aminal/terminal/ansi.go

70 lines
2.0 KiB
Go

package terminal
import "fmt"
// https://www.xfree86.org/4.8.0/ctlseqs.html
// https://vt100.net/docs/vt100-ug/chapter3.html
var ansiSequenceMap = map[rune]escapeSequenceHandler{
'[': csiHandler,
']': oscHandler,
'7': saveCursorHandler,
'8': restoreCursorHandler,
'D': indexHandler,
'M': reverseIndexHandler,
'c': swallowHandler(0), //RIS
'(': swallowHandler(1), // character set bullshit
')': swallowHandler(1), // character set bullshit
'*': swallowHandler(1), // character set bullshit
'+': swallowHandler(1), // character set bullshit
'>': swallowHandler(0), // numeric char selection //@todo
'=': swallowHandler(0), // alt char selection //@todo
}
func swallowHandler(n int) func(pty chan rune, terminal *Terminal) error {
return func(pty chan rune, terminal *Terminal) error {
for i := 0; i < n; i++ {
<-pty
}
return nil
}
}
func indexHandler(pty chan rune, terminal *Terminal) error {
// @todo is thus right?
// "This sequence causes the active position to move downward one line without changing the column position. If the active position is at the bottom margin, a scroll up is performed."
if terminal.ActiveBuffer().CursorLine() == terminal.ActiveBuffer().ViewHeight()-1 {
terminal.ActiveBuffer().NewLine()
return nil
}
terminal.ActiveBuffer().MovePosition(0, 1)
return nil
}
func reverseIndexHandler(pty chan rune, terminal *Terminal) error {
terminal.ActiveBuffer().MovePosition(0, -1)
return nil
}
func saveCursorHandler(pty chan rune, terminal *Terminal) error {
terminal.ActiveBuffer().SaveCursor()
return nil
}
func restoreCursorHandler(pty chan rune, terminal *Terminal) error {
terminal.ActiveBuffer().RestoreCursor()
return nil
}
func ansiHandler(pty chan rune, terminal *Terminal) error {
// if the byte is an escape character, read the next byte to determine which one
b := <-pty
handler, ok := ansiSequenceMap[b]
if ok {
return handler(pty, terminal)
}
return fmt.Errorf("Unknown ANSI control sequence byte: 0x%02X [%v]", b, string(b))
}