source: branches/WebJobManager/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/Editor/StringBuilderDocument.cs

// Copyright (c) 2010-2013 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.IO;
using System.Text;
using ICSharpCode.NRefactory.Utils;

namespace ICSharpCode.NRefactory.Editor
{
  /// <summary>
  /// Document based on a string builder.
  /// This class serves as a reference implementation for the IDocument interface.
  /// </summary>
  public class StringBuilderDocument : IDocument
  {
    readonly StringBuilder b;
    readonly TextSourceVersionProvider versionProvider = new TextSourceVersionProvider();
    
    /// <summary>
    /// Creates a new StringBuilderDocument.
    /// </summary>
    public StringBuilderDocument()
    {
      b = new StringBuilder();
    }
    
    /// <summary>
    /// Creates a new StringBuilderDocument with the specified initial text.
    /// </summary>
    public StringBuilderDocument(string text)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      b = new StringBuilder(text);
    }
    
    /// <summary>
    /// Creates a new StringBuilderDocument with the initial text copied from the specified text source.
    /// </summary>
    public StringBuilderDocument(ITextSource textSource)
    {
      if (textSource == null)
        throw new ArgumentNullException("textSource");
      b = new StringBuilder(textSource.TextLength);
      textSource.WriteTextTo(new StringWriter(b));
    }
    
    /// <inheritdoc/>
    public event EventHandler<TextChangeEventArgs> TextChanging;
    
    /// <inheritdoc/>
    public event EventHandler<TextChangeEventArgs> TextChanged;
    
    /// <inheritdoc/>
    public event EventHandler ChangeCompleted;
    
    /// <inheritdoc/>
    public ITextSourceVersion Version {
      get { return versionProvider.CurrentVersion; }
    }
    
    #region Line<->Offset
    /// <inheritdoc/>
    public int LineCount {
      get { return CreateDocumentSnapshot().LineCount; }
    }
    
    /// <inheritdoc/>
    public IDocumentLine GetLineByNumber(int lineNumber)
    {
      return CreateDocumentSnapshot().GetLineByNumber(lineNumber);
    }
    
    /// <inheritdoc/>
    public IDocumentLine GetLineByOffset(int offset)
    {
      return CreateDocumentSnapshot().GetLineByOffset(offset);
    }
    
    /// <inheritdoc/>
    public int GetOffset(int line, int column)
    {
      return CreateDocumentSnapshot().GetOffset(line, column);
    }
    
    /// <inheritdoc/>
    public int GetOffset(TextLocation location)
    {
      return CreateDocumentSnapshot().GetOffset(location);
    }
    
    /// <inheritdoc/>
    public TextLocation GetLocation(int offset)
    {
      return CreateDocumentSnapshot().GetLocation(offset);
    }
    #endregion
    
    #region Insert/Remove/Replace
    /// <inheritdoc/>
    public void Insert(int offset, string text)
    {
      Replace(offset, 0, text);
    }
    
    /// <inheritdoc/>
    public void Insert(int offset, ITextSource text)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      Replace(offset, 0, text.Text);
    }
    
    /// <inheritdoc/>
    public void Insert(int offset, string text, AnchorMovementType defaultAnchorMovementType)
    {
      if (offset < 0 || offset > this.TextLength)
        throw new ArgumentOutOfRangeException("offset");
      if (text == null)
        throw new ArgumentNullException("text");
      if (defaultAnchorMovementType == AnchorMovementType.BeforeInsertion)
        PerformChange(new InsertionWithMovementBefore(offset, text));
      else
        Replace(offset, 0, text);
    }
    
    /// <inheritdoc/>
    public void Insert(int offset, ITextSource text, AnchorMovementType defaultAnchorMovementType)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      Insert(offset, text.Text, defaultAnchorMovementType);
    }
    
    [Serializable]
    sealed class InsertionWithMovementBefore : TextChangeEventArgs
    {
      public InsertionWithMovementBefore(int offset, string newText) : base(offset, string.Empty, newText)
      {
      }
      
      public override int GetNewOffset(int offset, AnchorMovementType movementType)
      {
        if (offset == this.Offset && movementType == AnchorMovementType.Default)
          return offset;
        else
          return base.GetNewOffset(offset, movementType);
      }
    }
    
    /// <inheritdoc/>
    public void Remove(int offset, int length)
    {
      Replace(offset, length, string.Empty);
    }
    
    /// <inheritdoc/>
    public void Replace(int offset, int length, string newText)
    {
      if (offset < 0 || offset > this.TextLength)
        throw new ArgumentOutOfRangeException("offset");
      if (length < 0 || length > this.TextLength - offset)
        throw new ArgumentOutOfRangeException("length");
      if (newText == null)
        throw new ArgumentNullException("newText");
      PerformChange(new TextChangeEventArgs(offset, b.ToString(offset, length), newText));
    }
    
    /// <inheritdoc/>
    public void Replace(int offset, int length, ITextSource newText)
    {
      if (newText == null)
        throw new ArgumentNullException("newText");
      Replace(offset, length, newText.Text);
    }
    
    bool isInChange;
    
    void PerformChange(TextChangeEventArgs change)
    {
      // Ensure that all changes take place inside an update group.
      // Will also take care of throwing an exception if isInChange is set.
      StartUndoableAction();
      try {
        isInChange = true;
        try {
          if (TextChanging != null)
            TextChanging(this, change);
          
          // Perform changes to document and Version property
          documentSnapshot = null;
          cachedText = null;
          b.Remove(change.Offset, change.RemovalLength);
          b.Insert(change.Offset, change.InsertedText.Text);
          versionProvider.AppendChange(change);
          
          // Update anchors and fire Deleted events
          UpdateAnchors(change);
          
          if (TextChanged != null)
            TextChanged(this, change);
        } finally {
          isInChange = false;
        }
      } finally {
        EndUndoableAction();
      }
    }
    #endregion
    
    #region Undo
    int undoGroupNesting = 0;
    
    /// <inheritdoc/>
    public void StartUndoableAction()
    {
      // prevent changes from within the TextChanging/TextChanged event handlers
      if (isInChange)
        throw new InvalidOperationException();
      undoGroupNesting++;
    }
    
    /// <inheritdoc/>
    public void EndUndoableAction()
    {
      undoGroupNesting--;
      if (undoGroupNesting == 0) {
        if (ChangeCompleted != null)
          ChangeCompleted(this, EventArgs.Empty);
      }
    }
    
    /// <inheritdoc/>
    public IDisposable OpenUndoGroup()
    {
      StartUndoableAction();
      return new CallbackOnDispose(EndUndoableAction);
    }
    #endregion
    
    #region CreateSnapshot/CreateReader
    ReadOnlyDocument documentSnapshot;
    
    /// <inheritdoc/>
    public IDocument CreateDocumentSnapshot()
    {
      if (documentSnapshot == null)
        documentSnapshot = new ReadOnlyDocument(this, this.FileName);
      return documentSnapshot;
    }
    
    /// <inheritdoc/>
    public ITextSource CreateSnapshot()
    {
      return new StringTextSource(this.Text, versionProvider.CurrentVersion);
    }
    
    /// <inheritdoc/>
    public ITextSource CreateSnapshot(int offset, int length)
    {
      return new StringTextSource(GetText(offset, length));
    }
    
    /// <inheritdoc/>
    public TextReader CreateReader()
    {
      return new StringReader(this.Text);
    }
    
    /// <inheritdoc/>
    public TextReader CreateReader(int offset, int length)
    {
      return new StringReader(GetText(offset, length));
    }
    
    /// <inheritdoc/>
    public void WriteTextTo(TextWriter writer)
    {
      if (writer == null)
        throw new ArgumentNullException("writer");
      writer.Write(this.Text);
    }
    
    /// <inheritdoc/>
    public void WriteTextTo(TextWriter writer, int offset, int length)
    {
      if (writer == null)
        throw new ArgumentNullException("writer");
      writer.Write(GetText(offset, length));
    }
    #endregion
    
    #region GetText / IndexOf
    string cachedText;
    
    /// <inheritdoc/>
    public string Text {
      get {
        if (cachedText == null)
          cachedText = b.ToString();
        return cachedText;
      }
      set {
        Replace(0, b.Length, value);
      }
    }
    
    /// <inheritdoc/>
    public int TextLength {
      get { return b.Length; }
    }
    
    /// <inheritdoc/>
    public char GetCharAt(int offset)
    {
      return b[offset];
    }
    
    /// <inheritdoc/>
    public string GetText(int offset, int length)
    {
      return b.ToString(offset, length);
    }
    
    /// <inheritdoc/>
    public string GetText(ISegment segment)
    {
      if (segment == null)
        throw new ArgumentNullException("segment");
      return b.ToString(segment.Offset, segment.Length);
    }
    
    /// <inheritdoc/>
    public int IndexOf(char c, int startIndex, int count)
    {
      return this.Text.IndexOf(c, startIndex, count);
    }
    
    /// <inheritdoc/>
    public int IndexOfAny(char[] anyOf, int startIndex, int count)
    {
      return this.Text.IndexOfAny(anyOf, startIndex, count);
    }
    
    /// <inheritdoc/>
    public int IndexOf(string searchText, int startIndex, int count, StringComparison comparisonType)
    {
      return this.Text.IndexOf(searchText, startIndex, count, comparisonType);
    }
    
    /// <inheritdoc/>
    public int LastIndexOf(char c, int startIndex, int count)
    {
      return this.Text.LastIndexOf(c, startIndex + count - 1, count);
    }
    
    /// <inheritdoc/>
    public int LastIndexOf(string searchText, int startIndex, int count, StringComparison comparisonType)
    {
      return this.Text.LastIndexOf(searchText, startIndex + count - 1, count, comparisonType);
    }
    #endregion
    
    #region CreateAnchor
    readonly List<WeakReference> anchors = new List<WeakReference>();
    
    /// <inheritdoc/>
    public ITextAnchor CreateAnchor(int offset)
    {
      var newAnchor = new SimpleAnchor(this, offset);
      for (int i = 0; i < anchors.Count; i++) {
        if (!anchors[i].IsAlive)
          anchors[i] = new WeakReference(newAnchor);
      }
      anchors.Add(new WeakReference(newAnchor));
      return newAnchor;
    }
    
    void UpdateAnchors(TextChangeEventArgs change)
    {
      // First update all anchors, then fire the deleted events.
      List<int> deletedAnchors = new List<int>();
      for (int i = 0; i < anchors.Count; i++) {
        var anchor = anchors[i].Target as SimpleAnchor;
        if (anchor != null) {
          anchor.Update(change);
          if (anchor.IsDeleted)
            deletedAnchors.Add(i);
        }
      }
      deletedAnchors.Reverse();
      foreach (var index in deletedAnchors) {
        var anchor = anchors[index].Target as SimpleAnchor;
        if (anchor != null)
          anchor.RaiseDeletedEvent();
        anchors.RemoveAt(index);
      }
    }
    
    sealed class SimpleAnchor : ITextAnchor
    {
      readonly StringBuilderDocument document;
      int offset;
      
      public SimpleAnchor(StringBuilderDocument document, int offset)
      {
        this.document = document;
        this.offset = offset;
      }
      
      public event EventHandler Deleted;
      
      public TextLocation Location {
        get {
          if (IsDeleted)
            throw new InvalidOperationException();
          return document.GetLocation(offset);
        }
      }
      
      public int Offset {
        get {
          if (IsDeleted)
            throw new InvalidOperationException();
          return offset;
        }
      }
      
      public AnchorMovementType MovementType { get; set; }
      
      public bool SurviveDeletion { get; set; }
      
      public bool IsDeleted {
        get { return offset < 0; }
      }
      
      public void Update(TextChangeEventArgs change)
      {
        if (SurviveDeletion || offset <= change.Offset || offset >= change.Offset + change.RemovalLength) {
          offset = change.GetNewOffset(offset, MovementType);
        } else {
          offset = -1;
        }
      }
      
      public void RaiseDeletedEvent()
      {
        if (Deleted != null)
          Deleted(this, EventArgs.Empty);
      }
      
      public int Line {
        get { return this.Location.Line; }
      }
      
      public int Column {
        get { return this.Location.Column; }
      }
    }
    #endregion
    
    /// <inheritdoc/>
    public virtual object GetService(Type serviceType)
    {
      return null;
    }
    
    /// <inheritdoc/>
    public virtual event EventHandler FileNameChanged { add {} remove {} }
    
    /// <inheritdoc/>
    public virtual string FileName {
      get { return string.Empty; }
    }
  }
}