gilo/internal/editor/input.go
Timothy Warren 19ab06ac4f
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Allow inserting new lines
2021-04-02 18:43:49 -04:00

257 lines
5.0 KiB
Go

package editor
import (
"timshome.page/gilo/internal/editor/document"
"timshome.page/gilo/internal/gilo"
"timshome.page/gilo/internal/key"
"timshome.page/gilo/internal/terminal"
)
// ----------------------------------------------------------------------------
// !Constants representing input keys
// ----------------------------------------------------------------------------
const (
keyUp = "ARROW_UP"
keyDown = "ARROW_DOWN"
keyLeft = "ARROW_LEFT"
keyRight = "ARROW_RIGHT"
keyPageUp = "PAGE_UP"
keyPageDown = "PAGE_DOWN"
keyHome = "HOME"
keyEnd = "END"
keyDelete = "DELETE"
)
/**
* Determine what to do with an individual character of input
*/
func (e *editor) processKeypressChar(ch rune) bool {
switch ch {
case key.Ctrl('q'):
if e.document.IsDirty() && e.quitTimes > 0 {
e.SetStatusMessage("WARNING!!! File has unsaved changes. Press Ctrl-Q %d more tiems to quite.", e.quitTimes)
e.quitTimes -= 1
return true
}
// Clean up on exit
terminal.Write(terminal.ClearScreen + terminal.ResetCursor)
return false
case key.Ctrl('s'):
e.Save()
case key.Enter:
e.document.InsertNewline(e.cursor)
e.cursor.Y += 1
e.cursor.X = 0
case key.Backspace, key.Ctrl('h'):
e.delChar()
case key.Esc, key.Ctrl('l'):
// Modifier keys that return ANSI escape sequences
str := parseEscapeSequence()
// Don't swallow a character after ESC if it doesn't
// start an ANSI escape sequence
if len(str) == 1 {
return e.processKeypressChar(rune(str[0]))
}
e.processKeypressStr(str)
default:
e.insertChar(ch)
}
// Clear the quit message and restart the
// confirmation count if confirmation is not
// completed
if e.quitTimes != gilo.QuitTimes {
e.quitTimes = gilo.QuitTimes
e.SetStatusMessage("")
}
return true
}
/**
* Determine what do do with a parsed ANSI escape sequence
*/
func (e *editor) processKeypressStr(key string) {
switch key {
case keyUp,
keyDown,
keyLeft,
keyRight,
keyPageUp,
keyPageDown,
keyHome,
keyEnd:
e.moveCursor(key)
case keyDelete:
e.moveCursor(keyRight)
e.delChar()
}
}
func (e *editor) moveCursor(key string) {
var row *document.Row
if e.cursor.Y >= e.document.RowCount() {
row = nil
} else {
row = e.document.Row(e.cursor.Y)
}
switch key {
case keyLeft:
if e.cursor.X != 0 {
e.cursor.X -= 1
}
// Move from beginning of current row to end of previous row
if e.cursor.Y > 0 {
e.cursor.Y -= 1
e.cursor.X = e.document.Row(e.cursor.Y).Size()
}
case keyRight:
if row != nil && e.cursor.X < row.Size() {
e.cursor.X += 1
}
// Move from end of current line to beginning of next line
if row != nil && e.cursor.X == row.Size() && e.cursor.Y < e.document.RowCount()-1 {
e.cursor.Y += 1
e.cursor.X = 0
}
case keyUp:
if e.cursor.Y != 0 {
e.cursor.Y -= 1
}
case keyDown:
if e.cursor.Y < e.document.RowCount() {
e.cursor.Y += 1
}
case keyPageUp:
if e.cursor.Y > e.screen.Rows {
e.cursor.Y -= e.screen.Rows
} else {
e.cursor.Y = 0
}
case keyPageDown:
if e.cursor.Y+e.screen.Rows > e.document.RowCount() {
e.cursor.Y += e.screen.Rows
} else {
e.cursor.Y = e.document.RowCount() - 1
}
case keyHome:
e.cursor.X = 0
case keyEnd:
if row != nil {
e.cursor.X = row.Size()
}
}
if e.cursor.Y < e.document.RowCount() {
row = e.document.Row(e.cursor.Y)
rowLen := row.Size()
// Snap to the end of a shorter line from a longer one
if e.cursor.X > rowLen {
e.cursor.X = rowLen
}
}
}
// Convert the raw ANSI escape sequences to the type of key input
func parseEscapeSequence() string {
// If we aren't starting an escape sequence,
// return the character
startChar, _ := terminal.ReadKey()
if startChar != '[' && startChar != 'O' {
return string(startChar)
}
// Read one or two characters after
// \e[ or \eO, which is the end of the
// handled escape sequences
runes := [2]rune{'\000', '\000'}
for i := 0; i < 2; i++ {
ch, size := terminal.ReadKey()
if size == 0 {
return string(rune(key.Esc))
}
runes[i] = ch
if i == 0 && runes[0] >= 'A' && runes[0] <= 'Z' {
return escSeqToKey([]rune{startChar, runes[0]})
}
// \e[*~
if i == 1 && startChar == '[' && runes[1] == '~' {
return escSeqToKey([]rune{startChar, runes[0], runes[1]})
}
}
return string(rune(key.Esc))
}
func escSeqToKey(seq []rune) string {
// \eO*
// \e[*
if len(seq) == 2 {
startChar, cmd := seq[0], seq[1]
if startChar == 'O' {
switch cmd {
case 'H':
return keyHome
case 'F':
return keyEnd
}
} else if startChar == '[' {
switch cmd {
case 'A':
return keyUp
case 'B':
return keyDown
case 'C':
return keyRight
case 'D':
return keyLeft
case 'H':
return keyHome
case 'F':
return keyEnd
}
}
} else if len(seq) == 3 { // \e[*~
cmd := seq[1]
switch cmd {
case '1':
return keyHome
case '3':
return keyDelete
case '4':
return keyEnd
case '5':
return keyPageUp
case '6':
return keyPageDown
case '7':
return keyHome
case '8':
return keyEnd
}
}
return string(rune(key.Esc))
}