public override bool ToggleCase()
{
if (IsEmpty)
{
TextPoint nextPoint = _startPoint.Clone();
nextPoint.MoveToNextCharacter();
TextRange nextCharacter = _startPoint.GetTextRange(nextPoint);
string nextCharacterString = nextCharacter.GetText();
if (char.IsUpper(nextCharacterString, 0))
{
nextCharacterString = nextCharacterString.ToLower(CultureInfo.CurrentCulture);
}
else
{
nextCharacterString = nextCharacterString.ToUpper(CultureInfo.CurrentCulture);
}
return(nextCharacter.ReplaceText(nextCharacterString));
}
else
{
int startPosition = _startPoint.CurrentPosition;
using (ITextEdit textEdit = TextBuffer.AdvancedTextBuffer.CreateEdit())
{
for (int i = _startPoint.CurrentPosition; i < _endPoint.CurrentPosition; i++)
{
char newChar = textEdit.Snapshot[i];
if (char.IsUpper(newChar))
{
newChar = char.ToLower(newChar, CultureInfo.CurrentCulture);
}
else
{
newChar = char.ToUpper(newChar, CultureInfo.CurrentCulture);
}
if (!textEdit.Replace(i, 1, newChar.ToString(CultureInfo.CurrentCulture)))
{
textEdit.Cancel();
return(false); // break out early if any edit fails to reduce the time of the failure case
}
}
textEdit.Apply();
if (textEdit.Canceled)
{
return(false);
}
}
_startPoint.MoveTo(startPosition);
}
return(true);
}
public override void MoveToNextCharacter()
{
int currentPosition = this.CurrentPosition;
MoveTo(GetNextTextElementSpan().End);
// It's possible that the above code didn't actually move this point. Dev11 #109752 shows how
// this can happen, which is that GetNextTextElementSpan() above (which calls into WPF) may say
// that the current character doesn't combine with anything, but the _bufferPoint (which calls into
// framework methods that follow the unicode standard) will say that the character does combine. In that case
// the GetNextTextElementSpan().End isn't far enough away for this point to escape the combining character
// sequence, and the point is left where it is, at the start of a base character.
if (currentPosition == this.CurrentPosition &&
currentPosition != this.AdvancedTextPoint.Snapshot.Length)
{
_bufferPoint.MoveToNextCharacter();
Debug.Assert(currentPosition != this.CurrentPosition,
"DisplayTextPoint.MoveToNextCharacter was unable to successfully move forward. This may cause unexpected behavior or hangs.");
}
}
