go.crypto/ssh/terminal: support Unicode entry.
Previously, terminal only supported ASCII characters. This change
alters some []byte to []rune so that the full range of Unicode is
supported. The only thing that doesn't appear to work correctly are
grapheme clusters as the code still assumes one rune per glyph. Still,
this change allows many more languages to work than did previously.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13704043
diff --git a/terminal.go b/terminal.go
index bb69c5b..a0ddba3 100644
--- a/terminal.go
+++ b/terminal.go
@@ -7,6 +7,7 @@
import (
"io"
"sync"
+ "unicode/utf8"
)
// EscapeCodes contains escape sequences that can be written to the terminal in
@@ -35,11 +36,12 @@
// Terminal contains the state for running a VT100 terminal that is capable of
// reading lines of input.
type Terminal struct {
- // AutoCompleteCallback, if non-null, is called for each keypress
- // with the full input line and the current position of the cursor.
- // If it returns a nil newLine, the key press is processed normally.
- // Otherwise it returns a replacement line and the new cursor position.
- AutoCompleteCallback func(line []byte, pos, key int) (newLine []byte, newPos int)
+ // AutoCompleteCallback, if non-null, is called for each keypress with
+ // the full input line and the current position of the cursor (in
+ // bytes, as an index into |line|). If it returns ok=false, the key
+ // press is processed normally. Otherwise it returns a replacement line
+ // and the new cursor position.
+ AutoCompleteCallback func(line string, pos int, key rune) (newLine string, newPos int, ok bool)
// Escape contains a pointer to the escape codes for this terminal.
// It's always a valid pointer, although the escape codes themselves
@@ -54,7 +56,7 @@
prompt string
// line is the current line being entered.
- line []byte
+ line []rune
// pos is the logical position of the cursor in line
pos int
// echo is true if local echo is enabled
@@ -109,7 +111,7 @@
keyEnter = '\r'
keyEscape = 27
keyBackspace = 127
- keyUnknown = 256 + iota
+ keyUnknown = 0xd800 /* UTF-16 surrogate area */ + iota
keyUp
keyDown
keyLeft
@@ -123,10 +125,10 @@
)
// bytesToKey tries to parse a key sequence from b. If successful, it returns
-// the key and the remainder of the input. Otherwise it returns -1.
-func bytesToKey(b []byte) (int, []byte) {
+// the key and the remainder of the input. Otherwise it returns utf8.RuneError.
+func bytesToKey(b []byte) (rune, []byte) {
if len(b) == 0 {
- return -1, nil
+ return utf8.RuneError, nil
}
switch b[0] {
@@ -139,7 +141,11 @@
}
if b[0] != keyEscape {
- return int(b[0]), b[1:]
+ if !utf8.FullRune(b) {
+ return utf8.RuneError, b
+ }
+ r, l := utf8.DecodeRune(b)
+ return r, b[l:]
}
if len(b) >= 3 && b[0] == keyEscape && b[1] == '[' {
@@ -183,19 +189,20 @@
}
}
- return -1, b
+ return utf8.RuneError, b
}
// queue appends data to the end of t.outBuf
-func (t *Terminal) queue(data []byte) {
- t.outBuf = append(t.outBuf, data...)
+func (t *Terminal) queue(data []rune) {
+ t.outBuf = append(t.outBuf, []byte(string(data))...)
}
-var eraseUnderCursor = []byte{' ', keyEscape, '[', 'D'}
-var space = []byte{' '}
+var eraseUnderCursor = []rune{' ', keyEscape, '[', 'D'}
+var space = []rune{' '}
-func isPrintable(key int) bool {
- return key >= 32 && key < 127
+func isPrintable(key rune) bool {
+ isInSurrogateArea := key >= 0xd800 && key <= 0xdbff
+ return key >= 32 && !isInSurrogateArea
}
// moveCursorToPos appends data to t.outBuf which will move the cursor to the
@@ -235,7 +242,7 @@
}
func (t *Terminal) move(up, down, left, right int) {
- movement := make([]byte, 3*(up+down+left+right))
+ movement := make([]rune, 3*(up+down+left+right))
m := movement
for i := 0; i < up; i++ {
m[0] = keyEscape
@@ -266,13 +273,13 @@
}
func (t *Terminal) clearLineToRight() {
- op := []byte{keyEscape, '[', 'K'}
+ op := []rune{keyEscape, '[', 'K'}
t.queue(op)
}
const maxLineLength = 4096
-func (t *Terminal) setLine(newLine []byte, newPos int) {
+func (t *Terminal) setLine(newLine []rune, newPos int) {
if t.echo {
t.moveCursorToPos(0)
t.writeLine(newLine)
@@ -354,7 +361,7 @@
// handleKey processes the given key and, optionally, returns a line of text
// that the user has entered.
-func (t *Terminal) handleKey(key int) (line string, ok bool) {
+func (t *Terminal) handleKey(key rune) (line string, ok bool) {
switch key {
case keyBackspace:
if t.pos == 0 {
@@ -402,24 +409,24 @@
t.historyPending = string(t.line)
}
t.historyIndex++
- t.setLine([]byte(entry), len(entry))
+ t.setLine([]rune(entry), len(entry))
case keyDown:
switch t.historyIndex {
case -1:
return
case 0:
- t.setLine([]byte(t.historyPending), len(t.historyPending))
+ t.setLine([]rune(t.historyPending), len(t.historyPending))
t.historyIndex--
default:
entry, ok := t.history.NthPreviousEntry(t.historyIndex - 1)
if ok {
t.historyIndex--
- t.setLine([]byte(entry), len(entry))
+ t.setLine([]rune(entry), len(entry))
}
}
case keyEnter:
t.moveCursorToPos(len(t.line))
- t.queue([]byte("\r\n"))
+ t.queue([]rune("\r\n"))
line = string(t.line)
ok = true
t.line = t.line[:0]
@@ -441,12 +448,15 @@
t.moveCursorToPos(t.pos)
default:
if t.AutoCompleteCallback != nil {
+ prefix := string(t.line[:t.pos])
+ suffix := string(t.line[t.pos:])
+
t.lock.Unlock()
- newLine, newPos := t.AutoCompleteCallback(t.line, t.pos, key)
+ newLine, newPos, completeOk := t.AutoCompleteCallback(prefix+suffix, len(prefix), key)
t.lock.Lock()
- if newLine != nil {
- t.setLine(newLine, newPos)
+ if completeOk {
+ t.setLine([]rune(newLine), utf8.RuneCount([]byte(newLine)[:newPos]))
return
}
}
@@ -457,13 +467,13 @@
return
}
if len(t.line) == cap(t.line) {
- newLine := make([]byte, len(t.line), 2*(1+len(t.line)))
+ newLine := make([]rune, len(t.line), 2*(1+len(t.line)))
copy(newLine, t.line)
t.line = newLine
}
t.line = t.line[:len(t.line)+1]
copy(t.line[t.pos+1:], t.line[t.pos:])
- t.line[t.pos] = byte(key)
+ t.line[t.pos] = key
if t.echo {
t.writeLine(t.line[t.pos:])
}
@@ -473,7 +483,7 @@
return
}
-func (t *Terminal) writeLine(line []byte) {
+func (t *Terminal) writeLine(line []rune) {
for len(line) != 0 {
remainingOnLine := t.termWidth - t.cursorX
todo := len(line)
@@ -525,7 +535,7 @@
return
}
- t.queue([]byte(t.prompt))
+ t.queue([]rune(t.prompt))
chars := len(t.prompt)
if t.echo {
t.queue(t.line)
@@ -572,7 +582,7 @@
// t.lock must be held at this point
if t.cursorX == 0 && t.cursorY == 0 {
- t.writeLine([]byte(t.prompt))
+ t.writeLine([]rune(t.prompt))
t.c.Write(t.outBuf)
t.outBuf = t.outBuf[:0]
}
@@ -581,9 +591,9 @@
rest := t.remainder
lineOk := false
for !lineOk {
- var key int
+ var key rune
key, rest = bytesToKey(rest)
- if key < 0 {
+ if key == utf8.RuneError {
break
}
if key == keyCtrlD {
diff --git a/terminal_test.go b/terminal_test.go
index 75584d3..6ea92d9 100644
--- a/terminal_test.go
+++ b/terminal_test.go
@@ -137,6 +137,10 @@
in: "ab\x1b[D\013\r",
line: "a",
},
+ {
+ in: "Ξεσκεπάζω\r",
+ line: "Ξεσκεπάζω",
+ },
}
func TestKeyPresses(t *testing.T) {
