public void InsertAt(int offset, int length)
{
PruneObsolete();
for (var i = positions.Count - 1; i >= 0; i--)
{
var pos = positions[i];
if (pos.Offset < offset)
{
// the list is sorted, so once we hit the first element that is smaller
// than the offset we are looking for, we can stop iterating.
break;
}
if (pos.Offset == offset && pos.Bias == Bias.Forward)
{
// dont modify the start of a element or selection.
break;
}
TextPosition target;
if (!pos.Reference.TryGetTarget(out target))
{
positions.RemoveAt(i);
}
else
{
target.Offset += length;
positions[i] = new HardPosition(target);
}
}
positions.Sort();
}
public ITextPosition Create(int offset, Bias bias)
{
PruneObsolete();
var insertPosition = FindInsertPosition(offset, bias);
if (insertPosition >= 0)
{
TextPosition target;
if (positions[insertPosition].Reference.TryGetTarget(out target))
{
return(target);
}
target = new TextPosition(offset, bias);
positions[insertPosition] = new HardPosition(target);
return(target);
}
var pos = ~insertPosition;
var retval = new TextPosition(offset, bias);
positions.Insert(pos, new HardPosition(retval));
return(retval);
}
public void RemoveAt(int offset, int length)
{
PruneObsolete();
var endOffset = offset + length;
for (var i = positions.Count - 1; i >= 0; i--)
{
var pos = positions[i];
if (pos.Offset < offset)
{
// the list is sorted, so once we hit the first element that is smaller
// than the offset we are looking for, we can stop iterating.
break;
}
TextPosition target;
if (!pos.Reference.TryGetTarget(out target))
{
positions.RemoveAt(i);
}
else
{
if (target.Offset >= endOffset)
{
target.Offset -= length;
positions[i] = new HardPosition(target);
}
else if (target.Offset > offset)
{
target.Offset = offset;
positions[i] = new HardPosition(target);
}
}
}
positions.Sort();
}
bool IsReferenceDead(HardPosition position)
{
TextPosition target;
return(!position.Reference.TryGetTarget(out target));
}
