app: slim down window.go by moving editorState to separate file

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/window.go

@@ -9,8 +9,6 @@ import (
 	"image/color"
 	"runtime"
 	"time"
-	"unicode"
-	"unicode/utf16"
 	"unicode/utf8"
 
 	"gioui.org/f32"
@@ -120,11 +118,6 @@ type Window struct {
 	}
 }
 
-type editorState struct {
-	input.EditorState
-	compose key.Range
-}
-
 type callbacks struct {
 	w          *Window
 	d          driver
@@ -592,109 +585,6 @@ func (c *callbacks) ActionAt(p f32.Point) (system.Action, bool) {
 	return c.w.queue.ActionAt(p)
 }
 
-func (e *editorState) Replace(r key.Range, text string) {
-	if r.Start > r.End {
-		r.Start, r.End = r.End, r.Start
-	}
-	runes := []rune(text)
-	newEnd := r.Start + len(runes)
-	adjust := func(pos int) int {
-		switch {
-		case newEnd < pos && pos <= r.End:
-			return newEnd
-		case r.End < pos:
-			diff := newEnd - r.End
-			return pos + diff
-		}
-		return pos
-	}
-	e.Selection.Start = adjust(e.Selection.Start)
-	e.Selection.End = adjust(e.Selection.End)
-	if e.compose.Start != -1 {
-		e.compose.Start = adjust(e.compose.Start)
-		e.compose.End = adjust(e.compose.End)
-	}
-	s := e.Snippet
-	if r.End < s.Start || r.Start > s.End {
-		// Discard snippet if it doesn't overlap with replacement.
-		s = key.Snippet{
-			Range: key.Range{
-				Start: r.Start,
-				End:   r.Start,
-			},
-		}
-	}
-	var newSnippet []rune
-	snippet := []rune(s.Text)
-	// Append first part of existing snippet.
-	if end := r.Start - s.Start; end > 0 {
-		newSnippet = append(newSnippet, snippet[:end]...)
-	}
-	// Append replacement.
-	newSnippet = append(newSnippet, runes...)
-	// Append last part of existing snippet.
-	if start := r.End; start < s.End {
-		newSnippet = append(newSnippet, snippet[start-s.Start:]...)
-	}
-	// Adjust snippet range to include replacement.
-	if r.Start < s.Start {
-		s.Start = r.Start
-	}
-	s.End = s.Start + len(newSnippet)
-	s.Text = string(newSnippet)
-	e.Snippet = s
-}
-
-// UTF16Index converts the given index in runes into an index in utf16 characters.
-func (e *editorState) UTF16Index(runes int) int {
-	if runes == -1 {
-		return -1
-	}
-	if runes < e.Snippet.Start {
-		// Assume runes before sippet are one UTF-16 character each.
-		return runes
-	}
-	chars := e.Snippet.Start
-	runes -= e.Snippet.Start
-	for _, r := range e.Snippet.Text {
-		if runes == 0 {
-			break
-		}
-		runes--
-		chars++
-		if r1, _ := utf16.EncodeRune(r); r1 != unicode.ReplacementChar {
-			chars++
-		}
-	}
-	// Assume runes after snippets are one UTF-16 character each.
-	return chars + runes
-}
-
-// RunesIndex converts the given index in utf16 characters to an index in runes.
-func (e *editorState) RunesIndex(chars int) int {
-	if chars == -1 {
-		return -1
-	}
-	if chars < e.Snippet.Start {
-		// Assume runes before offset are one UTF-16 character each.
-		return chars
-	}
-	runes := e.Snippet.Start
-	chars -= e.Snippet.Start
-	for _, r := range e.Snippet.Text {
-		if chars == 0 {
-			break
-		}
-		chars--
-		runes++
-		if r1, _ := utf16.EncodeRune(r); r1 != unicode.ReplacementChar {
-			chars--
-		}
-	}
-	// Assume runes after snippets are one UTF-16 character each.
-	return runes + chars
-}
-
 func (w *Window) waitAck(d driver) {
 	for {
 		select {