feat: implement cross-platform support

README.md

@@ -93,8 +93,8 @@ func CloseAlternativeScreen()
 ```go
 func Down(n int)
 ```
-Down moves the cursor n cells down. If the cursor is already at the edge of the
-screen, this has no effect.
+
+Down moves the cursor n cells down. If the cursor is already at the edge of the screen, this has no effect.
 
 #### func  Hide
 
@@ -107,14 +107,15 @@ func Hide()
 ```go
 func Left(n int)
 ```
-Left moves the cursor n cells left. If the cursor is already at the edge of the
-screen, this has no effect.
+
+Left moves the cursor n cells left. If the cursor is already at the edge of the screen, this has no effect.
 
 #### func  Move
 
 ```go
 func Move(row int, column int)
 ```
+
 Move moves the cursor to a specific row and column.
 
 #### func  NextLine
@@ -146,8 +147,8 @@ func RestorePosition()
 ```go
 func Right(n int)
 ```
-Right moves the cursor n cells right. If the cursor is already at the edge of
-the screen, this has no effect.
+
+Right moves the cursor n cells right. If the cursor is already at the edge of the screen, this has no effect.
 
 #### func  SavePosition
 
@@ -166,8 +167,8 @@ func Show()
 ```go
 func Up(n int)
 ```
-Up moves the cursor n cells up. If the cursor is already at the edge of the
-screen, this has no effect.
+
+Up moves the cursor n cells up. If the cursor is already at the edge of the screen, this has no effect.
 
 ---
 

cursor.go

@@ -1,110 +1,57 @@
+// +build !windows
+
 package cursor
 
 import (
 	"fmt"
-	"strings"
-)
-
-const (
-	ansiPrefix = "\x1b["
-
-	upTemplate    = "%dA"
-	downTemplate  = "%dB"
-	leftTemplate  = "%dD"
-	rightTemplate = "%dC"
-
-	nextLineTemplate     = "%dE"
-	previousLineTemplate = "%dF"
-
-	positionTemplate        = "%d;%dH"
-	savePositionTemplate    = "s"
-	restorePositionTemplate = "u"
-
-	openAlternativeScreenTemplate  = "?1049h"
-	closeAlternativeScreenTemplate = "?1049l"
-
-	clearDisplayTemplate = "%dJ"
-	clearLineTemplate    = "%dK"
-
-	showTemplate = "?25h"
-	hideTemplate = "?25l"
+	"path/filepath"
 )
 
-// Move cursor.
-
-// Up moves the cursor n cells up. If the cursor is already at the edge of the screen, this has no effect.
+// Up moves the cursor n lines up relative to the current position.
 func Up(n int) {
-	fmt.Printf(ansiPrefix+upTemplate, n)
+	fmt.Printf("\x1b[%dA", n)
+	height += n
 }
 
-// Down moves the cursor n cells down. If the cursor is already at the edge of the screen, this has no effect.
+// Down moves the cursor n lines down relative to the current position.
 func Down(n int) {
-	fmt.Printf(ansiPrefix+downTemplate, n)
+	fmt.Printf("\x1b[%dB", n)
+	height -= n
 }
 
-// Left moves the cursor n cells left. If the cursor is already at the edge of the screen, this has no effect.
-func Left(n int) {
-	fmt.Printf(ansiPrefix+leftTemplate, n)
-}
-
-// Right moves the cursor n cells right. If the cursor is already at the edge of the screen, this has no effect.
+// Right moves the cursor n characters to the right relative to the current position.
 func Right(n int) {
-	fmt.Printf(ansiPrefix+rightTemplate, n)
+	fmt.Printf("\x1b[%dC", n)
 }
 
-// Move moves the cursor to a specific row and column.
-func Move(row int, column int) {
-	fmt.Printf(ansiPrefix+positionTemplate, row, column)
-}
-
-func NextLine(n int) {
-	fmt.Printf(ansiPrefix+nextLineTemplate, n)
-}
-
-func PrevLine(n int) {
-	fmt.Printf(ansiPrefix+previousLineTemplate, n)
-}
-
-func SavePosition() {
-	fmt.Print(ansiPrefix + savePositionTemplate)
-}
-
-func RestorePosition() {
-	fmt.Print(ansiPrefix + restorePositionTemplate)
+// Left moves the cursor n characters to the left relative to the current position.
+func Left(n int) {
+	fmt.Printf("\x1b[%dD", n)
 }
 
-// Alternative screen.
-
-func OpenAlternativeScreen() {
-	fmt.Print(ansiPrefix + openAlternativeScreenTemplate)
+// HorizontalAbsolute moves the cursor to n horizontally.
+// The position n is absolute to the start of the line.
+func HorizontalAbsolute(n int) {
+	n += 1 // Moves the line to the character after n
+	fmt.Printf("\x1b[%dG", n)
+	filepath.Base()
 }
 
-func CloseAlternativeScreen() {
-	fmt.Print(ansiPrefix + closeAlternativeScreenTemplate)
+// Show the cursor if it was hidden previously.
+// Don't forget to show the cursor atleast at the end of your application.
+// Otherwise the user might have a terminal with a permanently hidden cursor, until he reopens the terminal.
+func Show() {
+	fmt.Print("\x1b[?25h")
 }
 
-// Erase
-
-func ClearScreen() {
-	fmt.Printf(ansiPrefix+clearDisplayTemplate, 2)
-	Move(1, 1)
+// Hide the cursor.
+// Don't forget to show the cursor atleast at the end of your application with Show.
+// Otherwise the user might have a terminal with a permanently hidden cursor, until he reopens the terminal.
+func Hide() {
+	fmt.Print("\x1b[?25l")
 }
 
+// ClearLine clears the current line and moves the cursor to it's start position.
 func ClearLine() {
-	fmt.Printf(ansiPrefix+clearLineTemplate, 2)
-}
-
-func ClearLines(n int) {
-	clear := fmt.Sprintf(ansiPrefix+clearLineTemplate, 2)
-	fmt.Print(clear + strings.Repeat(fmt.Sprintf(ansiPrefix+upTemplate, 1)+clear, n))
-}
-
-// Show and hide cursor
-
-func Show() {
-	fmt.Printf(ansiPrefix + showTemplate)
-}
-
-func Hide() {
-	fmt.Printf(ansiPrefix + hideTemplate)
+	fmt.Print("\x1b[2K")
 }

cursor_test.go

@@ -1,144 +1,27 @@
 package cursor
 
 import (
-	"io"
+	"fmt"
 	"testing"
-
-	"github.com/atomicgo/testutil"
 )
 
-func equal(t *testing.T, output string, input func(w io.Writer) error) {
-	t.Helper()
-	in, _ := testutil.CaptureStdout(input)
-	if in != output {
-		t.Errorf("Input: '%s' is not equal to '%s'", in, output)
+func TestHeightChanges(t *testing.T) {
+	for i := 0; i < 4; i++ {
+		fmt.Println()
+	}
+	Up(3)
+	if height != 3 {
+		t.Errorf("height should be 3 but is %d", height)
+	}
+	Down(3)
+	if height != 0 {
+		t.Errorf("height should be 0 but is %d", height)
 	}
 }
 
-func TestClearLine(t *testing.T) {
-	equal(t, "\x1b[2K", func(w io.Writer) error {
-		ClearLine()
-
-		return nil
-	})
-}
-
-func TestClearLines(t *testing.T) {
-	equal(t, "\x1b[2K\x1b[1A\x1b[2K\x1b[1A\x1b[2K\x1b[1A\x1b[2K", func(w io.Writer) error {
-		ClearLines(3)
-
-		return nil
-	})
-}
-
-func TestClearScreen(t *testing.T) {
-	equal(t, "\x1b[2J\x1b[1;1H", func(w io.Writer) error {
-		ClearScreen()
-
-		return nil
-	})
-}
-
-func TestCloseAlternativeScreen(t *testing.T) {
-	equal(t, "\x1b[?1049l", func(w io.Writer) error {
-		CloseAlternativeScreen()
-
-		return nil
-	})
-}
-
-func TestDown(t *testing.T) {
-	equal(t, "\x1b[6B", func(w io.Writer) error {
-		Down(6)
-
-		return nil
-	})
-}
-
-func TestHide(t *testing.T) {
-	equal(t, "\x1b[?25l", func(w io.Writer) error {
-		Hide()
-
-		return nil
-	})
-}
-
-func TestLeft(t *testing.T) {
-	equal(t, "\x1b[6D", func(w io.Writer) error {
-		Left(6)
-
-		return nil
-	})
-}
-
-func TestMove(t *testing.T) {
-	equal(t, "\x1b[6;7H", func(w io.Writer) error {
-		Move(6, 7)
-
-		return nil
-	})
-}
-
-func TestNextLine(t *testing.T) {
-	equal(t, "\x1b[6E", func(w io.Writer) error {
-		NextLine(6)
-
-		return nil
-	})
-}
-
-func TestOpenAlternativeScreen(t *testing.T) {
-	equal(t, "\x1b[?1049h", func(w io.Writer) error {
-		OpenAlternativeScreen()
-
-		return nil
-	})
-}
-
-func TestPrevLine(t *testing.T) {
-	equal(t, "\x1b[6F", func(w io.Writer) error {
-		PrevLine(6)
-
-		return nil
-	})
-}
-
-func TestRestorePosition(t *testing.T) {
-	equal(t, "\x1b[u", func(w io.Writer) error {
-		RestorePosition()
-
-		return nil
-	})
-}
-
-func TestRight(t *testing.T) {
-	equal(t, "\x1b[6C", func(w io.Writer) error {
-		Right(6)
-
-		return nil
-	})
-}
-
-func TestSavePosition(t *testing.T) {
-	equal(t, "\x1b[s", func(w io.Writer) error {
-		SavePosition()
-
-		return nil
-	})
-}
-
-func TestShow(t *testing.T) {
-	equal(t, "\x1b[?25h", func(w io.Writer) error {
-		Show()
-
-		return nil
-	})
-}
-
-func TestUp(t *testing.T) {
-	equal(t, "\x1b[6A", func(w io.Writer) error {
-		Up(6)
-
-		return nil
-	})
+func TestHeightCannotBeNegative(t *testing.T) {
+	Down(10)
+	if height < 0 {
+		t.Errorf("height is negative: %d", height)
+	}
 }