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-rw-r--r--vendor/golang.org/x/term/terminal.go987
1 files changed, 987 insertions, 0 deletions
diff --git a/vendor/golang.org/x/term/terminal.go b/vendor/golang.org/x/term/terminal.go
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+++ b/vendor/golang.org/x/term/terminal.go
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+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package term
+
+import (
+ "bytes"
+ "io"
+ "runtime"
+ "strconv"
+ "sync"
+ "unicode/utf8"
+)
+
+// EscapeCodes contains escape sequences that can be written to the terminal in
+// order to achieve different styles of text.
+type EscapeCodes struct {
+ // Foreground colors
+ Black, Red, Green, Yellow, Blue, Magenta, Cyan, White []byte
+
+ // Reset all attributes
+ Reset []byte
+}
+
+var vt100EscapeCodes = EscapeCodes{
+ Black: []byte{keyEscape, '[', '3', '0', 'm'},
+ Red: []byte{keyEscape, '[', '3', '1', 'm'},
+ Green: []byte{keyEscape, '[', '3', '2', 'm'},
+ Yellow: []byte{keyEscape, '[', '3', '3', 'm'},
+ Blue: []byte{keyEscape, '[', '3', '4', 'm'},
+ Magenta: []byte{keyEscape, '[', '3', '5', 'm'},
+ Cyan: []byte{keyEscape, '[', '3', '6', 'm'},
+ White: []byte{keyEscape, '[', '3', '7', 'm'},
+
+ Reset: []byte{keyEscape, '[', '0', 'm'},
+}
+
+// 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 (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
+ // may be empty if the terminal doesn't support them.
+ Escape *EscapeCodes
+
+ // lock protects the terminal and the state in this object from
+ // concurrent processing of a key press and a Write() call.
+ lock sync.Mutex
+
+ c io.ReadWriter
+ prompt []rune
+
+ // line is the current line being entered.
+ line []rune
+ // pos is the logical position of the cursor in line
+ pos int
+ // echo is true if local echo is enabled
+ echo bool
+ // pasteActive is true iff there is a bracketed paste operation in
+ // progress.
+ pasteActive bool
+
+ // cursorX contains the current X value of the cursor where the left
+ // edge is 0. cursorY contains the row number where the first row of
+ // the current line is 0.
+ cursorX, cursorY int
+ // maxLine is the greatest value of cursorY so far.
+ maxLine int
+
+ termWidth, termHeight int
+
+ // outBuf contains the terminal data to be sent.
+ outBuf []byte
+ // remainder contains the remainder of any partial key sequences after
+ // a read. It aliases into inBuf.
+ remainder []byte
+ inBuf [256]byte
+
+ // history contains previously entered commands so that they can be
+ // accessed with the up and down keys.
+ history stRingBuffer
+ // historyIndex stores the currently accessed history entry, where zero
+ // means the immediately previous entry.
+ historyIndex int
+ // When navigating up and down the history it's possible to return to
+ // the incomplete, initial line. That value is stored in
+ // historyPending.
+ historyPending string
+}
+
+// NewTerminal runs a VT100 terminal on the given ReadWriter. If the ReadWriter is
+// a local terminal, that terminal must first have been put into raw mode.
+// prompt is a string that is written at the start of each input line (i.e.
+// "> ").
+func NewTerminal(c io.ReadWriter, prompt string) *Terminal {
+ return &Terminal{
+ Escape: &vt100EscapeCodes,
+ c: c,
+ prompt: []rune(prompt),
+ termWidth: 80,
+ termHeight: 24,
+ echo: true,
+ historyIndex: -1,
+ }
+}
+
+const (
+ keyCtrlC = 3
+ keyCtrlD = 4
+ keyCtrlU = 21
+ keyEnter = '\r'
+ keyEscape = 27
+ keyBackspace = 127
+ keyUnknown = 0xd800 /* UTF-16 surrogate area */ + iota
+ keyUp
+ keyDown
+ keyLeft
+ keyRight
+ keyAltLeft
+ keyAltRight
+ keyHome
+ keyEnd
+ keyDeleteWord
+ keyDeleteLine
+ keyClearScreen
+ keyPasteStart
+ keyPasteEnd
+)
+
+var (
+ crlf = []byte{'\r', '\n'}
+ pasteStart = []byte{keyEscape, '[', '2', '0', '0', '~'}
+ pasteEnd = []byte{keyEscape, '[', '2', '0', '1', '~'}
+)
+
+// bytesToKey tries to parse a key sequence from b. If successful, it returns
+// the key and the remainder of the input. Otherwise it returns utf8.RuneError.
+func bytesToKey(b []byte, pasteActive bool) (rune, []byte) {
+ if len(b) == 0 {
+ return utf8.RuneError, nil
+ }
+
+ if !pasteActive {
+ switch b[0] {
+ case 1: // ^A
+ return keyHome, b[1:]
+ case 2: // ^B
+ return keyLeft, b[1:]
+ case 5: // ^E
+ return keyEnd, b[1:]
+ case 6: // ^F
+ return keyRight, b[1:]
+ case 8: // ^H
+ return keyBackspace, b[1:]
+ case 11: // ^K
+ return keyDeleteLine, b[1:]
+ case 12: // ^L
+ return keyClearScreen, b[1:]
+ case 23: // ^W
+ return keyDeleteWord, b[1:]
+ case 14: // ^N
+ return keyDown, b[1:]
+ case 16: // ^P
+ return keyUp, b[1:]
+ }
+ }
+
+ if b[0] != keyEscape {
+ if !utf8.FullRune(b) {
+ return utf8.RuneError, b
+ }
+ r, l := utf8.DecodeRune(b)
+ return r, b[l:]
+ }
+
+ if !pasteActive && len(b) >= 3 && b[0] == keyEscape && b[1] == '[' {
+ switch b[2] {
+ case 'A':
+ return keyUp, b[3:]
+ case 'B':
+ return keyDown, b[3:]
+ case 'C':
+ return keyRight, b[3:]
+ case 'D':
+ return keyLeft, b[3:]
+ case 'H':
+ return keyHome, b[3:]
+ case 'F':
+ return keyEnd, b[3:]
+ }
+ }
+
+ if !pasteActive && len(b) >= 6 && b[0] == keyEscape && b[1] == '[' && b[2] == '1' && b[3] == ';' && b[4] == '3' {
+ switch b[5] {
+ case 'C':
+ return keyAltRight, b[6:]
+ case 'D':
+ return keyAltLeft, b[6:]
+ }
+ }
+
+ if !pasteActive && len(b) >= 6 && bytes.Equal(b[:6], pasteStart) {
+ return keyPasteStart, b[6:]
+ }
+
+ if pasteActive && len(b) >= 6 && bytes.Equal(b[:6], pasteEnd) {
+ return keyPasteEnd, b[6:]
+ }
+
+ // If we get here then we have a key that we don't recognise, or a
+ // partial sequence. It's not clear how one should find the end of a
+ // sequence without knowing them all, but it seems that [a-zA-Z~] only
+ // appears at the end of a sequence.
+ for i, c := range b[0:] {
+ if c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '~' {
+ return keyUnknown, b[i+1:]
+ }
+ }
+
+ return utf8.RuneError, b
+}
+
+// queue appends data to the end of t.outBuf
+func (t *Terminal) queue(data []rune) {
+ t.outBuf = append(t.outBuf, []byte(string(data))...)
+}
+
+var eraseUnderCursor = []rune{' ', keyEscape, '[', 'D'}
+var space = []rune{' '}
+
+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
+// given, logical position in the text.
+func (t *Terminal) moveCursorToPos(pos int) {
+ if !t.echo {
+ return
+ }
+
+ x := visualLength(t.prompt) + pos
+ y := x / t.termWidth
+ x = x % t.termWidth
+
+ up := 0
+ if y < t.cursorY {
+ up = t.cursorY - y
+ }
+
+ down := 0
+ if y > t.cursorY {
+ down = y - t.cursorY
+ }
+
+ left := 0
+ if x < t.cursorX {
+ left = t.cursorX - x
+ }
+
+ right := 0
+ if x > t.cursorX {
+ right = x - t.cursorX
+ }
+
+ t.cursorX = x
+ t.cursorY = y
+ t.move(up, down, left, right)
+}
+
+func (t *Terminal) move(up, down, left, right int) {
+ m := []rune{}
+
+ // 1 unit up can be expressed as ^[[A or ^[A
+ // 5 units up can be expressed as ^[[5A
+
+ if up == 1 {
+ m = append(m, keyEscape, '[', 'A')
+ } else if up > 1 {
+ m = append(m, keyEscape, '[')
+ m = append(m, []rune(strconv.Itoa(up))...)
+ m = append(m, 'A')
+ }
+
+ if down == 1 {
+ m = append(m, keyEscape, '[', 'B')
+ } else if down > 1 {
+ m = append(m, keyEscape, '[')
+ m = append(m, []rune(strconv.Itoa(down))...)
+ m = append(m, 'B')
+ }
+
+ if right == 1 {
+ m = append(m, keyEscape, '[', 'C')
+ } else if right > 1 {
+ m = append(m, keyEscape, '[')
+ m = append(m, []rune(strconv.Itoa(right))...)
+ m = append(m, 'C')
+ }
+
+ if left == 1 {
+ m = append(m, keyEscape, '[', 'D')
+ } else if left > 1 {
+ m = append(m, keyEscape, '[')
+ m = append(m, []rune(strconv.Itoa(left))...)
+ m = append(m, 'D')
+ }
+
+ t.queue(m)
+}
+
+func (t *Terminal) clearLineToRight() {
+ op := []rune{keyEscape, '[', 'K'}
+ t.queue(op)
+}
+
+const maxLineLength = 4096
+
+func (t *Terminal) setLine(newLine []rune, newPos int) {
+ if t.echo {
+ t.moveCursorToPos(0)
+ t.writeLine(newLine)
+ for i := len(newLine); i < len(t.line); i++ {
+ t.writeLine(space)
+ }
+ t.moveCursorToPos(newPos)
+ }
+ t.line = newLine
+ t.pos = newPos
+}
+
+func (t *Terminal) advanceCursor(places int) {
+ t.cursorX += places
+ t.cursorY += t.cursorX / t.termWidth
+ if t.cursorY > t.maxLine {
+ t.maxLine = t.cursorY
+ }
+ t.cursorX = t.cursorX % t.termWidth
+
+ if places > 0 && t.cursorX == 0 {
+ // Normally terminals will advance the current position
+ // when writing a character. But that doesn't happen
+ // for the last character in a line. However, when
+ // writing a character (except a new line) that causes
+ // a line wrap, the position will be advanced two
+ // places.
+ //
+ // So, if we are stopping at the end of a line, we
+ // need to write a newline so that our cursor can be
+ // advanced to the next line.
+ t.outBuf = append(t.outBuf, '\r', '\n')
+ }
+}
+
+func (t *Terminal) eraseNPreviousChars(n int) {
+ if n == 0 {
+ return
+ }
+
+ if t.pos < n {
+ n = t.pos
+ }
+ t.pos -= n
+ t.moveCursorToPos(t.pos)
+
+ copy(t.line[t.pos:], t.line[n+t.pos:])
+ t.line = t.line[:len(t.line)-n]
+ if t.echo {
+ t.writeLine(t.line[t.pos:])
+ for i := 0; i < n; i++ {
+ t.queue(space)
+ }
+ t.advanceCursor(n)
+ t.moveCursorToPos(t.pos)
+ }
+}
+
+// countToLeftWord returns then number of characters from the cursor to the
+// start of the previous word.
+func (t *Terminal) countToLeftWord() int {
+ if t.pos == 0 {
+ return 0
+ }
+
+ pos := t.pos - 1
+ for pos > 0 {
+ if t.line[pos] != ' ' {
+ break
+ }
+ pos--
+ }
+ for pos > 0 {
+ if t.line[pos] == ' ' {
+ pos++
+ break
+ }
+ pos--
+ }
+
+ return t.pos - pos
+}
+
+// countToRightWord returns then number of characters from the cursor to the
+// start of the next word.
+func (t *Terminal) countToRightWord() int {
+ pos := t.pos
+ for pos < len(t.line) {
+ if t.line[pos] == ' ' {
+ break
+ }
+ pos++
+ }
+ for pos < len(t.line) {
+ if t.line[pos] != ' ' {
+ break
+ }
+ pos++
+ }
+ return pos - t.pos
+}
+
+// visualLength returns the number of visible glyphs in s.
+func visualLength(runes []rune) int {
+ inEscapeSeq := false
+ length := 0
+
+ for _, r := range runes {
+ switch {
+ case inEscapeSeq:
+ if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') {
+ inEscapeSeq = false
+ }
+ case r == '\x1b':
+ inEscapeSeq = true
+ default:
+ length++
+ }
+ }
+
+ return length
+}
+
+// handleKey processes the given key and, optionally, returns a line of text
+// that the user has entered.
+func (t *Terminal) handleKey(key rune) (line string, ok bool) {
+ if t.pasteActive && key != keyEnter {
+ t.addKeyToLine(key)
+ return
+ }
+
+ switch key {
+ case keyBackspace:
+ if t.pos == 0 {
+ return
+ }
+ t.eraseNPreviousChars(1)
+ case keyAltLeft:
+ // move left by a word.
+ t.pos -= t.countToLeftWord()
+ t.moveCursorToPos(t.pos)
+ case keyAltRight:
+ // move right by a word.
+ t.pos += t.countToRightWord()
+ t.moveCursorToPos(t.pos)
+ case keyLeft:
+ if t.pos == 0 {
+ return
+ }
+ t.pos--
+ t.moveCursorToPos(t.pos)
+ case keyRight:
+ if t.pos == len(t.line) {
+ return
+ }
+ t.pos++
+ t.moveCursorToPos(t.pos)
+ case keyHome:
+ if t.pos == 0 {
+ return
+ }
+ t.pos = 0
+ t.moveCursorToPos(t.pos)
+ case keyEnd:
+ if t.pos == len(t.line) {
+ return
+ }
+ t.pos = len(t.line)
+ t.moveCursorToPos(t.pos)
+ case keyUp:
+ entry, ok := t.history.NthPreviousEntry(t.historyIndex + 1)
+ if !ok {
+ return "", false
+ }
+ if t.historyIndex == -1 {
+ t.historyPending = string(t.line)
+ }
+ t.historyIndex++
+ runes := []rune(entry)
+ t.setLine(runes, len(runes))
+ case keyDown:
+ switch t.historyIndex {
+ case -1:
+ return
+ case 0:
+ runes := []rune(t.historyPending)
+ t.setLine(runes, len(runes))
+ t.historyIndex--
+ default:
+ entry, ok := t.history.NthPreviousEntry(t.historyIndex - 1)
+ if ok {
+ t.historyIndex--
+ runes := []rune(entry)
+ t.setLine(runes, len(runes))
+ }
+ }
+ case keyEnter:
+ t.moveCursorToPos(len(t.line))
+ t.queue([]rune("\r\n"))
+ line = string(t.line)
+ ok = true
+ t.line = t.line[:0]
+ t.pos = 0
+ t.cursorX = 0
+ t.cursorY = 0
+ t.maxLine = 0
+ case keyDeleteWord:
+ // Delete zero or more spaces and then one or more characters.
+ t.eraseNPreviousChars(t.countToLeftWord())
+ case keyDeleteLine:
+ // Delete everything from the current cursor position to the
+ // end of line.
+ for i := t.pos; i < len(t.line); i++ {
+ t.queue(space)
+ t.advanceCursor(1)
+ }
+ t.line = t.line[:t.pos]
+ t.moveCursorToPos(t.pos)
+ case keyCtrlD:
+ // Erase the character under the current position.
+ // The EOF case when the line is empty is handled in
+ // readLine().
+ if t.pos < len(t.line) {
+ t.pos++
+ t.eraseNPreviousChars(1)
+ }
+ case keyCtrlU:
+ t.eraseNPreviousChars(t.pos)
+ case keyClearScreen:
+ // Erases the screen and moves the cursor to the home position.
+ t.queue([]rune("\x1b[2J\x1b[H"))
+ t.queue(t.prompt)
+ t.cursorX, t.cursorY = 0, 0
+ t.advanceCursor(visualLength(t.prompt))
+ t.setLine(t.line, t.pos)
+ default:
+ if t.AutoCompleteCallback != nil {
+ prefix := string(t.line[:t.pos])
+ suffix := string(t.line[t.pos:])
+
+ t.lock.Unlock()
+ newLine, newPos, completeOk := t.AutoCompleteCallback(prefix+suffix, len(prefix), key)
+ t.lock.Lock()
+
+ if completeOk {
+ t.setLine([]rune(newLine), utf8.RuneCount([]byte(newLine)[:newPos]))
+ return
+ }
+ }
+ if !isPrintable(key) {
+ return
+ }
+ if len(t.line) == maxLineLength {
+ return
+ }
+ t.addKeyToLine(key)
+ }
+ return
+}
+
+// addKeyToLine inserts the given key at the current position in the current
+// line.
+func (t *Terminal) addKeyToLine(key rune) {
+ if len(t.line) == cap(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] = key
+ if t.echo {
+ t.writeLine(t.line[t.pos:])
+ }
+ t.pos++
+ t.moveCursorToPos(t.pos)
+}
+
+func (t *Terminal) writeLine(line []rune) {
+ for len(line) != 0 {
+ remainingOnLine := t.termWidth - t.cursorX
+ todo := len(line)
+ if todo > remainingOnLine {
+ todo = remainingOnLine
+ }
+ t.queue(line[:todo])
+ t.advanceCursor(visualLength(line[:todo]))
+ line = line[todo:]
+ }
+}
+
+// writeWithCRLF writes buf to w but replaces all occurrences of \n with \r\n.
+func writeWithCRLF(w io.Writer, buf []byte) (n int, err error) {
+ for len(buf) > 0 {
+ i := bytes.IndexByte(buf, '\n')
+ todo := len(buf)
+ if i >= 0 {
+ todo = i
+ }
+
+ var nn int
+ nn, err = w.Write(buf[:todo])
+ n += nn
+ if err != nil {
+ return n, err
+ }
+ buf = buf[todo:]
+
+ if i >= 0 {
+ if _, err = w.Write(crlf); err != nil {
+ return n, err
+ }
+ n++
+ buf = buf[1:]
+ }
+ }
+
+ return n, nil
+}
+
+func (t *Terminal) Write(buf []byte) (n int, err error) {
+ t.lock.Lock()
+ defer t.lock.Unlock()
+
+ if t.cursorX == 0 && t.cursorY == 0 {
+ // This is the easy case: there's nothing on the screen that we
+ // have to move out of the way.
+ return writeWithCRLF(t.c, buf)
+ }
+
+ // We have a prompt and possibly user input on the screen. We
+ // have to clear it first.
+ t.move(0 /* up */, 0 /* down */, t.cursorX /* left */, 0 /* right */)
+ t.cursorX = 0
+ t.clearLineToRight()
+
+ for t.cursorY > 0 {
+ t.move(1 /* up */, 0, 0, 0)
+ t.cursorY--
+ t.clearLineToRight()
+ }
+
+ if _, err = t.c.Write(t.outBuf); err != nil {
+ return
+ }
+ t.outBuf = t.outBuf[:0]
+
+ if n, err = writeWithCRLF(t.c, buf); err != nil {
+ return
+ }
+
+ t.writeLine(t.prompt)
+ if t.echo {
+ t.writeLine(t.line)
+ }
+
+ t.moveCursorToPos(t.pos)
+
+ if _, err = t.c.Write(t.outBuf); err != nil {
+ return
+ }
+ t.outBuf = t.outBuf[:0]
+ return
+}
+
+// ReadPassword temporarily changes the prompt and reads a password, without
+// echo, from the terminal.
+func (t *Terminal) ReadPassword(prompt string) (line string, err error) {
+ t.lock.Lock()
+ defer t.lock.Unlock()
+
+ oldPrompt := t.prompt
+ t.prompt = []rune(prompt)
+ t.echo = false
+
+ line, err = t.readLine()
+
+ t.prompt = oldPrompt
+ t.echo = true
+
+ return
+}
+
+// ReadLine returns a line of input from the terminal.
+func (t *Terminal) ReadLine() (line string, err error) {
+ t.lock.Lock()
+ defer t.lock.Unlock()
+
+ return t.readLine()
+}
+
+func (t *Terminal) readLine() (line string, err error) {
+ // t.lock must be held at this point
+
+ if t.cursorX == 0 && t.cursorY == 0 {
+ t.writeLine(t.prompt)
+ t.c.Write(t.outBuf)
+ t.outBuf = t.outBuf[:0]
+ }
+
+ lineIsPasted := t.pasteActive
+
+ for {
+ rest := t.remainder
+ lineOk := false
+ for !lineOk {
+ var key rune
+ key, rest = bytesToKey(rest, t.pasteActive)
+ if key == utf8.RuneError {
+ break
+ }
+ if !t.pasteActive {
+ if key == keyCtrlD {
+ if len(t.line) == 0 {
+ return "", io.EOF
+ }
+ }
+ if key == keyCtrlC {
+ return "", io.EOF
+ }
+ if key == keyPasteStart {
+ t.pasteActive = true
+ if len(t.line) == 0 {
+ lineIsPasted = true
+ }
+ continue
+ }
+ } else if key == keyPasteEnd {
+ t.pasteActive = false
+ continue
+ }
+ if !t.pasteActive {
+ lineIsPasted = false
+ }
+ line, lineOk = t.handleKey(key)
+ }
+ if len(rest) > 0 {
+ n := copy(t.inBuf[:], rest)
+ t.remainder = t.inBuf[:n]
+ } else {
+ t.remainder = nil
+ }
+ t.c.Write(t.outBuf)
+ t.outBuf = t.outBuf[:0]
+ if lineOk {
+ if t.echo {
+ t.historyIndex = -1
+ t.history.Add(line)
+ }
+ if lineIsPasted {
+ err = ErrPasteIndicator
+ }
+ return
+ }
+
+ // t.remainder is a slice at the beginning of t.inBuf
+ // containing a partial key sequence
+ readBuf := t.inBuf[len(t.remainder):]
+ var n int
+
+ t.lock.Unlock()
+ n, err = t.c.Read(readBuf)
+ t.lock.Lock()
+
+ if err != nil {
+ return
+ }
+
+ t.remainder = t.inBuf[:n+len(t.remainder)]
+ }
+}
+
+// SetPrompt sets the prompt to be used when reading subsequent lines.
+func (t *Terminal) SetPrompt(prompt string) {
+ t.lock.Lock()
+ defer t.lock.Unlock()
+
+ t.prompt = []rune(prompt)
+}
+
+func (t *Terminal) clearAndRepaintLinePlusNPrevious(numPrevLines int) {
+ // Move cursor to column zero at the start of the line.
+ t.move(t.cursorY, 0, t.cursorX, 0)
+ t.cursorX, t.cursorY = 0, 0
+ t.clearLineToRight()
+ for t.cursorY < numPrevLines {
+ // Move down a line
+ t.move(0, 1, 0, 0)
+ t.cursorY++
+ t.clearLineToRight()
+ }
+ // Move back to beginning.
+ t.move(t.cursorY, 0, 0, 0)
+ t.cursorX, t.cursorY = 0, 0
+
+ t.queue(t.prompt)
+ t.advanceCursor(visualLength(t.prompt))
+ t.writeLine(t.line)
+ t.moveCursorToPos(t.pos)
+}
+
+func (t *Terminal) SetSize(width, height int) error {
+ t.lock.Lock()
+ defer t.lock.Unlock()
+
+ if width == 0 {
+ width = 1
+ }
+
+ oldWidth := t.termWidth
+ t.termWidth, t.termHeight = width, height
+
+ switch {
+ case width == oldWidth:
+ // If the width didn't change then nothing else needs to be
+ // done.
+ return nil
+ case len(t.line) == 0 && t.cursorX == 0 && t.cursorY == 0:
+ // If there is nothing on current line and no prompt printed,
+ // just do nothing
+ return nil
+ case width < oldWidth:
+ // Some terminals (e.g. xterm) will truncate lines that were
+ // too long when shinking. Others, (e.g. gnome-terminal) will
+ // attempt to wrap them. For the former, repainting t.maxLine
+ // works great, but that behaviour goes badly wrong in the case
+ // of the latter because they have doubled every full line.
+
+ // We assume that we are working on a terminal that wraps lines
+ // and adjust the cursor position based on every previous line
+ // wrapping and turning into two. This causes the prompt on
+ // xterms to move upwards, which isn't great, but it avoids a
+ // huge mess with gnome-terminal.
+ if t.cursorX >= t.termWidth {
+ t.cursorX = t.termWidth - 1
+ }
+ t.cursorY *= 2
+ t.clearAndRepaintLinePlusNPrevious(t.maxLine * 2)
+ case width > oldWidth:
+ // If the terminal expands then our position calculations will
+ // be wrong in the future because we think the cursor is
+ // |t.pos| chars into the string, but there will be a gap at
+ // the end of any wrapped line.
+ //
+ // But the position will actually be correct until we move, so
+ // we can move back to the beginning and repaint everything.
+ t.clearAndRepaintLinePlusNPrevious(t.maxLine)
+ }
+
+ _, err := t.c.Write(t.outBuf)
+ t.outBuf = t.outBuf[:0]
+ return err
+}
+
+type pasteIndicatorError struct{}
+
+func (pasteIndicatorError) Error() string {
+ return "terminal: ErrPasteIndicator not correctly handled"
+}
+
+// ErrPasteIndicator may be returned from ReadLine as the error, in addition
+// to valid line data. It indicates that bracketed paste mode is enabled and
+// that the returned line consists only of pasted data. Programs may wish to
+// interpret pasted data more literally than typed data.
+var ErrPasteIndicator = pasteIndicatorError{}
+
+// SetBracketedPasteMode requests that the terminal bracket paste operations
+// with markers. Not all terminals support this but, if it is supported, then
+// enabling this mode will stop any autocomplete callback from running due to
+// pastes. Additionally, any lines that are completely pasted will be returned
+// from ReadLine with the error set to ErrPasteIndicator.
+func (t *Terminal) SetBracketedPasteMode(on bool) {
+ if on {
+ io.WriteString(t.c, "\x1b[?2004h")
+ } else {
+ io.WriteString(t.c, "\x1b[?2004l")
+ }
+}
+
+// stRingBuffer is a ring buffer of strings.
+type stRingBuffer struct {
+ // entries contains max elements.
+ entries []string
+ max int
+ // head contains the index of the element most recently added to the ring.
+ head int
+ // size contains the number of elements in the ring.
+ size int
+}
+
+func (s *stRingBuffer) Add(a string) {
+ if s.entries == nil {
+ const defaultNumEntries = 100
+ s.entries = make([]string, defaultNumEntries)
+ s.max = defaultNumEntries
+ }
+
+ s.head = (s.head + 1) % s.max
+ s.entries[s.head] = a
+ if s.size < s.max {
+ s.size++
+ }
+}
+
+// NthPreviousEntry returns the value passed to the nth previous call to Add.
+// If n is zero then the immediately prior value is returned, if one, then the
+// next most recent, and so on. If such an element doesn't exist then ok is
+// false.
+func (s *stRingBuffer) NthPreviousEntry(n int) (value string, ok bool) {
+ if n >= s.size {
+ return "", false
+ }
+ index := s.head - n
+ if index < 0 {
+ index += s.max
+ }
+ return s.entries[index], true
+}
+
+// readPasswordLine reads from reader until it finds \n or io.EOF.
+// The slice returned does not include the \n.
+// readPasswordLine also ignores any \r it finds.
+// Windows uses \r as end of line. So, on Windows, readPasswordLine
+// reads until it finds \r and ignores any \n it finds during processing.
+func readPasswordLine(reader io.Reader) ([]byte, error) {
+ var buf [1]byte
+ var ret []byte
+
+ for {
+ n, err := reader.Read(buf[:])
+ if n > 0 {
+ switch buf[0] {
+ case '\b':
+ if len(ret) > 0 {
+ ret = ret[:len(ret)-1]
+ }
+ case '\n':
+ if runtime.GOOS != "windows" {
+ return ret, nil
+ }
+ // otherwise ignore \n
+ case '\r':
+ if runtime.GOOS == "windows" {
+ return ret, nil
+ }
+ // otherwise ignore \r
+ default:
+ ret = append(ret, buf[0])
+ }
+ continue
+ }
+ if err != nil {
+ if err == io.EOF && len(ret) > 0 {
+ return ret, nil
+ }
+ return ret, err
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 03:25:38 +0000