public virtual InlineSpan getSpanForPosition(TextPosition position)
{
D.assert(debugAssertIsValid());
Accumulator offset = new Accumulator();
InlineSpan result = null;
visitChildren((InlineSpan span) => {
result = span.getSpanForPositionVisitor(position, offset);
return(result == null);
});
return(result);
}
public int?codeUnitAt(int index)
{
if (index < 0)
{
return(null);
}
Accumulator offset = new Accumulator();
int? result = null;
visitChildren((InlineSpan span) => {
result = span.codeUnitAtVisitor(index, offset);
return(result == null);
});
return(result);
}
protected override int?codeUnitAtVisitor(int index, Accumulator offset)
{
if (text == null)
{
return(null);
}
if (index - offset.value < text.Length)
{
return(text[index - offset.value]);
}
offset.increment(text.Length);
return(null);
}
protected abstract int?codeUnitAtVisitor(int index, Accumulator offset);
protected abstract InlineSpan getSpanForPositionVisitor(TextPosition position, Accumulator offset);
protected override InlineSpan getSpanForPositionVisitor(TextPosition position, Accumulator offset)
{
if (text == null)
{
return(null);
}
TextAffinity affinity = position.affinity;
int targetOffset = position.offset;
int endOffset = offset.value + text.Length;
if (offset.value == targetOffset && affinity == TextAffinity.downstream ||
offset.value < targetOffset && targetOffset < endOffset ||
endOffset == targetOffset && affinity == TextAffinity.upstream)
{
return(this);
}
offset.increment(text.Length);
return(null);
}
