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// 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.
//
// Description:
// ContentLocatorPart represents a set of name/value pairs that identify a
// piece of data within a certain context. The names and values are
// strings.
//
// Spec: Simplifying Store Cache Model.doc
//
using System.ComponentModel;
using System.Globalization;
using System.Xml;
using MS.Internal.Annotations;
using MS.Internal.Annotations.Anchoring;
namespace System.Windows.Annotations
{
/// <summary>
/// ContentLocatorPart represents a set of name/value pairs that identify a
/// piece of data within a certain context. The names and values are
/// all strings.
/// </summary>
public sealed class ContentLocatorPart : INotifyPropertyChanged2, IOwnedObject
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
/// <summary>
/// Creates a ContentLocatorPart with the specified type name and namespace.
/// </summary>
/// <param name="partType">fully qualified locator part's type</param>
/// <exception cref="ArgumentNullException">partType is null</exception>
/// <exception cref="ArgumentException">partType.Namespace or partType.Name is null or empty string</exception>
public ContentLocatorPart(XmlQualifiedName partType)
{
ArgumentNullException.ThrowIfNull(partType);
if (String.IsNullOrEmpty(partType.Name))
{
throw new ArgumentException(SR.TypeNameMustBeSpecified, "partType.Name");
}
if (String.IsNullOrEmpty(partType.Namespace))
{
throw new ArgumentException(SR.TypeNameMustBeSpecified, "partType.Namespace");
}
_type = partType;
_nameValues = new ObservableDictionary();
_nameValues.PropertyChanged += OnPropertyChanged;
}
#endregion Constructors
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Compares two ContentLocatorParts for equality. They are equal if they
/// contain the same set of name/value pairs.
/// </summary>
/// <param name="obj">second locator part</param>
/// <returns>true - the ContentLocatorParts are equal, false - different</returns>
public override bool Equals(object obj)
{
ContentLocatorPart part = obj as ContentLocatorPart;
string otherValue;
// We are equal to ourselves
if (part == this)
{
return true;
}
// Not a locator part
if (part == null)
{
return false;
}
// Have different type names
if (!_type.Equals(part.PartType))
{
return false;
}
// Have different number of name/value pairs
if (part.NameValuePairs.Count != _nameValues.Count)
{
return false;
}
foreach (KeyValuePair<string, string> k_v in _nameValues)
{
// A name/value pair isn't present or has a different value
if (!part._nameValues.TryGetValue(k_v.Key, out otherValue))
{
return false;
}
if (k_v.Value != otherValue)
{
return false;
}
}
return true;
}
/// <summary>
/// Returns the hashcode for this ContentLocatorPart.
/// </summary>
/// <returns>hashcode</returns>
public override int GetHashCode()
{
return base.GetHashCode();
}
/// <summary>
/// Create a deep clone of this ContentLocatorPart. The returned ContentLocatorPart
/// is equal to this ContentLocatorPart.
/// </summary>
/// <returns>a deep clone of this ContentLocatorPart; never returns null</returns>
public object Clone()
{
ContentLocatorPart newPart = new ContentLocatorPart(_type);
foreach (KeyValuePair<string, string> k_v in _nameValues)
{
newPart.NameValuePairs.Add(k_v.Key, k_v.Value);
}
return newPart;
}
#endregion Public Methods
//------------------------------------------------------
//
// Public Operators
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
#region Public Properties
/// <summary>
///
/// </summary>
public IDictionary<string, string> NameValuePairs
{
get
{
return _nameValues;
}
}
/// <summary>
/// Returns the ContentLocatorPart's type name.
/// </summary>
/// <value>qualified type name for this ContentLocatorPart</value>
public XmlQualifiedName PartType
{
get
{
return _type;
}
}
#endregion Public Properties
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
#region Public Events
/// <summary>
///
/// </summary>
event PropertyChangedEventHandler INotifyPropertyChanged.PropertyChanged
{
add{ _propertyChanged += value; }
remove{ _propertyChanged -= value; }
}
#endregion Public Events
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
/// <summary>
/// Determines if a locator part matches this locator part. Matches is
/// different from equals because a locator part may be defined to match
/// a range of locator parts, not just exact replicas.
/// </summary>
internal bool Matches(ContentLocatorPart part)
{
bool overlaps = false;
string overlapsString;
_nameValues.TryGetValue(TextSelectionProcessor.IncludeOverlaps, out overlapsString);
// If IncludeOverlaps is true, a match is any locator part
// whose range overlaps with ours
if (Boolean.TryParse(overlapsString, out overlaps) && overlaps)
{
// We match ourselves
if (part == this)
{
return true;
}
// Have different type names
if (!_type.Equals(part.PartType))
{
return false;
}
int desiredStartOffset;
int desiredEndOffset;
TextSelectionProcessor.GetMaxMinLocatorPartValues(this, out desiredStartOffset, out desiredEndOffset);
int startOffset;
int endOffset;
TextSelectionProcessor.GetMaxMinLocatorPartValues(part, out startOffset, out endOffset);
// Take care of an exact match to us (which may include offset==MinValue
// which we don't want to handle with the formula below.
if (desiredStartOffset == startOffset && desiredEndOffset == endOffset)
{
return true;
}
// Take care of the special case of no content to match to
if (desiredStartOffset == int.MinValue)
{
return false;
}
if ((startOffset >= desiredStartOffset && startOffset <= desiredEndOffset)
|| (startOffset < desiredStartOffset && endOffset >= desiredStartOffset))
{
return true;
}
return false;
}
return this.Equals(part);
}
/// <summary>
/// Produces an XPath fragment that selects for matches to this ContentLocatorPart.
/// </summary>
/// <param name="namespaceManager">namespace manager used to look up prefixes</param>
/// <returns>an XPath fragment that selects for matches to this ContentLocatorPart</returns>
internal string GetQueryFragment(XmlNamespaceManager namespaceManager)
{
bool overlaps = false;
string overlapsString;
_nameValues.TryGetValue(TextSelectionProcessor.IncludeOverlaps, out overlapsString);
if (Boolean.TryParse(overlapsString, out overlaps) && overlaps)
{
return GetOverlapQueryFragment(namespaceManager);
}
else
{
return GetExactQueryFragment(namespaceManager);
}
}
#endregion Internal Methods
//------------------------------------------------------
//
// Internal Operators
//
//------------------------------------------------------
//------------------------------------------------------
//
// Internal Properties
//
//------------------------------------------------------
#region Internal Properties
/// <summary>
/// </summary>
bool IOwnedObject.Owned
{
get
{
return _owned;
}
set
{
_owned = value;
}
}
#endregion Internal Properties
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
/// <summary>
/// Notify the owner this ContentLocatorPart has changed.
/// </summary>
private void OnPropertyChanged(Object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
if (_propertyChanged != null)
{
_propertyChanged(this, new System.ComponentModel.PropertyChangedEventArgs("NameValuePairs"));
}
}
/// <summary>
/// Produces an XPath fragment that selects for ContentLocatorParts with an anchor that
/// intersects with the range specified by this ContentLocatorPart.
/// </summary>
/// <param name="namespaceManager">namespace manager used to look up prefixes</param>
private string GetOverlapQueryFragment(XmlNamespaceManager namespaceManager)
{
string corePrefix = namespaceManager.LookupPrefix(AnnotationXmlConstants.Namespaces.CoreSchemaNamespace);
string prefix = namespaceManager.LookupPrefix(this.PartType.Namespace);
string res = prefix == null ? "" : (prefix + ":");
res += $"{TextSelectionProcessor.CharacterRangeElementName.Name}/{corePrefix}:{AnnotationXmlConstants.Elements.Item}";
int startOffset;
int endOffset;
TextSelectionProcessor.GetMaxMinLocatorPartValues(this, out startOffset, out endOffset);
string startStr = startOffset.ToString(NumberFormatInfo.InvariantInfo);
string endStr = endOffset.ToString(NumberFormatInfo.InvariantInfo);
// Note: this will never match if offsetStr == 0. Which makes sense - there
// is no content to get anchors for.
res += $"[starts-with(@{AnnotationXmlConstants.Attributes.ItemName}, \"{TextSelectionProcessor.SegmentAttribute}\") and ((substring-before(@{AnnotationXmlConstants.Attributes.ItemValue},\",\") >= {startStr} and substring-before(@{AnnotationXmlConstants.Attributes.ItemValue},\",\") <= {endStr}) or (substring-before(@{AnnotationXmlConstants.Attributes.ItemValue},\",\") < {startStr} and substring-after(@{AnnotationXmlConstants.Attributes.ItemValue},\",\") >= {startStr}))]";
return res;
}
/// <summary>
/// Produces an XPath fragment that selects ContentLocatorParts of the same type
/// and containing the exact name/values this ContentLocatorPart contains.
/// </summary>
/// <param name="namespaceManager">namespaceManager used to generate the XPath fragment</param>
private string GetExactQueryFragment(XmlNamespaceManager namespaceManager)
{
string corePrefix = namespaceManager.LookupPrefix(AnnotationXmlConstants.Namespaces.CoreSchemaNamespace);
string prefix = namespaceManager.LookupPrefix(this.PartType.Namespace);
string res = prefix == null ? "" : (prefix + ":");
res += this.PartType.Name;
bool and = false;
foreach (KeyValuePair<string, string> k_v in ((ICollection<KeyValuePair<string, string>>)this.NameValuePairs))
{
if (and)
{
res += $"/parent::*/{corePrefix}:{AnnotationXmlConstants.Elements.Item}[";
}
else
{
and = true;
res += $"/{corePrefix}:{AnnotationXmlConstants.Elements.Item}[";
}
res += $"@{AnnotationXmlConstants.Attributes.ItemName}=\"{k_v.Key}\" and @{AnnotationXmlConstants.Attributes.ItemValue}=\"{k_v.Value}\"]";
}
if (and)
{
res += "/parent::*";
}
return res;
}
#endregion Private Methods
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
/// <summary>
/// </summary>
private bool _owned;
/// <summary>
/// The ContentLocatorPart's type name.
/// </summary>
private XmlQualifiedName _type;
/// <summary>
/// The internal data structure.
/// </summary>
private ObservableDictionary _nameValues;
///
private event PropertyChangedEventHandler _propertyChanged;
#endregion Private Fields
}
}
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