gilo/editor/editor.go
2021-03-30 15:45:13 -04:00

145 lines
2.4 KiB
Go

package editor
import (
"timshome.page/gilo/fn"
"timshome.page/gilo/terminal"
)
// ----------------------------------------------------------------------------
// !Editor
// ----------------------------------------------------------------------------
type cursor struct {
x int
y int
}
type editor struct {
screen *terminal.Screen
cursor *cursor
}
func New() *editor {
screen := terminal.Size()
cursor := &cursor { 0, 0 }
return &editor{screen, cursor }
}
func (e *editor) ProcessKeypress() bool {
var str string
ch, _ := terminal.ReadKey()
if ch == fn.Ctrl('q') {
// Clean up on exit
terminal.Write(terminal.ClearScreen + terminal.ResetCursor)
return false
}
if ch == '\x1b' {
str = string('\x1b') + parseEscapeSequence()
} else {
str = string(ch)
}
switch str {
case keyUp, keyDown, keyLeft, keyRight, keyPageUp, keyPageDown, keyHome, keyEnd:
e.moveCursor(str)
return true
default:
// Do something later
terminal.Write("Code: %v", str)
}
return true
}
func (e *editor) moveCursor (key string) {
switch key {
case keyLeft:
if e.cursor.x != 0 {
e.cursor.x -= 1
}
case keyRight:
if e.cursor.x != e.screen.Cols-1 {
e.cursor.x += 1
}
case keyUp:
if e.cursor.y != 0 {
e.cursor.y -= 1
}
case keyDown:
if e.cursor.y != e.screen.Rows-1 {
e.cursor.y += 1
}
case keyPageUp:
e.cursor.y = 0
case keyPageDown:
e.cursor.y = e.screen.Rows
case keyHome:
e.cursor.x = 0
case keyEnd:
e.cursor.x = e.screen.Cols
}
}
func parseEscapeSequence () string {
var runes []rune
for i := 0; i < 3; i++ {
ch, size := terminal.ReadKey()
if size == 0 {
return "\x1b"
}
runes = append(runes, ch)
if i == 1 && runes[1] >= 'A' {
if runes[0] == 'O' {
switch runes[1] {
case 'H':
return keyHome
case 'F':
return keyEnd
}
}
if runes[0] == '[' {
switch runes[1] {
case 'A':
return keyUp
case 'B':
return keyDown
case 'C':
return keyRight
case 'D':
return keyLeft
case 'H':
return keyHome
case 'F':
return keyEnd
}
}
}
if i == 2 && runes[0] == '[' && runes[2] == '~' {
switch runes[1] {
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('\x1b')
}