Merge pull request #13 from elk-language/better-line-wrapping

Better line wrapping

document.go

@@ -337,6 +337,16 @@ func (d *Document) CursorPositionRow() (row istrings.RuneNumber) {
  return
 }
 
+// TextEndPositionRow returns the row of the end of the current text. (0-based.)
+func (d *Document) TextEndPositionRow() (row istrings.RuneNumber) {
+ textLength := istrings.RuneCount(d.Text)
+ if textLength == 0 {
+ return 0
+ }
+ row, _ = d.findLineStartIndex(textLength - 1)
+ return
+}
+
 // CursorPositionCol returns the current column. (0-based.)
 func (d *Document) CursorPositionCol() (col istrings.RuneNumber) {
  _, index := d.findLineStartIndex(d.cursorPosition)

position_test.go

@@ -32,6 +32,14 @@ func TestPositionAtEndOfString(t *testing.T) {
  Y: 0,
  },
  },
+ "one word": {
+ input: "foo",
+ columns: 20,
+ want: Position{
+ X: 3,
+ Y: 0,
+ },
+ },
  "one-line fits in columns": {
  input: "foo bar",
  columns: 20,
@@ -48,6 +56,14 @@ func TestPositionAtEndOfString(t *testing.T) {
  Y: 2,
  },
  },
+ "one-line wrapping": {
+ input: "foobar",
+ columns: 3,
+ want: Position{
+ X: 0,
+ Y: 2,
+ },
+ },
  }
 
  for name, tc := range tests {

prompt.go

@@ -208,8 +208,8 @@ keySwitch:
  p.buf = NewBuffer()
  p.history.Clear()
  case Up, ControlP:
- cursor := p.buf.Document().GetCursorPosition(p.renderer.col)
- if cursor.Y != 0 {
+ line := p.buf.Document().CursorPositionRow()
+ if line > 0 {
  p.buf.CursorUp(1)
  break
  }
@@ -222,9 +222,9 @@ keySwitch:
  }
 
  case Down, ControlN:
- endOfTextCursor := p.buf.Document().GetEndOfTextPosition(p.renderer.col)
- cursor := p.buf.Document().GetCursorPosition(p.renderer.col)
- if endOfTextCursor.Y > cursor.Y {
+ endOfTextRow := p.buf.Document().TextEndPositionRow()
+ row := p.buf.Document().CursorPositionRow()
+ if endOfTextRow > row {
  p.buf.CursorDown(1)
  break
  }

renderer.go

@@ -1,7 +1,6 @@
 package prompt
 
 import (
- "runtime"
  "strings"
  "unicode/utf8"
 
@@ -126,6 +125,7 @@ func (r *Renderer) renderCompletion(buf *Buffer, completions *CompletionManager)
  return
  }
  prefix := r.prefixCallback()
+ prefixWidth := istrings.GetWidth(prefix)
  formatted, width := formatSuggestions(
  suggestions,
  r.col-istrings.GetWidth(prefix)-1, // -1 means a width of scrollbar
@@ -140,7 +140,7 @@ func (r *Renderer) renderCompletion(buf *Buffer, completions *CompletionManager)
  formatted = formatted[completions.verticalScroll : completions.verticalScroll+windowHeight]
  r.prepareArea(windowHeight)
 
- cursor := positionAtEndOfString(prefix+buf.Document().TextBeforeCursor(), r.col)
+ cursor := positionAtEndOfString(prefix+buf.Document().TextBeforeCursor(), r.col-prefixWidth)
  x := cursor.X
  if x+width >= r.col {
  cursor = r.backward(cursor, x+width-r.col)
@@ -194,7 +194,6 @@ func (r *Renderer) renderCompletion(buf *Buffer, completions *CompletionManager)
  r.out.SetColor(DefaultColor, DefaultColor, false)
 
  c := cursor.Add(Position{X: width})
- r.lineWrap(&c)
  r.backward(c, width)
  }
 
@@ -219,7 +218,7 @@ func (r *Renderer) Render(buffer *Buffer, completion *CompletionManager, lexer L
  text := buffer.Text()
  prefix := r.prefixCallback()
  prefixWidth := istrings.GetWidth(prefix)
- cursor := positionAtEndOfString(text, r.col)
+ cursor := positionAtEndOfString(text, r.col-prefixWidth)
  cursor.X += prefixWidth
 
  // prepare area
@@ -239,10 +238,9 @@ func (r *Renderer) Render(buffer *Buffer, completion *CompletionManager, lexer L
 
  r.out.SetColor(DefaultColor, DefaultColor, false)
 
- r.lineWrap(&cursor)
-
- targetCursor := buffer.DisplayCursorPosition(r.col)
+ targetCursor := buffer.DisplayCursorPosition(r.col - prefixWidth)
  targetCursor.X += prefixWidth
+ // Log("col: %#v, targetCursor: %#v, cursor: %#v\n", r.col-prefixWidth, targetCursor, cursor)
  cursor = r.move(cursor, targetCursor)
 
  r.renderCompletion(buffer, completion)
@@ -263,9 +261,7 @@ func (r *Renderer) Render(buffer *Buffer, completion *CompletionManager, lexer L
 
  r.out.SetColor(DefaultColor, DefaultColor, false)
 
- cursor = cursor.Join(positionAtEndOfString(rest, r.col))
-
- r.lineWrap(&cursor)
+ cursor = cursor.Join(positionAtEndOfString(rest, r.col-prefixWidth))
 
  cursor = r.move(cursor, endOfSuggestionPos)
  }
@@ -279,21 +275,32 @@ func (r *Renderer) renderText(lexer Lexer, text string) {
  }
 
  prefix := r.prefixCallback()
+ prefixWidth := istrings.GetWidth(prefix)
+ col := r.col - prefixWidth
  multilinePrefix := r.getMultilinePrefix(prefix)
  firstIteration := true
  var lineBuffer strings.Builder
+ var lineCharIndex istrings.Width
+
  for _, char := range text {
- lineBuffer.WriteRune(char)
- if char != '\n' {
+ if lineCharIndex >= col || char == '\n' {
+ lineBuffer.WriteRune('\n')
+ r.renderLine(prefix, lineBuffer.String(), r.inputTextColor)
+ lineCharIndex = 0
+ lineBuffer.Reset()
+ if char != '\n' {
+ lineBuffer.WriteRune(char)
+ lineCharIndex += istrings.GetRuneWidth(char)
+ }
+ if firstIteration {
+ prefix = multilinePrefix
+ firstIteration = false
+ }
  continue
  }
 
- r.renderLine(prefix, lineBuffer.String(), r.inputTextColor)
- lineBuffer.Reset()
- if firstIteration {
- prefix = multilinePrefix
- firstIteration = false
- }
+ lineBuffer.WriteRune(char)
+ lineCharIndex += istrings.GetRuneWidth(char)
  }
 
  r.renderLine(prefix, lineBuffer.String(), r.inputTextColor)
@@ -353,8 +360,11 @@ func (r *Renderer) lex(lexer Lexer, input string) {
  s := input
 
  prefix := r.prefixCallback()
- r.renderPrefix(prefix)
+ prefixWidth := istrings.GetWidth(prefix)
+ col := r.col - prefixWidth
  multilinePrefix := r.getMultilinePrefix(prefix)
+ r.renderPrefix(prefix)
+ var lineCharIndex istrings.Width
  for {
  token, ok := lexer.Next()
  if !ok {
@@ -365,15 +375,25 @@ func (r *Renderer) lex(lexer Lexer, input string) {
  s = strings.TrimPrefix(s, text)
 
  var lineBuffer strings.Builder
+
  for _, char := range text {
- lineBuffer.WriteRune(char)
- if char != '\n' {
+ if lineCharIndex >= col || char == '\n' {
+ if char != '\n' {
+ lineBuffer.WriteByte('\n')
+ }
+ r.writeString(lineBuffer.String(), token.Color())
+ r.renderPrefix(multilinePrefix)
+ lineCharIndex = 0
+ lineBuffer.Reset()
+ if char != '\n' {
+ lineBuffer.WriteRune(char)
+ lineCharIndex += istrings.GetRuneWidth(char)
+ }
  continue
  }
 
- r.writeString(lineBuffer.String(), token.Color())
- r.renderPrefix(multilinePrefix)
- lineBuffer.Reset()
+ lineBuffer.WriteRune(char)
+ lineCharIndex += istrings.GetRuneWidth(char)
  }
  r.writeString(lineBuffer.String(), token.Color())
  }
@@ -382,11 +402,17 @@ func (r *Renderer) lex(lexer Lexer, input string) {
 // BreakLine to break line.
 func (r *Renderer) BreakLine(buffer *Buffer, lexer Lexer) {
  // Erasing and Renderer
- cursor := positionAtEndOfString(buffer.Document().TextBeforeCursor()+r.prefixCallback(), r.col)
+ prefix := r.prefixCallback()
+ prefixWidth := istrings.GetWidth(prefix)
+ cursor := positionAtEndOfString(buffer.Document().TextBeforeCursor(), r.col-prefixWidth)
+ cursor.X += prefixWidth
  r.clear(cursor)
 
- text := buffer.Document().Text + "\n"
+ text := buffer.Document().Text
  r.renderText(lexer, text)
+ if _, err := r.out.WriteString("\n"); err != nil {
+ panic(err)
+ }
 
  r.out.SetColor(DefaultColor, DefaultColor, false)
 
@@ -420,14 +446,6 @@ func (r *Renderer) move(from, to Position) Position {
  return to
 }
 
-func (r *Renderer) lineWrap(cursor *Position) {
- if runtime.GOOS != "windows" && cursor.X > 0 && cursor.X%r.col == 0 {
- cursor.X = 0
- cursor.Y += 1
- r.out.WriteRaw([]byte{'\n'})
- }
-}
-
 func clamp(high, low, x float64) float64 {
  switch {
  case high < x: