started work on new buffer

buffer/buffer.go

@@ -0,0 +1,74 @@
+package buffer
+
+import (
+	"fmt"
+)
+
+type Buffer struct {
+	lines       []line
+	x           int
+	y           int
+	columnCount int
+	lineCount   int
+}
+
+// NewBuffer creates a new terminal buffer
+func NewBuffer(columns int) *Buffer {
+	return &Buffer{
+		x:           0,
+		y:           0,
+		lines:       []line{},
+		columnCount: columns,
+	}
+}
+
+// Column returns cursor column
+func (buffer *Buffer) Column() int {
+	return buffer.x
+}
+
+// Line returns cursor line
+func (buffer *Buffer) Line() int {
+	return buffer.y
+}
+
+// Width returns the width of the buffer in columns
+func (buffer *Buffer) Width() int {
+	return buffer.columnCount
+}
+
+// Write will write a rune to the terminal at the position of the cursor, and increment the cursor position
+func (buffer *Buffer) Write(r rune) {
+	for buffer.Line() >= len(buffer.lines) {
+		buffer.lines = append(buffer.lines, newLine())
+	}
+	line := &buffer.lines[buffer.Line()]
+	for buffer.Column() >= len(line.cells) {
+		line.cells = append(line.cells, newCell())
+	}
+	cell := line.cells[buffer.Column()]
+	cell.setRune(r)
+}
+
+func (buffer *Buffer) incrementCursorPosition() {
+
+	if buffer.Column()+1 < buffer.Width() {
+		buffer.x++
+	} else {
+		buffer.y++
+		buffer.x = 0
+	}
+}
+
+func (buffer *Buffer) SetPosition(col int, line int) error {
+	if buffer.x >= buffer.Width() {
+		return fmt.Errorf("Cannot set cursor position: column %d is outside of the current buffer width (%d columns)", col, buffer.Width())
+	}
+	buffer.x = col
+	buffer.y = line
+	return nil
+}
+
+func (buffer *Buffer) SetSize(cols int, lines int) {
+
+}

buffer/buffer_test.go

@@ -0,0 +1,60 @@
+package buffer
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBufferCreation(t *testing.T) {
+	b := NewBuffer(10)
+	assert.Equal(t, 10, b.Width())
+	assert.Equal(t, 0, b.Column())
+	assert.Equal(t, 0, b.Line())
+	assert.NotNil(t, b.lines)
+}
+
+func TestBufferCursorIncrement(t *testing.T) {
+
+	b := NewBuffer(5)
+	b.incrementCursorPosition()
+	require.Equal(t, 1, b.Column())
+	require.Equal(t, 0, b.Line())
+
+	b.incrementCursorPosition()
+	require.Equal(t, 2, b.Column())
+	require.Equal(t, 0, b.Line())
+
+	b.incrementCursorPosition()
+	require.Equal(t, 3, b.Column())
+	require.Equal(t, 0, b.Line())
+
+	b.incrementCursorPosition()
+	require.Equal(t, 4, b.Column())
+	require.Equal(t, 0, b.Line())
+
+	b.incrementCursorPosition()
+	require.Equal(t, 0, b.Column())
+	require.Equal(t, 1, b.Line())
+
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+	b.incrementCursorPosition()
+
+	require.Equal(t, 0, b.Column())
+	require.Equal(t, 3, b.Line())
+
+}
+
+func TestBufferWrite(t *testing.T) {
+
+}

buffer/cell.go

@@ -0,0 +1,27 @@
+package buffer
+
+type Cell struct {
+	r          rune
+	attr       CellAttributes
+	hasContent bool
+}
+
+type CellAttributes struct {
+	FgColour  [3]float32
+	BgColour  [3]float32
+	Bold      bool
+	Dim       bool
+	Underline bool
+	Blink     bool
+	Reverse   bool
+	Hidden    bool
+}
+
+func newCell() Cell {
+	return Cell{}
+}
+
+func (cell *Cell) setRune(r rune) {
+	cell.r = r
+	cell.hasContent = true
+}

buffer/cursor.go

@@ -0,0 +1,5 @@
+package buffer
+
+type Cursor struct {
+	// holds current attr data
+}

buffer/line.go

@@ -0,0 +1,13 @@
+package buffer
+
+type line struct {
+	wrapped bool // whether line was wrapped onto from the previous one
+	cells   []Cell
+}
+
+func newLine() line {
+	return line{
+		wrapped: false,
+		cells:   []Cell{},
+	}
+}

buffer/view.go

@@ -0,0 +1,4 @@
+package buffer
+
+type View struct {
+}

terminal/buffer.go

@@ -1,4 +0,0 @@
-package terminal
-
-type Buffer struct {
-}