source: tags/3.3.11/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Completion/ICompletionContextProvider.cs

// 
// IMemberProvider.cs
//  
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
// 
// Copyright (c) 2012 Xamarin Inc.
// 
// 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 ICSharpCode.NRefactory.TypeSystem;
using ICSharpCode.NRefactory.Editor;
using ICSharpCode.NRefactory.CSharp.TypeSystem;
using System.Linq;
using ICSharpCode.NRefactory.CSharp.Resolver;

namespace ICSharpCode.NRefactory.CSharp.Completion
{
  public interface ICompletionContextProvider
  {
    IList<string> ConditionalSymbols {
      get;
    }

    void GetCurrentMembers (int offset, out IUnresolvedTypeDefinition currentType, out IUnresolvedMember currentMember);

    Tuple<string, TextLocation> GetMemberTextToCaret(int caretOffset, IUnresolvedTypeDefinition currentType, IUnresolvedMember currentMember);

    CSharpAstResolver GetResolver (CSharpResolver resolver, AstNode rootNode);
  }

  public class DefaultCompletionContextProvider : ICompletionContextProvider
  {
    readonly IDocument document;
    readonly CSharpUnresolvedFile unresolvedFile;
    readonly List<string> symbols = new List<string> ();

    public IList<string> ConditionalSymbols {
      get {
        return symbols;
      }
    }

    public DefaultCompletionContextProvider (IDocument document, CSharpUnresolvedFile unresolvedFile)
    {
      if (document == null)
        throw new ArgumentNullException("document");
      if (unresolvedFile == null)
        throw new ArgumentNullException("unresolvedFile");
      this.document = document;
      this.unresolvedFile = unresolvedFile;
    }

    public void AddSymbol (string sym)
    {
      symbols.Add (sym);
    }
    public void GetCurrentMembers(int offset, out IUnresolvedTypeDefinition currentType, out IUnresolvedMember currentMember)
    {
      //var document = engine.document;
      var location = document.GetLocation(offset);
      
      currentType = null;
      
      foreach (var type in unresolvedFile.TopLevelTypeDefinitions) {
        if (type.Region.Begin < location)
          currentType = type;
      }
      currentType = FindInnerType (currentType, location);
      
      // location is beyond last reported end region, now we need to check, if the end region changed
      if (currentType != null && currentType.Region.End < location) {
        if (!IsInsideType (currentType, location))
          currentType = null;
      }
      currentMember = null;
      if (currentType != null) {
        foreach (var member in currentType.Members) {
          if (member.Region.Begin < location && (currentMember == null || currentMember.Region.Begin < member.Region.Begin))
            currentMember = member;
        }
      }
      
      // location is beyond last reported end region, now we need to check, if the end region changed
      // NOTE: Enums are a special case, there the "last" field needs to be treated as current member
      if (currentMember != null && currentMember.Region.End < location && currentType.Kind != TypeKind.Enum) {
        if (!IsInsideType (currentMember, location))
          currentMember = null;
      }/*
      var stack = GetBracketStack (engine.GetMemberTextToCaret ().Item1);
      if (stack.Count == 0)
        currentMember = null;*/
    }

    IUnresolvedTypeDefinition FindInnerType (IUnresolvedTypeDefinition parent, TextLocation location)
    {
      if (parent == null)
        return null;
      var currentType = parent;
      foreach (var type in parent.NestedTypes) {
        if (type.Region.Begin < location  && location < type.Region.End)
          currentType = FindInnerType (type, location);
      }
      
      return currentType;
    }
    
    bool IsInsideType (IUnresolvedEntity currentType, TextLocation location)
    {
      if (currentType.Region.IsEmpty)
        return false;
      int startOffset = document.GetOffset (currentType.Region.Begin);
      int endOffset = document.GetOffset (location);
      //bool foundEndBracket = false;
    
      var bracketStack = new Stack<char> ();
    
      bool isInString = false, isInChar = false;
      bool isInLineComment = false, isInBlockComment = false;
      
      for (int i = startOffset; i < endOffset; i++) {
        char ch = document.GetCharAt (i);
        switch (ch) {
          case '(':
          case '[':
          case '{':
            if (!isInString && !isInChar && !isInLineComment && !isInBlockComment)
              bracketStack.Push (ch);
            break;
          case ')':
          case ']':
          case '}':
            if (!isInString && !isInChar && !isInLineComment && !isInBlockComment)
            if (bracketStack.Count > 0)
              bracketStack.Pop ();
            break;
          case '/':
            if (isInBlockComment) {
              if (i > 0 && document.GetCharAt (i - 1) == '*') 
                isInBlockComment = false;
            } else if (!isInString && !isInChar && i + 1 < document.TextLength) {
              char nextChar = document.GetCharAt (i + 1);
              if (nextChar == '/')
                isInLineComment = true;
              if (!isInLineComment && nextChar == '*')
                isInBlockComment = true;
            }
            break;
          case '"':
            if (!(isInChar || isInLineComment || isInBlockComment)) 
              isInString = !isInString;
            break;
          case '\'':
            if (!(isInString || isInLineComment || isInBlockComment)) 
              isInChar = !isInChar;
            break;
          default :     
            if (NewLine.IsNewLine(ch)) {
              isInLineComment = false;
            }
            break;
          }
        }
      return bracketStack.Any (t => t == '{');
    }
  
    public Tuple<string, TextLocation> GetMemberTextToCaret(int caretOffset, IUnresolvedTypeDefinition currentType, IUnresolvedMember currentMember)
    {
      int startOffset;
      if (currentMember != null && currentType != null && currentType.Kind != TypeKind.Enum) {
        startOffset = document.GetOffset(currentMember.Region.Begin);
      } else if (currentType != null) {
        startOffset = document.GetOffset(currentType.Region.Begin);
      } else {
        startOffset = 0;
      }
      while (startOffset > 0) {
        char ch = document.GetCharAt(startOffset - 1);
        if (ch != ' ' && ch != '\t') {
          break;
        }
        --startOffset;
      }

      return Tuple.Create (document.GetText (startOffset, caretOffset - startOffset), document.GetLocation (startOffset));
    }


    public CSharpAstResolver GetResolver (CSharpResolver resolver, AstNode rootNode)
    {
      return new CSharpAstResolver (resolver, rootNode, unresolvedFile);
    }


  }
}