/*
openDICOM.NET openDICOM# 0.1.1
openDICOM# provides a library for DICOM related development on Mono.
Copyright (C) 2006-2007 Albert Gnandt
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
$Id: Tag.cs 48 2007-03-28 13:49:15Z agnandt $
*/
using System;
using System.IO;
using System.Globalization;
using System.Text.RegularExpressions;
using openDicom;
using openDicom.Registry;
using openDicom.Encoding;
namespace openDicom.DataStructure{
/// <summary>
/// This class represents a DICOM tag (gggg,eeee).
/// </summary>
public sealed class Tag: IComparable, IDicomStreamMember
{
private string group = "0000";
/// <summary>
/// Access of a tag instance's group id. Group is a hexadecimal
/// string value of format "gggg".
/// </summary>
public string Group
{
get { return group; }
set
{
if (value != null)
{
if (Regex.IsMatch(value, "^[0-9A-Fa-f]{4}$"))
group = value.ToUpper();
else
throw new DicomException("Tag.Group is invalid.",
this, "Group", value);
}
else
throw new DicomException("Tag.Group is null.", this);
}
}
private string element = "0000";
/// <summary>
/// Access of a tag instance's element id. Element is a hexadecimal
/// string value of format "eeee".
/// </summary>
public string Element
{
get { return element; }
set
{
if (value != null)
{
if (Regex.IsMatch(value, "^[0-9A-Fa-f]{4}$"))
element = value.ToUpper();
else
throw new DicomException("Tag.Element is invalid.",
this, "Element", value);
}
else
throw new DicomException("Tag.Element is null.");
}
}
/// <summary>
/// Returns true, if this tag is a private tag, a tag defined by
/// user, else false. A private tag is not registered to a data
/// element dictionary.
/// </summary>
public bool IsUserDefined
{
get
{
return ! DataElementDictionary.Global.Contains(this);
}
}
private long streamPosition = -1;
/// <summary>
/// Access this instance's stream position. If a tag does
/// not belong to a stream, a position of -1 will be returned.
/// </summary>
public long StreamPosition
{
get { return streamPosition; }
}
private TransferSyntax transferSyntax = null;
/// <summary>
/// Access this instance's transfer syntax.
/// </summary>
public TransferSyntax TransferSyntax
{
set { transferSyntax = value; }
get
{
if (transferSyntax != null)
return transferSyntax;
else
throw new DicomException("Transfer syntax is null. " +
"Make sure you are not referencing a dictionary " +
"entry tag.", "Tag.TransferSyntax");
}
}
/// <summary>
/// Creates a new tag instance from specified string representation
/// tag.
/// </summary>
/// <param name="tag">
/// Tag representation as string of format "(gggg,eeee)".
/// </param>
public Tag(string tag): this(tag, (TransferSyntax) null) {}
public Tag(string tag, TransferSyntax transferSyntax)
{
tag = tag.ToUpper().Replace(" ", null);
if (Regex.IsMatch(tag, "^\\([0-9A-F]{4}\\,[0-9A-F]{4}\\)$"))
{
string[] s = tag.Split(',');
Group = s[0].TrimStart('(').Trim();
Element = s[1].TrimEnd(')').Trim();
TransferSyntax = transferSyntax;
}
else
throw new DicomException("Tag is invalid.", this, "tag", tag);
}
/// <summary>
/// Creates a new tag instance from specified string representations
/// (group,element).
/// </summary>
/// <param name="group">
/// Group id as string of format "gggg".
/// </param>
/// <param name="element">
/// Element id as string of format "eeee".
/// </param>
public Tag(string group, string element): this(group, element, null) {}
public Tag(string group, string element, TransferSyntax transferSyntax)
{
Group = group;
Element = element;
TransferSyntax = transferSyntax;
}
/// <summary>
/// Creates a new tag instance from specified integer representations
/// (group,element).
/// </summary>
/// <param name="group">
/// Group id value.
/// </param>
/// <param name="element">
/// Element id value.
/// </param>
public Tag(int group, int element): this(group, element, null) {}
public Tag(int group, int element, TransferSyntax transferSyntax)
{
TransferSyntax = transferSyntax;
SetInt(group, element);
}
/// <summary>
/// Creates a new tag instance from a DICOM output stream.
/// </summary>
/// <param name="stream">
/// Any kind of DICOM output stream.
/// </param>
public Tag(Stream stream): this(stream, null) {}
public Tag(Stream stream, TransferSyntax transferSyntax)
{
TransferSyntax = transferSyntax;
LoadFrom(stream);
}
private void SetInt(int group, int element)
{
if (group < 0x0000 || group > 0xFFFF)
throw new ArgumentOutOfRangeException("Tag.Group");
if (element < 0x0000 || element > 0xFFFF)
throw new ArgumentOutOfRangeException("Tag.Element");
Group = string.Format("{0:X4}", group);
Element = string.Format("{0:X4}", element);
}
/// <summary>
/// Re-creates this instance from a DICOM output stream.
/// </summary>
/// <param name="stream">
/// Any kind of DICOM output stream.
/// </param>
public void LoadFrom(Stream stream)
{
streamPosition = stream.Position;
DicomContext.Set(stream, null);
if (stream != null)
{
byte[] buffer = new byte[2];
stream.Read(buffer, 0, 2);
int group = BitConverter.ToUInt16(
TransferSyntax.CorrectByteOrdering(buffer), 0);
stream.Read(buffer, 0, 2);
int element = BitConverter.ToUInt16(
TransferSyntax.CorrectByteOrdering(buffer), 0);
SetInt(group, element);
}
else
throw new DicomException("Tag.LoadFrom.Stream is null.",
this);
DicomContext.Reset();
}
/// <summary>
/// Saves this instance to a DICOM input stream.
/// </summary>
/// <param name="stream">
/// Any kind of DICOM input stream.
/// </param>
public void SaveTo(Stream stream)
{
streamPosition = stream.Position;
DicomContext.Set(stream, this);
if (stream != null)
{
byte[] group = BitConverter.GetBytes(ushort.Parse(Group,
NumberStyles.HexNumber));
byte[] element = BitConverter.GetBytes(ushort.Parse(Element,
NumberStyles.HexNumber));
group = TransferSyntax.CorrectByteOrdering(group);
element = TransferSyntax.CorrectByteOrdering(element);
byte[] buffer = new byte[4];
Array.Copy(group, 0, buffer, 0, 2);
Array.Copy(element, 0, buffer, 2, 2);
stream.Write(buffer, 0, 4);
}
else
throw new DicomException("Tag.SaveToStream.Stream is null.",
this);
DicomContext.Reset();
}
/// <summary>
/// Determines whether this instance is equal to another DICOM
/// tag instance.
/// </summary>
/// <param name="tag">
/// An instance of class Tag.
/// </param>
/// <return>
/// True, if equality is given, else false.
/// </return>
public bool Equals(Tag tag)
{
return CompareTo(tag) == 0;
}
/// <summary>
/// Determines whether this instance is equal to a string
/// representation of the format "(gggg,eeee)".
/// </summary>
/// <param name="tag">
/// An instance of class Tag.
/// </param>
/// <returns>
/// True, if equality is given, else false.
/// </returns>
public bool Equals(string tag)
{
tag = tag.ToUpper().Replace(" ", null);
if (Regex.IsMatch(tag, "^\\([0-9A-F]{4}\\,[0-9A-F]{4}\\)$"))
return ToString().Equals(tag);
else
throw new DicomException("Tag is invalid.", this, "tag", tag);
}
/// <summary>
/// Implementation of the IComparable interface. So the use
/// of this instance within collections is guaranteed.
/// </summary>
public int CompareTo(object obj)
{
return ToString().CompareTo(((Tag) obj).ToString());
}
/// <summary>
/// Corresponding data element dictionary entry.
/// </summary>
/// <returns>
/// A DICOM data element dictionary entry. If this instance represents
/// a private tag, a completely useable dictionary entry of type
/// unknown is returned.
/// </returns>
public DataElementDictionaryEntry GetDictionaryEntry()
{
if (IsUserDefined)
// no data element dictionary entry exists
return new DataElementDictionaryEntry(this, "Unknown");
else
// data element dictionary entry exists
return DataElementDictionary.Global.GetDictionaryEntry(this);
}
/// <summary>
/// DICOM tag string representation.
/// </summary>
/// <returns>
/// A DICOM tag as string of format "(gggg,eeee)".
/// </returns>
public override string ToString()
{
return string.Format("({0},{1})", Group, Element);
}
}
}
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