// Copyright 2021 The TCell Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use file except in compliance with the License.
// You may obtain a copy of the license at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tcell
import (
"bytes"
"errors"
"io"
"os"
"strconv"
"strings"
"sync"
"time"
"unicode/utf8"
"golang.org/x/term"
"golang.org/x/text/transform"
"github.com/gdamore/tcell/v2/terminfo"
// import the stock terminals
_ "github.com/gdamore/tcell/v2/terminfo/base"
)
// NewTerminfoScreen returns a Screen that uses the stock TTY interface
// and POSIX terminal control, combined with a terminfo description taken from
// the $TERM environment variable. It returns an error if the terminal
// is not supported for any reason.
//
// For terminals that do not support dynamic resize events, the $LINES
// $COLUMNS environment variables can be set to the actual window size,
// otherwise defaults taken from the terminal database are used.
func NewTerminfoScreen() (Screen, error) {
return NewTerminfoScreenFromTty(nil)
}
// LookupTerminfo attempts to find a definition for the named $TERM falling
// back to attempting to parse the output from infocmp.
func LookupTerminfo(name string) (ti *terminfo.Terminfo, e error) {
ti, e = terminfo.LookupTerminfo(name)
if e != nil {
ti, e = loadDynamicTerminfo(name)
if e != nil {
return nil, e
}
terminfo.AddTerminfo(ti)
}
return
}
// NewTerminfoScreenFromTtyTerminfo returns a Screen using a custom Tty
// implementation and custom terminfo specification.
// If the passed in tty is nil, then a reasonable default (typically /dev/tty)
// is presumed, at least on UNIX hosts. (Windows hosts will typically fail this
// call altogether.)
// If passed terminfo is nil, then TERM environment variable is queried for
// terminal specification.
func NewTerminfoScreenFromTtyTerminfo(tty Tty, ti *terminfo.Terminfo) (s Screen, e error) {
if ti == nil {
ti, e = LookupTerminfo(os.Getenv("TERM"))
if e != nil {
return
}
}
t := &tScreen{ti: ti, tty: tty}
t.keyexist = make(map[Key]bool)
t.keycodes = make(map[string]*tKeyCode)
if len(ti.Mouse) > 0 {
t.mouse = []byte(ti.Mouse)
}
t.prepareKeys()
t.buildAcsMap()
t.resizeQ = make(chan bool, 1)
t.fallback = make(map[rune]string)
for k, v := range RuneFallbacks {
t.fallback[k] = v
}
return t, nil
}
// NewTerminfoScreenFromTty returns a Screen using a custom Tty implementation.
// If the passed in tty is nil, then a reasonable default (typically /dev/tty)
// is presumed, at least on UNIX hosts. (Windows hosts will typically fail this
// call altogether.)
func NewTerminfoScreenFromTty(tty Tty) (Screen, error) {
return NewTerminfoScreenFromTtyTerminfo(tty, nil)
}
// tKeyCode represents a combination of a key code and modifiers.
type tKeyCode struct {
key Key
mod ModMask
}
// tScreen represents a screen backed by a terminfo implementation.
type tScreen struct {
ti *terminfo.Terminfo
tty Tty
h int
w int
fini bool
cells CellBuffer
buffering bool // true if we are collecting writes to buf instead of sending directly to out
buf bytes.Buffer
curstyle Style
style Style
evch chan Event
resizeQ chan bool
quit chan struct{}
keyexist map[Key]bool
keycodes map[string]*tKeyCode
keychan chan []byte
keytimer *time.Timer
keyexpire time.Time
cx int
cy int
mouse []byte
clear bool
cursorx int
cursory int
wasbtn bool
acs map[rune]string
charset string
encoder transform.Transformer
decoder transform.Transformer
fallback map[rune]string
colors map[Color]Color
palette []Color
truecolor bool
escaped bool
buttondn bool
finiOnce sync.Once
enablePaste string
disablePaste string
cursorStyles map[CursorStyle]string
cursorStyle CursorStyle
saved *term.State
stopQ chan struct{}
running bool
wg sync.WaitGroup
mouseFlags MouseFlags
pasteEnabled bool
sync.Mutex
}
func (t *tScreen) Init() error {
if e := t.initialize(); e != nil {
return e
}
t.evch = make(chan Event, 10)
t.keychan = make(chan []byte, 10)
t.keytimer = time.NewTimer(time.Millisecond * 50)
t.charset = "UTF-8"
t.charset = getCharset()
if enc := GetEncoding(t.charset); enc != nil {
t.encoder = enc.NewEncoder()
t.decoder = enc.NewDecoder()
} else {
return ErrNoCharset
}
ti := t.ti
// environment overrides
w := ti.Columns
h := ti.Lines
if i, _ := strconv.Atoi(os.Getenv("LINES")); i != 0 {
h = i
}
if i, _ := strconv.Atoi(os.Getenv("COLUMNS")); i != 0 {
w = i
}
if t.ti.SetFgBgRGB != "" || t.ti.SetFgRGB != "" || t.ti.SetBgRGB != "" {
t.truecolor = true
}
// A user who wants to have his themes honored can
// set this environment variable.
if os.Getenv("TCELL_TRUECOLOR") == "disable" {
t.truecolor = false
}
t.colors = make(map[Color]Color)
t.palette = make([]Color, t.nColors())
for i := 0; i < t.nColors(); i++ {
t.palette[i] = Color(i) | ColorValid
// identity map for our builtin colors
t.colors[Color(i)|ColorValid] = Color(i) | ColorValid
}
t.quit = make(chan struct{})
t.Lock()
t.cx = -1
t.cy = -1
t.style = StyleDefault
t.cells.Resize(w, h)
t.cursorx = -1
t.cursory = -1
t.resize()
t.Unlock()
if err := t.engage(); err != nil {
return err
}
return nil
}
func (t *tScreen) prepareKeyMod(key Key, mod ModMask, val string) {
if val != "" {
// Do not override codes that already exist
if _, exist := t.keycodes[val]; !exist {
t.keyexist[key] = true
t.keycodes[val] = &tKeyCode{key: key, mod: mod}
}
}
}
func (t *tScreen) prepareKeyModReplace(key Key, replace Key, mod ModMask, val string) {
if val != "" {
// Do not override codes that already exist
if old, exist := t.keycodes[val]; !exist || old.key == replace {
t.keyexist[key] = true
t.keycodes[val] = &tKeyCode{key: key, mod: mod}
}
}
}
func (t *tScreen) prepareKeyModXTerm(key Key, val string) {
if strings.HasPrefix(val, "\x1b[") && strings.HasSuffix(val, "~") {
// Drop the trailing ~
val = val[:len(val)-1]
// These suffixes are calculated assuming Xterm style modifier suffixes.
// Please see https://invisible-island.net/xterm/ctlseqs/ctlseqs.pdf for
// more information (specifically "PC-Style Function Keys").
t.prepareKeyModReplace(key, key+12, ModShift, val+";2~")
t.prepareKeyModReplace(key, key+48, ModAlt, val+";3~")
t.prepareKeyModReplace(key, key+60, ModAlt|ModShift, val+";4~")
t.prepareKeyModReplace(key, key+24, ModCtrl, val+";5~")
t.prepareKeyModReplace(key, key+36, ModCtrl|ModShift, val+";6~")
t.prepareKeyMod(key, ModAlt|ModCtrl, val+";7~")
t.prepareKeyMod(key, ModShift|ModAlt|ModCtrl, val+";8~")
t.prepareKeyMod(key, ModMeta, val+";9~")
t.prepareKeyMod(key, ModMeta|ModShift, val+";10~")
t.prepareKeyMod(key, ModMeta|ModAlt, val+";11~")
t.prepareKeyMod(key, ModMeta|ModAlt|ModShift, val+";12~")
t.prepareKeyMod(key, ModMeta|ModCtrl, val+";13~")
t.prepareKeyMod(key, ModMeta|ModCtrl|ModShift, val+";14~")
t.prepareKeyMod(key, ModMeta|ModCtrl|ModAlt, val+";15~")
t.prepareKeyMod(key, ModMeta|ModCtrl|ModAlt|ModShift, val+";16~")
} else if strings.HasPrefix(val, "\x1bO") && len(val) == 3 {
val = val[2:]
t.prepareKeyModReplace(key, key+12, ModShift, "\x1b[1;2"+val)
t.prepareKeyModReplace(key, key+48, ModAlt, "\x1b[1;3"+val)
t.prepareKeyModReplace(key, key+24, ModCtrl, "\x1b[1;5"+val)
t.prepareKeyModReplace(key, key+36, ModCtrl|ModShift, "\x1b[1;6"+val)
t.prepareKeyModReplace(key, key+60, ModAlt|ModShift, "\x1b[1;4"+val)
t.prepareKeyMod(key, ModAlt|ModCtrl, "\x1b[1;7"+val)
t.prepareKeyMod(key, ModShift|ModAlt|ModCtrl, "\x1b[1;8"+val)
t.prepareKeyMod(key, ModMeta, "\x1b[1;9"+val)
t.prepareKeyMod(key, ModMeta|ModShift, "\x1b[1;10"+val)
t.prepareKeyMod(key, ModMeta|ModAlt, "\x1b[1;11"+val)
t.prepareKeyMod(key, ModMeta|ModAlt|ModShift, "\x1b[1;12"+val)
t.prepareKeyMod(key, ModMeta|ModCtrl, "\x1b[1;13"+val)
t.prepareKeyMod(key, ModMeta|ModCtrl|ModShift, "\x1b[1;14"+val)
t.prepareKeyMod(key, ModMeta|ModCtrl|ModAlt, "\x1b[1;15"+val)
t.prepareKeyMod(key, ModMeta|ModCtrl|ModAlt|ModShift, "\x1b[1;16"+val)
}
}
func (t *tScreen) prepareXtermModifiers() {
if t.ti.Modifiers != terminfo.ModifiersXTerm {
return
}
t.prepareKeyModXTerm(KeyRight, t.ti.KeyRight)
t.prepareKeyModXTerm(KeyLeft, t.ti.KeyLeft)
t.prepareKeyModXTerm(KeyUp, t.ti.KeyUp)
t.prepareKeyModXTerm(KeyDown, t.ti.KeyDown)
t.prepareKeyModXTerm(KeyInsert, t.ti.KeyInsert)
t.prepareKeyModXTerm(KeyDelete, t.ti.KeyDelete)
t.prepareKeyModXTerm(KeyPgUp, t.ti.KeyPgUp)
t.prepareKeyModXTerm(KeyPgDn, t.ti.KeyPgDn)
t.prepareKeyModXTerm(KeyHome, t.ti.KeyHome)
t.prepareKeyModXTerm(KeyEnd, t.ti.KeyEnd)
t.prepareKeyModXTerm(KeyF1, t.ti.KeyF1)
t.prepareKeyModXTerm(KeyF2, t.ti.KeyF2)
t.prepareKeyModXTerm(KeyF3, t.ti.KeyF3)
t.prepareKeyModXTerm(KeyF4, t.ti.KeyF4)
t.prepareKeyModXTerm(KeyF5, t.ti.KeyF5)
t.prepareKeyModXTerm(KeyF6, t.ti.KeyF6)
t.prepareKeyModXTerm(KeyF7, t.ti.KeyF7)
t.prepareKeyModXTerm(KeyF8, t.ti.KeyF8)
t.prepareKeyModXTerm(KeyF9, t.ti.KeyF9)
t.prepareKeyModXTerm(KeyF10, t.ti.KeyF10)
t.prepareKeyModXTerm(KeyF11, t.ti.KeyF11)
t.prepareKeyModXTerm(KeyF12, t.ti.KeyF12)
}
func (t *tScreen) prepareBracketedPaste() {
// Another workaround for lack of reporting in terminfo.
// We assume if the terminal has a mouse entry, that it
// offers bracketed paste. But we allow specific overrides
// via our terminal database.
if t.ti.EnablePaste != "" {
t.enablePaste = t.ti.EnablePaste
t.disablePaste = t.ti.DisablePaste
t.prepareKey(keyPasteStart, t.ti.PasteStart)
t.prepareKey(keyPasteEnd, t.ti.PasteEnd)
} else if t.ti.Mouse != "" {
t.enablePaste = "\x1b[?2004h"
t.disablePaste = "\x1b[?2004l"
t.prepareKey(keyPasteStart, "\x1b[200~")
t.prepareKey(keyPasteEnd, "\x1b[201~")
}
}
func (t *tScreen) prepareCursorStyles() {
// Another workaround for lack of reporting in terminfo.
// We assume if the terminal has a mouse entry, that it
// offers bracketed paste. But we allow specific overrides
// via our terminal database.
if t.ti.CursorDefault != "" {
t.cursorStyles = map[CursorStyle]string{
CursorStyleDefault: t.ti.CursorDefault,
CursorStyleBlinkingBlock: t.ti.CursorBlinkingBlock,
CursorStyleSteadyBlock: t.ti.CursorSteadyBlock,
CursorStyleBlinkingUnderline: t.ti.CursorBlinkingUnderline,
CursorStyleSteadyUnderline: t.ti.CursorSteadyUnderline,
CursorStyleBlinkingBar: t.ti.CursorBlinkingBar,
CursorStyleSteadyBar: t.ti.CursorSteadyBar,
}
} else if t.ti.Mouse != "" {
t.cursorStyles = map[CursorStyle]string{
CursorStyleDefault: "\x1b[0 q",
CursorStyleBlinkingBlock: "\x1b[1 q",
CursorStyleSteadyBlock: "\x1b[2 q",
CursorStyleBlinkingUnderline: "\x1b[3 q",
CursorStyleSteadyUnderline: "\x1b[4 q",
CursorStyleBlinkingBar: "\x1b[5 q",
CursorStyleSteadyBar: "\x1b[6 q",
}
}
}
func (t *tScreen) prepareKey(key Key, val string) {
t.prepareKeyMod(key, ModNone, val)
}
func (t *tScreen) prepareKeys() {
ti := t.ti
t.prepareKey(KeyBackspace, ti.KeyBackspace)
t.prepareKey(KeyF1, ti.KeyF1)
t.prepareKey(KeyF2, ti.KeyF2)
t.prepareKey(KeyF3, ti.KeyF3)
t.prepareKey(KeyF4, ti.KeyF4)
t.prepareKey(KeyF5, ti.KeyF5)
t.prepareKey(KeyF6, ti.KeyF6)
t.prepareKey(KeyF7, ti.KeyF7)
t.prepareKey(KeyF8, ti.KeyF8)
t.prepareKey(KeyF9, ti.KeyF9)
t.prepareKey(KeyF10, ti.KeyF10)
t.prepareKey(KeyF11, ti.KeyF11)
t.prepareKey(KeyF12, ti.KeyF12)
t.prepareKey(KeyF13, ti.KeyF13)
t.prepareKey(KeyF14, ti.KeyF14)
t.prepareKey(KeyF15, ti.KeyF15)
t.prepareKey(KeyF16, ti.KeyF16)
t.prepareKey(KeyF17, ti.KeyF17)
t.prepareKey(KeyF18, ti.KeyF18)
t.prepareKey(KeyF19, ti.KeyF19)
t.prepareKey(KeyF20, ti.KeyF20)
t.prepareKey(KeyF21, ti.KeyF21)
t.prepareKey(KeyF22, ti.KeyF22)
t.prepareKey(KeyF23, ti.KeyF23)
t.prepareKey(KeyF24, ti.KeyF24)
t.prepareKey(KeyF25, ti.KeyF25)
t.prepareKey(KeyF26, ti.KeyF26)
t.prepareKey(KeyF27, ti.KeyF27)
t.prepareKey(KeyF28, ti.KeyF28)
t.prepareKey(KeyF29, ti.KeyF29)
t.prepareKey(KeyF30, ti.KeyF30)
t.prepareKey(KeyF31, ti.KeyF31)
t.prepareKey(KeyF32, ti.KeyF32)
t.prepareKey(KeyF33, ti.KeyF33)
t.prepareKey(KeyF34, ti.KeyF34)
t.prepareKey(KeyF35, ti.KeyF35)
t.prepareKey(KeyF36, ti.KeyF36)
t.prepareKey(KeyF37, ti.KeyF37)
t.prepareKey(KeyF38, ti.KeyF38)
t.prepareKey(KeyF39, ti.KeyF39)
t.prepareKey(KeyF40, ti.KeyF40)
t.prepareKey(KeyF41, ti.KeyF41)
t.prepareKey(KeyF42, ti.KeyF42)
t.prepareKey(KeyF43, ti.KeyF43)
t.prepareKey(KeyF44, ti.KeyF44)
t.prepareKey(KeyF45, ti.KeyF45)
t.prepareKey(KeyF46, ti.KeyF46)
t.prepareKey(KeyF47, ti.KeyF47)
t.prepareKey(KeyF48, ti.KeyF48)
t.prepareKey(KeyF49, ti.KeyF49)
t.prepareKey(KeyF50, ti.KeyF50)
t.prepareKey(KeyF51, ti.KeyF51)
t.prepareKey(KeyF52, ti.KeyF52)
t.prepareKey(KeyF53, ti.KeyF53)
t.prepareKey(KeyF54, ti.KeyF54)
t.prepareKey(KeyF55, ti.KeyF55)
t.prepareKey(KeyF56, ti.KeyF56)
t.prepareKey(KeyF57, ti.KeyF57)
t.prepareKey(KeyF58, ti.KeyF58)
t.prepareKey(KeyF59, ti.KeyF59)
t.prepareKey(KeyF60, ti.KeyF60)
t.prepareKey(KeyF61, ti.KeyF61)
t.prepareKey(KeyF62, ti.KeyF62)
t.prepareKey(KeyF63, ti.KeyF63)
t.prepareKey(KeyF64, ti.KeyF64)
t.prepareKey(KeyInsert, ti.KeyInsert)
t.prepareKey(KeyDelete, ti.KeyDelete)
t.prepareKey(KeyHome, ti.KeyHome)
t.prepareKey(KeyEnd, ti.KeyEnd)
t.prepareKey(KeyUp, ti.KeyUp)
t.prepareKey(KeyDown, ti.KeyDown)
t.prepareKey(KeyLeft, ti.KeyLeft)
t.prepareKey(KeyRight, ti.KeyRight)
t.prepareKey(KeyPgUp, ti.KeyPgUp)
t.prepareKey(KeyPgDn, ti.KeyPgDn)
t.prepareKey(KeyHelp, ti.KeyHelp)
t.prepareKey(KeyPrint, ti.KeyPrint)
t.prepareKey(KeyCancel, ti.KeyCancel)
t.prepareKey(KeyExit, ti.KeyExit)
t.prepareKey(KeyBacktab, ti.KeyBacktab)
t.prepareKeyMod(KeyRight, ModShift, ti.KeyShfRight)
t.prepareKeyMod(KeyLeft, ModShift, ti.KeyShfLeft)
t.prepareKeyMod(KeyUp, ModShift, ti.KeyShfUp)
t.prepareKeyMod(KeyDown, ModShift, ti.KeyShfDown)
t.prepareKeyMod(KeyHome, ModShift, ti.KeyShfHome)
t.prepareKeyMod(KeyEnd, ModShift, ti.KeyShfEnd)
t.prepareKeyMod(KeyPgUp, ModShift, ti.KeyShfPgUp)
t.prepareKeyMod(KeyPgDn, ModShift, ti.KeyShfPgDn)
t.prepareKeyMod(KeyRight, ModCtrl, ti.KeyCtrlRight)
t.prepareKeyMod(KeyLeft, ModCtrl, ti.KeyCtrlLeft)
t.prepareKeyMod(KeyUp, ModCtrl, ti.KeyCtrlUp)
t.prepareKeyMod(KeyDown, ModCtrl, ti.KeyCtrlDown)
t.prepareKeyMod(KeyHome, ModCtrl, ti.KeyCtrlHome)
t.prepareKeyMod(KeyEnd, ModCtrl, ti.KeyCtrlEnd)
// Sadly, xterm handling of keycodes is somewhat erratic. In
// particular, different codes are sent depending on application
// mode is in use or not, and the entries for many of these are
// simply absent from terminfo on many systems. So we insert
// a number of escape sequences if they are not already used, in
// order to have the widest correct usage. Note that prepareKey
// will not inject codes if the escape sequence is already known.
// We also only do this for terminals that have the application
// mode present.
// Cursor mode
if ti.EnterKeypad != "" {
t.prepareKey(KeyUp, "\x1b[A")
t.prepareKey(KeyDown, "\x1b[B")
t.prepareKey(KeyRight, "\x1b[C")
t.prepareKey(KeyLeft, "\x1b[D")
t.prepareKey(KeyEnd, "\x1b[F")
t.prepareKey(KeyHome, "\x1b[H")
t.prepareKey(KeyDelete, "\x1b[3~")
t.prepareKey(KeyHome, "\x1b[1~")
t.prepareKey(KeyEnd, "\x1b[4~")
t.prepareKey(KeyPgUp, "\x1b[5~")
t.prepareKey(KeyPgDn, "\x1b[6~")
// Application mode
t.prepareKey(KeyUp, "\x1bOA")
t.prepareKey(KeyDown, "\x1bOB")
t.prepareKey(KeyRight, "\x1bOC")
t.prepareKey(KeyLeft, "\x1bOD")
t.prepareKey(KeyHome, "\x1bOH")
}
t.prepareKey(keyPasteStart, ti.PasteStart)
t.prepareKey(keyPasteEnd, ti.PasteEnd)
t.prepareXtermModifiers()
t.prepareBracketedPaste()
t.prepareCursorStyles()
outer:
// Add key mappings for control keys.
for i := 0; i < ' '; i++ {
// Do not insert direct key codes for ambiguous keys.
// For example, ESC is used for lots of other keys, so
// when parsing this we don't want to fast path handling
// of it, but instead wait a bit before parsing it as in
// isolation.
for esc := range t.keycodes {
if []byte(esc)[0] == byte(i) {
continue outer
}
}
t.keyexist[Key(i)] = true
mod := ModCtrl
switch Key(i) {
case KeyBS, KeyTAB, KeyESC, KeyCR:
// directly type-able- no control sequence
mod = ModNone
}
t.keycodes[string(rune(i))] = &tKeyCode{key: Key(i), mod: mod}
}
}
func (t *tScreen) Fini() {
t.finiOnce.Do(t.finish)
}
func (t *tScreen) finish() {
close(t.quit)
t.finalize()
}
func (t *tScreen) SetStyle(style Style) {
t.Lock()
if !t.fini {
t.style = style
}
t.Unlock()
}
func (t *tScreen) Clear() {
t.Fill(' ', t.style)
t.Lock()
t.clear = true
w, h := t.cells.Size()
// because we are going to clear (see t.clear) in the next cycle,
// let's also unmark the dirty bit so that we don't waste cycles
// drawing things that are already dealt with via the clear escape sequence.
for row := 0; row < h; row++ {
for col := 0; col < w; col++ {
t.cells.SetDirty(col, row, false)
}
}
t.Unlock()
}
func (t *tScreen) Fill(r rune, style Style) {
t.Lock()
if !t.fini {
t.cells.Fill(r, style)
}
t.Unlock()
}
func (t *tScreen) SetContent(x, y int, mainc rune, combc []rune, style Style) {
t.Lock()
if !t.fini {
t.cells.SetContent(x, y, mainc, combc, style)
}
t.Unlock()
}
func (t *tScreen) GetContent(x, y int) (rune, []rune, Style, int) {
t.Lock()
mainc, combc, style, width := t.cells.GetContent(x, y)
t.Unlock()
return mainc, combc, style, width
}
func (t *tScreen) SetCell(x, y int, style Style, ch ...rune) {
if len(ch) > 0 {
t.SetContent(x, y, ch[0], ch[1:], style)
} else {
t.SetContent(x, y, ' ', nil, style)
}
}
func (t *tScreen) encodeRune(r rune, buf []byte) []byte {
nb := make([]byte, 6)
ob := make([]byte, 6)
num := utf8.EncodeRune(ob, r)
ob = ob[:num]
dst := 0
var err error
if enc := t.encoder; enc != nil {
enc.Reset()
dst, _, err = enc.Transform(nb, ob, true)
}
if err != nil || dst == 0 || nb[0] == '\x1a' {
// Combining characters are elided
if len(buf) == 0 {
if acs, ok := t.acs[r]; ok {
buf = append(buf, []byte(acs)...)
} else if fb, ok := t.fallback[r]; ok {
buf = append(buf, []byte(fb)...)
} else {
buf = append(buf, '?')
}
}
} else {
buf = append(buf, nb[:dst]...)
}
return buf
}
func (t *tScreen) sendFgBg(fg Color, bg Color) {
ti := t.ti
if ti.Colors == 0 {
return
}
if fg == ColorReset || bg == ColorReset {
t.TPuts(ti.ResetFgBg)
}
if t.truecolor {
if ti.SetFgBgRGB != "" && fg.IsRGB() && bg.IsRGB() {
r1, g1, b1 := fg.RGB()
r2, g2, b2 := bg.RGB()
t.TPuts(ti.TParm(ti.SetFgBgRGB,
int(r1), int(g1), int(b1),
int(r2), int(g2), int(b2)))
return
}
if fg.IsRGB() && ti.SetFgRGB != "" {
r, g, b := fg.RGB()
t.TPuts(ti.TParm(ti.SetFgRGB, int(r), int(g), int(b)))
fg = ColorDefault
}
if bg.IsRGB() && ti.SetBgRGB != "" {
r, g, b := bg.RGB()
t.TPuts(ti.TParm(ti.SetBgRGB,
int(r), int(g), int(b)))
bg = ColorDefault
}
}
if fg.Valid() {
if v, ok := t.colors[fg]; ok {
fg = v
} else {
v = FindColor(fg, t.palette)
t.colors[fg] = v
fg = v
}
}
if bg.Valid() {
if v, ok := t.colors[bg]; ok {
bg = v
} else {
v = FindColor(bg, t.palette)
t.colors[bg] = v
bg = v
}
}
if fg.Valid() && bg.Valid() && ti.SetFgBg != "" {
t.TPuts(ti.TParm(ti.SetFgBg, int(fg&0xff), int(bg&0xff)))
} else {
if fg.Valid() && ti.SetFg != "" {
t.TPuts(ti.TParm(ti.SetFg, int(fg&0xff)))
}
if bg.Valid() && ti.SetBg != "" {
t.TPuts(ti.TParm(ti.SetBg, int(bg&0xff)))
}
}
}
func (t *tScreen) drawCell(x, y int) int {
ti := t.ti
mainc, combc, style, width := t.cells.GetContent(x, y)
if !t.cells.Dirty(x, y) {
return width
}
if y == t.h-1 && x == t.w-1 && t.ti.AutoMargin && ti.InsertChar != "" {
// our solution is somewhat goofy.
// we write to the second to the last cell what we want in the last cell, then we
// insert a character at that 2nd to last position to shift the last column into
// place, then we rewrite that 2nd to last cell. Old terminals suck.
t.TPuts(ti.TGoto(x-1, y))
defer func() {
t.TPuts(ti.TGoto(x-1, y))
t.TPuts(ti.InsertChar)
t.cy = y
t.cx = x - 1
t.cells.SetDirty(x-1, y, true)
_ = t.drawCell(x-1, y)
t.TPuts(t.ti.TGoto(0, 0))
t.cy = 0
t.cx = 0
}()
} else if t.cy != y || t.cx != x {
t.TPuts(ti.TGoto(x, y))
t.cx = x
t.cy = y
}
if style == StyleDefault {
style = t.style
}
if style != t.curstyle {
fg, bg, attrs := style.Decompose()
t.TPuts(ti.AttrOff)
t.sendFgBg(fg, bg)
if attrs&AttrBold != 0 {
t.TPuts(ti.Bold)
}
if attrs&AttrUnderline != 0 {
t.TPuts(ti.Underline)
}
if attrs&AttrReverse != 0 {
t.TPuts(ti.Reverse)
}
if attrs&AttrBlink != 0 {
t.TPuts(ti.Blink)
}
if attrs&AttrDim != 0 {
t.TPuts(ti.Dim)
}
if attrs&AttrItalic != 0 {
t.TPuts(ti.Italic)
}
if attrs&AttrStrikeThrough != 0 {
t.TPuts(ti.StrikeThrough)
}
t.curstyle = style
}
// now emit runes - taking care to not overrun width with a
// wide character, and to ensure that we emit exactly one regular
// character followed up by any residual combing characters
if width < 1 {
width = 1
}
var str string
buf := make([]byte, 0, 6)
buf = t.encodeRune(mainc, buf)
for _, r := range combc {
buf = t.encodeRune(r, buf)
}
str = string(buf)
if width > 1 && str == "?" {
// No FullWidth character support
str = "? "
t.cx = -1
}
if x > t.w-width {
// too wide to fit; emit a single space instead
width = 1
str = " "
}
t.writeString(str)
t.cx += width
t.cells.SetDirty(x, y, false)
if width > 1 {
t.cx = -1
}
return width
}
func (t *tScreen) ShowCursor(x, y int) {
t.Lock()
t.cursorx = x
t.cursory = y
t.Unlock()
}
func (t *tScreen) SetCursorStyle(cs CursorStyle) {
t.Lock()
t.cursorStyle = cs
t.Unlock()
}
func (t *tScreen) HideCursor() {
t.ShowCursor(-1, -1)
}
func (t *tScreen) showCursor() {
x, y := t.cursorx, t.cursory
w, h := t.cells.Size()
if x < 0 || y < 0 || x >= w || y >= h {
t.hideCursor()
return
}
t.TPuts(t.ti.TGoto(x, y))
t.TPuts(t.ti.ShowCursor)
if t.cursorStyles != nil {
if esc, ok := t.cursorStyles[t.cursorStyle]; ok {
t.TPuts(esc)
}
}
t.cx = x
t.cy = y
}
// writeString sends a string to the terminal. The string is sent as-is and
// this function does not expand inline padding indications (of the form
// $<[delay]> where [delay] is msec). In order to have these expanded, use
// TPuts. If the screen is "buffering", the string is collected in a buffer,
// with the intention that the entire buffer be sent to the terminal in one
// write operation at some point later.
func (t *tScreen) writeString(s string) {
if t.buffering {
_, _ = io.WriteString(&t.buf, s)
} else {
_, _ = io.WriteString(t.tty, s)
}
}
func (t *tScreen) TPuts(s string) {
if t.buffering {
t.ti.TPuts(&t.buf, s)
} else {
t.ti.TPuts(t.tty, s)
}
}
func (t *tScreen) Show() {
t.Lock()
if !t.fini {
t.resize()
t.draw()
}
t.Unlock()
}
func (t *tScreen) clearScreen() {
fg, bg, _ := t.style.Decompose()
t.sendFgBg(fg, bg)
t.TPuts(t.ti.Clear)
t.clear = false
}
func (t *tScreen) hideCursor() {
// does not update cursor position
if t.ti.HideCursor != "" {
t.TPuts(t.ti.HideCursor)
} else {
// No way to hide cursor, stick it
// at bottom right of screen
t.cx, t.cy = t.cells.Size()
t.TPuts(t.ti.TGoto(t.cx, t.cy))
}
}
func (t *tScreen) draw() {
// clobber cursor position, because we're gonna change it all
t.cx = -1
t.cy = -1
t.buf.Reset()
t.buffering = true
defer func() {
t.buffering = false
}()
// hide the cursor while we move stuff around
t.hideCursor()
if t.clear {
t.clearScreen()
}
for y := 0; y < t.h; y++ {
for x := 0; x < t.w; x++ {
width := t.drawCell(x, y)
if width > 1 {
if x+1 < t.w {
// this is necessary so that if we ever
// go back to drawing that cell, we
// actually will *draw* it.
t.cells.SetDirty(x+1, y, true)
}
}
x += width - 1
}
}
// restore the cursor
t.showCursor()
_, _ = t.buf.WriteTo(t.tty)
}
func (t *tScreen) EnableMouse(flags ...MouseFlags) {
var f MouseFlags
flagsPresent := false
for _, flag := range flags {
f |= flag
flagsPresent = true
}
if !flagsPresent {
f = MouseMotionEvents | MouseDragEvents | MouseButtonEvents
}
t.Lock()
t.mouseFlags = f
t.enableMouse(f)
t.Unlock()
}
func (t *tScreen) enableMouse(f MouseFlags) {
// Rather than using terminfo to find mouse escape sequences, we rely on the fact that
// pretty much *every* terminal that supports mouse tracking follows the
// XTerm standards (the modern ones).
if len(t.mouse) != 0 {
// start by disabling all tracking.
t.TPuts("\x1b[?1000l\x1b[?1002l\x1b[?1003l\x1b[?1006l")
if f&MouseButtonEvents != 0 {
t.TPuts("\x1b[?1000h")
}
if f&MouseDragEvents != 0 {
t.TPuts("\x1b[?1002h")
}
if f&MouseMotionEvents != 0 {
t.TPuts("\x1b[?1003h")
}
t.TPuts("\x1b[?1006h")
}
}
func (t *tScreen) DisableMouse() {
t.Lock()
t.mouseFlags = 0
t.enableMouse(0)
t.Unlock()
}
func (t *tScreen) EnablePaste() {
t.Lock()
t.pasteEnabled = true
t.enablePasting(true)
t.Unlock()
}
func (t *tScreen) DisablePaste() {
t.Lock()
t.pasteEnabled = false
t.enablePasting(false)
t.Unlock()
}
func (t *tScreen) enablePasting(on bool) {
var s string
if on {
s = t.enablePaste
} else {
s = t.disablePaste
}
if s != "" {
t.TPuts(s)
}
}
func (t *tScreen) Size() (int, int) {
t.Lock()
w, h := t.w, t.h
t.Unlock()
return w, h
}
func (t *tScreen) resize() {
if w, h, e := t.tty.WindowSize(); e == nil {
if w != t.w || h != t.h {
t.cx = -1
t.cy = -1
t.cells.Resize(w, h)
t.cells.Invalidate()
t.h = h
t.w = w
ev := NewEventResize(w, h)
_ = t.PostEvent(ev)
}
}
}
func (t *tScreen) Colors() int {
// this doesn't change, no need for lock
if t.truecolor {
return 1 << 24
}
return t.ti.Colors
}
// nColors returns the size of the built-in palette.
// This is distinct from Colors(), as it will generally
// always be a small number. (<= 256)
func (t *tScreen) nColors() int {
return t.ti.Colors
}
func (t *tScreen) ChannelEvents(ch chan<- Event, quit <-chan struct{}) {
defer close(ch)
for {
select {
case <-quit:
return
case <-t.quit:
return
case ev := <-t.evch:
select {
case <-quit:
return
case <-t.quit:
return
case ch <- ev:
}
}
}
}
func (t *tScreen) PollEvent() Event {
select {
case <-t.quit:
return nil
case ev := <-t.evch:
return ev
}
}
func (t *tScreen) HasPendingEvent() bool {
return len(t.evch) > 0
}
// vtACSNames is a map of bytes defined by terminfo that are used in
// the terminals Alternate Character Set to represent other glyphs.
// For example, the upper left corner of the box drawing set can be
// displayed by printing "l" while in the alternate character set.
// Its not quite that simple, since the "l" is the terminfo name,
// and it may be necessary to use a different character based on
// the terminal implementation (or the terminal may lack support for
// this altogether). See buildAcsMap below for detail.
var vtACSNames = map[byte]rune{
'+': RuneRArrow,
',': RuneLArrow,
'-': RuneUArrow,
'.': RuneDArrow,
'0': RuneBlock,
'`': RuneDiamond,
'a': RuneCkBoard,
'b': '␉', // VT100, Not defined by terminfo
'c': '␌', // VT100, Not defined by terminfo
'd': '␋', // VT100, Not defined by terminfo
'e': '␊', // VT100, Not defined by terminfo
'f': RuneDegree,
'g': RunePlMinus,
'h': RuneBoard,
'i': RuneLantern,
'j': RuneLRCorner,
'k': RuneURCorner,
'l': RuneULCorner,
'm': RuneLLCorner,
'n': RunePlus,
'o': RuneS1,
'p': RuneS3,
'q': RuneHLine,
'r': RuneS7,
's': RuneS9,
't': RuneLTee,
'u': RuneRTee,
'v': RuneBTee,
'w': RuneTTee,
'x': RuneVLine,
'y': RuneLEqual,
'z': RuneGEqual,
'{': RunePi,
'|': RuneNEqual,
'}': RuneSterling,
'~': RuneBullet,
}
// buildAcsMap builds a map of characters that we translate from Unicode to
// alternate character encodings. To do this, we use the standard VT100 ACS
// maps. This is only done if the terminal lacks support for Unicode; we
// always prefer to emit Unicode glyphs when we are able.
func (t *tScreen) buildAcsMap() {
acsstr := t.ti.AltChars
t.acs = make(map[rune]string)
for len(acsstr) > 2 {
srcv := acsstr[0]
dstv := string(acsstr[1])
if r, ok := vtACSNames[srcv]; ok {
t.acs[r] = t.ti.EnterAcs + dstv + t.ti.ExitAcs
}
acsstr = acsstr[2:]
}
}
func (t *tScreen) PostEventWait(ev Event) {
t.evch <- ev
}
func (t *tScreen) PostEvent(ev Event) error {
select {
case t.evch <- ev:
return nil
default:
return ErrEventQFull
}
}
func (t *tScreen) clip(x, y int) (int, int) {
w, h := t.cells.Size()
if x < 0 {
x = 0
}
if y < 0 {
y = 0
}
if x > w-1 {
x = w - 1
}
if y > h-1 {
y = h - 1
}
return x, y
}
// buildMouseEvent returns an event based on the supplied coordinates and button
// state. Note that the screen's mouse button state is updated based on the
// input to this function (i.e. it mutates the receiver).
func (t *tScreen) buildMouseEvent(x, y, btn int) *EventMouse {
// XTerm mouse events only report at most one button at a time,
// which may include a wheel button. Wheel motion events are
// reported as single impulses, while other button events are reported
// as separate press & release events.
button := ButtonNone
mod := ModNone
// Mouse wheel has bit 6 set, no release events. It should be noted
// that wheel events are sometimes misdelivered as mouse button events
// during a click-drag, so we debounce these, considering them to be
// button press events unless we see an intervening release event.
switch btn & 0x43 {
case 0:
button = Button1
t.wasbtn = true
case 1:
button = Button3 // Note we prefer to treat right as button 2
t.wasbtn = true
case 2:
button = Button2 // And the middle button as button 3
t.wasbtn = true
case 3:
button = ButtonNone
t.wasbtn = false
case 0x40:
if !t.wasbtn {
button = WheelUp
} else {
button = Button1
}
case 0x41:
if !t.wasbtn {
button = WheelDown
} else {
button = Button2
}
}
if btn&0x4 != 0 {
mod |= ModShift
}
if btn&0x8 != 0 {
mod |= ModAlt
}
if btn&0x10 != 0 {
mod |= ModCtrl
}
// Some terminals will report mouse coordinates outside the
// screen, especially with click-drag events. Clip the coordinates
// to the screen in that case.
x, y = t.clip(x, y)
return NewEventMouse(x, y, button, mod)
}
// parseSgrMouse attempts to locate an SGR mouse record at the start of the
// buffer. It returns true, true if it found one, and the associated bytes
// be removed from the buffer. It returns true, false if the buffer might
// contain such an event, but more bytes are necessary (partial match), and
// false, false if the content is definitely *not* an SGR mouse record.
func (t *tScreen) parseSgrMouse(buf *bytes.Buffer, evs *[]Event) (bool, bool) {
b := buf.Bytes()
var x, y, btn, state int
dig := false
neg := false
motion := false
i := 0
val := 0
for i = range b {
switch b[i] {
case '\x1b':
if state != 0 {
return false, false
}
state = 1
case '\x9b':
if state != 0 {
return false, false
}
state = 2
case '[':
if state != 1 {
return false, false
}
state = 2
case '<':
if state != 2 {
return false, false
}
val = 0
dig = false
neg = false
state = 3
case '-':
if state != 3 && state != 4 && state != 5 {
return false, false
}
if dig || neg {
return false, false
}
neg = true // stay in state
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
if state != 3 && state != 4 && state != 5 {
return false, false
}
val *= 10
val += int(b[i] - '0')
dig = true // stay in state
case ';':
if neg {
val = -val
}
switch state {
case 3:
btn, val = val, 0
neg, dig, state = false, false, 4
case 4:
x, val = val-1, 0
neg, dig, state = false, false, 5
default:
return false, false
}
case 'm', 'M':
if state != 5 {
return false, false
}
if neg {
val = -val
}
y = val - 1
motion = (btn & 32) != 0
btn &^= 32
if b[i] == 'm' {
// mouse release, clear all buttons
btn |= 3
btn &^= 0x40
t.buttondn = false
} else if motion {
/*
* Some broken terminals appear to send
* mouse button one motion events, instead of
* encoding 35 (no buttons) into these events.
* We resolve these by looking for a non-motion
* event first.
*/
if !t.buttondn {
btn |= 3
btn &^= 0x40
}
} else {
t.buttondn = true
}
// consume the event bytes
for i >= 0 {
_, _ = buf.ReadByte()
i--
}
*evs = append(*evs, t.buildMouseEvent(x, y, btn))
return true, true
}
}
// incomplete & inconclusive at this point
return true, false
}
// parseXtermMouse is like parseSgrMouse, but it parses a legacy
// X11 mouse record.
func (t *tScreen) parseXtermMouse(buf *bytes.Buffer, evs *[]Event) (bool, bool) {
b := buf.Bytes()
state := 0
btn := 0
x := 0
y := 0
for i := range b {
switch state {
case 0:
switch b[i] {
case '\x1b':
state = 1
case '\x9b':
state = 2
default:
return false, false
}
case 1:
if b[i] != '[' {
return false, false
}
state = 2
case 2:
if b[i] != 'M' {
return false, false
}
state++
case 3:
btn = int(b[i])
state++
case 4:
x = int(b[i]) - 32 - 1
state++
case 5:
y = int(b[i]) - 32 - 1
for i >= 0 {
_, _ = buf.ReadByte()
i--
}
*evs = append(*evs, t.buildMouseEvent(x, y, btn))
return true, true
}
}
return true, false
}
func (t *tScreen) parseFunctionKey(buf *bytes.Buffer, evs *[]Event) (bool, bool) {
b := buf.Bytes()
partial := false
for e, k := range t.keycodes {
esc := []byte(e)
if (len(esc) == 1) && (esc[0] == '\x1b') {
continue
}
if bytes.HasPrefix(b, esc) {
// matched
var r rune
if len(esc) == 1 {
r = rune(b[0])
}
mod := k.mod
if t.escaped {
mod |= ModAlt
t.escaped = false
}
switch k.key {
case keyPasteStart:
*evs = append(*evs, NewEventPaste(true))
case keyPasteEnd:
*evs = append(*evs, NewEventPaste(false))
default:
*evs = append(*evs, NewEventKey(k.key, r, mod))
}
for i := 0; i < len(esc); i++ {
_, _ = buf.ReadByte()
}
return true, true
}
if bytes.HasPrefix(esc, b) {
partial = true
}
}
return partial, false
}
func (t *tScreen) parseRune(buf *bytes.Buffer, evs *[]Event) (bool, bool) {
b := buf.Bytes()
if b[0] >= ' ' && b[0] <= 0x7F {
// printable ASCII easy to deal with -- no encodings
mod := ModNone
if t.escaped {
mod = ModAlt
t.escaped = false
}
*evs = append(*evs, NewEventKey(KeyRune, rune(b[0]), mod))
_, _ = buf.ReadByte()
return true, true
}
if b[0] < 0x80 {
// Low numbered values are control keys, not runes.
return false, false
}
utf := make([]byte, 12)
for l := 1; l <= len(b); l++ {
t.decoder.Reset()
nOut, nIn, e := t.decoder.Transform(utf, b[:l], true)
if e == transform.ErrShortSrc {
continue
}
if nOut != 0 {
r, _ := utf8.DecodeRune(utf[:nOut])
if r != utf8.RuneError {
mod := ModNone
if t.escaped {
mod = ModAlt
t.escaped = false
}
*evs = append(*evs, NewEventKey(KeyRune, r, mod))
}
for nIn > 0 {
_, _ = buf.ReadByte()
nIn--
}
return true, true
}
}
// Looks like potential escape
return true, false
}
func (t *tScreen) scanInput(buf *bytes.Buffer, expire bool) {
evs := t.collectEventsFromInput(buf, expire)
for _, ev := range evs {
t.PostEventWait(ev)
}
}
// Return an array of Events extracted from the supplied buffer. This is done
// while holding the screen's lock - the events can then be queued for
// application processing with the lock released.
func (t *tScreen) collectEventsFromInput(buf *bytes.Buffer, expire bool) []Event {
res := make([]Event, 0, 20)
t.Lock()
defer t.Unlock()
for {
b := buf.Bytes()
if len(b) == 0 {
buf.Reset()
return res
}
partials := 0
if part, comp := t.parseRune(buf, &res); comp {
continue
} else if part {
partials++
}
if part, comp := t.parseFunctionKey(buf, &res); comp {
continue
} else if part {
partials++
}
// Only parse mouse records if this term claims to have
// mouse support
if t.ti.Mouse != "" {
if part, comp := t.parseXtermMouse(buf, &res); comp {
continue
} else if part {
partials++
}
if part, comp := t.parseSgrMouse(buf, &res); comp {
continue
} else if part {
partials++
}
}
if partials == 0 || expire {
if b[0] == '\x1b' {
if len(b) == 1 {
res = append(res, NewEventKey(KeyEsc, 0, ModNone))
t.escaped = false
} else {
t.escaped = true
}
_, _ = buf.ReadByte()
continue
}
// Nothing was going to match, or we timed out
// waiting for more data -- just deliver the characters
// to the app & let them sort it out. Possibly we
// should only do this for control characters like ESC.
by, _ := buf.ReadByte()
mod := ModNone
if t.escaped {
t.escaped = false
mod = ModAlt
}
res = append(res, NewEventKey(KeyRune, rune(by), mod))
continue
}
// well we have some partial data, wait until we get
// some more
break
}
return res
}
func (t *tScreen) mainLoop(stopQ chan struct{}) {
defer t.wg.Done()
buf := &bytes.Buffer{}
for {
select {
case <-stopQ:
return
case <-t.quit:
return
case <-t.resizeQ:
t.Lock()
t.cx = -1
t.cy = -1
t.resize()
t.cells.Invalidate()
t.draw()
t.Unlock()
continue
case <-t.keytimer.C:
// If the timer fired, and the current time
// is after the expiration of the escape sequence,
// then we assume the escape sequence reached it's
// conclusion, and process the chunk independently.
// This lets us detect conflicts such as a lone ESC.
if buf.Len() > 0 {
if time.Now().After(t.keyexpire) {
t.scanInput(buf, true)
}
}
if buf.Len() > 0 {
if !t.keytimer.Stop() {
select {
case <-t.keytimer.C:
default:
}
}
t.keytimer.Reset(time.Millisecond * 50)
}
case chunk := <-t.keychan:
buf.Write(chunk)
t.keyexpire = time.Now().Add(time.Millisecond * 50)
t.scanInput(buf, false)
if !t.keytimer.Stop() {
select {
case <-t.keytimer.C:
default:
}
}
if buf.Len() > 0 {
t.keytimer.Reset(time.Millisecond * 50)
}
}
}
}
func (t *tScreen) inputLoop(stopQ chan struct{}) {
defer t.wg.Done()
for {
select {
case <-stopQ:
return
default:
}
chunk := make([]byte, 128)
n, e := t.tty.Read(chunk)
switch e {
case nil:
default:
t.Lock()
running := t.running
t.Unlock()
if running {
_ = t.PostEvent(NewEventError(e))
}
return
}
if n > 0 {
t.keychan <- chunk[:n]
}
}
}
func (t *tScreen) Sync() {
t.Lock()
t.cx = -1
t.cy = -1
if !t.fini {
t.resize()
t.clear = true
t.cells.Invalidate()
t.draw()
}
t.Unlock()
}
func (t *tScreen) CharacterSet() string {
return t.charset
}
func (t *tScreen) RegisterRuneFallback(orig rune, fallback string) {
t.Lock()
t.fallback[orig] = fallback
t.Unlock()
}
func (t *tScreen) UnregisterRuneFallback(orig rune) {
t.Lock()
delete(t.fallback, orig)
t.Unlock()
}
func (t *tScreen) CanDisplay(r rune, checkFallbacks bool) bool {
if enc := t.encoder; enc != nil {
nb := make([]byte, 6)
ob := make([]byte, 6)
num := utf8.EncodeRune(ob, r)
enc.Reset()
dst, _, err := enc.Transform(nb, ob[:num], true)
if dst != 0 && err == nil && nb[0] != '\x1A' {
return true
}
}
// Terminal fallbacks always permitted, since we assume they are
// basically nearly perfect renditions.
if _, ok := t.acs[r]; ok {
return true
}
if !checkFallbacks {
return false
}
if _, ok := t.fallback[r]; ok {
return true
}
return false
}
func (t *tScreen) HasMouse() bool {
return len(t.mouse) != 0
}
func (t *tScreen) HasKey(k Key) bool {
if k == KeyRune {
return true
}
return t.keyexist[k]
}
func (t *tScreen) Resize(int, int, int, int) {}
func (t *tScreen) Suspend() error {
t.disengage()
return nil
}
func (t *tScreen) Resume() error {
return t.engage()
}
// engage is used to place the terminal in raw mode and establish screen size, etc.
// Thing of this is as tcell "engaging" the clutch, as it's going to be driving the
// terminal interface.
func (t *tScreen) engage() error {
t.Lock()
defer t.Unlock()
if t.tty == nil {
return ErrNoScreen
}
t.tty.NotifyResize(func() {
select {
case t.resizeQ <- true:
default:
}
})
if t.running {
return errors.New("already engaged")
}
if err := t.tty.Start(); err != nil {
return err
}
t.running = true
if w, h, err := t.tty.WindowSize(); err == nil && w != 0 && h != 0 {
t.cells.Resize(w, h)
}
stopQ := make(chan struct{})
t.stopQ = stopQ
t.enableMouse(t.mouseFlags)
t.enablePasting(t.pasteEnabled)
ti := t.ti
t.TPuts(ti.EnterCA)
t.TPuts(ti.EnterKeypad)
t.TPuts(ti.HideCursor)
t.TPuts(ti.EnableAcs)
t.TPuts(ti.Clear)
t.wg.Add(2)
go t.inputLoop(stopQ)
go t.mainLoop(stopQ)
return nil
}
// disengage is used to release the terminal back to support from the caller.
// Think of this as tcell disengaging the clutch, so that another application
// can take over the terminal interface. This restores the TTY mode that was
// present when the application was first started.
func (t *tScreen) disengage() {
t.Lock()
if !t.running {
t.Unlock()
return
}
t.running = false
stopQ := t.stopQ
close(stopQ)
_ = t.tty.Drain()
t.Unlock()
t.tty.NotifyResize(nil)
// wait for everything to shut down
t.wg.Wait()
// shutdown the screen and disable special modes (e.g. mouse and bracketed paste)
ti := t.ti
t.cells.Resize(0, 0)
t.TPuts(ti.ShowCursor)
if t.cursorStyles != nil && t.cursorStyle != CursorStyleDefault {
t.TPuts(t.cursorStyles[t.cursorStyle])
}
t.TPuts(ti.ResetFgBg)
t.TPuts(ti.AttrOff)
t.TPuts(ti.Clear)
t.TPuts(ti.ExitCA)
t.TPuts(ti.ExitKeypad)
t.enableMouse(0)
t.enablePasting(false)
_ = t.tty.Stop()
}
// Beep emits a beep to the terminal.
func (t *tScreen) Beep() error {
t.writeString(string(byte(7)))
return nil
}
// finalize is used to at application shutdown, and restores the terminal
// to it's initial state. It should not be called more than once.
func (t *tScreen) finalize() {
t.disengage()
_ = t.tty.Close()
}