private static MeasuredRectangle MeasureBackward(TextCaret caret, ITextCaretMeasurer measurer)
{
if (caret.IsAtBlockStart || caret.Block?.Tag == null)
{
return(MeasuredRectangle.Invalid);
}
return(measurer.MeasureTextPosition(caret.GetPreviousPosition()));
}
private static MeasuredRectangle MeasureForward(TextCaret caret, ITextCaretMeasurer measurer)
{
if (caret.IsAtBlockEnd || caret.Block?.Tag == null)
{
Debug.Assert(!caret.IsAtBlockEnd, "This usually indicates an error");
return(MeasuredRectangle.Invalid);
}
return(measurer.MeasureTextPosition(caret));
}