93 lines
2.0 KiB
Go
93 lines
2.0 KiB
Go
package ansi
|
|
|
|
import (
|
|
"fmt"
|
|
"image/color"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/lucasb-eyer/go-colorful"
|
|
)
|
|
|
|
// colorToHexString returns a hex string representation of a color.
|
|
func colorToHexString(c color.Color) string {
|
|
if c == nil {
|
|
return ""
|
|
}
|
|
shift := func(v uint32) uint32 {
|
|
if v > 0xff {
|
|
return v >> 8
|
|
}
|
|
return v
|
|
}
|
|
r, g, b, _ := c.RGBA()
|
|
r, g, b = shift(r), shift(g), shift(b)
|
|
return fmt.Sprintf("#%02x%02x%02x", r, g, b)
|
|
}
|
|
|
|
// rgbToHex converts red, green, and blue values to a hexadecimal value.
|
|
//
|
|
// hex := rgbToHex(0, 0, 255) // 0x0000FF
|
|
func rgbToHex(r, g, b uint32) uint32 {
|
|
return r<<16 + g<<8 + b
|
|
}
|
|
|
|
type shiftable interface {
|
|
~uint | ~uint16 | ~uint32 | ~uint64
|
|
}
|
|
|
|
func shift[T shiftable](x T) T {
|
|
if x > 0xff {
|
|
x >>= 8
|
|
}
|
|
return x
|
|
}
|
|
|
|
// XParseColor is a helper function that parses a string into a color.Color. It
|
|
// provides a similar interface to the XParseColor function in Xlib. It
|
|
// supports the following formats:
|
|
//
|
|
// - #RGB
|
|
// - #RRGGBB
|
|
// - rgb:RRRR/GGGG/BBBB
|
|
// - rgba:RRRR/GGGG/BBBB/AAAA
|
|
//
|
|
// If the string is not a valid color, nil is returned.
|
|
//
|
|
// See: https://linux.die.net/man/3/xparsecolor
|
|
func XParseColor(s string) color.Color {
|
|
switch {
|
|
case strings.HasPrefix(s, "#"):
|
|
c, err := colorful.Hex(s)
|
|
if err != nil {
|
|
return nil
|
|
}
|
|
|
|
return c
|
|
case strings.HasPrefix(s, "rgb:"):
|
|
parts := strings.Split(s[4:], "/")
|
|
if len(parts) != 3 {
|
|
return nil
|
|
}
|
|
|
|
r, _ := strconv.ParseUint(parts[0], 16, 32)
|
|
g, _ := strconv.ParseUint(parts[1], 16, 32)
|
|
b, _ := strconv.ParseUint(parts[2], 16, 32)
|
|
|
|
return color.RGBA{uint8(shift(r)), uint8(shift(g)), uint8(shift(b)), 255} //nolint:gosec
|
|
case strings.HasPrefix(s, "rgba:"):
|
|
parts := strings.Split(s[5:], "/")
|
|
if len(parts) != 4 {
|
|
return nil
|
|
}
|
|
|
|
r, _ := strconv.ParseUint(parts[0], 16, 32)
|
|
g, _ := strconv.ParseUint(parts[1], 16, 32)
|
|
b, _ := strconv.ParseUint(parts[2], 16, 32)
|
|
a, _ := strconv.ParseUint(parts[3], 16, 32)
|
|
|
|
return color.RGBA{uint8(shift(r)), uint8(shift(g)), uint8(shift(b)), uint8(shift(a))} //nolint:gosec
|
|
}
|
|
return nil
|
|
}
|