source: branches/ContextAlgorithms/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.Xml-5.5.0/AXmlReader.cs @ 15624

// Copyright (c) 2009-2013 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using ICSharpCode.NRefactory.Editor;

namespace ICSharpCode.NRefactory.Xml
{
  /// <summary>
  /// XmlReader implementation that reads from an <see cref="AXmlDocument"/>.
  /// </summary>
  sealed class AXmlReader : XmlReader, IXmlLineInfo
  {
    readonly ObjectIterator objectIterator;
    readonly XmlReaderSettings settings;
    Func<int, TextLocation> offsetToTextLocation;
    readonly XmlNameTable nameTable;
    readonly XmlNamespaceManager nsManager;
    ReadState readState = ReadState.Initial;
    XmlNodeType elementNodeType = XmlNodeType.None;
    IList<InternalAttribute> attributes;
    int attributeIndex = -1;
    bool inAttributeValue;
    
    internal AXmlReader(ObjectIterator objectIterator, XmlReaderSettings settings = null, Func<int, TextLocation> offsetToTextLocation = null)
    {
      this.objectIterator = objectIterator;
      this.settings = settings ?? new XmlReaderSettings();
      this.offsetToTextLocation = offsetToTextLocation;
      this.nameTable = this.settings.NameTable ?? new NameTable();
      this.nsManager = new XmlNamespaceManager(this.nameTable);
      objectIterator.StopAtElementEnd = true;
    }
    
    public override void ResolveEntity()
    {
      throw new NotSupportedException();
    }
    
    public override ReadState ReadState {
      get { return readState; }
    }
    
    public override XmlReaderSettings Settings {
      get { return settings; }
    }
    
    public override bool ReadAttributeValue()
    {
      if (attributeIndex >= 0 && !inAttributeValue) {
        inAttributeValue = true;
        return true;
      }
      return false;
    }
    
    public override bool Read()
    {
      switch (readState) {
        case ReadState.Initial:
          readState = ReadState.Interactive;
          return ReadCurrentPosition();
        case ReadState.Interactive:
          LeaveNode();
          objectIterator.MoveInto();
          return ReadCurrentPosition();
        default:
          return false;
      }
    }
    
    bool ReadCurrentPosition()
    {
      attributes = null;
      attributeIndex = -1;
      inAttributeValue = false;
      while (true) {
        var obj = objectIterator.CurrentObject;
        if (obj == null) {
          readState = ReadState.EndOfFile;
          elementNodeType = XmlNodeType.None;
          return false;
        } else if (objectIterator.IsAtElementEnd) {
          if (IsEmptyElement) {
            // Don't report EndElement for empty elements
            nsManager.PopScope();
          } else {
            elementNodeType = XmlNodeType.EndElement;
            return true;
          }
        } else if (obj is InternalElement) {
          // element start
          elementNodeType = XmlNodeType.Element;
          InternalTag startTag = ((InternalTag)obj.NestedObjects[0]);
          nsManager.PushScope();
          if (startTag.NestedObjects != null) {
            attributes = startTag.NestedObjects.OfType<InternalAttribute>().ToList();
            for (int i = 0; i < attributes.Count; i++) {
              var attr = attributes[i];
              if (attr.Name.StartsWith("xmlns:", StringComparison.Ordinal))
                nsManager.AddNamespace(AXmlObject.GetLocalName(attr.Name), attr.Value);
              else if (attr.Name == "xmlns")
                nsManager.AddNamespace(string.Empty, attr.Value);
            }
          }
          return true;
        } else if (obj is InternalText) {
          InternalText text = (InternalText)obj;
          if (text.ContainsOnlyWhitespace) {
            elementNodeType = XmlNodeType.Whitespace;
          } else {
            elementNodeType = XmlNodeType.Text;
          }
          return true;
        } else if (obj is InternalTag) {
          InternalTag tag = (InternalTag)obj;
          if (tag.IsStartOrEmptyTag || tag.IsEndTag) {
            // start/end tags can be skipped as the parent InternalElement already handles them
          } else if (tag.IsComment && !settings.IgnoreComments) {
            elementNodeType = XmlNodeType.Comment;
            return true;
          } else if (tag.IsProcessingInstruction && !settings.IgnoreProcessingInstructions) {
            if (tag.Name == "xml") {
              elementNodeType = XmlNodeType.XmlDeclaration;
              attributes = tag.NestedObjects.OfType<InternalAttribute>().ToList();
            } else {
              elementNodeType = XmlNodeType.ProcessingInstruction;
            }
            return true;
          } else if (tag.IsCData) {
            elementNodeType = XmlNodeType.CDATA;
            return true;
          } else {
            // TODO all other tags
          }
        } else {
          throw new NotSupportedException();
        }
        objectIterator.MoveInto();
      }
    }
    
    void LeaveNode()
    {
      if (elementNodeType == XmlNodeType.EndElement) {
        nsManager.PopScope();
      }
    }
    
    public override void Skip()
    {
      if (readState == ReadState.Interactive) {
        MoveToElement();
        LeaveNode();
        objectIterator.MoveNext();
        ReadCurrentPosition();
      }
    }
    
    public override string Prefix {
      get {
        if (readState != ReadState.Interactive)
          return string.Empty;
        if (attributeIndex >= 0) {
          if (inAttributeValue)
            return string.Empty;
          return nameTable.Add(AXmlObject.GetNamespacePrefix(attributes[attributeIndex].Name));
        }
        InternalElement element = objectIterator.CurrentObject as InternalElement;
        return element != null ? nameTable.Add(element.Prefix) : string.Empty;
      }
    }
    
    public override string NamespaceURI {
      get {
        if (readState != ReadState.Interactive)
          return string.Empty;
        if (attributeIndex >= 0 && !inAttributeValue && attributes[attributeIndex].Name == "xmlns")
          return AXmlObject.XmlnsNamespace;
        return LookupNamespace(this.Prefix) ?? string.Empty;
      }
    }
    
    public override string LocalName {
      get {
        if (readState != ReadState.Interactive)
          return string.Empty;
        if (attributeIndex >= 0) {
          if (inAttributeValue)
            return string.Empty;
          return nameTable.Add(AXmlObject.GetLocalName(attributes[attributeIndex].Name));
        }
        string result;
        switch (elementNodeType) {
          case XmlNodeType.Element:
          case XmlNodeType.EndElement:
            result = ((InternalElement)objectIterator.CurrentObject).LocalName;
            break;
          case XmlNodeType.XmlDeclaration:
            result = "xml";
            break;
          default:
            return string.Empty;
        }
        return nameTable.Add(result);
      }
    }
    
    public override string Name {
      get {
        if (readState != ReadState.Interactive)
          return string.Empty;
        if (attributeIndex >= 0) {
          if (inAttributeValue)
            return string.Empty;
          return nameTable.Add(attributes[attributeIndex].Name);
        }
        string result;
        switch (elementNodeType) {
          case XmlNodeType.Element:
          case XmlNodeType.EndElement:
            result = ((InternalElement)objectIterator.CurrentObject).Name;
            break;
          case XmlNodeType.XmlDeclaration:
            result = "xml";
            break;
          default:
            return string.Empty;
        }
        return nameTable.Add(result);
      }
    }
    
    public override bool IsEmptyElement {
      get {
        if (readState != ReadState.Interactive || attributeIndex >= 0)
          return false;
        InternalElement element = objectIterator.CurrentObject as InternalElement;
        return element != null && element.NestedObjects.Length == 1;
      }
    }
    
    public override string Value {
      get {
        if (readState != ReadState.Interactive)
          return string.Empty;
        if (attributeIndex >= 0)
          return attributes[attributeIndex].Value;
        switch (elementNodeType) {
          case XmlNodeType.Text:
          case XmlNodeType.Whitespace:
            return ((InternalText)objectIterator.CurrentObject).Value;
          case XmlNodeType.Comment:
          case XmlNodeType.CDATA:
            var nestedObjects = objectIterator.CurrentObject.NestedObjects;
            if (nestedObjects.Length == 1)
              return ((InternalText)nestedObjects[0]).Value;
            else
              return string.Empty;
          case XmlNodeType.XmlDeclaration:
            StringBuilder b = new StringBuilder();
            foreach (var attr in objectIterator.CurrentObject.NestedObjects.OfType<InternalAttribute>()) {
              if (b.Length > 0)
                b.Append(' ');
              b.Append(attr.Name);
              b.Append('=');
              b.Append('"');
              b.Append(attr.Value);
              b.Append('"');
            }
            return b.ToString();
          default:
            return string.Empty;
        }
      }
    }
    
    public override bool HasValue {
      get {
        if (readState != ReadState.Interactive)
          return false;
        if (attributeIndex >= 0)
          return true;
        switch (elementNodeType) {
          case XmlNodeType.Text:
          case XmlNodeType.Whitespace:
          case XmlNodeType.Comment:
          case XmlNodeType.XmlDeclaration:
          case XmlNodeType.CDATA:
            return true;
          default:
            return false;
        }
      }
    }
    
    public override XmlNodeType NodeType {
      get {
        if (attributeIndex >= 0)
          return inAttributeValue ? XmlNodeType.Text : XmlNodeType.Attribute;
        else
          return elementNodeType;
      }
    }
    
    public override XmlNameTable NameTable {
      get { return nameTable; }
    }
    
    public override bool MoveToFirstAttribute()
    {
      return DoMoveToAttribute(0);
    }
    
    public override bool MoveToNextAttribute()
    {
      return DoMoveToAttribute(attributeIndex + 1);
    }
    
    public override void MoveToAttribute(int i)
    {
      if (!DoMoveToAttribute(i))
        throw new ArgumentOutOfRangeException("i");
    }
    
    bool DoMoveToAttribute(int i)
    {
      if (i >= 0 && i < this.AttributeCount) {
        attributeIndex = i;
        inAttributeValue = false;
        return true;
      }
      return false;
    }
    
    public override bool MoveToElement()
    {
      if (attributeIndex >= 0) {
        attributeIndex = -1;
        inAttributeValue = false;
        return true;
      }
      return false;
    }
    
    int GetAttributeIndex(string name)
    {
      if (attributes == null)
        return -1;
      for (int i = 0; i < attributes.Count; i++) {
        if (attributes[i].Name == name)
          return i;
      }
      return -1;
    }
    
    int GetAttributeIndex(string name, string ns)
    {
      if (attributes == null)
        return -1;
      for (int i = 0; i < attributes.Count; i++) {
        if (AXmlObject.GetLocalName(attributes[i].Name) == name && (LookupNamespace(AXmlObject.GetNamespacePrefix(attributes[i].Name)) ?? string.Empty) == ns)
          return i;
      }
      return -1;
    }
    
    public override bool MoveToAttribute(string name, string ns)
    {
      return DoMoveToAttribute(GetAttributeIndex(name, ns));
    }
    
    public override bool MoveToAttribute(string name)
    {
      return DoMoveToAttribute(GetAttributeIndex(name));
    }
    
    public override string LookupNamespace(string prefix)
    {
      return nsManager.LookupNamespace(prefix);
    }
    
    public override string GetAttribute(int i)
    {
      if (attributes == null || i < 0 || i >= attributes.Count)
        return null;
      return attributes[i].Value;
    }
    
    public override string GetAttribute(string name, string namespaceURI)
    {
      return GetAttribute(GetAttributeIndex(name, namespaceURI));
    }
    
    public override string GetAttribute(string name)
    {
      return GetAttribute(GetAttributeIndex(name));
    }
    
    public override bool EOF {
      get { return readState == ReadState.EndOfFile; }
    }
    
    public override int Depth {
      get {
        if (attributeIndex < 0)
          return objectIterator.Depth;
        else
          return objectIterator.Depth + (inAttributeValue ? 2 : 1);
      }
    }
    
    public override void Close()
    {
      readState = ReadState.Closed;
      offsetToTextLocation = null;
    }
    
    public override string BaseURI {
      get { return string.Empty; }
    }
    
    public override int AttributeCount {
      get { return attributes != null ? attributes.Count : 0; }
    }
    
    int CurrentPosition {
      get {
        if (attributeIndex < 0)
          return objectIterator.CurrentPosition;
        else
          return objectIterator.CurrentPosition + attributes[attributeIndex].StartRelativeToParent;
      }
    }
    
    public int LineNumber {
      get {
        if (offsetToTextLocation != null)
          return offsetToTextLocation(CurrentPosition).Line;
        else
          return 0;
      }
    }
    
    public int LinePosition {
      get {
        if (offsetToTextLocation != null)
          return offsetToTextLocation(CurrentPosition).Column - 1;
        else
          return 0;
      }
    }
    
    bool IXmlLineInfo.HasLineInfo()
    {
      return offsetToTextLocation != null;
    }
  }
}