mirror of
https://github.com/taigrr/gopher-os
synced 2025-01-18 04:43:13 -08:00
50da8ab106
Since the Go runtime is not yet setup there is no support for spinlocking if a lock cannot be acquired. This makes the locking code useless for now.
108 lines
2.2 KiB
Go
108 lines
2.2 KiB
Go
package tty
|
|
|
|
import "github.com/achilleasa/gopher-os/kernel/driver/video/console"
|
|
|
|
const (
|
|
defaultFg = console.LightGrey
|
|
defaultBg = console.Black
|
|
)
|
|
|
|
// Vt implements a simple terminal that can process LF and CR characters. The
|
|
// terminal uses a console device for its output.
|
|
type Vt struct {
|
|
// Go interfaces will not work before we can get memory allocation working.
|
|
// Till then we need to use concrete types instead.
|
|
cons *console.Ega
|
|
|
|
width uint16
|
|
height uint16
|
|
|
|
curX uint16
|
|
curY uint16
|
|
curAttr console.Attr
|
|
}
|
|
|
|
// AttachTo links the terminal with the specified console device and updates
|
|
// the terminal's dimensions to match the ones reported by the attached device.
|
|
func (t *Vt) AttachTo(cons *console.Ega) {
|
|
t.cons = cons
|
|
t.width, t.height = cons.Dimensions()
|
|
t.curX = 0
|
|
t.curY = 0
|
|
|
|
// Default to lightgrey on black text.
|
|
t.curAttr = makeAttr(defaultFg, defaultBg)
|
|
}
|
|
|
|
// Clear clears the terminal.
|
|
func (t *Vt) Clear() {
|
|
t.clear()
|
|
}
|
|
|
|
// Position returns the current cursor position (x, y).
|
|
func (t *Vt) Position() (uint16, uint16) {
|
|
return t.curX, t.curY
|
|
}
|
|
|
|
// SetPosition sets the current cursor position to (x,y).
|
|
func (t *Vt) SetPosition(x, y uint16) {
|
|
if x >= t.width {
|
|
x = t.width - 1
|
|
}
|
|
|
|
if y >= t.height {
|
|
y = t.height - 1
|
|
}
|
|
|
|
t.curX, t.curY = x, y
|
|
}
|
|
|
|
// Write implements io.Writer.
|
|
func (t *Vt) Write(data []byte) (int, error) {
|
|
attr := t.curAttr
|
|
for _, b := range data {
|
|
switch b {
|
|
case '\r':
|
|
t.cr()
|
|
case '\n':
|
|
t.cr()
|
|
t.lf()
|
|
default:
|
|
t.cons.Write(b, attr, t.curX, t.curY)
|
|
t.curX++
|
|
if t.curX == t.width {
|
|
t.lf()
|
|
}
|
|
}
|
|
}
|
|
|
|
return len(data), nil
|
|
}
|
|
|
|
// cls clears the terminal.
|
|
func (t *Vt) clear() {
|
|
t.cons.Clear(0, 0, t.width, t.height)
|
|
}
|
|
|
|
// cr resets the x coordinate of the terminal cursor to 0.
|
|
func (t *Vt) cr() {
|
|
t.curX = 0
|
|
}
|
|
|
|
// lf advances the y coordinate of the terminal cursor by one line scrolling
|
|
// the terminal contents if the end of the last terminal line is reached.
|
|
func (t *Vt) lf() {
|
|
if t.curY+1 < t.height {
|
|
t.curY++
|
|
return
|
|
}
|
|
|
|
t.cons.Scroll(console.Up, 1)
|
|
t.cons.Clear(0, t.height-1, t.width, 1)
|
|
return
|
|
}
|
|
|
|
func makeAttr(fg, bg console.Attr) console.Attr {
|
|
return (bg << 4) | (fg & 0xF)
|
|
}
|