elvish/pkg/ui/color.go
2020-03-31 23:11:59 +01:00

118 lines
3.2 KiB
Go

package ui
import (
"fmt"
"strconv"
"strings"
)
// Color represents a color.
type Color interface {
fgSGR() string
bgSGR() string
String() string
}
// Builtin ANSI colors.
var (
Black Color = ansiColor(0)
Red Color = ansiColor(1)
Green Color = ansiColor(2)
Yellow Color = ansiColor(3)
Blue Color = ansiColor(4)
Magenta Color = ansiColor(5)
Cyan Color = ansiColor(6)
White Color = ansiColor(7)
BrightBlack Color = ansiBrightColor(0)
BrightRed Color = ansiBrightColor(1)
BrightGreen Color = ansiBrightColor(2)
BrightYellow Color = ansiBrightColor(3)
BrightBlue Color = ansiBrightColor(4)
BrightMagenta Color = ansiBrightColor(5)
BrightCyan Color = ansiBrightColor(6)
BrightWhite Color = ansiBrightColor(7)
)
// XTerm256Color returns a color from the xterm 256-color palette.
func XTerm256Color(i uint8) Color { return xterm256Color(i) }
// TrueColor returns a 24-bit true color.
func TrueColor(r, g, b uint8) Color { return trueColor{r, g, b} }
var colorNames = []string{
"black", "red", "green", "yellow",
"blue", "magenta", "cyan", "white",
}
var colorByName = map[string]Color{
"black": Black,
"red": Red,
"green": Green,
"yellow": Yellow,
"blue": Blue,
"magenta": Magenta,
"cyan": Cyan,
"white": White,
"bright-black": BrightBlack,
"bright-red": BrightRed,
"bright-green": BrightGreen,
"bright-yellow": BrightYellow,
"bright-blue": BrightBlue,
"bright-magenta": BrightMagenta,
"bright-cyan": BrightCyan,
"bright-white": BrightWhite,
}
type ansiColor uint8
func (c ansiColor) fgSGR() string { return strconv.Itoa(30 + int(c)) }
func (c ansiColor) bgSGR() string { return strconv.Itoa(40 + int(c)) }
func (c ansiColor) String() string { return colorNames[c] }
type ansiBrightColor uint8
func (c ansiBrightColor) fgSGR() string { return strconv.Itoa(90 + int(c)) }
func (c ansiBrightColor) bgSGR() string { return strconv.Itoa(100 + int(c)) }
func (c ansiBrightColor) String() string { return "bright-" + colorNames[c] }
type xterm256Color uint8
func (c xterm256Color) fgSGR() string { return "38;5;" + strconv.Itoa(int(c)) }
func (c xterm256Color) bgSGR() string { return "48;5;" + strconv.Itoa(int(c)) }
func (c xterm256Color) String() string { return "color" + strconv.Itoa(int(c)) }
type trueColor struct{ r, g, b uint8 }
func (c trueColor) fgSGR() string { return "38;2;" + c.rgbSGR() }
func (c trueColor) bgSGR() string { return "48;2;" + c.rgbSGR() }
func (c trueColor) String() string {
return fmt.Sprintf("#%02x%02x%02x", c.r, c.g, c.b)
}
func (c trueColor) rgbSGR() string {
return fmt.Sprintf("%d;%d;%d", c.r, c.g, c.b)
}
func parseColor(name string) Color {
if color, ok := colorByName[name]; ok {
return color
}
if strings.HasPrefix(name, "color") {
i, err := strconv.Atoi(name[5:])
if err == nil && 0 <= i && i < 256 {
return XTerm256Color(uint8(i))
}
} else if strings.HasPrefix(name, "#") && len(name) == 7 {
r, rErr := strconv.ParseUint(name[1:3], 16, 8)
g, gErr := strconv.ParseUint(name[3:5], 16, 8)
b, bErr := strconv.ParseUint(name[5:7], 16, 8)
if rErr == nil && gErr == nil && bErr == nil {
return TrueColor(uint8(r), uint8(g), uint8(b))
}
}
return nil
}