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8.2 KiB
Go

// Copyright 2014 The gocui Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gocui
import (
"strconv"
"github.com/go-errors/errors"
)
type escapeInterpreter struct {
state escapeState
curch rune
csiParam []string
curFgColor, curBgColor Attribute
mode OutputMode
instruction instruction
}
type (
escapeState int
fontEffect int
)
type instruction interface{ isInstruction() }
type eraseInLineFromCursor struct{}
func (self eraseInLineFromCursor) isInstruction() {}
type noInstruction struct{}
func (self noInstruction) isInstruction() {}
const (
stateNone escapeState = iota
stateEscape
stateCSI
stateParams
stateOSC
stateOSCEscape
bold fontEffect = 1
faint fontEffect = 2
italic fontEffect = 3
underline fontEffect = 4
blink fontEffect = 5
reverse fontEffect = 7
strike fontEffect = 9
setForegroundColor int = 38
defaultForegroundColor int = 39
setBackgroundColor int = 48
defaultBackgroundColor int = 49
)
var (
errNotCSI = errors.New("Not a CSI escape sequence")
errCSIParseError = errors.New("CSI escape sequence parsing error")
errCSITooLong = errors.New("CSI escape sequence is too long")
)
// runes in case of error will output the non-parsed runes as a string.
func (ei *escapeInterpreter) runes() []rune {
switch ei.state {
case stateNone:
return []rune{0x1b}
case stateEscape:
return []rune{0x1b, ei.curch}
case stateCSI:
return []rune{0x1b, '[', ei.curch}
case stateParams:
ret := []rune{0x1b, '['}
for _, s := range ei.csiParam {
ret = append(ret, []rune(s)...)
ret = append(ret, ';')
}
return append(ret, ei.curch)
}
return nil
}
// newEscapeInterpreter returns an escapeInterpreter that will be able to parse
// terminal escape sequences.
func newEscapeInterpreter(mode OutputMode) *escapeInterpreter {
ei := &escapeInterpreter{
state: stateNone,
curFgColor: ColorDefault,
curBgColor: ColorDefault,
mode: mode,
instruction: noInstruction{},
}
return ei
}
// reset sets the escapeInterpreter in initial state.
func (ei *escapeInterpreter) reset() {
ei.state = stateNone
ei.curFgColor = ColorDefault
ei.curBgColor = ColorDefault
ei.csiParam = nil
}
func (ei *escapeInterpreter) instructionRead() {
ei.instruction = noInstruction{}
}
// parseOne parses a rune. If isEscape is true, it means that the rune is part
// of an escape sequence, and as such should not be printed verbatim. Otherwise,
// it's not an escape sequence.
func (ei *escapeInterpreter) parseOne(ch rune) (isEscape bool, err error) {
// Sanity checks
if len(ei.csiParam) > 20 {
return false, errCSITooLong
}
if len(ei.csiParam) > 0 && len(ei.csiParam[len(ei.csiParam)-1]) > 255 {
return false, errCSITooLong
}
ei.curch = ch
switch ei.state {
case stateNone:
if ch == 0x1b {
ei.state = stateEscape
return true, nil
}
return false, nil
case stateEscape:
switch ch {
case '[':
ei.state = stateCSI
return true, nil
case ']':
ei.state = stateOSC
return true, nil
default:
return false, errNotCSI
}
case stateCSI:
switch {
case ch >= '0' && ch <= '9':
ei.csiParam = append(ei.csiParam, "")
case ch == 'm':
ei.csiParam = append(ei.csiParam, "0")
case ch == 'K':
// fall through
default:
return false, errCSIParseError
}
ei.state = stateParams
fallthrough
case stateParams:
switch {
case ch >= '0' && ch <= '9':
ei.csiParam[len(ei.csiParam)-1] += string(ch)
return true, nil
case ch == ';':
ei.csiParam = append(ei.csiParam, "")
return true, nil
case ch == 'm':
if err := ei.outputCSI(); err != nil {
return false, errCSIParseError
}
ei.state = stateNone
ei.csiParam = nil
return true, nil
case ch == 'K':
p := 0
if len(ei.csiParam) != 0 && ei.csiParam[0] != "" {
p, err = strconv.Atoi(ei.csiParam[0])
if err != nil {
return false, errCSIParseError
}
}
if p == 0 {
ei.instruction = eraseInLineFromCursor{}
} else {
// non-zero values of P not supported
ei.instruction = noInstruction{}
}
ei.state = stateNone
ei.csiParam = nil
return true, nil
default:
return false, errCSIParseError
}
case stateOSC:
switch ch {
case 0x1b:
ei.state = stateOSCEscape
return true, nil
}
return true, nil
case stateOSCEscape:
ei.state = stateNone
return true, nil
}
return false, nil
}
func (ei *escapeInterpreter) outputCSI() error {
n := len(ei.csiParam)
for i := 0; i < n; {
p, err := strconv.Atoi(ei.csiParam[i])
if err != nil {
return errCSIParseError
}
skip := 1
switch {
case p == 0: // reset style and color
ei.curFgColor = ColorDefault
ei.curBgColor = ColorDefault
case p >= 1 && p <= 9: // set style
ei.curFgColor |= getFontEffect(p)
case p >= 21 && p <= 29: // reset style
ei.curFgColor &= ^getFontEffect(p - 20)
case p >= 30 && p <= 37: // set foreground color
ei.curFgColor &= AttrStyleBits
ei.curFgColor |= Get256Color(int32(p) - 30)
case p == setForegroundColor: // set foreground color (256-color or true color)
var color Attribute
var err error
color, skip, err = ei.csiColor(ei.csiParam[i:])
if err != nil {
return err
}
ei.curFgColor &= AttrStyleBits
ei.curFgColor |= color
case p == defaultForegroundColor: // reset foreground color
ei.curFgColor &= AttrStyleBits
ei.curFgColor |= ColorDefault
case p >= 40 && p <= 47: // set background color
ei.curBgColor &= AttrStyleBits
ei.curBgColor |= Get256Color(int32(p) - 40)
case p == setBackgroundColor: // set background color (256-color or true color)
var color Attribute
var err error
color, skip, err = ei.csiColor(ei.csiParam[i:])
if err != nil {
return err
}
ei.curBgColor &= AttrStyleBits
ei.curBgColor |= color
case p == defaultBackgroundColor: // reset background color
ei.curBgColor &= AttrStyleBits
ei.curBgColor |= ColorDefault
case p >= 90 && p <= 97: // set bright foreground color
ei.curFgColor &= AttrStyleBits
ei.curFgColor |= Get256Color(int32(p) - 90 + 8)
case p >= 100 && p <= 107: // set bright background color
ei.curBgColor &= AttrStyleBits
ei.curBgColor |= Get256Color(int32(p) - 100 + 8)
default:
}
i += skip
}
return nil
}
func (ei *escapeInterpreter) csiColor(param []string) (color Attribute, skip int, err error) {
if len(param) < 2 {
err = errCSIParseError
return
}
switch param[1] {
case "2":
// 24-bit color
if ei.mode < OutputTrue {
err = errCSIParseError
return
}
if len(param) < 5 {
err = errCSIParseError
return
}
var red, green, blue int
red, err = strconv.Atoi(param[2])
if err != nil {
err = errCSIParseError
return
}
green, err = strconv.Atoi(param[3])
if err != nil {
err = errCSIParseError
return
}
blue, err = strconv.Atoi(param[4])
if err != nil {
err = errCSIParseError
return
}
return NewRGBColor(int32(red), int32(green), int32(blue)), 5, nil
case "5":
// 8-bit color
if ei.mode < Output256 {
err = errCSIParseError
return
}
if len(param) < 3 {
err = errCSIParseError
return
}
var hex int
hex, err = strconv.Atoi(param[2])
if err != nil {
err = errCSIParseError
return
}
return Get256Color(int32(hex)), 3, nil
default:
err = errCSIParseError
return
}
}
// splitFgBg splits foreground and background color according to ANSI sequence.
//
// num (number of segments in ansi) is used to determine if it's 256 mode or rgb mode (3 - 256-color, 5 - rgb-color)
func splitFgBg(params []string, num int) [][]string {
var out [][]string
var current []string
for _, p := range params {
if len(current) == num && (p == "48" || p == "38") {
out = append(out, current)
current = []string{}
}
current = append(current, p)
}
if len(current) > 0 {
out = append(out, current)
}
return out
}
func getFontEffect(f int) Attribute {
switch fontEffect(f) {
case bold:
return AttrBold
case faint:
return AttrDim
case italic:
return AttrItalic
case underline:
return AttrUnderline
case blink:
return AttrBlink
case reverse:
return AttrReverse
case strike:
return AttrStrikeThrough
}
return AttrNone
}