overlay.go RawHistoryFolder

1package daemon
2
3import (
4	"unicode"
5	"unicode/utf8"
6)
7
8type overlayEvents struct {
9	rune      func(rune)
10	backspace func()
11	enter     func()
12	tab       func()
13	cancel    func()
14	up        func()
15	down      func()
16	left      func()
17	right     func()
18}
19
20func routeOverlayBytes(data []byte, pending *[]byte, ev overlayEvents) {
21	if pending != nil && len(*pending) > 0 {
22		combined := make([]byte, 0, len(*pending)+len(data))
23		combined = append(combined, (*pending)...)
24		combined = append(combined, data...)
25		data = combined
26		*pending = nil
27	}
28
29	for i := 0; i < len(data); {
30		switch data[i] {
31		case 0x1b:
32			consumed, incomplete := routeOverlayEscape(data[i:], ev)
33			if incomplete {
34				if pending != nil {
35					*pending = append((*pending)[:0], data[i:]...)
36				}
37				return
38			}
39			if consumed > 0 {
40				i += consumed
41				continue
42			}
43			call(ev.cancel)
44			i++
45		case 0x03:
46			call(ev.cancel)
47			i++
48		case 0x0e:
49			call(ev.down)
50			i++
51		case 0x10:
52			call(ev.up)
53			i++
54		case '\r', '\n':
55			call(ev.enter)
56			i++
57		case 0x09:
58			call(ev.tab)
59			i++
60		case 0x7f, 0x08:
61			call(ev.backspace)
62			i++
63		default:
64			r, size := utf8.DecodeRune(data[i:])
65			if r == utf8.RuneError {
66				if !utf8.FullRune(data[i:]) {
67					if pending != nil {
68						*pending = append((*pending)[:0], data[i:]...)
69					}
70					return
71				}
72				i++
73				continue
74			}
75			if !unicode.IsControl(r) && ev.rune != nil {
76				ev.rune(r)
77			}
78			i += size
79		}
80	}
81}
82
83func routeOverlayEscape(data []byte, ev overlayEvents) (consumed int, incomplete bool) {
84	if len(data) < 2 {
85		return 0, false
86	}
87	switch data[1] {
88	case 'O':
89		if len(data) < 3 {
90			return 0, true
91		}
92		switch data[2] {
93		case 'A':
94			call(ev.up)
95		case 'B':
96			call(ev.down)
97		case 'C':
98			call(ev.right)
99		case 'D':
100			call(ev.left)
101		}
102		return 3, false
103	case '[':
104		for i := 2; i < len(data); i++ {
105			if data[i] < 0x40 || data[i] > 0x7e {
106				continue
107			}
108			if i == 2 {
109				switch data[i] {
110				case 'A':
111					call(ev.up)
112				case 'B':
113					call(ev.down)
114				case 'C':
115					call(ev.right)
116				case 'D':
117					call(ev.left)
118				}
119			}
120			return i + 1, false
121		}
122		return 0, true
123	default:
124		return 0, false
125	}
126}
127
128func call(fn func()) {
129	if fn != nil {
130		fn()
131	}
132}