tea/vendor/github.com/muesli/reflow/ansi/writer.go

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package ansi
import (
"bytes"
"io"
"unicode/utf8"
)
type Writer struct {
Forward io.Writer
ansi bool
ansiseq bytes.Buffer
lastseq bytes.Buffer
seqchanged bool
runeBuf []byte
}
// Write is used to write content to the ANSI buffer.
func (w *Writer) Write(b []byte) (int, error) {
for _, c := range string(b) {
if c == Marker {
// ANSI escape sequence
w.ansi = true
w.seqchanged = true
_, _ = w.ansiseq.WriteRune(c)
} else if w.ansi {
_, _ = w.ansiseq.WriteRune(c)
if IsTerminator(c) {
// ANSI sequence terminated
w.ansi = false
if bytes.HasSuffix(w.ansiseq.Bytes(), []byte("[0m")) {
// reset sequence
w.lastseq.Reset()
w.seqchanged = false
} else if c == 'm' {
// color code
_, _ = w.lastseq.Write(w.ansiseq.Bytes())
}
_, _ = w.ansiseq.WriteTo(w.Forward)
}
} else {
_, err := w.writeRune(c)
if err != nil {
return 0, err
}
}
}
return len(b), nil
}
func (w *Writer) writeRune(r rune) (int, error) {
if w.runeBuf == nil {
w.runeBuf = make([]byte, utf8.UTFMax)
}
n := utf8.EncodeRune(w.runeBuf, r)
return w.Forward.Write(w.runeBuf[:n])
}
func (w *Writer) LastSequence() string {
return w.lastseq.String()
}
func (w *Writer) ResetAnsi() {
if !w.seqchanged {
return
}
_, _ = w.Forward.Write([]byte("\x1b[0m"))
}
func (w *Writer) RestoreAnsi() {
_, _ = w.Forward.Write(w.lastseq.Bytes())
}