110 lines
2.2 KiB
Go
110 lines
2.2 KiB
Go
// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
|
|
|
|
package wcswidth
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"kitty/tools/utils"
|
|
)
|
|
|
|
var _ = fmt.Print
|
|
|
|
func IsFlagCodepoint(ch rune) bool {
|
|
return 0x1F1E6 <= ch && ch <= 0x1F1FF
|
|
}
|
|
|
|
func IsFlagPair(a rune, b rune) bool {
|
|
return IsFlagCodepoint(a) && IsFlagCodepoint(b)
|
|
}
|
|
|
|
type ecparser_state uint8
|
|
|
|
type WCWidthIterator struct {
|
|
prev_ch rune
|
|
prev_width, current_width int
|
|
parser EscapeCodeParser
|
|
state ecparser_state
|
|
rune_count uint
|
|
}
|
|
|
|
func CreateWCWidthIterator() *WCWidthIterator {
|
|
var ans WCWidthIterator
|
|
ans.parser.HandleRune = ans.handle_rune
|
|
return &ans
|
|
}
|
|
|
|
func (self *WCWidthIterator) Reset() {
|
|
self.prev_ch = 0
|
|
self.prev_width = 0
|
|
self.current_width = 0
|
|
self.rune_count = 0
|
|
self.parser.Reset()
|
|
}
|
|
|
|
func (self *WCWidthIterator) handle_rune(ch rune) error {
|
|
self.rune_count += 1
|
|
const (
|
|
normal ecparser_state = 0
|
|
flag_pair_started ecparser_state = 3
|
|
)
|
|
switch self.state {
|
|
case flag_pair_started:
|
|
self.state = normal
|
|
if IsFlagPair(self.prev_ch, ch) {
|
|
break
|
|
}
|
|
fallthrough
|
|
case normal:
|
|
switch ch {
|
|
case 0xfe0f:
|
|
if IsEmojiPresentationBase(self.prev_ch) && self.prev_width == 1 {
|
|
self.current_width += 1
|
|
self.prev_width = 2
|
|
} else {
|
|
self.prev_width = 0
|
|
}
|
|
case 0xfe0e:
|
|
if IsEmojiPresentationBase(self.prev_ch) && self.prev_width == 2 {
|
|
self.current_width -= 1
|
|
self.prev_width = 1
|
|
} else {
|
|
self.prev_width = 0
|
|
}
|
|
default:
|
|
if IsFlagCodepoint(ch) {
|
|
self.state = flag_pair_started
|
|
}
|
|
w := Runewidth(ch)
|
|
switch w {
|
|
case -1:
|
|
case 0:
|
|
self.prev_width = 0
|
|
case 2:
|
|
self.prev_width = 2
|
|
default:
|
|
self.prev_width = 1
|
|
}
|
|
self.current_width += self.prev_width
|
|
}
|
|
}
|
|
self.prev_ch = ch
|
|
return nil
|
|
}
|
|
|
|
func (self *WCWidthIterator) ParseByte(b byte) (ans int) {
|
|
self.parser.ParseByte(b)
|
|
return self.current_width
|
|
}
|
|
|
|
func (self *WCWidthIterator) Parse(b []byte) (ans int) {
|
|
self.current_width = 0
|
|
self.parser.Parse(b)
|
|
return self.current_width
|
|
}
|
|
|
|
func Stringwidth(text string) int {
|
|
w := CreateWCWidthIterator()
|
|
return w.Parse(utils.UnsafeStringToBytes(text))
|
|
}
|