public TextEditingValue(string text = "", TextSelection selection = null, TextRange composing = null)
{
this.text = text;
this.composing = composing ?? TextRange.empty;
if (selection != null && selection.start >= 0 && selection.end >= 0)
{
// handle surrogate pair emoji, which takes 2 utf16 chars
// if selection cuts in the middle of the emoji, move it to the end
int start = selection.start, end = selection.end;
if (start < text.Length && char.IsLowSurrogate(text[start]))
{
start++;
}
if (end < text.Length && char.IsLowSurrogate(text[end]))
{
end++;
}
this.selection = selection.copyWith(start, end);
}
else
{
this.selection = TextSelection.collapsed(-1);
}
}
//unity-specific
public TextEditingValue moveExtent(int move)
{
int offset = selection.extentOffset + move;
offset = Mathf.Max(0, offset);
offset = Mathf.Min(offset, text.Length);
return(copyWith(selection: selection.copyWith(extentOffset: offset)));
}