bubbletea/key_sequences.go

120 lines
3.1 KiB
Go

package tea
import (
"bytes"
"sort"
"unicode/utf8"
)
// extSequences is used by the map-based algorithm below. It contains
// the sequences plus their alternatives with an escape character
// prefixed, plus the control chars, plus the space.
// It does not contain the NUL character, which is handled specially
// by detectOneMsg.
var extSequences = func() map[string]Key {
s := map[string]Key{}
for seq, key := range sequences {
key := key
s[seq] = key
if !key.Alt {
key.Alt = true
s["\x1b"+seq] = key
}
}
for i := keyNUL + 1; i <= keyDEL; i++ {
if i == keyESC {
continue
}
s[string([]byte{byte(i)})] = Key{Type: i}
s[string([]byte{'\x1b', byte(i)})] = Key{Type: i, Alt: true}
if i == keyUS {
i = keyDEL - 1
}
}
s[" "] = Key{Type: KeySpace, Runes: spaceRunes}
s["\x1b "] = Key{Type: KeySpace, Alt: true, Runes: spaceRunes}
s["\x1b\x1b"] = Key{Type: KeyEscape, Alt: true}
return s
}()
// seqLengths is the sizes of valid sequences, starting with the
// largest size.
var seqLengths = func() []int {
sizes := map[int]struct{}{}
for seq := range extSequences {
sizes[len(seq)] = struct{}{}
}
lsizes := make([]int, 0, len(sizes))
for sz := range sizes {
lsizes = append(lsizes, sz)
}
sort.Slice(lsizes, func(i, j int) bool { return lsizes[i] > lsizes[j] })
return lsizes
}()
// detectSequence uses a longest prefix match over the input
// sequence and a hash map.
func detectSequence(input []byte) (hasSeq bool, width int, msg Msg) {
seqs := extSequences
for _, sz := range seqLengths {
if sz > len(input) {
continue
}
prefix := input[:sz]
key, ok := seqs[string(prefix)]
if ok {
return true, sz, KeyMsg(key)
}
}
// Is this an unknown CSI sequence?
if loc := unknownCSIRe.FindIndex(input); loc != nil {
return true, loc[1], unknownCSISequenceMsg(input[:loc[1]])
}
return false, 0, nil
}
// detectBracketedPaste detects an input pasted while bracketed
// paste mode was enabled.
//
// Note: this function is a no-op if bracketed paste was not enabled
// on the terminal, since in that case we'd never see this
// particular escape sequence.
func detectBracketedPaste(input []byte) (hasBp bool, width int, msg Msg) {
// Detect the start sequence.
const bpStart = "\x1b[200~"
if len(input) < len(bpStart) || string(input[:len(bpStart)]) != bpStart {
return false, 0, nil
}
// Skip over the start sequence.
input = input[len(bpStart):]
// If we saw the start sequence, then we must have an end sequence
// as well. Find it.
const bpEnd = "\x1b[201~"
idx := bytes.Index(input, []byte(bpEnd))
inputLen := len(bpStart) + idx + len(bpEnd)
if idx == -1 {
// We have encountered the end of the input buffer without seeing
// the marker for the end of the bracketed paste.
// Tell the outer loop we have done a short read and we want more.
return true, 0, nil
}
// The paste is everything in-between.
paste := input[:idx]
// All there is in-between is runes, not to be interpreted further.
k := Key{Type: KeyRunes, Paste: true}
for len(paste) > 0 {
r, w := utf8.DecodeRune(paste)
if r != utf8.RuneError {
k.Runes = append(k.Runes, r)
}
paste = paste[w:]
}
return true, inputLen, KeyMsg(k)
}