subsonic-tui/vendor/github.com/gdamore/tcell/v2/simulation.go

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// Copyright 2022 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 (
"sync"
"unicode/utf8"
"golang.org/x/text/transform"
)
// NewSimulationScreen returns a SimulationScreen. Note that
// SimulationScreen is also a Screen.
func NewSimulationScreen(charset string) SimulationScreen {
if charset == "" {
charset = "UTF-8"
}
s := &simscreen{charset: charset}
return s
}
// SimulationScreen represents a screen simulation. This is intended to
// be a superset of normal Screens, but also adds some important interfaces
// for testing.
type SimulationScreen interface {
// InjectKeyBytes injects a stream of bytes corresponding to
// the native encoding (see charset). It turns true if the entire
// set of bytes were processed and delivered as KeyEvents, false
// if any bytes were not fully understood. Any bytes that are not
// fully converted are discarded.
InjectKeyBytes(buf []byte) bool
// InjectKey injects a key event. The rune is a UTF-8 rune, post
// any translation.
InjectKey(key Key, r rune, mod ModMask)
// InjectMouse injects a mouse event.
InjectMouse(x, y int, buttons ButtonMask, mod ModMask)
// GetContents returns screen contents as an array of
// cells, along with the physical width & height. Note that the
// physical contents will be used until the next time SetSize()
// is called.
GetContents() (cells []SimCell, width int, height int)
// GetCursor returns the cursor details.
GetCursor() (x int, y int, visible bool)
Screen
}
// SimCell represents a simulated screen cell. The purpose of this
// is to track on screen content.
type SimCell struct {
// Bytes is the actual character bytes. Normally this is
// rune data, but it could be be data in another encoding system.
Bytes []byte
// Style is the style used to display the data.
Style Style
// Runes is the list of runes, unadulterated, in UTF-8.
Runes []rune
}
type simscreen struct {
physw int
physh int
fini bool
style Style
evch chan Event
quit chan struct{}
front []SimCell
back CellBuffer
clear bool
cursorx int
cursory int
cursorvis bool
mouse bool
paste bool
charset string
encoder transform.Transformer
decoder transform.Transformer
fillchar rune
fillstyle Style
fallback map[rune]string
sync.Mutex
}
func (s *simscreen) Init() error {
s.evch = make(chan Event, 10)
s.quit = make(chan struct{})
s.fillchar = 'X'
s.fillstyle = StyleDefault
s.mouse = false
s.physw = 80
s.physh = 25
s.cursorx = -1
s.cursory = -1
s.style = StyleDefault
if enc := GetEncoding(s.charset); enc != nil {
s.encoder = enc.NewEncoder()
s.decoder = enc.NewDecoder()
} else {
return ErrNoCharset
}
s.front = make([]SimCell, s.physw*s.physh)
s.back.Resize(80, 25)
// default fallbacks
s.fallback = make(map[rune]string)
for k, v := range RuneFallbacks {
s.fallback[k] = v
}
return nil
}
func (s *simscreen) Fini() {
s.Lock()
s.fini = true
s.back.Resize(0, 0)
s.Unlock()
if s.quit != nil {
close(s.quit)
}
s.physw = 0
s.physh = 0
s.front = nil
}
func (s *simscreen) SetStyle(style Style) {
s.Lock()
s.style = style
s.Unlock()
}
func (s *simscreen) Clear() {
s.Fill(' ', s.style)
}
func (s *simscreen) Fill(r rune, style Style) {
s.Lock()
s.back.Fill(r, style)
s.Unlock()
}
func (s *simscreen) SetCell(x, y int, style Style, ch ...rune) {
if len(ch) > 0 {
s.SetContent(x, y, ch[0], ch[1:], style)
} else {
s.SetContent(x, y, ' ', nil, style)
}
}
func (s *simscreen) SetContent(x, y int, mainc rune, combc []rune, st Style) {
s.Lock()
s.back.SetContent(x, y, mainc, combc, st)
s.Unlock()
}
func (s *simscreen) GetContent(x, y int) (rune, []rune, Style, int) {
var mainc rune
var combc []rune
var style Style
var width int
s.Lock()
mainc, combc, style, width = s.back.GetContent(x, y)
s.Unlock()
return mainc, combc, style, width
}
func (s *simscreen) drawCell(x, y int) int {
mainc, combc, style, width := s.back.GetContent(x, y)
if !s.back.Dirty(x, y) {
return width
}
if x >= s.physw || y >= s.physh || x < 0 || y < 0 {
return width
}
simc := &s.front[(y*s.physw)+x]
if style == StyleDefault {
style = s.style
}
simc.Style = style
simc.Runes = append([]rune{mainc}, combc...)
// 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
simc.Bytes = nil
if x > s.physw-width {
simc.Runes = []rune{' '}
simc.Bytes = []byte{' '}
return width
}
lbuf := make([]byte, 12)
ubuf := make([]byte, 12)
nout := 0
for _, r := range simc.Runes {
l := utf8.EncodeRune(ubuf, r)
nout, _, _ = s.encoder.Transform(lbuf, ubuf[:l], true)
if nout == 0 || lbuf[0] == '\x1a' {
// skip combining
if subst, ok := s.fallback[r]; ok {
simc.Bytes = append(simc.Bytes,
[]byte(subst)...)
} else if r >= ' ' && r <= '~' {
simc.Bytes = append(simc.Bytes, byte(r))
} else if simc.Bytes == nil {
simc.Bytes = append(simc.Bytes, '?')
}
} else {
simc.Bytes = append(simc.Bytes, lbuf[:nout]...)
}
}
s.back.SetDirty(x, y, false)
return width
}
func (s *simscreen) ShowCursor(x, y int) {
s.Lock()
s.cursorx, s.cursory = x, y
s.showCursor()
s.Unlock()
}
func (s *simscreen) HideCursor() {
s.ShowCursor(-1, -1)
}
func (s *simscreen) showCursor() {
x, y := s.cursorx, s.cursory
if x < 0 || y < 0 || x >= s.physw || y >= s.physh {
s.cursorvis = false
} else {
s.cursorvis = true
}
}
func (s *simscreen) hideCursor() {
// does not update cursor position
s.cursorvis = false
}
func (s *simscreen) SetCursorStyle(CursorStyle) {}
func (s *simscreen) Show() {
s.Lock()
s.resize()
s.draw()
s.Unlock()
}
func (s *simscreen) clearScreen() {
// We emulate a hardware clear by filling with a specific pattern
for i := range s.front {
s.front[i].Style = s.fillstyle
s.front[i].Runes = []rune{s.fillchar}
s.front[i].Bytes = []byte{byte(s.fillchar)}
}
s.clear = false
}
func (s *simscreen) draw() {
s.hideCursor()
if s.clear {
s.clearScreen()
}
w, h := s.back.Size()
for y := 0; y < h; y++ {
for x := 0; x < w; x++ {
width := s.drawCell(x, y)
x += width - 1
}
}
s.showCursor()
}
func (s *simscreen) EnableMouse(...MouseFlags) {
s.mouse = true
}
func (s *simscreen) DisableMouse() {
s.mouse = false
}
func (s *simscreen) EnablePaste() {
s.paste = true
}
func (s *simscreen) DisablePaste() {
s.paste = false
}
func (s *simscreen) EnableFocus() {
}
func (s *simscreen) DisableFocus() {
}
func (s *simscreen) Size() (int, int) {
s.Lock()
w, h := s.back.Size()
s.Unlock()
return w, h
}
func (s *simscreen) resize() {
w, h := s.physw, s.physh
ow, oh := s.back.Size()
if w != ow || h != oh {
s.back.Resize(w, h)
ev := NewEventResize(w, h)
s.PostEvent(ev)
}
}
func (s *simscreen) Colors() int {
return 256
}
func (s *simscreen) ChannelEvents(ch chan<- Event, quit <-chan struct{}) {
defer close(ch)
for {
select {
case <-quit:
return
case <-s.quit:
return
case ev := <-s.evch:
select {
case <-quit:
return
case <-s.quit:
return
case ch <- ev:
}
}
}
}
func (s *simscreen) PollEvent() Event {
select {
case <-s.quit:
return nil
case ev := <-s.evch:
return ev
}
}
func (s *simscreen) HasPendingEvent() bool {
return len(s.evch) > 0
}
func (s *simscreen) PostEventWait(ev Event) {
s.evch <- ev
}
func (s *simscreen) PostEvent(ev Event) error {
select {
case s.evch <- ev:
return nil
default:
return ErrEventQFull
}
}
func (s *simscreen) InjectMouse(x, y int, buttons ButtonMask, mod ModMask) {
ev := NewEventMouse(x, y, buttons, mod)
s.PostEvent(ev)
}
func (s *simscreen) InjectKey(key Key, r rune, mod ModMask) {
ev := NewEventKey(key, r, mod)
s.PostEvent(ev)
}
func (s *simscreen) InjectKeyBytes(b []byte) bool {
failed := false
outer:
for len(b) > 0 {
if b[0] >= ' ' && b[0] <= 0x7F {
// printable ASCII easy to deal with -- no encodings
ev := NewEventKey(KeyRune, rune(b[0]), ModNone)
s.PostEvent(ev)
b = b[1:]
continue
}
if b[0] < 0x80 {
mod := ModNone
// No encodings start with low numbered values
if Key(b[0]) >= KeyCtrlA && Key(b[0]) <= KeyCtrlZ {
mod = ModCtrl
}
ev := NewEventKey(Key(b[0]), 0, mod)
s.PostEvent(ev)
b = b[1:]
continue
}
utfb := make([]byte, len(b)*4) // worst case
for l := 1; l < len(b); l++ {
s.decoder.Reset()
nout, nin, _ := s.decoder.Transform(utfb, b[:l], true)
if nout != 0 {
r, _ := utf8.DecodeRune(utfb[:nout])
if r != utf8.RuneError {
ev := NewEventKey(KeyRune, r, ModNone)
s.PostEvent(ev)
}
b = b[nin:]
continue outer
}
}
failed = true
b = b[1:]
continue
}
return !failed
}
func (s *simscreen) Sync() {
s.Lock()
s.clear = true
s.resize()
s.back.Invalidate()
s.draw()
s.Unlock()
}
func (s *simscreen) CharacterSet() string {
return s.charset
}
func (s *simscreen) SetSize(w, h int) {
s.Lock()
newc := make([]SimCell, w*h)
for row := 0; row < h && row < s.physh; row++ {
for col := 0; col < w && col < s.physw; col++ {
newc[(row*w)+col] = s.front[(row*s.physw)+col]
}
}
s.cursorx, s.cursory = -1, -1
s.physw, s.physh = w, h
s.front = newc
s.back.Resize(w, h)
s.Unlock()
}
func (s *simscreen) GetContents() ([]SimCell, int, int) {
s.Lock()
cells, w, h := s.front, s.physw, s.physh
s.Unlock()
return cells, w, h
}
func (s *simscreen) GetCursor() (int, int, bool) {
s.Lock()
x, y, vis := s.cursorx, s.cursory, s.cursorvis
s.Unlock()
return x, y, vis
}
func (s *simscreen) RegisterRuneFallback(r rune, subst string) {
s.Lock()
s.fallback[r] = subst
s.Unlock()
}
func (s *simscreen) UnregisterRuneFallback(r rune) {
s.Lock()
delete(s.fallback, r)
s.Unlock()
}
func (s *simscreen) CanDisplay(r rune, checkFallbacks bool) bool {
if enc := s.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
}
}
if !checkFallbacks {
return false
}
if _, ok := s.fallback[r]; ok {
return true
}
return false
}
func (s *simscreen) HasMouse() bool {
return false
}
func (s *simscreen) Resize(int, int, int, int) {}
func (s *simscreen) HasKey(Key) bool {
return true
}
func (s *simscreen) Beep() error {
return nil
}
func (s *simscreen) Suspend() error {
return nil
}
func (s *simscreen) Resume() error {
return nil
}
func (s *simscreen) LockRegion(x, y, width, height int, lock bool) {
s.Lock()
defer s.Unlock()
for j := y; j < (y + height); j += 1 {
for i := x; i < (x + width); i += 1 {
switch lock {
case true:
s.back.LockCell(i, j)
case false:
s.back.UnlockCell(i, j)
}
}
}
}
func (s *simscreen) Tty() (Tty, bool) {
return nil, false
}