Fix scrolling with wrapped lines

README.md

@@ -21,15 +21,20 @@ package main
 import (
  "fmt"
  "github.com/elk-language/go-prompt"
+ pstrings "github.com/elk-language/go-prompt/strings"
 )
 
-func completer(d prompt.Document) []prompt.Suggest {
+func completer(d prompt.Document) ([]prompt.Suggest, pstrings.RuneNumber, pstrings.RuneNumber) {
+ endIndex := d.CurrentRuneIndex()
+ w := d.GetWordBeforeCursor()
+ startIndex := endIndex - pstrings.RuneCount(w)
+
  s := []prompt.Suggest{
  {Text: "users", Description: "Store the username and age"},
  {Text: "articles", Description: "Store the article text posted by user"},
  {Text: "comments", Description: "Store the text commented to articles"},
  }
- return prompt.FilterHasPrefix(s, d.GetWordBeforeCursor(), true)
+ return prompt.FilterHasPrefix(s, w, true), startIndex, endIndex
 }
 
 func main() {

buffer.go

@@ -179,6 +179,7 @@ func (b *Buffer) DeleteBeforeCursor(count istrings.RuneNumber, columns istrings.
  cursorPosition: b.cursorPosition - istrings.RuneNumber(len([]rune(deleted))),
  }, columns, rows)
  }
+ b.RecalculateStartLine(columns, rows)
  return
 }
 
@@ -205,6 +206,7 @@ func (b *Buffer) Delete(count istrings.RuneNumber, col istrings.Width, row int)
  )
 
  deleted := string(deletedRunes)
+ b.RecalculateStartLine(col, row)
  return deleted
  }
 

renderer.go

@@ -250,6 +250,7 @@ func (r *Renderer) renderText(lexer Lexer, input string, startLine int) {
  for _, char := range input {
  if lineCharIndex >= col || char == '\n' {
  lineNumber++
+ lineCharIndex = 0
  if lineNumber-1 < startLine {
  continue
  }
@@ -258,7 +259,6 @@ func (r *Renderer) renderText(lexer Lexer, input string, startLine int) {
  }
  lineBuffer.WriteRune('\n')
  r.renderLine(prefix, lineBuffer.String(), r.inputTextColor)
- lineCharIndex = 0
  lineBuffer.Reset()
  if char != '\n' {
  lineBuffer.WriteRune(char)
@@ -271,11 +271,11 @@ func (r *Renderer) renderText(lexer Lexer, input string, startLine int) {
  continue
  }
 
+ lineCharIndex += istrings.GetRuneWidth(char)
  if lineNumber < startLine {
  continue
  }
  lineBuffer.WriteRune(char)
- lineCharIndex += istrings.GetRuneWidth(char)
  }
 
  r.renderLine(prefix, lineBuffer.String(), r.inputTextColor)
@@ -376,6 +376,7 @@ tokenLoop:
  for _, char := range text {
  if lineCharIndex >= col || char == '\n' {
  lineNumber++
+ lineCharIndex = 0
  if lineNumber-1 < startLine {
  continue charLoop
  }
@@ -385,7 +386,6 @@ tokenLoop:
  lineBuffer = append(lineBuffer, '\n')
  r.writeColor(lineBuffer, token.Color())
  r.renderPrefix(multilinePrefix)
- lineCharIndex = 0
  lineBuffer = lineBuffer[:0]
  if char != '\n' {
  size := utf8.EncodeRune(runeBuffer, char)
@@ -395,12 +395,12 @@ tokenLoop:
  continue charLoop
  }
 
+ lineCharIndex += istrings.GetRuneWidth(char)
  if lineNumber < startLine {
  continue charLoop
  }
  size := utf8.EncodeRune(runeBuffer, char)
  lineBuffer = append(lineBuffer, runeBuffer[:size]...)
- lineCharIndex += istrings.GetRuneWidth(char)
  }
  if len(lineBuffer) > 0 {
  r.writeColor(lineBuffer, token.Color())