized with color.Printf().
func (c *Color) PrintfFunc() func(format string, a ...interface{}) {
return func(format string, a ...interface{}) {
c.Printf(format, a...)
}
}
// FprintlnFunc returns a new function that prints the passed arguments as
// colorized with color.Fprintln().
func (c *Color) FprintlnFunc() func(w io.Writer, a ...interface{}) {
return func(w io.Writer, a ...interface{}) {
c.Fprintln(w, a...)
}
}
// PrintlnFunc returns a new function that prints the passed arguments as
// colorized with color.Println().
func (c *Color) PrintlnFunc() func(a ...interface{}) {
return func(a ...interface{}) {
c.Println(a...)
}
}
// SprintFunc returns a new function that returns colorized strings for the
// given arguments with fmt.Sprint(). Useful to put into or mix into other
// string. Windows users should use this in conjunction with color.Output, example:
//
// put := New(FgYellow).SprintFunc()
// fmt.Fprintf(color.Output, "This is a %s", put("warning"))
func (c *Color) SprintFunc() func(a ...interface{}) string {
return func(a ...interface{}) string {
return c.wrap(fmt.Sprint(a...))
}
}
// SprintfFunc returns a new function that returns colorized strings for the
// given arguments with fmt.Sprintf(). Useful to put into or mix into other
// string. Windows users should use this in conjunction with color.Output.
func (c *Color) SprintfFunc() func(format string, a ...interface{}) string {
return func(format string, a ...interface{}) string {
return c.wrap(fmt.Sprintf(format, a...))
}
}
// SprintlnFunc returns a new function that returns colorized strings for the
// given arguments with fmt.Sprintln(). Useful to put into or mix into other
// string. Windows users should use this in conjunction with color.Output.
func (c *Color) SprintlnFunc() func(a ...interface{}) string {
return func(a ...interface{}) string {
return c.wrap(fmt.Sprintln(a...))
}
}
// sequence returns a formatted SGR sequence to be plugged into a "\x1b[...m"
// an example output might be: "1;36" -> bold cyan
func (c *Color) sequence() string {
format := make([]string, len(c.params))
for i, v := range c.params {
format[i] = strconv.Itoa(int(v))
}
return strings.Join(format, ";")
}
// wrap wraps the s string with the colors attributes. The string is ready to
// be printed.
func (c *Color) wrap(s string) string {
if c.isNoColorSet() {
return s
}
return c.format() + s + c.unformat()
}
func (c *Color) format() string {
return fmt.Sprintf("%s[%sm", escape, c.sequence())
}
func (c *Color) unformat() string {
return fmt.Sprintf("%s[%dm", escape, Reset)
}
// DisableColor disables the color output. Useful to not change any existing
// code and still being able to output. Can be used for flags like
// "--no-color". To enable back use EnableColor() method.
func (c *Color) DisableColor() {
c.noColor = boolPtr(true)
}
// EnableColor enables the color output. Use it in conjunction with
// DisableColor(). Otherwise this method has no side effects.
func (c *Color) EnableColor() {
c.noColor = boolPtr(false)
}
func (c *Color) isNoColorSet() bool {
// check first if we have user setted action
if c.noColor != nil {
return *c.noColor
}
// if not return the global option, which is disabled by default
return NoColor
}
// Equals returns a boolean value indicating whether two colors are equal.
func (c *Color) Equals(c2 *Color) bool {
if len(c.params) != len(c2.params) {
return false
}
for _, attr := range c.params {
if !c2.attrExists(attr) {
return false
}
}
return true
}
func (c *Color) attrExists(a Attr) bool {
for _, attr := range c.params {
if attr == a {
return true
}
}
return false
}
func boolPtr(v bool) *bool {
return &v
}
func getCachedColor(p Attr) *Color {
colorsCacheMu.Lock()
defer colorsCacheMu.Unlock()
c, ok := colorsCache[p]
if !ok {
c = NewColor(p)
colorsCache[p] = c
}
return c
}
func colorPrint(format string, p Attr, a ...interface{}) {
c := getCachedColor(p)
if !strings.HasSuffix(format, "\n") {
format += "\n"
}
if len(a) == 0 {
c.Print(format)
} else {
c.Printf(format, a...)
}
}
func colorString(format string, p Attr, a ...interface{}) string {
c := getCachedColor(p)
if len(a) == 0 {
return c.SprintFunc()(format)
}
return c.SprintfFunc()(format, a...)
}
// Black is a convenient helper function to print with black foreground. A
// newline is appended to format by default.
func Black(format string, a ...interface{}) { colorPrint(format, FgBlack, a...) }
// Red is a convenient helper function to print with red foreground. A
// newline is appended to format by default.
func Red(format string, a ...interface{}) { colorPrint(format, FgRed, a...) }
// Green is a convenient helper function to print with green foreground. A
// newline is appended to format by default.
func Green(format string, a ...interface{}) { colorPrint(format, FgGreen, a...) }
// Yellow is a convenient helper function to print with yellow foreground.
// A newline is appended to format by default.
func Yellow(format string, a ...interface{}) { colorPrint(format, FgYellow, a...) }
// Blue is a convenient helper function to print with blue foreground. A
// newline is appended to format by default.
func Blue(format string, a ...interface{}) { colorPrint(format, FgBlue, a...) }
// Magenta is a convenient helper function to print with magenta foreground.
// A newline is appended to format by default.
func Magenta(format string, a ...interface{}) { colorPrint(format, FgMagenta, a...) }
// Cyan is a convenient helper function to print with cyan foreground. A
// newline is appended to format by default.
func Cyan(format string, a ...interface{}) { colorPrint(format, FgCyan, a...) }
// White is a convenient helper function to print with white foreground. A
// newline is appended to format by default.
func White(format string, a ...interface{}) { colorPrint(format, FgWhite, a...) }
// BlackString is a convenient helper function to return a string with black
// foreground.
func BlackString(format string, a ...interface{}) string { return colorString(format, FgBlack, a...) }
// RedString is a convenient helper function to return a string with red
// foreground.
func RedString(format string, a ...interface{}) string { return colorString(format, FgRed, a...) }
// GreenString is a convenient helper function to return a string with green
// foreground.
func GreenString(format string, a ...interface{}) string { return colorString(format, FgGreen, a...) }
// YellowString is a convenient helper function to return a string with yellow
// foreground.
func YellowString(format string, a ...interface{}) string { return colorString(format, FgYellow, a...) }
// BlueString is a convenient helper function to return a string with blue
// foreground.
func BlueString(format string, a ...interface{}) string { return colorString(format, FgBlue, a...) }
// MagentaString is a convenient helper function to return a string with magenta
// foreground.
func MagentaString(format string, a ...interface{}) string {
return colorString(format, FgMagenta, a...)
}
// CyanString is a convenient helper function to return a string with cyan
// foreground.
func CyanString(format string, a ...interface{}) string { return colorString(format, FgCyan, a...) }
// WhiteString is a convenient helper function to return a string with white
// foreground.
func WhiteString(format string, a ...interface{}) string { return colorString(format, FgWhite, a...) }
// HiBlack is a convenient helper function to print with hi-intensity black foreground. A
// newline is appended to format by default.
func HiBlack(format string, a ...interface{}) { colorPrint(format, FgHiBlack, a...) }
// HiRed is a convenient helper function to print with hi-intensity red foreground. A
// newline is appended to format by default.
func HiRed(format string, a ...interface{}) { colorPrint(format, FgHiRed, a...) }
// HiGreen is a convenient helper function to print with hi-intensity green foreground. A
// newline is appended to format by default.
func HiGreen(format string, a ...interface{}) { colorPrint(format, FgHiGreen, a...) }
// HiYellow is a convenient helper function to print with hi-intensity yellow foreground.
// A newline is appended to format by default.
func HiYellow(format string, a ...interface{}) { colorPrint(format, FgHiYellow, a...) }
// HiBlue is a convenient helper function to print with hi-intensity blue foreground. A
// newline is appended to format by default.
func HiBlue(format string, a ...interface{}) { colorPrint(format, FgHiBlue, a...) }
// HiMagenta is a convenient helper function to print with hi-intensity magenta foreground.
// A newline is appended to format by default.
func HiMagenta(format string, a ...interface{}) { colorPrint(format, FgHiMagenta, a...) }
// HiCyan is a convenient helper function to print with hi-intensity cyan foreground. A
// newline is appended to format by default.
func HiCyan(format string, a ...interface{}) { colorPrint(format, FgHiCyan, a...) }
// HiWhite is a convenient helper function to print with hi-intensity white foreground. A
// newline is appended to format by default.
func HiWhite(format string, a ...interface{}) { colorPrint(format, FgHiWhite, a...) }
// HiBlackString is a convenient helper function to return a string with hi-intensity black
// foreground.
func HiBlackString(format string, a ...interface{}) string {
return colorString(format, FgHiBlack, a...)
}
// HiRedString is a convenient helper function to return a string with hi-intensity red
// foreground.
func HiRedString(format string, a ...interface{}) string { return colorString(format, FgHiRed, a...) }
// HiGreenString is a convenient helper function to return a string with hi-intensity green
// foreground.
func HiGreenString(format string, a ...interface{}) string {
return colorString(format, FgHiGreen, a...)
}
// HiYellowString is a convenient helper function to return a string with hi-intensity yellow
// foreground.
func HiYellowString(format string, a ...interface{}) string {
return colorString(format, FgHiYellow, a...)
}
// HiBlueString is a convenient helper function to return a string with hi-intensity blue
// foreground.
func HiBlueString(format string, a ...interface{}) string { return colorString(format, FgHiBlue, a...) }
// HiMagentaString is a convenient helper function to return a string with hi-intensity magenta
// foreground.
func HiMagentaString(format string, a ...interface{}) string {
return colorString(format, FgHiMagenta, a...)
}
// HiCyanString is a convenient helper function to return a string with hi-intensity cyan
// foreground.
func HiCyanString(format string, a ...interface{}) string { return colorString(format, FgHiCyan, a...) }
// HiWhiteString is a convenient helper function to return a string with hi-intensity white
// foreground.
func HiWhiteString(format string, a ...interface{}) string {
return colorString(format, FgHiWhite, a...)
}