1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
|
package ansi
import (
"bytes"
"strconv"
"github.com/charmbracelet/x/ansi/parser"
)
// DcsSequence represents a Device Control String (DCS) escape sequence.
//
// The DCS sequence is used to send device control strings to the terminal. The
// sequence starts with the C1 control code character DCS (0x9B) or ESC P in
// 7-bit environments, followed by parameter bytes, intermediate bytes, a
// command byte, followed by data bytes, and ends with the C1 control code
// character ST (0x9C) or ESC \ in 7-bit environments.
//
// This follows the parameter string format.
// See ECMA-48 § 5.4.1
type DcsSequence struct {
// Params contains the raw parameters of the sequence.
// This is a slice of integers, where each integer is a 32-bit integer
// containing the parameter value in the lower 31 bits and a flag in the
// most significant bit indicating whether there are more sub-parameters.
Params []int
// Data contains the string raw data of the sequence.
// This is the data between the final byte and the escape sequence terminator.
Data []byte
// Cmd contains the raw command of the sequence.
// The command is a 32-bit integer containing the DCS command byte in the
// lower 8 bits, the private marker in the next 8 bits, and the intermediate
// byte in the next 8 bits.
//
// DCS > 0 ; 1 $ r <data> ST
//
// Is represented as:
//
// 'r' | '>' << 8 | '$' << 16
Cmd int
}
var _ Sequence = DcsSequence{}
// Marker returns the marker byte of the DCS sequence.
// This is always gonna be one of the following '<' '=' '>' '?' and in the
// range of 0x3C-0x3F.
// Zero is returned if the sequence does not have a marker.
func (s DcsSequence) Marker() int {
return parser.Marker(s.Cmd)
}
// Intermediate returns the intermediate byte of the DCS sequence.
// An intermediate byte is in the range of 0x20-0x2F. This includes these
// characters from ' ', '!', '"', '#', '$', '%', '&', ”', '(', ')', '*', '+',
// ',', '-', '.', '/'.
// Zero is returned if the sequence does not have an intermediate byte.
func (s DcsSequence) Intermediate() int {
return parser.Intermediate(s.Cmd)
}
// Command returns the command byte of the CSI sequence.
func (s DcsSequence) Command() int {
return parser.Command(s.Cmd)
}
// Param returns the parameter at the given index.
// It returns -1 if the parameter does not exist.
func (s DcsSequence) Param(i int) int {
return parser.Param(s.Params, i)
}
// HasMore returns true if the parameter has more sub-parameters.
func (s DcsSequence) HasMore(i int) bool {
return parser.HasMore(s.Params, i)
}
// Subparams returns the sub-parameters of the given parameter.
// It returns nil if the parameter does not exist.
func (s DcsSequence) Subparams(i int) []int {
return parser.Subparams(s.Params, i)
}
// Len returns the number of parameters in the sequence.
// This will return the number of parameters in the sequence, excluding any
// sub-parameters.
func (s DcsSequence) Len() int {
return parser.Len(s.Params)
}
// Range iterates over the parameters of the sequence and calls the given
// function for each parameter.
// The function should return false to stop the iteration.
func (s DcsSequence) Range(fn func(i int, param int, hasMore bool) bool) {
parser.Range(s.Params, fn)
}
// Clone returns a copy of the DCS sequence.
func (s DcsSequence) Clone() Sequence {
return DcsSequence{
Params: append([]int(nil), s.Params...),
Data: append([]byte(nil), s.Data...),
Cmd: s.Cmd,
}
}
// String returns a string representation of the sequence.
// The string will always be in the 7-bit format i.e (ESC P p..p i..i f <data> ESC \).
func (s DcsSequence) String() string {
return s.buffer().String()
}
// buffer returns a buffer containing the sequence.
func (s DcsSequence) buffer() *bytes.Buffer {
var b bytes.Buffer
b.WriteString("\x1bP")
if m := s.Marker(); m != 0 {
b.WriteByte(byte(m))
}
s.Range(func(i, param int, hasMore bool) bool {
if param >= -1 {
b.WriteString(strconv.Itoa(param))
}
if i < len(s.Params)-1 {
if hasMore {
b.WriteByte(':')
} else {
b.WriteByte(';')
}
}
return true
})
if i := s.Intermediate(); i != 0 {
b.WriteByte(byte(i))
}
b.WriteByte(byte(s.Command()))
b.Write(s.Data)
b.WriteByte(ESC)
b.WriteByte('\\')
return &b
}
// Bytes returns the byte representation of the sequence.
// The bytes will always be in the 7-bit format i.e (ESC P p..p i..i F <data> ESC \).
func (s DcsSequence) Bytes() []byte {
return s.buffer().Bytes()
}
|