/// <summary>
/// Gets a sequence item.
/// </summary>
/// <remarks>
/// This method is only meaningfull if this instance has a VR SQ.
/// </remarks>
/// <param name="oneBasedIndex">The one based index.</param>
/// <returns>The sequence item.</returns>
public override SequenceItem GetItem(int oneBasedIndex)
{
SequenceItem sequenceItem = null;
if (this.VR == VR.SQ)
{
if ((oneBasedIndex >= 1) && (oneBasedIndex <= ItemCount))
{
TagSequence sequenceItemTagSequence = TagSequence.Clone();
Tag lastTag = sequenceItemTagSequence.Tags[sequenceItemTagSequence.Tags.Count - 1] as Tag;
lastTag.IndexNumber = oneBasedIndex;
sequenceItem = new SequenceItem(sequenceItemTagSequence, DvtkDataSequence[oneBasedIndex - 1]);
}
else
{
sequenceItem = new SequenceItem();
Thread.WriteWarningCurrentThread("Getting sequence item " + oneBasedIndex.ToString() + " from attribute with tag sequence " + TagSequence.ToString() + " containing " + ItemCount.ToString() + " items. Returning an empty sequence item.");
}
}
else
{
sequenceItem = new SequenceItem();
Thread.WriteWarningCurrentThread("Getting a sequence item from attribute with tag sequence " + TagSequence.ToString() + " and VR " + this.VR.ToString() + ". Returning an empty sequence item.");
}
return(sequenceItem);
}
/// <summary>
/// Get all attributes that are refered to by this tag sequence.
///
/// Precondition for the supplied TagSequence:
/// All but the last tag contains an index.
/// The last tag doesn't contain an index.
/// </summary>
/// <param name="tagSequence">The tag sequence.</param>
/// <returns>The attributes.</returns>
internal AttributeCollection GetAttributes(TagSequence tagSequence)
{
AttributeCollection attributeCollection = new AttributeCollection();
Tag firstTag = (tagSequence.Tags[0]) as Tag;
Attribute firstAttribute = GetAttribute(firstTag.AsUInt32);
if (firstAttribute is InvalidAttribute)
{
// Do nothing, just return an empty set.
}
else
{
if (tagSequence.Tags.Count > 1)
// Expecting a sequence attribute as first tag.
{
if (firstAttribute.VR == VR.SQ)
{
int fromIndex = 0;
int toIndex = 0;
if (firstTag.ContainsWildcardIndex)
{
fromIndex = 1;
toIndex = firstAttribute.ItemCount;
}
else
{
fromIndex = firstTag.IndexNumber;
toIndex = firstTag.IndexNumber;
}
TagSequence itemTagSequence = tagSequence.Clone();
itemTagSequence.Tags.RemoveAt(0);
for (int index = fromIndex; index <= toIndex; index++)
{
SequenceItem item = firstAttribute.GetItem(index);
AttributeCollection itemAttributeCollection = item.GetAttributes(itemTagSequence);
attributeCollection.AddRange(itemAttributeCollection);
}
}
else
{
// Do nothing, just return an empty set.
}
}
else
// Expecting a non-sequence attribute as tag.
{
attributeCollection.Add(firstAttribute);
}
}
return(attributeCollection);
}
