bubbletea/key.go

657 lines
20 KiB
Go

package tea
import (
"errors"
"fmt"
"io"
"unicode/utf8"
"github.com/mattn/go-localereader"
)
// KeyMsg contains information about a keypress. KeyMsgs are always sent to
// the program's update function. There are a couple general patterns you could
// use to check for keypresses:
//
// // Switch on the string representation of the key (shorter)
// switch msg := msg.(type) {
// case KeyMsg:
// switch msg.String() {
// case "enter":
// fmt.Println("you pressed enter!")
// case "a":
// fmt.Println("you pressed a!")
// }
// }
//
// // Switch on the key type (more foolproof)
// switch msg := msg.(type) {
// case KeyMsg:
// switch msg.Type {
// case KeyEnter:
// fmt.Println("you pressed enter!")
// case KeyRunes:
// switch string(msg.Runes) {
// case "a":
// fmt.Println("you pressed a!")
// }
// }
// }
//
// Note that Key.Runes will always contain at least one character, so you can
// always safely call Key.Runes[0]. In most cases Key.Runes will only contain
// one character, though certain input method editors (most notably Chinese
// IMEs) can input multiple runes at once.
type KeyMsg Key
// String returns a string representation for a key message. It's safe (and
// encouraged) for use in key comparison.
func (k KeyMsg) String() (str string) {
return Key(k).String()
}
// Key contains information about a keypress.
type Key struct {
Type KeyType
Runes []rune
Alt bool
}
// String returns a friendly string representation for a key. It's safe (and
// encouraged) for use in key comparison.
//
// k := Key{Type: KeyEnter}
// fmt.Println(k)
// // Output: enter
func (k Key) String() (str string) {
if k.Alt {
str += "alt+"
}
if k.Type == KeyRunes {
str += string(k.Runes)
return str
} else if s, ok := keyNames[k.Type]; ok {
str += s
return str
}
return ""
}
// KeyType indicates the key pressed, such as KeyEnter or KeyBreak or KeyCtrlC.
// All other keys will be type KeyRunes. To get the rune value, check the Rune
// method on a Key struct, or use the Key.String() method:
//
// k := Key{Type: KeyRunes, Runes: []rune{'a'}, Alt: true}
// if k.Type == KeyRunes {
//
// fmt.Println(k.Runes)
// // Output: a
//
// fmt.Println(k.String())
// // Output: alt+a
//
// }
type KeyType int
func (k KeyType) String() (str string) {
if s, ok := keyNames[k]; ok {
return s
}
return ""
}
// Control keys. We could do this with an iota, but the values are very
// specific, so we set the values explicitly to avoid any confusion.
//
// See also:
// https://en.wikipedia.org/wiki/C0_and_C1_control_codes
const (
keyNUL KeyType = 0 // null, \0
keySOH KeyType = 1 // start of heading
keySTX KeyType = 2 // start of text
keyETX KeyType = 3 // break, ctrl+c
keyEOT KeyType = 4 // end of transmission
keyENQ KeyType = 5 // enquiry
keyACK KeyType = 6 // acknowledge
keyBEL KeyType = 7 // bell, \a
keyBS KeyType = 8 // backspace
keyHT KeyType = 9 // horizontal tabulation, \t
keyLF KeyType = 10 // line feed, \n
keyVT KeyType = 11 // vertical tabulation \v
keyFF KeyType = 12 // form feed \f
keyCR KeyType = 13 // carriage return, \r
keySO KeyType = 14 // shift out
keySI KeyType = 15 // shift in
keyDLE KeyType = 16 // data link escape
keyDC1 KeyType = 17 // device control one
keyDC2 KeyType = 18 // device control two
keyDC3 KeyType = 19 // device control three
keyDC4 KeyType = 20 // device control four
keyNAK KeyType = 21 // negative acknowledge
keySYN KeyType = 22 // synchronous idle
keyETB KeyType = 23 // end of transmission block
keyCAN KeyType = 24 // cancel
keyEM KeyType = 25 // end of medium
keySUB KeyType = 26 // substitution
keyESC KeyType = 27 // escape, \e
keyFS KeyType = 28 // file separator
keyGS KeyType = 29 // group separator
keyRS KeyType = 30 // record separator
keyUS KeyType = 31 // unit separator
keyDEL KeyType = 127 // delete. on most systems this is mapped to backspace, I hear
)
// Control key aliases.
const (
KeyNull KeyType = keyNUL
KeyBreak KeyType = keyETX
KeyEnter KeyType = keyCR
KeyBackspace KeyType = keyDEL
KeyTab KeyType = keyHT
KeyEsc KeyType = keyESC
KeyEscape KeyType = keyESC
KeyCtrlAt KeyType = keyNUL // ctrl+@
KeyCtrlA KeyType = keySOH
KeyCtrlB KeyType = keySTX
KeyCtrlC KeyType = keyETX
KeyCtrlD KeyType = keyEOT
KeyCtrlE KeyType = keyENQ
KeyCtrlF KeyType = keyACK
KeyCtrlG KeyType = keyBEL
KeyCtrlH KeyType = keyBS
KeyCtrlI KeyType = keyHT
KeyCtrlJ KeyType = keyLF
KeyCtrlK KeyType = keyVT
KeyCtrlL KeyType = keyFF
KeyCtrlM KeyType = keyCR
KeyCtrlN KeyType = keySO
KeyCtrlO KeyType = keySI
KeyCtrlP KeyType = keyDLE
KeyCtrlQ KeyType = keyDC1
KeyCtrlR KeyType = keyDC2
KeyCtrlS KeyType = keyDC3
KeyCtrlT KeyType = keyDC4
KeyCtrlU KeyType = keyNAK
KeyCtrlV KeyType = keySYN
KeyCtrlW KeyType = keyETB
KeyCtrlX KeyType = keyCAN
KeyCtrlY KeyType = keyEM
KeyCtrlZ KeyType = keySUB
KeyCtrlOpenBracket KeyType = keyESC // ctrl+[
KeyCtrlBackslash KeyType = keyFS // ctrl+\
KeyCtrlCloseBracket KeyType = keyGS // ctrl+]
KeyCtrlCaret KeyType = keyRS // ctrl+^
KeyCtrlUnderscore KeyType = keyUS // ctrl+_
KeyCtrlQuestionMark KeyType = keyDEL // ctrl+?
)
// Other keys.
const (
KeyRunes KeyType = -(iota + 1)
KeyUp
KeyDown
KeyRight
KeyLeft
KeyShiftTab
KeyHome
KeyEnd
KeyPgUp
KeyPgDown
KeyDelete
KeyInsert
KeySpace
KeyCtrlUp
KeyCtrlDown
KeyCtrlRight
KeyCtrlLeft
KeyCtrlHome
KeyCtrlEnd
KeyShiftUp
KeyShiftDown
KeyShiftRight
KeyShiftLeft
KeyShiftHome
KeyShiftEnd
KeyCtrlShiftUp
KeyCtrlShiftDown
KeyCtrlShiftLeft
KeyCtrlShiftRight
KeyCtrlShiftHome
KeyCtrlShiftEnd
KeyF1
KeyF2
KeyF3
KeyF4
KeyF5
KeyF6
KeyF7
KeyF8
KeyF9
KeyF10
KeyF11
KeyF12
KeyF13
KeyF14
KeyF15
KeyF16
KeyF17
KeyF18
KeyF19
KeyF20
)
// Mappings for control keys and other special keys to friendly consts.
var keyNames = map[KeyType]string{
// Control keys.
keyNUL: "ctrl+@", // also ctrl+` (that's ctrl+backtick)
keySOH: "ctrl+a",
keySTX: "ctrl+b",
keyETX: "ctrl+c",
keyEOT: "ctrl+d",
keyENQ: "ctrl+e",
keyACK: "ctrl+f",
keyBEL: "ctrl+g",
keyBS: "ctrl+h",
keyHT: "tab", // also ctrl+i
keyLF: "ctrl+j",
keyVT: "ctrl+k",
keyFF: "ctrl+l",
keyCR: "enter",
keySO: "ctrl+n",
keySI: "ctrl+o",
keyDLE: "ctrl+p",
keyDC1: "ctrl+q",
keyDC2: "ctrl+r",
keyDC3: "ctrl+s",
keyDC4: "ctrl+t",
keyNAK: "ctrl+u",
keySYN: "ctrl+v",
keyETB: "ctrl+w",
keyCAN: "ctrl+x",
keyEM: "ctrl+y",
keySUB: "ctrl+z",
keyESC: "esc",
keyFS: "ctrl+\\",
keyGS: "ctrl+]",
keyRS: "ctrl+^",
keyUS: "ctrl+_",
keyDEL: "backspace",
// Other keys.
KeyRunes: "runes",
KeyUp: "up",
KeyDown: "down",
KeyRight: "right",
KeySpace: " ", // for backwards compatibility
KeyLeft: "left",
KeyShiftTab: "shift+tab",
KeyHome: "home",
KeyEnd: "end",
KeyCtrlHome: "ctrl+home",
KeyCtrlEnd: "ctrl+end",
KeyShiftHome: "shift+home",
KeyShiftEnd: "shift+end",
KeyCtrlShiftHome: "ctrl+shift+home",
KeyCtrlShiftEnd: "ctrl+shift+end",
KeyPgUp: "pgup",
KeyPgDown: "pgdown",
KeyDelete: "delete",
KeyInsert: "insert",
KeyCtrlUp: "ctrl+up",
KeyCtrlDown: "ctrl+down",
KeyCtrlRight: "ctrl+right",
KeyCtrlLeft: "ctrl+left",
KeyShiftUp: "shift+up",
KeyShiftDown: "shift+down",
KeyShiftRight: "shift+right",
KeyShiftLeft: "shift+left",
KeyCtrlShiftUp: "ctrl+shift+up",
KeyCtrlShiftDown: "ctrl+shift+down",
KeyCtrlShiftLeft: "ctrl+shift+left",
KeyCtrlShiftRight: "ctrl+shift+right",
KeyF1: "f1",
KeyF2: "f2",
KeyF3: "f3",
KeyF4: "f4",
KeyF5: "f5",
KeyF6: "f6",
KeyF7: "f7",
KeyF8: "f8",
KeyF9: "f9",
KeyF10: "f10",
KeyF11: "f11",
KeyF12: "f12",
KeyF13: "f13",
KeyF14: "f14",
KeyF15: "f15",
KeyF16: "f16",
KeyF17: "f17",
KeyF18: "f18",
KeyF19: "f19",
KeyF20: "f20",
}
// Sequence mappings.
var sequences = map[string]Key{
// Arrow keys
"\x1b[A": {Type: KeyUp},
"\x1b[B": {Type: KeyDown},
"\x1b[C": {Type: KeyRight},
"\x1b[D": {Type: KeyLeft},
"\x1b[1;2A": {Type: KeyShiftUp},
"\x1b[1;2B": {Type: KeyShiftDown},
"\x1b[1;2C": {Type: KeyShiftRight},
"\x1b[1;2D": {Type: KeyShiftLeft},
"\x1b[OA": {Type: KeyShiftUp}, // DECCKM
"\x1b[OB": {Type: KeyShiftDown}, // DECCKM
"\x1b[OC": {Type: KeyShiftRight}, // DECCKM
"\x1b[OD": {Type: KeyShiftLeft}, // DECCKM
"\x1b[a": {Type: KeyShiftUp}, // urxvt
"\x1b[b": {Type: KeyShiftDown}, // urxvt
"\x1b[c": {Type: KeyShiftRight}, // urxvt
"\x1b[d": {Type: KeyShiftLeft}, // urxvt
"\x1b[1;3A": {Type: KeyUp, Alt: true},
"\x1b[1;3B": {Type: KeyDown, Alt: true},
"\x1b[1;3C": {Type: KeyRight, Alt: true},
"\x1b[1;3D": {Type: KeyLeft, Alt: true},
"\x1b\x1b[A": {Type: KeyUp, Alt: true}, // urxvt
"\x1b\x1b[B": {Type: KeyDown, Alt: true}, // urxvt
"\x1b\x1b[C": {Type: KeyRight, Alt: true}, // urxvt
"\x1b\x1b[D": {Type: KeyLeft, Alt: true}, // urxvt
"\x1b[1;4A": {Type: KeyShiftUp, Alt: true},
"\x1b[1;4B": {Type: KeyShiftDown, Alt: true},
"\x1b[1;4C": {Type: KeyShiftRight, Alt: true},
"\x1b[1;4D": {Type: KeyShiftLeft, Alt: true},
"\x1b\x1b[a": {Type: KeyShiftUp, Alt: true}, // urxvt
"\x1b\x1b[b": {Type: KeyShiftDown, Alt: true}, // urxvt
"\x1b\x1b[c": {Type: KeyShiftRight, Alt: true}, // urxvt
"\x1b\x1b[d": {Type: KeyShiftLeft, Alt: true}, // urxvt
"\x1b[1;5A": {Type: KeyCtrlUp},
"\x1b[1;5B": {Type: KeyCtrlDown},
"\x1b[1;5C": {Type: KeyCtrlRight},
"\x1b[1;5D": {Type: KeyCtrlLeft},
"\x1b[Oa": {Type: KeyCtrlUp, Alt: true}, // urxvt
"\x1b[Ob": {Type: KeyCtrlDown, Alt: true}, // urxvt
"\x1b[Oc": {Type: KeyCtrlRight, Alt: true}, // urxvt
"\x1b[Od": {Type: KeyCtrlLeft, Alt: true}, // urxvt
"\x1b[1;6A": {Type: KeyCtrlShiftUp},
"\x1b[1;6B": {Type: KeyCtrlShiftDown},
"\x1b[1;6C": {Type: KeyCtrlShiftRight},
"\x1b[1;6D": {Type: KeyCtrlShiftLeft},
"\x1b[1;7A": {Type: KeyCtrlUp, Alt: true},
"\x1b[1;7B": {Type: KeyCtrlDown, Alt: true},
"\x1b[1;7C": {Type: KeyCtrlRight, Alt: true},
"\x1b[1;7D": {Type: KeyCtrlLeft, Alt: true},
"\x1b[1;8A": {Type: KeyCtrlShiftUp, Alt: true},
"\x1b[1;8B": {Type: KeyCtrlShiftDown, Alt: true},
"\x1b[1;8C": {Type: KeyCtrlShiftRight, Alt: true},
"\x1b[1;8D": {Type: KeyCtrlShiftLeft, Alt: true},
// Miscellaneous keys
"\x1b[Z": {Type: KeyShiftTab},
"\x1b[3~": {Type: KeyDelete},
"\x1b[3;3~": {Type: KeyDelete, Alt: true},
"\x1b\x1b[3~": {Type: KeyDelete, Alt: true}, // urxvt
"\x1b[5~": {Type: KeyPgUp},
"\x1b[5;3~": {Type: KeyPgUp, Alt: true},
"\x1b\x1b[5~": {Type: KeyPgUp, Alt: true}, // urxvt
"\x1b[6~": {Type: KeyPgDown},
"\x1b[6;3~": {Type: KeyPgDown, Alt: true},
"\x1b\x1b[6~": {Type: KeyPgDown, Alt: true}, // urxvt
"\x1b[1~": {Type: KeyHome},
"\x1b[H": {Type: KeyHome}, // xterm, lxterm
"\x1b[1;3H": {Type: KeyHome, Alt: true}, // xterm, lxterm
"\x1b[1;5H": {Type: KeyCtrlHome}, // xterm, lxterm
"\x1b[1;7H": {Type: KeyCtrlHome, Alt: true}, // xterm, lxterm
"\x1b[1;2H": {Type: KeyShiftHome}, // xterm, lxterm
"\x1b[1;4H": {Type: KeyShiftHome, Alt: true}, // xterm, lxterm
"\x1b[1;6H": {Type: KeyCtrlShiftHome}, // xterm, lxterm
"\x1b[1;8H": {Type: KeyCtrlShiftHome, Alt: true}, // xterm, lxterm
"\x1b[4~": {Type: KeyEnd},
"\x1b[F": {Type: KeyEnd}, // xterm, lxterm
"\x1b[1;3F": {Type: KeyEnd, Alt: true}, // xterm, lxterm
"\x1b[1;5F": {Type: KeyCtrlEnd}, // xterm, lxterm
"\x1b[1;7F": {Type: KeyCtrlEnd, Alt: true}, // xterm, lxterm
"\x1b[1;2F": {Type: KeyShiftEnd}, // xterm, lxterm
"\x1b[1;4F": {Type: KeyShiftEnd, Alt: true}, // xterm, lxterm
"\x1b[1;6F": {Type: KeyCtrlShiftEnd}, // xterm, lxterm
"\x1b[1;8F": {Type: KeyCtrlShiftEnd, Alt: true}, // xterm, lxterm
"\x1b[7~": {Type: KeyHome}, // urxvt
"\x1b\x1b[7~": {Type: KeyHome, Alt: true}, // urxvt
"\x1b[7^": {Type: KeyCtrlHome}, // urxvt
"\x1b\x1b[7^": {Type: KeyCtrlHome, Alt: true}, // urxvt
"\x1b[7$": {Type: KeyShiftHome}, // urxvt
"\x1b\x1b[7$": {Type: KeyShiftHome, Alt: true}, // urxvt
"\x1b[7@": {Type: KeyCtrlShiftHome}, // urxvt
"\x1b\x1b[7@": {Type: KeyCtrlShiftHome, Alt: true}, // urxvt
"\x1b[8~": {Type: KeyEnd}, // urxvt
"\x1b\x1b[8~": {Type: KeyEnd, Alt: true}, // urxvt
"\x1b[8^": {Type: KeyCtrlEnd}, // urxvt
"\x1b\x1b[8^": {Type: KeyCtrlEnd, Alt: true}, // urxvt
"\x1b[8$": {Type: KeyShiftEnd}, // urxvt
"\x1b\x1b[8$": {Type: KeyShiftEnd, Alt: true}, // urxvt
"\x1b[8@": {Type: KeyCtrlShiftEnd}, // urxvt
"\x1b\x1b[8@": {Type: KeyCtrlShiftEnd, Alt: true}, // urxvt
// Function keys, Linux console
"\x1b[[A": {Type: KeyF1}, // linux console
"\x1b[[B": {Type: KeyF2}, // linux console
"\x1b[[C": {Type: KeyF3}, // linux console
"\x1b[[D": {Type: KeyF4}, // linux console
"\x1b[[E": {Type: KeyF5}, // linux console
// Function keys, X11
"\x1bOP": {Type: KeyF1}, // vt100, xterm
"\x1bOQ": {Type: KeyF2}, // vt100, xterm
"\x1bOR": {Type: KeyF3}, // vt100, xterm
"\x1bOS": {Type: KeyF4}, // vt100, xterm
"\x1b[1;3P": {Type: KeyF1, Alt: true}, // vt100, xterm
"\x1b[1;3Q": {Type: KeyF2, Alt: true}, // vt100, xterm
"\x1b[1;3R": {Type: KeyF3, Alt: true}, // vt100, xterm
"\x1b[1;3S": {Type: KeyF4, Alt: true}, // vt100, xterm
"\x1b[11~": {Type: KeyF1}, // urxvt
"\x1b[12~": {Type: KeyF2}, // urxvt
"\x1b[13~": {Type: KeyF3}, // urxvt
"\x1b[14~": {Type: KeyF4}, // urxvt
"\x1b\x1b[11~": {Type: KeyF1, Alt: true}, // urxvt
"\x1b\x1b[12~": {Type: KeyF2, Alt: true}, // urxvt
"\x1b\x1b[13~": {Type: KeyF3, Alt: true}, // urxvt
"\x1b\x1b[14~": {Type: KeyF4, Alt: true}, // urxvt
"\x1b[15~": {Type: KeyF5}, // vt100, xterm, also urxvt
"\x1b[15;3~": {Type: KeyF5, Alt: true}, // vt100, xterm, also urxvt
"\x1b\x1b[15~": {Type: KeyF5, Alt: true}, // urxvt
"\x1b[17~": {Type: KeyF6}, // vt100, xterm, also urxvt
"\x1b[18~": {Type: KeyF7}, // vt100, xterm, also urxvt
"\x1b[19~": {Type: KeyF8}, // vt100, xterm, also urxvt
"\x1b[20~": {Type: KeyF9}, // vt100, xterm, also urxvt
"\x1b[21~": {Type: KeyF10}, // vt100, xterm, also urxvt
"\x1b\x1b[17~": {Type: KeyF6, Alt: true}, // urxvt
"\x1b\x1b[18~": {Type: KeyF7, Alt: true}, // urxvt
"\x1b\x1b[19~": {Type: KeyF8, Alt: true}, // urxvt
"\x1b\x1b[20~": {Type: KeyF9, Alt: true}, // urxvt
"\x1b\x1b[21~": {Type: KeyF10, Alt: true}, // urxvt
"\x1b[17;3~": {Type: KeyF6, Alt: true}, // vt100, xterm
"\x1b[18;3~": {Type: KeyF7, Alt: true}, // vt100, xterm
"\x1b[19;3~": {Type: KeyF8, Alt: true}, // vt100, xterm
"\x1b[20;3~": {Type: KeyF9, Alt: true}, // vt100, xterm
"\x1b[21;3~": {Type: KeyF10, Alt: true}, // vt100, xterm
"\x1b[23~": {Type: KeyF11}, // vt100, xterm, also urxvt
"\x1b[24~": {Type: KeyF12}, // vt100, xterm, also urxvt
"\x1b[23;3~": {Type: KeyF11, Alt: true}, // vt100, xterm
"\x1b[24;3~": {Type: KeyF12, Alt: true}, // vt100, xterm
"\x1b\x1b[23~": {Type: KeyF11, Alt: true}, // urxvt
"\x1b\x1b[24~": {Type: KeyF12, Alt: true}, // urxvt
"\x1b[1;2P": {Type: KeyF13},
"\x1b[1;2Q": {Type: KeyF14},
"\x1b[25~": {Type: KeyF13}, // vt100, xterm, also urxvt
"\x1b[26~": {Type: KeyF14}, // vt100, xterm, also urxvt
"\x1b[25;3~": {Type: KeyF13, Alt: true}, // vt100, xterm
"\x1b[26;3~": {Type: KeyF14, Alt: true}, // vt100, xterm
"\x1b\x1b[25~": {Type: KeyF13, Alt: true}, // urxvt
"\x1b\x1b[26~": {Type: KeyF14, Alt: true}, // urxvt
"\x1b[1;2R": {Type: KeyF15},
"\x1b[1;2S": {Type: KeyF16},
"\x1b[28~": {Type: KeyF15}, // vt100, xterm, also urxvt
"\x1b[29~": {Type: KeyF16}, // vt100, xterm, also urxvt
"\x1b[28;3~": {Type: KeyF15, Alt: true}, // vt100, xterm
"\x1b[29;3~": {Type: KeyF16, Alt: true}, // vt100, xterm
"\x1b\x1b[28~": {Type: KeyF15, Alt: true}, // urxvt
"\x1b\x1b[29~": {Type: KeyF16, Alt: true}, // urxvt
"\x1b[15;2~": {Type: KeyF17},
"\x1b[17;2~": {Type: KeyF18},
"\x1b[18;2~": {Type: KeyF19},
"\x1b[19;2~": {Type: KeyF20},
"\x1b[31~": {Type: KeyF17},
"\x1b[32~": {Type: KeyF18},
"\x1b[33~": {Type: KeyF19},
"\x1b[34~": {Type: KeyF20},
"\x1b\x1b[31~": {Type: KeyF17, Alt: true}, // urxvt
"\x1b\x1b[32~": {Type: KeyF18, Alt: true}, // urxvt
"\x1b\x1b[33~": {Type: KeyF19, Alt: true}, // urxvt
"\x1b\x1b[34~": {Type: KeyF20, Alt: true}, // urxvt
}
// Hex code mappings.
var hexes = map[string]Key{
"1b0d": {Type: KeyEnter, Alt: true},
"1b7f": {Type: KeyBackspace, Alt: true},
// Powershell
"1b4f41": {Type: KeyUp, Alt: false},
"1b4f42": {Type: KeyDown, Alt: false},
"1b4f43": {Type: KeyRight, Alt: false},
"1b4f44": {Type: KeyLeft, Alt: false},
}
// readInputs reads keypress and mouse inputs from a TTY and returns messages
// containing information about the key or mouse events accordingly.
func readInputs(input io.Reader) ([]Msg, error) {
var buf [256]byte
// Read and block
numBytes, err := input.Read(buf[:])
if err != nil {
return nil, err
}
b := buf[:numBytes]
b, err = localereader.UTF8(b)
if err != nil {
return nil, err
}
// Check if it's a mouse event. For now we're parsing X10-type mouse events
// only.
mouseEvent, err := parseX10MouseEvents(b)
if err == nil {
var m []Msg
for _, v := range mouseEvent {
m = append(m, MouseMsg(v))
}
return m, nil
}
var runeSets [][]rune
var runes []rune
// Translate input into runes. In most cases we'll receive exactly one
// rune, but there are cases, particularly when an input method editor is
// used, where we can receive multiple runes at once.
for i, w := 0, 0; i < len(b); i += w {
r, width := utf8.DecodeRune(b[i:])
if r == utf8.RuneError {
return nil, errors.New("could not decode rune")
}
if r == '\x1b' && len(runes) > 1 {
// a new key sequence has started
runeSets = append(runeSets, runes)
runes = []rune{}
}
runes = append(runes, r)
w = width
}
// add the final set of runes we decoded
runeSets = append(runeSets, runes)
if len(runeSets) == 0 {
return nil, errors.New("received 0 runes from input")
}
var msgs []Msg
for _, runes := range runeSets {
// Is it a sequence, like an arrow key?
if k, ok := sequences[string(runes)]; ok {
msgs = append(msgs, KeyMsg(k))
continue
}
// Some of these need special handling.
hex := fmt.Sprintf("%x", runes)
if k, ok := hexes[hex]; ok {
msgs = append(msgs, KeyMsg(k))
continue
}
// Is the alt key pressed? If so, the buffer will be prefixed with an
// escape.
alt := false
if len(runes) > 1 && runes[0] == 0x1b {
alt = true
runes = runes[1:]
}
for _, v := range runes {
// Is the first rune a control character?
r := KeyType(v)
if r <= keyUS || r == keyDEL {
msgs = append(msgs, KeyMsg(Key{Type: r, Alt: alt}))
continue
}
// If it's a space, override the type with KeySpace (but still include
// the rune).
if r == ' ' {
msgs = append(msgs, KeyMsg(Key{Type: KeySpace, Runes: []rune{v}, Alt: alt}))
continue
}
// Welp, just regular, ol' runes.
msgs = append(msgs, KeyMsg(Key{Type: KeyRunes, Runes: []rune{v}, Alt: alt}))
}
}
return msgs, nil
}