|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
#pragma warning disable 1634, 1691
//
// Description:
// ContentLocatorBase contains an ordered set of ContentLocatorParts which each identify
// a piece of content within a certain context. Resolving one part
// provides the context to resolve the next part. Locators are used
// to refer to external data in a structured way.
//
// Spec: Simplifying Store Cache Model.doc
//
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
using MS.Internal;
using MS.Internal.Annotations;
#pragma warning disable 1634, 1691 // suppressing PreSharp warnings
namespace System.Windows.Annotations
{
/// <summary>
/// ContentLocatorBase contains an ordered set of ContentLocatorParts which each identify
/// a piece of content within a certain context. Resolving one part
/// provides the context to resolve the next part. Locators are used
/// to refer to external data in a structured way.
/// </summary>
[XmlRoot(Namespace = AnnotationXmlConstants.Namespaces.CoreSchemaNamespace, ElementName = AnnotationXmlConstants.Elements.ContentLocator)]
public sealed class ContentLocator : ContentLocatorBase, IXmlSerializable
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
/// <summary>
/// Creates an instance of ContentLocator.
/// </summary>
public ContentLocator()
{
_parts = new AnnotationObservableCollection<ContentLocatorPart>();
_parts.CollectionChanged += OnCollectionChanged;
}
#endregion Constructors
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Determines if this list begins with the ContentLocatorParts that
/// make up matchList. All ContentLocatorParts in matchList must
/// be present and in the same order in this list for
/// true to be returned.
/// </summary>
/// <param name="locator">the list to compare with</param>
/// <returns>
/// true if this list begins with the ContentLocatorParts in locator;
/// false otherwise. If locator is longer than this locator, will
/// return false as well.
/// </returns>
/// <exception cref="ArgumentNullException">locator is null</exception>
public bool StartsWith(ContentLocator locator)
{
ArgumentNullException.ThrowIfNull(locator);
Invariant.Assert(locator.Parts != null, "Locator has null Parts property.");
// If this locator is shorter than matchList, then this can't contain matchList.
#pragma warning suppress 6506 // Invariant.Assert(locator.Parts != null)
if (this.Parts.Count < locator.Parts.Count)
{
return false;
}
for (int locatorPartIndex = 0; locatorPartIndex < locator.Parts.Count; locatorPartIndex++)
{
ContentLocatorPart left = locator.Parts[locatorPartIndex];
ContentLocatorPart right = this.Parts[locatorPartIndex];
// ContentLocator parts can be null so check for that case here
if (left == null && right != null)
{
return false;
}
if (!left.Matches(right))
{
return false;
}
}
return true;
}
/// <summary>
/// Creates a deep copy of this list. A new list with a clone of
/// every ContentLocatorPart in this list, in the same order, is returned.
/// Never returns null.
/// </summary>
/// <returns>a deep copy of this list</returns>
public override Object Clone()
{
ContentLocator clone = new ContentLocator();
ContentLocatorPart newPart = null;
foreach (ContentLocatorPart part in this.Parts)
{
if (part != null)
newPart = (ContentLocatorPart)part.Clone();
else
newPart = null;
clone.Parts.Add(newPart);
}
return clone;
}
#region IXmlSerializable Implementation
/// <summary>
/// Returns the null. The annotations schema can be found at
/// http://schemas.microsoft.com/windows/annotations/2003/11/core.
/// </summary>
public XmlSchema GetSchema()
{
return null;
}
/// <summary>
/// Writes the internal data for this ContentLocator to the writer. This
/// method is used by an XmlSerializer to serialize a ContentLocator. Don't
/// use this method directly, to serialize a ContentLocator to Xml, use an
/// XmlSerializer.
/// </summary>
/// <param name="writer">the writer to write internal data to</param>
/// <exception cref="ArgumentNullException">writer is null</exception>
public void WriteXml(XmlWriter writer)
{
ArgumentNullException.ThrowIfNull(writer);
string prefix = writer.LookupPrefix(AnnotationXmlConstants.Namespaces.CoreSchemaNamespace);
if (prefix == null)
{
writer.WriteAttributeString(AnnotationXmlConstants.Prefixes.XmlnsPrefix, AnnotationXmlConstants.Prefixes.CoreSchemaPrefix, null, AnnotationXmlConstants.Namespaces.CoreSchemaNamespace);
}
prefix = writer.LookupPrefix(AnnotationXmlConstants.Namespaces.BaseSchemaNamespace);
if (prefix == null)
{
writer.WriteAttributeString(AnnotationXmlConstants.Prefixes.XmlnsPrefix, AnnotationXmlConstants.Prefixes.BaseSchemaPrefix, null, AnnotationXmlConstants.Namespaces.BaseSchemaNamespace);
}
// Write each ContentLocatorPart as its own element
foreach (ContentLocatorPart part in _parts)
{
prefix = writer.LookupPrefix(part.PartType.Namespace);
if (String.IsNullOrEmpty(prefix))
{
prefix = "tmp";
}
// ContentLocatorParts cannot write themselves out becuase the element
// name is based on the part's type. The ContentLocatorPart instance
// has no way (through normal serialization) to change the element
// name it writes out at runtime.
writer.WriteStartElement(prefix, part.PartType.Name, part.PartType.Namespace);
// Each name/value pair for the ContentLocatorPart becomes an attribute
foreach (KeyValuePair<string, string> pair in part.NameValuePairs)
{
writer.WriteStartElement(AnnotationXmlConstants.Elements.Item, AnnotationXmlConstants.Namespaces.CoreSchemaNamespace);
writer.WriteAttributeString(AnnotationXmlConstants.Attributes.ItemName, pair.Key);
writer.WriteAttributeString(AnnotationXmlConstants.Attributes.ItemValue, pair.Value);
writer.WriteEndElement();
}
writer.WriteEndElement();
}
}
/// <summary>
/// Reads the internal data for this ContentLocator from the reader. This
/// method is used by an XmlSerializer to deserialize a ContentLocator. Don't
/// use this method directly, to deserialize a ContentLocator from Xml, use an
/// XmlSerializer.
/// </summary>
/// <param name="reader">the reader to read internal data from</param>
/// <exception cref="ArgumentNullException">reader is null</exception>
public void ReadXml(XmlReader reader)
{
ArgumentNullException.ThrowIfNull(reader);
// We expect no attributes on a "ContentLocator",
// so throw using the name of one of the unexpected attributes
Annotation.CheckForNonNamespaceAttribute(reader, AnnotationXmlConstants.Elements.ContentLocator);
if (!reader.IsEmptyElement)
{
reader.Read(); // Reads the start of the "ContentLocator" element
// ContentLocatorParts cannot write themselves out (see above). They could read
// themselves in but instead of having write code in one place and read
// code somewhere else - we keep it together in this class.
while (!(AnnotationXmlConstants.Elements.ContentLocator == reader.LocalName && XmlNodeType.EndElement == reader.NodeType))
{
if (XmlNodeType.Element != reader.NodeType)
{
throw new XmlException(SR.Format(SR.InvalidXmlContent, AnnotationXmlConstants.Elements.ContentLocator));
}
ContentLocatorPart part = new ContentLocatorPart(new XmlQualifiedName(reader.LocalName, reader.NamespaceURI));
// Read each of the Item elements within the ContentLocatorPart
if (!reader.IsEmptyElement)
{
// We expect no attributes on a locator part tag,
// so throw using the name of one of the unexpected attributes
Annotation.CheckForNonNamespaceAttribute(reader, part.PartType.Name);
reader.Read(); // Read the start of the locator part tag
while (!(XmlNodeType.EndElement == reader.NodeType && part.PartType.Name == reader.LocalName))
{
if (AnnotationXmlConstants.Elements.Item == reader.LocalName && reader.NamespaceURI == AnnotationXmlConstants.Namespaces.CoreSchemaNamespace)
{
string name = null;
string value = null;
while (reader.MoveToNextAttribute())
{
switch (reader.LocalName)
{
case AnnotationXmlConstants.Attributes.ItemName:
name = reader.Value;
break;
case AnnotationXmlConstants.Attributes.ItemValue:
value = reader.Value;
break;
default:
if (!Annotation.IsNamespaceDeclaration(reader))
throw new XmlException(SR.Format(SR.UnexpectedAttribute, reader.LocalName, AnnotationXmlConstants.Elements.Item));
break;
}
}
if (name == null)
{
throw new XmlException(SR.Format(SR.RequiredAttributeMissing, AnnotationXmlConstants.Attributes.ItemName, AnnotationXmlConstants.Elements.Item));
}
if (value == null)
{
throw new XmlException(SR.Format(SR.RequiredAttributeMissing, AnnotationXmlConstants.Attributes.ItemValue, AnnotationXmlConstants.Elements.Item));
}
reader.MoveToContent();
part.NameValuePairs.Add(name, value);
bool isEmpty = reader.IsEmptyElement;
reader.Read(); // Read the beginning of the complete Item tag
if (!isEmpty)
{
if (!(XmlNodeType.EndElement == reader.NodeType && AnnotationXmlConstants.Elements.Item == reader.LocalName))
{
// Should not contain any content, only attributes
throw new XmlException(SR.Format(SR.InvalidXmlContent, AnnotationXmlConstants.Elements.Item));
}
else
{
reader.Read(); // Read the end of the Item tag
}
}
}
else
{
// The locator part contains data other than just "Item" tags
throw new XmlException(SR.Format(SR.InvalidXmlContent, part.PartType.Name));
}
}
}
_parts.Add(part);
reader.Read(); // Read the ContentLocatorPart element
}
}
reader.Read(); // Reads the end of the "ContentLocator" element (or whole element if empty)
}
#endregion IXmlSerializable Implementation
#endregion Public Methods
//------------------------------------------------------
//
// Public Operators
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
#region Public Properties
/// <summary>
///
/// </summary>
public Collection<ContentLocatorPart> Parts
{
get
{
return _parts;
}
}
#endregion Public Properties
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region InternalMethods
/// <summary>
/// Creates the dot product of this ContentLocator and the list of
/// ContentLocatorParts. The result is n Locators where n is the number of
/// ContentLocatorParts passed in.
/// One of the resulting Locators is this ContentLocator. If there are no
/// additional ContentLocatorParts a list with just this ContentLocator (unmodified)
/// is returned.
/// </summary>
/// <param name="additionalLocatorParts">array of ContentLocatorParts</param>
/// <returns>array of Locators (one for each additional ContentLocatorPart)</returns>
internal IList<ContentLocatorBase> DotProduct(IList<ContentLocatorPart> additionalLocatorParts)
{
List<ContentLocatorBase> results = null;
// If there aren't any additional locator parts - this is basically a no-op
if (additionalLocatorParts == null || additionalLocatorParts.Count == 0)
{
results = new List<ContentLocatorBase>(1);
results.Add(this);
}
else
{
results = new List<ContentLocatorBase>(additionalLocatorParts.Count);
for (int i = 1; i < additionalLocatorParts.Count; i++)
{
ContentLocator loc = (ContentLocator)this.Clone();
loc.Parts.Add(additionalLocatorParts[i]);
results.Add(loc);
}
this.Parts.Add(additionalLocatorParts[0]);
results.Insert(0, this);
}
return results;
}
/// <summary>
/// Merges this ContentLocator with a ContentLocatorBase. If other is a
/// ContentLocatorGroup, each of its Locators are added to clones of
/// this ContentLocatorBase and are added to a new ContentLocatorGroup which is
/// returned. If other is a ContentLocatorBase, its appended to this
/// ContentLocatorBase and this ContentLocatorBase is returned.
/// Both operation modify this ContentLocatorBase.
/// </summary>
/// <param name="other">the ContentLocatorBase to merge with</param>
/// <returns>a ContentLocatorBase containing the final merged product</returns>
internal override ContentLocatorBase Merge(ContentLocatorBase other)
{
if (other == null)
return this;
ContentLocatorGroup locatorGroup = other as ContentLocatorGroup;
if (locatorGroup != null)
{
ContentLocatorGroup newGroup = new ContentLocatorGroup();
ContentLocator temp = null;
// Create n-1 clones of this LPS and append all but one
// LPSs in the set to the clones, adding the clones to a
// new ContentLocatorGroup
foreach (ContentLocator loc in locatorGroup.Locators)
{
if (temp == null)
{
temp = loc;
}
else
{
ContentLocator clone = (ContentLocator)this.Clone();
clone.Append(loc);
newGroup.Locators.Add(clone);
}
}
// Finally, add the remaining LPS in the set to this LPS
// and add this to the new ContentLocatorGroup
if (temp != null)
{
this.Append(temp);
newGroup.Locators.Add(this);
}
if (newGroup.Locators.Count == 0)
return this;
else
return newGroup;
}
else
{
// Safe cast - ContentLocator only has two subclasses
this.Append((ContentLocator)other);
return this;
}
}
/// <summary>
/// Appends a ContentLocator to this ContentLocator. The passed in
/// ContentLocator is not modified in anyway. Its ContentLocatorParts are cloned.
/// </summary>
/// <param name="other">locator to append</param>
internal void Append(ContentLocator other)
{
Invariant.Assert(other != null, "Parameter 'other' is null.");
foreach(ContentLocatorPart part in other.Parts)
{
this.Parts.Add((ContentLocatorPart)part.Clone());
}
}
#endregion Internal Methods
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
/// <summary>
/// Listens for change events from the list of parts. Fires a change event
/// for this ContentLocator when an event is received.
/// </summary>
private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
FireLocatorChanged("Parts");
}
#endregion Private Methods
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
/// <summary>
/// List of ContentLocatorParts in this locator.
/// </summary>
private AnnotationObservableCollection<ContentLocatorPart> _parts;
#endregion Private Fields
}
}
|