alt buffer

buffer/buffer.go

@@ -86,15 +86,15 @@ func (buffer *Buffer) CursorAttr() *CellAttributes {
 	return &buffer.cursorAttr
 }
 
-func (buffer *Buffer) GetCell(viewCol int, viewRow int) *Cell {
+func (buffer *Buffer) GetCell(viewCol uint16, viewRow uint16) *Cell {
 
-	rawLine := buffer.convertViewLineToRawLine(uint16(viewRow))
+	rawLine := buffer.convertViewLineToRawLine(viewRow)
 
 	if viewCol < 0 || rawLine < 0 || int(rawLine) >= len(buffer.lines) {
 		return nil
 	}
 	line := &buffer.lines[rawLine]
-	if viewCol >= len(line.cells) {
+	if int(viewCol) >= len(line.cells) {
 		return nil
 	}
 	return &line.cells[viewCol]
@@ -245,6 +245,23 @@ func (buffer *Buffer) Backspace() {
 	}
 }
 
+func (buffer *Buffer) BackspaceDelete() {
+
+	if buffer.cursorX == 0 {
+		line := buffer.getCurrentLine()
+		if line.wrapped {
+			buffer.MovePosition(int16(buffer.Width()-1), -1)
+			buffer.GetCell(buffer.cursorX, buffer.cursorY).erase()
+		} else {
+			//@todo ring bell or whatever
+			fmt.Println("BELL?")
+		}
+	} else {
+		buffer.MovePosition(-1, 0)
+		buffer.GetCell(buffer.cursorX, buffer.cursorY).erase()
+	}
+}
+
 func (buffer *Buffer) CarriageReturn() {
 	defer buffer.emitDisplayChange()
 	buffer.cursorX = 0
@@ -425,6 +442,7 @@ func (buffer *Buffer) EraseDisplayToCursor() {
 }
 
 func (buffer *Buffer) ResizeView(width uint16, height uint16) {
+
 	defer buffer.emitDisplayChange()
 
 	if buffer.viewHeight == 0 {

buffer/coverage.out

@@ -1,58 +0,0 @@
-mode: set
-gitlab.com/liamg/raft/buffer/buffer.go:17.59,25.2 3 1
-gitlab.com/liamg/raft/buffer/buffer.go:28.45,30.2 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:33.43,35.2 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:38.40,40.40 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:43.2,43.75 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:40.40,42.3 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:47.38,49.2 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:51.42,53.2 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:55.36,57.2 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:59.43,61.2 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:63.53,64.49 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:64.49,66.3 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:70.44,71.26 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:71.26,73.16 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:77.3,78.53 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:81.3,84.35 4 1
-gitlab.com/liamg/raft/buffer/buffer.go:73.16,75.12 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:78.53,80.4 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:88.49,90.46 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:90.46,92.3 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:92.8,93.44 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:93.44,98.4 4 1
-gitlab.com/liamg/raft/buffer/buffer.go:98.9,100.50 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:100.50,105.5 4 1
-gitlab.com/liamg/raft/buffer/buffer.go:105.10,106.58 1 0
-gitlab.com/liamg/raft/buffer/buffer.go:107.5,108.26 2 0
-gitlab.com/liamg/raft/buffer/buffer.go:114.33,116.25 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:124.2,124.43 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:116.25,118.19 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:118.19,121.4 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:124.43,127.3 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:127.8,130.3 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:133.54,135.33 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:139.2,139.33 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:143.2,143.86 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:135.33,137.3 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:139.33,141.3 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:146.60,147.31 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:151.2,151.33 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:155.2,156.23 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:147.31,150.3 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:151.33,154.3 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:159.48,161.80 2 1
-gitlab.com/liamg/raft/buffer/buffer.go:166.2,166.14 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:161.80,162.38 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:162.38,164.4 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:171.31,172.48 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:175.2,175.26 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:172.48,174.3 1 1
-gitlab.com/liamg/raft/buffer/buffer.go:178.63,183.2 2 1
-gitlab.com/liamg/raft/buffer/cell.go:20.21,22.2 1 1
-gitlab.com/liamg/raft/buffer/cell.go:24.35,27.2 2 1
-gitlab.com/liamg/raft/buffer/line.go:8.21,13.2 1 1
-gitlab.com/liamg/raft/buffer/line.go:15.44,17.2 1 1
-gitlab.com/liamg/raft/buffer/line.go:19.35,21.34 2 1
-gitlab.com/liamg/raft/buffer/line.go:24.2,24.22 1 1
-gitlab.com/liamg/raft/buffer/line.go:21.34,23.3 1 1

gui/gui.go

@@ -75,7 +75,7 @@ func (gui *GUI) glfwScrollCallback(w *glfw.Window, xoff float64, yoff float64) {
 	}
 }
 
-func (gui *GUI) getTermSize() (int, int) {
+func (gui *GUI) getTermSize() (uint, uint) {
 	if gui.renderer == nil {
 		return 0, 0
 	}
@@ -201,14 +201,14 @@ func (gui *GUI) Render() error {
 			lines := gui.terminal.GetVisibleLines()
 			for y := 0; y < len(lines); y++ {
 				for x, cell := range lines[y].Cells() {
-					gui.renderer.DrawCell(cell, x, y)
+					gui.renderer.DrawCell(cell, uint(x), uint(y))
 				}
 			}
 
 			if gui.terminal.Modes().ShowCursor {
-				cx := int(gui.terminal.GetLogicalCursorX())
+				cx := uint(gui.terminal.GetLogicalCursorX())
-				cy := int(gui.terminal.GetLogicalCursorY())
+				cy := uint(gui.terminal.GetLogicalCursorY())
-				cy = int(cy) + int(gui.terminal.GetScrollOffset())
+				cy = cy + uint(gui.terminal.GetScrollOffset())
 				gui.renderer.DrawCursor(cx, cy, gui.config.ColourScheme.Cursor)
 			}
 

gui/renderer.go

@@ -12,9 +12,9 @@ import (
 
 type Renderer interface {
 	SetArea(areaX int, areaY int, areaWidth int, areaHeight int)
-	DrawCell(cell buffer.Cell, col int, row int)
+	DrawCell(cell buffer.Cell, col uint, row uint)
-	DrawCursor(col int, row int, colour config.Colour)
+	DrawCursor(col uint, row uint, colour config.Colour)
-	GetTermSize() (int, int)
+	GetTermSize() (uint, uint)
 }
 
 type OpenGLRenderer struct {
@@ -27,10 +27,10 @@ type OpenGLRenderer struct {
 	cellWidth           float32
 	cellHeight          float32
 	verticalCellPadding float32
-	termCols            int
+	termCols            uint
-	termRows            int
+	termRows            uint
-	cellPositions       map[[2]int][2]float32
+	cellPositions       map[[2]uint][2]float32
-	rectangles          map[[2]int]*rectangle
+	rectangles          map[[2]uint]*rectangle
 	config              config.Config
 	colourAttr          uint32
 	program             uint32
@@ -124,8 +124,8 @@ func NewOpenGLRenderer(config config.Config, font *glfont.Font, fontScale int32,
 		areaX:         areaX,
 		areaY:         areaY,
 		fontScale:     fontScale,
-		cellPositions: map[[2]int][2]float32{},
+		cellPositions: map[[2]uint][2]float32{},
-		rectangles:    map[[2]int]*rectangle{},
+		rectangles:    map[[2]uint]*rectangle{},
 		config:        config,
 		colourAttr:    colourAttr,
 		program:       program,
@@ -134,7 +134,7 @@ func NewOpenGLRenderer(config config.Config, font *glfont.Font, fontScale int32,
 	return r
 }
 
-func (r *OpenGLRenderer) GetTermSize() (int, int) {
+func (r *OpenGLRenderer) GetTermSize() (uint, uint) {
 	return r.termCols, r.termRows
 }
 
@@ -156,31 +156,31 @@ func (r *OpenGLRenderer) SetFont(font *glfont.Font) { // @todo check for monospa
 	r.verticalCellPadding = (0.25 * float32(r.fontScale))
 	r.cellWidth = font.Width(1, "X")
 	r.cellHeight = font.Height(1, "X") + (r.verticalCellPadding * 2) // vertical padding
-	r.termCols = int(math.Floor(float64(float32(r.areaWidth) / r.cellWidth)))
+	r.termCols = uint(math.Floor(float64(float32(r.areaWidth) / r.cellWidth)))
-	r.termRows = int(math.Floor(float64(float32(r.areaHeight) / r.cellHeight)))
+	r.termRows = uint(math.Floor(float64(float32(r.areaHeight) / r.cellHeight)))
 	r.calculatePositions()
 	r.generateRectangles()
 }
 
 func (r *OpenGLRenderer) calculatePositions() {
-	for line := 0; line < r.termRows; line++ {
+	for line := uint(0); line < r.termRows; line++ {
-		for col := 0; col < r.termCols; col++ {
+		for col := uint(0); col < r.termCols; col++ {
 			// rounding to whole pixels makes everything nice
 			x := float32(math.Round(float64((float32(col) * r.cellWidth))))
 			y := float32(math.Round(float64(
 				(float32(line) * r.cellHeight) + (r.cellHeight / 2) + r.verticalCellPadding,
 			)))
-			r.cellPositions[[2]int{col, line}] = [2]float32{x, y}
+			r.cellPositions[[2]uint{col, line}] = [2]float32{x, y}
 		}
 	}
 }
 
 func (r *OpenGLRenderer) generateRectangles() {
 	gl.UseProgram(r.program)
-	for line := 0; line < r.termRows; line++ {
+	for line := uint(0); line < r.termRows; line++ {
-		for col := 0; col < r.termCols; col++ {
+		for col := uint(0); col < r.termCols; col++ {
 
-			rect, ok := r.rectangles[[2]int{col, line}]
+			rect, ok := r.rectangles[[2]uint{col, line}]
 			if ok {
 				rect.Free()
 			}
@@ -188,14 +188,14 @@ func (r *OpenGLRenderer) generateRectangles() {
 			// rounding to whole pixels makes everything nice
 			x := float32(float64((float32(col) * r.cellWidth)))
 			y := float32(float64((float32(line) * r.cellHeight) + (r.cellHeight)))
-			r.rectangles[[2]int{col, line}] = r.newRectangle(x, y, r.colourAttr)
+			r.rectangles[[2]uint{col, line}] = r.newRectangle(x, y, r.colourAttr)
 		}
 	}
 }
 
-func (r *OpenGLRenderer) DrawCursor(col int, row int, colour config.Colour) {
+func (r *OpenGLRenderer) DrawCursor(col uint, row uint, colour config.Colour) {
 
-	rect, ok := r.rectangles[[2]int{col, row}]
+	rect, ok := r.rectangles[[2]uint{col, row}]
 	if !ok { // probably trying to draw during resize - perhaps add a mutex?
 		return
 	}
@@ -218,7 +218,7 @@ func (r *OpenGLRenderer) DrawCursor(col int, row int, colour config.Colour) {
 	//gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
 }
 
-func (r *OpenGLRenderer) DrawCell(cell buffer.Cell, col int, row int) {
+func (r *OpenGLRenderer) DrawCell(cell buffer.Cell, col uint, row uint) {
 
 	if cell.Attr().Hidden || (cell.Rune() == 0x00) {
 		return
@@ -235,7 +235,7 @@ func (r *OpenGLRenderer) DrawCell(cell buffer.Cell, col int, row int) {
 		bg = cell.Bg()
 	}
 
-	pos, ok := r.cellPositions[[2]int{col, row}]
+	pos, ok := r.cellPositions[[2]uint{col, row}]
 	if !ok {
 		panic(fmt.Sprintf("Missing position data for cell at %d,%d", col, row))
 	}
@@ -245,7 +245,7 @@ func (r *OpenGLRenderer) DrawCell(cell buffer.Cell, col int, row int) {
 	// don't bother rendering rectangles that are the same colour as the background
 	if bg != r.config.ColourScheme.Background {
 
-		rect, ok := r.rectangles[[2]int{col, row}]
+		rect, ok := r.rectangles[[2]uint{col, row}]
 		if !ok {
 			panic(fmt.Sprintf("Missing rectangle data for cell at %d,%d", col, row))
 		}

main.go

@@ -84,6 +84,8 @@ func main() {
 	// parse this
 	conf := getConfig()
 
+	os.Setenv("TERM", "xterm-256color")
+
 	logger, err := getLogger(conf)
 	if err != nil {
 		fmt.Printf("Failed to create logger: %s\n", err)

terminal/ansi.go

@@ -15,36 +15,36 @@ var ansiSequenceMap = map[rune]escapeSequenceHandler{
 func indexHandler(buffer 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.buffer.CursorLine() == terminal.buffer.ViewHeight()-1 {
+	if terminal.ActiveBuffer().CursorLine() == terminal.ActiveBuffer().ViewHeight()-1 {
-		terminal.buffer.NewLine()
+		terminal.ActiveBuffer().NewLine()
 		return nil
 	}
-	terminal.buffer.MovePosition(0, 1)
+	terminal.ActiveBuffer().MovePosition(0, 1)
 	return nil
 }
 
 func reverseIndexHandler(buffer chan rune, terminal *Terminal) error {
-	terminal.buffer.MovePosition(0, -1)
+	terminal.ActiveBuffer().MovePosition(0, -1)
 	return nil
 }
 
 func saveCursorHandler(buffer chan rune, terminal *Terminal) error {
-	terminal.buffer.SaveCursor()
+	terminal.ActiveBuffer().SaveCursor()
 	return nil
 }
 
 func restoreCursorHandler(buffer chan rune, terminal *Terminal) error {
-	terminal.buffer.RestoreCursor()
+	terminal.ActiveBuffer().RestoreCursor()
 	return nil
 }
 
-func ansiHandler(buffer chan rune, terminal *Terminal) error {
+func ansiHandler(pty chan rune, terminal *Terminal) error {
 	// if the byte is an escape character, read the next byte to determine which one
-	b := <-buffer
+	b := <-pty
 
 	handler, ok := ansiSequenceMap[b]
 	if ok {
-		return handler(buffer, terminal)
+		return handler(pty, terminal)
 	}
 
 	switch b {
@@ -52,7 +52,7 @@ func ansiHandler(buffer chan rune, terminal *Terminal) error {
 	case 'c':
 		terminal.logger.Errorf("RIS not yet supported")
 	case '(':
-		b = <-buffer
+		b = <-pty
 		switch b {
 		case 'A': //uk @todo handle these?
 			//terminal.charSet = C0
@@ -60,7 +60,7 @@ func ansiHandler(buffer chan rune, terminal *Terminal) error {
 			//terminal.charSet = C0
 		}
 	case ')':
-		b = <-buffer
+		b = <-pty
 		switch b {
 		case 'A': //uk @todo handle these?
 			//terminal.charSet = C1
@@ -68,7 +68,7 @@ func ansiHandler(buffer chan rune, terminal *Terminal) error {
 			//terminal.charSet = C1
 		}
 	case '*':
-		b = <-buffer
+		b = <-pty
 		switch b {
 		case 'A': //uk @todo handle these?
 			//terminal.charSet = C2
@@ -76,7 +76,7 @@ func ansiHandler(buffer chan rune, terminal *Terminal) error {
 			//terminal.charSet = C2
 		}
 	case '+':
-		b = <-buffer
+		b = <-pty
 		switch b {
 		case 'A': //uk @todo handle these?
 			//terminal.charSet = C3
@@ -90,7 +90,7 @@ func ansiHandler(buffer chan rune, terminal *Terminal) error {
 	case '?':
 		pm := ""
 		for {
-			b = <-buffer
+			b = <-pty
 			switch b {
 			case 'h':
 				switch pm {

terminal/csi.go

@@ -22,10 +22,28 @@ func csiSetMode(modeStr string, enabled bool, terminal *Terminal) error {
 	switch modeStr {
 	case "?1":
 		terminal.modes.ApplicationCursorKeys = enabled
-	case "?12":
+	case "?12", "?13":
 		terminal.modes.BlinkingCursor = enabled
 	case "?25":
 		terminal.modes.ShowCursor = enabled
+	case "?47", "?1047":
+		if enabled {
+			terminal.UseAltBuffer()
+		} else {
+			terminal.UseMainBuffer()
+		}
+	case "?1048":
+		if enabled {
+			terminal.ActiveBuffer().SaveCursor()
+		} else {
+			terminal.ActiveBuffer().RestoreCursor()
+		}
+	case "?1049":
+		if enabled {
+			terminal.UseAltBuffer()
+		} else {
+			terminal.UseMainBuffer()
+		}
 	default:
 		return fmt.Errorf("Unsupported CSI %sl code", modeStr)
 	}
@@ -43,7 +61,7 @@ func csiEraseCharactersHandler(params []string, intermediate string, terminal *T
 		}
 	}
 
-	terminal.buffer.EraseCharacters(count)
+	terminal.ActiveBuffer().EraseCharacters(count)
 
 	return nil
 }
@@ -71,7 +89,7 @@ func csiLinePositionAbsolute(params []string, intermediate string, terminal *Ter
 		}
 	}
 
-	terminal.buffer.SetPosition(uint16(col), terminal.buffer.CursorLine())
+	terminal.ActiveBuffer().SetPosition(uint16(col), terminal.ActiveBuffer().CursorLine())
 
 	return nil
 }
@@ -79,7 +97,7 @@ func csiLinePositionAbsolute(params []string, intermediate string, terminal *Ter
 type csiSequenceHandler func(params []string, intermediate string, terminal *Terminal) error
 
 // CSI: Control Sequence Introducer [
-func csiHandler(buffer chan rune, terminal *Terminal) error {
+func csiHandler(pty chan rune, terminal *Terminal) error {
 	var final rune
 	var b rune
 	var err error
@@ -87,7 +105,7 @@ func csiHandler(buffer chan rune, terminal *Terminal) error {
 	intermediate := ""
 CSI:
 	for {
-		b = <-buffer
+		b = <-pty
 		switch true {
 		case b >= 0x30 && b <= 0x3F:
 			param = param + string(b)
@@ -117,7 +135,7 @@ CSI:
 					distance = 1
 				}
 			}
-			terminal.buffer.MovePosition(0, -int16(distance))
+			terminal.ActiveBuffer().MovePosition(0, -int16(distance))
 		case 'B':
 			distance := 1
 			if len(params) > 0 {
@@ -128,7 +146,7 @@ CSI:
 				}
 			}
 
-			terminal.buffer.MovePosition(0, int16(distance))
+			terminal.ActiveBuffer().MovePosition(0, int16(distance))
 		case 'C':
 
 			distance := 1
@@ -140,7 +158,7 @@ CSI:
 				}
 			}
 
-			terminal.buffer.MovePosition(int16(distance), 0)
+			terminal.ActiveBuffer().MovePosition(int16(distance), 0)
 
 		case 'D':
 
@@ -153,7 +171,7 @@ CSI:
 				}
 			}
 
-			terminal.buffer.MovePosition(-int16(distance), 0)
+			terminal.ActiveBuffer().MovePosition(-int16(distance), 0)
 
 		case 'E':
 			distance := 1
@@ -165,8 +183,8 @@ CSI:
 				}
 			}
 
-			terminal.buffer.MovePosition(0, int16(distance))
+			terminal.ActiveBuffer().MovePosition(0, int16(distance))
-			terminal.buffer.SetPosition(0, terminal.buffer.CursorLine())
+			terminal.ActiveBuffer().SetPosition(0, terminal.ActiveBuffer().CursorLine())
 
 		case 'F':
 
@@ -178,8 +196,8 @@ CSI:
 					distance = 1
 				}
 			}
-			terminal.buffer.MovePosition(0, -int16(distance))
+			terminal.ActiveBuffer().MovePosition(0, -int16(distance))
-			terminal.buffer.SetPosition(0, terminal.buffer.CursorLine())
+			terminal.ActiveBuffer().SetPosition(0, terminal.ActiveBuffer().CursorLine())
 
 		case 'G':
 
@@ -192,7 +210,7 @@ CSI:
 				}
 			}
 
-			terminal.buffer.SetPosition(uint16(distance-1), terminal.buffer.CursorLine())
+			terminal.ActiveBuffer().SetPosition(uint16(distance-1), terminal.ActiveBuffer().CursorLine())
 
 		case 'H', 'f':
 
@@ -213,7 +231,7 @@ CSI:
 				}
 			}
 
-			terminal.buffer.SetPosition(uint16(x-1), uint16(y-1))
+			terminal.ActiveBuffer().SetPosition(uint16(x-1), uint16(y-1))
 
 		default:
 			err = fmt.Errorf("Unknown CSI control sequence: 0x%02X (ESC[%s%s%s)", final, param, intermediate, string(final))
@@ -232,7 +250,9 @@ func csiDeleteHandler(params []string, intermediate string, terminal *Terminal)
 			n = 1
 		}
 	}
-	_ = n
+
+	terminal.ActiveBuffer().EraseCharacters(n)
+
 	return nil
 }
 
@@ -246,11 +266,11 @@ func csiEraseInDisplayHandler(params []string, intermediate string, terminal *Te
 	switch n {
 
 	case "0", "":
-		terminal.buffer.EraseDisplayFromCursor()
+		terminal.ActiveBuffer().EraseDisplayFromCursor()
 	case "1":
-		terminal.buffer.EraseDisplayToCursor()
+		terminal.ActiveBuffer().EraseDisplayToCursor()
 	case "2":
-		terminal.buffer.EraseDisplay()
+		terminal.ActiveBuffer().EraseDisplay()
 	default:
 		return fmt.Errorf("Unsupported ED: CSI %s J", n)
 	}
@@ -268,11 +288,11 @@ func csiEraseInLineHandler(params []string, intermediate string, terminal *Termi
 
 	switch n {
 	case "0", "": //erase adter cursor
-		terminal.buffer.EraseLineFromCursor()
+		terminal.ActiveBuffer().EraseLineFromCursor()
 	case "1": // erase to cursor inclusive
-		terminal.buffer.EraseLineToCursor()
+		terminal.ActiveBuffer().EraseLineToCursor()
 	case "2": // erase entire
-		terminal.buffer.EraseLine()
+		terminal.ActiveBuffer().EraseLine()
 	default:
 		return fmt.Errorf("Unsupported EL: CSI %s K", n)
 	}

terminal/delete_test.go

@@ -1,91 +0,0 @@
-package terminal
-
-import "testing"
-
-func TestDelete(t *testing.T) {
-	terminal := &Terminal{
-		lines: []Line{
-			{
-				Cells: []Cell{
-					{
-						r: 'a',
-					},
-					{
-						r: 'b',
-					},
-					{
-						r: 'c',
-					},
-					{
-						r: 'd',
-					},
-					{
-						r: 'e',
-					},
-				},
-			},
-			{
-				Cells: []Cell{
-					{
-						r: 'f',
-					},
-					{
-						r: 'g',
-					},
-					{
-						r: 'h',
-					},
-					{
-						r: 'i',
-					},
-					{
-						r: 'j',
-					},
-				},
-			},
-			{
-				Cells: []Cell{
-					{
-						r: 'k',
-					},
-					{
-						r: 'l',
-					},
-					{
-						r: 'm',
-					},
-					{
-						r: 'n',
-					},
-					{
-						r: 'o',
-					},
-				},
-			},
-		},
-	}
-
-	terminal.position = Position{
-		Col:  3,
-		Line: 1,
-	}
-
-	if err := terminal.delete(2); err != nil {
-		t.Errorf("Delete failed: %s", err)
-	}
-
-	if len(terminal.lines) != 3 {
-		t.Errorf("No. of lines has changed by deleting characters")
-	}
-
-	if "fgh" != terminal.lines[1].String() {
-		t.Errorf("Unexpected string after deletion: %s", terminal.lines[1].String())
-	}
-	if "abcde" != terminal.lines[0].String() {
-		t.Errorf("Unexpected string after deletion: %s", terminal.lines[0].String())
-	}
-
-	if "klmno" != terminal.lines[2].String() {
-		t.Errorf("Unexpected string after deletion: %s", terminal.lines[2].String())
-	}
-}

terminal/output.go

@@ -8,7 +8,7 @@ import (
 
 type TerminalCharSet int
 
-type escapeSequenceHandler func(buffer chan rune, terminal *Terminal) error
+type escapeSequenceHandler func(pty chan rune, terminal *Terminal) error
 
 var escapeSequenceMap = map[rune]escapeSequenceHandler{
 	0x1b: ansiHandler,
@@ -28,7 +28,7 @@ func (terminal *Terminal) Resume() {
 	}
 }
 
-func (terminal *Terminal) processInput(ctx context.Context, buffer chan rune) {
+func (terminal *Terminal) processInput(ctx context.Context, pty chan rune) {
 
 	// https://en.wikipedia.org/wiki/ANSI_escape_code
 
@@ -47,12 +47,12 @@ func (terminal *Terminal) processInput(ctx context.Context, buffer chan rune) {
 		//if terminal.config.slomo
 		//time.Sleep(time.Millisecond * 100)
 
-		b := <-buffer
+		b := <-pty
 
 		handler, ok := escapeSequenceMap[b]
 
 		if ok {
-			if err := handler(buffer, terminal); err != nil {
+			if err := handler(pty, terminal); err != nil {
 				terminal.logger.Errorf("Error handling escape sequence 0x%X: %s", b, err)
 			}
 			continue
@@ -62,19 +62,19 @@ func (terminal *Terminal) processInput(ctx context.Context, buffer chan rune) {
 
 		switch b {
 		case 0x0a:
-			terminal.buffer.NewLine()
+			terminal.ActiveBuffer().NewLine()
 		case 0x0d:
-			terminal.buffer.CarriageReturn()
+			terminal.ActiveBuffer().CarriageReturn()
 		case 0x08:
 			// backspace
-			terminal.buffer.Backspace()
+			terminal.ActiveBuffer().Backspace()
 		case 0x07:
 			// @todo ring bell - flash red or some shit?
 		default:
 			// render character at current location
 			//		fmt.Printf("%s\n", string([]byte{b}))
 			if b >= 0x20 {
-				terminal.buffer.Write(b)
+				terminal.ActiveBuffer().Write(b)
 			} else {
 				terminal.logger.Error("Non-readable rune received: 0x%X", b)
 			}

terminal/sgr.go

@@ -12,103 +12,103 @@ func sgrSequenceHandler(params []string, intermediate string, terminal *Terminal
 		param := params[i]
 		switch param {
 		case "00", "0", "":
-			attr := terminal.buffer.CursorAttr()
+			attr := terminal.ActiveBuffer().CursorAttr()
 			*attr = buffer.CellAttributes{
 				FgColour: terminal.config.ColourScheme.Foreground,
 				BgColour: terminal.config.ColourScheme.Background,
 			}
 		case "1", "01":
-			terminal.buffer.CursorAttr().Bold = true
+			terminal.ActiveBuffer().CursorAttr().Bold = true
 		case "2", "02":
-			terminal.buffer.CursorAttr().Dim = true
+			terminal.ActiveBuffer().CursorAttr().Dim = true
 		case "4", "04":
-			terminal.buffer.CursorAttr().Underline = true
+			terminal.ActiveBuffer().CursorAttr().Underline = true
 		case "5", "05":
-			terminal.buffer.CursorAttr().Blink = true
+			terminal.ActiveBuffer().CursorAttr().Blink = true
 		case "7", "07":
-			terminal.buffer.CursorAttr().Reverse = true
+			terminal.ActiveBuffer().CursorAttr().Reverse = true
 		case "8", "08":
-			terminal.buffer.CursorAttr().Hidden = true
+			terminal.ActiveBuffer().CursorAttr().Hidden = true
 		case "21":
-			terminal.buffer.CursorAttr().Bold = false
+			terminal.ActiveBuffer().CursorAttr().Bold = false
 		case "22":
-			terminal.buffer.CursorAttr().Dim = false
+			terminal.ActiveBuffer().CursorAttr().Dim = false
 		case "24":
-			terminal.buffer.CursorAttr().Underline = false
+			terminal.ActiveBuffer().CursorAttr().Underline = false
 		case "25":
-			terminal.buffer.CursorAttr().Blink = false
+			terminal.ActiveBuffer().CursorAttr().Blink = false
 		case "27":
-			terminal.buffer.CursorAttr().Reverse = false
+			terminal.ActiveBuffer().CursorAttr().Reverse = false
 		case "28":
-			terminal.buffer.CursorAttr().Hidden = false
+			terminal.ActiveBuffer().CursorAttr().Hidden = false
 		case "39":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Foreground
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Foreground
 		case "30":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Black
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Black
 		case "31":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Red
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Red
 		case "32":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Green
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Green
 		case "33":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Yellow
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Yellow
 		case "34":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Blue
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Blue
 		case "35":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Magenta
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Magenta
 		case "36":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.Cyan
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.Cyan
 		case "37":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.White
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.White
 		case "90":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.DarkGrey
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.DarkGrey
 		case "91":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.LightRed
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.LightRed
 		case "92":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.LightGreen
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.LightGreen
 		case "93":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.LightYellow
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.LightYellow
 		case "94":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.LightBlue
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.LightBlue
 		case "95":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.LightMagenta
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.LightMagenta
 		case "96":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.LightCyan
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.LightCyan
 		case "97":
-			terminal.buffer.CursorAttr().FgColour = terminal.config.ColourScheme.White
+			terminal.ActiveBuffer().CursorAttr().FgColour = terminal.config.ColourScheme.White
 		case "49":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Background
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Background
 		case "40":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Black
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Black
 		case "41":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Red
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Red
 		case "42":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Green
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Green
 		case "43":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Yellow
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Yellow
 		case "44":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Blue
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Blue
 		case "45":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Magenta
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Magenta
 		case "46":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.Cyan
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.Cyan
 		case "47":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.White
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.White
 		case "100":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.DarkGrey
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.DarkGrey
 		case "101":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.LightRed
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.LightRed
 		case "102":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.LightGreen
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.LightGreen
 		case "103":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.LightYellow
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.LightYellow
 		case "104":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.LightBlue
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.LightBlue
 		case "105":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.LightMagenta
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.LightMagenta
 		case "106":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.LightCyan
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.LightCyan
 		case "107":
-			terminal.buffer.CursorAttr().BgColour = terminal.config.ColourScheme.White
+			terminal.ActiveBuffer().CursorAttr().BgColour = terminal.config.ColourScheme.White
 		default:
 			return fmt.Errorf("Unknown SGR control sequence: (ESC[%s%sm)", param, intermediate)
 		}

terminal/terminal.go

@@ -15,18 +15,24 @@ import (
 	"go.uber.org/zap"
 )
 
+const (
+	MainBuffer uint8 = 0
+	AltBuffer  uint8 = 1
+)
+
 type Terminal struct {
-	buffer        *buffer.Buffer
+	buffers           []*buffer.Buffer
-	lock          sync.Mutex
+	activeBufferIndex uint8
-	pty           *os.File
+	lock              sync.Mutex
-	logger        *zap.SugaredLogger
+	pty               *os.File
-	title         string
+	logger            *zap.SugaredLogger
-	size          Winsize
+	title             string
-	config        config.Config
+	size              Winsize
-	titleHandlers []chan bool
+	config            config.Config
-	pauseChan     chan bool
+	titleHandlers     []chan bool
-	resumeChan    chan bool
+	pauseChan         chan bool
-	modes         Modes
+	resumeChan        chan bool
+	modes             Modes
 }
 
 type Modes struct {
@@ -50,10 +56,16 @@ type Position struct {
 func New(pty *os.File, logger *zap.SugaredLogger, config config.Config) *Terminal {
 
 	return &Terminal{
-		buffer: buffer.NewBuffer(0, 0, buffer.CellAttributes{
+		buffers: []*buffer.Buffer{
-			FgColour: config.ColourScheme.Foreground,
+			buffer.NewBuffer(1, 1, buffer.CellAttributes{
-			BgColour: config.ColourScheme.Background,
+				FgColour: config.ColourScheme.Foreground,
-		}),
+				BgColour: config.ColourScheme.Background,
+			}),
+			buffer.NewBuffer(1, 1, buffer.CellAttributes{
+				FgColour: config.ColourScheme.Foreground,
+				BgColour: config.ColourScheme.Background,
+			}),
+		},
 		pty:           pty,
 		logger:        logger,
 		config:        config,
@@ -66,38 +78,54 @@ func New(pty *os.File, logger *zap.SugaredLogger, config config.Config) *Termina
 	}
 }
 
+func (terminal *Terminal) UseMainBuffer() {
+	terminal.activeBufferIndex = MainBuffer
+	terminal.SetSize(uint(terminal.size.Width), uint(terminal.size.Height))
+}
+
+func (terminal *Terminal) UseAltBuffer() {
+	terminal.activeBufferIndex = AltBuffer
+	terminal.SetSize(uint(terminal.size.Width), uint(terminal.size.Height))
+}
+
+func (terminal *Terminal) ActiveBuffer() *buffer.Buffer {
+	return terminal.buffers[terminal.activeBufferIndex]
+}
+
 func (terminal *Terminal) GetScrollOffset() uint {
-	return terminal.buffer.GetScrollOffset()
+	return terminal.ActiveBuffer().GetScrollOffset()
 }
 
 func (terminal *Terminal) ScrollDown(lines uint16) {
-	terminal.buffer.ScrollDown(lines)
+	terminal.ActiveBuffer().ScrollDown(lines)
 }
 
 func (terminal *Terminal) ScrollUp(lines uint16) {
-	terminal.buffer.ScrollUp(lines)
+	terminal.ActiveBuffer().ScrollUp(lines)
 }
 
 func (terminal *Terminal) ScrollPageDown() {
-	terminal.buffer.ScrollPageDown()
+	terminal.ActiveBuffer().ScrollPageDown()
 }
 func (terminal *Terminal) ScrollPageUp() {
-	terminal.buffer.ScrollPageUp()
+	terminal.ActiveBuffer().ScrollPageUp()
 }
 func (terminal *Terminal) ScrollToEnd() {
-	terminal.buffer.ScrollToEnd()
+	terminal.ActiveBuffer().ScrollToEnd()
 }
 
 func (terminal *Terminal) GetVisibleLines() []buffer.Line {
-	return terminal.buffer.GetVisibleLines()
+	return terminal.ActiveBuffer().GetVisibleLines()
 }
 
-func (terminal *Terminal) GetCell(col int, row int) *buffer.Cell {
+func (terminal *Terminal) GetCell(col uint16, row uint16) *buffer.Cell {
-	return terminal.buffer.GetCell(col, row)
+	return terminal.ActiveBuffer().GetCell(col, row)
 }
 
 func (terminal *Terminal) AttachDisplayChangeHandler(handler chan bool) {
-	terminal.buffer.AttachDisplayChangeHandler(handler)
+	for i := range terminal.buffers {
+		terminal.buffers[i].AttachDisplayChangeHandler(handler)
+	}
 }
 
 func (terminal *Terminal) AttachTitleChangeHandler(handler chan bool) {
@@ -117,19 +145,19 @@ func (terminal *Terminal) emitTitleChange() {
 }
 
 func (terminal *Terminal) GetLogicalCursorX() uint16 {
-	if terminal.buffer.CursorColumn() >= terminal.buffer.Width() {
+	if terminal.ActiveBuffer().CursorColumn() >= terminal.ActiveBuffer().Width() {
 		return 0
 	}
 
-	return terminal.buffer.CursorColumn()
+	return terminal.ActiveBuffer().CursorColumn()
 }
 
 func (terminal *Terminal) GetLogicalCursorY() uint16 {
-	if terminal.buffer.CursorColumn() >= terminal.buffer.Width() {
+	if terminal.ActiveBuffer().CursorColumn() >= terminal.ActiveBuffer().Width() {
-		return terminal.buffer.CursorLine() + 1
+		return terminal.ActiveBuffer().CursorLine() + 1
 	}
 
-	return terminal.buffer.CursorLine()
+	return terminal.ActiveBuffer().CursorLine()
 }
 
 func (terminal *Terminal) GetTitle() string {
@@ -174,21 +202,21 @@ func (terminal *Terminal) Read() error {
 }
 
 func (terminal *Terminal) Clear() {
-	terminal.buffer.Clear()
+	terminal.ActiveBuffer().Clear()
 }
 
 func (terminal *Terminal) GetSize() (int, int) {
 	return int(terminal.size.Width), int(terminal.size.Height)
 }
 
-func (terminal *Terminal) SetSize(newCols int, newLines int) error {
+func (terminal *Terminal) SetSize(newCols uint, newLines uint) error {
 	terminal.lock.Lock()
 	defer terminal.lock.Unlock()
 
 	terminal.size.Width = uint16(newCols)
 	terminal.size.Height = uint16(newLines)
 
-	terminal.buffer.ResizeView(terminal.size.Width, terminal.size.Height)
+	terminal.ActiveBuffer().ResizeView(terminal.size.Width, terminal.size.Height)
 
 	_, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(terminal.pty.Fd()),
 		uintptr(syscall.TIOCSWINSZ), uintptr(unsafe.Pointer(&terminal.size)))