source: branches/RemoveBackwardsCompatibility/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Formatter/FormattingChanges.cs

//
// CSharpFormatter.cs
//
// Author:
//       Mike KrÃŒger <mkrueger@xamarin.com>
//
// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
//
// 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 ICSharpCode.NRefactory.Editor;
using System.Threading;
using System.Linq;
using ICSharpCode.NRefactory.CSharp.Refactoring;
using ICSharpCode.NRefactory.TypeSystem;
using System.Collections.Generic;

namespace ICSharpCode.NRefactory.CSharp
{
  /// <summary>
  /// The formatting changes are used to format a specific region inside a document and apply a minimal formatting
  /// changeset to a given document. This is useful for a text editor environment.
  /// </summary>
  public class FormattingChanges
  {
    readonly IDocument document;
    readonly internal List<TextReplaceAction> changes = new List<TextReplaceAction> ();

    internal FormattingChanges (IDocument document)
    {
      if (document == null)
        throw new ArgumentNullException("document");
      this.document = document;
    }

    public int Count {
      get {
        return changes.Count;
      }
    }

    /// <summary>
    /// Applies the changes to the input document.
    /// </summary>
    public void ApplyChanges()
    {
      ApplyChanges(0, document.TextLength, document.Replace, (o, l, v) => document.GetText(o, l) == v);
    }

    public void ApplyChanges(int startOffset, int length)
    {
      ApplyChanges(startOffset, length, document.Replace, (o, l, v) => document.GetText(o, l) == v);
    }

    /// <summary>
    /// Applies the changes to the given Script instance.
    /// </summary>
    public void ApplyChanges(Script script)
    {
      ApplyChanges(0, document.TextLength, script.Replace);
    }

    public void ApplyChanges(int startOffset, int length, Script script)
    {
      ApplyChanges(startOffset, length, script.Replace);
    }

    public void ApplyChanges(int startOffset, int length, Action<int, int, string> documentReplace, Func<int, int, string, bool> filter = null)
    {
      int endOffset = startOffset + length;
      //      Console.WriteLine ("apply:"+ startOffset + "->" + endOffset);
      //      Console.WriteLine (document.Text.Substring (0, startOffset) + new string ('x',length) + document.Text.Substring (startOffset+ length));

      TextReplaceAction previousChange = null;
      int delta = 0;
      var depChanges = new List<TextReplaceAction> ();
      foreach (var change in changes.OrderBy(c => c.Offset)) {
        if (previousChange != null) {
          if (change.Equals(previousChange)) {
            // ignore duplicate changes
            continue;
          }
          if (change.Offset < previousChange.Offset + previousChange.RemovalLength) {
            throw new InvalidOperationException ("Detected overlapping changes " + change + "/" + previousChange);
          }
        }
        previousChange = change;
        bool skipChange = change.Offset + change.RemovalLength < startOffset || change.Offset > endOffset;
        skipChange |= filter != null && filter(change.Offset + delta, change.RemovalLength, change.NewText);
        skipChange &= !depChanges.Contains(change);
        if (!skipChange) {
          documentReplace(change.Offset + delta, change.RemovalLength, change.NewText);
          delta += change.NewText.Length - change.RemovalLength;
          if (change.DependsOn != null) {
            depChanges.Add(change.DependsOn);
          }
        }
      }
      changes.Clear();
    }

    internal TextReplaceAction AddChange(int offset, int removedChars, string insertedText)
    {
      if (offset < 0)
        throw new ArgumentOutOfRangeException("offset", "Should be >= 0");
      if (offset >= document.TextLength)
        throw new ArgumentOutOfRangeException("offset", "Should be < document.TextLength");
      if (removedChars < 0)
        throw new ArgumentOutOfRangeException("removedChars", "Should be >= 0");
      if (removedChars > offset + document.TextLength)
        throw new ArgumentOutOfRangeException("removedChars", "Tried to remove beyond end of text");
      if (removedChars == 0 && string.IsNullOrEmpty (insertedText))
        return null;
      var action = new TextReplaceAction (offset, removedChars, insertedText);
      changes.Add(action);
      return action;
    }
    
    internal sealed class TextReplaceAction
    {
      internal readonly int Offset;
      internal readonly int RemovalLength;
      internal readonly string NewText;
      internal TextReplaceAction DependsOn;

      public TextReplaceAction (int offset, int removalLength, string newText)
      {
        this.Offset = offset;
        this.RemovalLength = removalLength;
        this.NewText = newText ?? string.Empty;
      }

      public override bool Equals(object obj)
      {
        TextReplaceAction other = obj as TextReplaceAction;
        if (other == null) {
          return false;
        }
        return this.Offset == other.Offset && this.RemovalLength == other.RemovalLength && this.NewText == other.NewText;
      }

      public override int GetHashCode()
      {
        return 0;
      }

      public override string ToString()
      {
        return string.Format("[TextReplaceAction: Offset={0}, RemovalLength={1}, NewText={2}]", Offset, RemovalLength, NewText);
      }
    }
  }
}