source: trunk/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Formatter/Indent.cs @ 17578

// 
// Indent.cs
//  
// Author:
//       Mike Krüger <mkrueger@novell.com>
// 
// Copyright (c) 2010 Novell, Inc (http://www.novell.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 System.Collections.Generic;
using System.Linq;

namespace ICSharpCode.NRefactory.CSharp
{
  public enum IndentType
  {
    Block,
    DoubleBlock,
    Continuation,
    Alignment,
    Label,
    Empty
  }

  public class Indent
  {
    readonly CloneableStack<IndentType> indentStack = new CloneableStack<IndentType>();
    readonly TextEditorOptions options;
    int curIndent;
    int extraSpaces;
    string indentString;

    public int CurIndent {
      get {
        return curIndent;
      }
    }

    public Indent(TextEditorOptions options)
    {
      this.options = options;
      Reset();
    }

    Indent(Indent engine)
    {
      this.indentStack = engine.indentStack.Clone();
      this.options = engine.options;
      this.curIndent = engine.curIndent;
      this.extraSpaces = engine.extraSpaces;
      this.indentString = engine.indentString;
    }

    public Indent Clone()
    {
      return new Indent(this);
    }

    public void Reset()
    {
      curIndent = 0;
      indentString = "";
      indentStack.Clear();
    }

    public void Push(IndentType type)
    {
      indentStack.Push(type);
      curIndent += GetIndent(type);
      Update();
    }

    public void Push(Indent indent)
    {
      foreach (var i in indent.indentStack)
        Push(i);
    }

    public void Pop()
    {
      curIndent -= GetIndent(indentStack.Pop());
      Update();
    }

    public bool PopIf(IndentType type)
    {
      if (Count > 0 && Peek() == type)
      {
        Pop();
        return true;
      }

      return false;
    }

    public void PopWhile(IndentType type)
    {
      while (Count > 0 && Peek() == type)
      {
        Pop();
      }
    }

    public bool PopTry()
    {
      if (Count > 0)
      {
        Pop();
        return true;
      }

      return false;
    }

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

    public IndentType Peek()
    {
      return indentStack.Peek();
    }

    int GetIndent(IndentType indentType)
    {
      switch (indentType) {
        case IndentType.Block:
          return options.IndentSize;
        case IndentType.DoubleBlock:
          return options.IndentSize * 2;
        case IndentType.Alignment:
        case IndentType.Continuation:
          return options.ContinuationIndent;
        case IndentType.Label:
          return options.LabelIndent;
        case IndentType.Empty:
          return 0;
        default:
          throw new ArgumentOutOfRangeException();
      }
    }

    void Update()
    {
      if (options.TabsToSpaces) {
        indentString = new string(' ', curIndent + ExtraSpaces);
        return;
      }
      indentString = new string('\t', curIndent / options.TabSize) + new string(' ', curIndent % options.TabSize) + new string(' ', ExtraSpaces);
    }

    public int ExtraSpaces {
      get {
        return extraSpaces;
      }
      set {
        if (value < 0)
          throw new ArgumentOutOfRangeException("ExtraSpaces >= 0 but was " + value);
        extraSpaces = value;
        Update();
      }
    }


    public string IndentString {
      get {
        return indentString;
      }
    }

    public override string ToString()
    {
      return string.Format("[Indent: curIndent={0}]", curIndent);
    }

    public Indent GetIndentWithoutSpace ()
    {
      var result = new Indent(options);
      foreach (var i in indentStack)
          result.Push(i);
      return result;
    }

    public static Indent ConvertFrom(string indentString, Indent correctIndent, TextEditorOptions options = null)
    {
      options = options ?? TextEditorOptions.Default;
      var result = new Indent(options);

      var indent = string.Concat(indentString.Where(c => c == ' ' || c == '\t'));
      var indentTypes = new Stack<IndentType>(correctIndent.indentStack);

      foreach (var _ in indent.TakeWhile(c => c == '\t'))
      {
        if (indentTypes.Count > 0)
          result.Push(indentTypes.Pop());
        else
          result.Push(IndentType.Continuation);
      }

      result.ExtraSpaces = indent
        .SkipWhile(c => c == '\t')
        .TakeWhile(c => c == ' ')
        .Count();

      return result;
    }

    public void RemoveAlignment()
    {
      ExtraSpaces = 0;
      if (Count > 0 && Peek() == IndentType.Alignment)
        Pop();
    }

    public void SetAlignment(int i, bool forceSpaces = false)
    {
      var alignChars = Math.Max(0, i);
      if (forceSpaces) {
        ExtraSpaces = alignChars;
        return;
      }
      RemoveAlignment();
      Push(IndentType.Alignment);
    }

  }
}