source: branches/2929_PrioritizedGrammarEnumeration/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Utils/PlainRichTextWriter.cs @ 18242

// Copyright (c) 2014 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
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// DEALINGS IN THE SOFTWARE.

using System;
using System.IO;
using System.Text;

namespace ICSharpCode.AvalonEdit.Utils
{
  /// <summary>
  /// RichTextWriter implementation that writes plain text only
  /// and ignores all formatted spans.
  /// </summary>
  class PlainRichTextWriter : RichTextWriter
  {
    /// <summary>
    /// The text writer that was passed to the PlainRichTextWriter constructor.
    /// </summary>
    protected readonly TextWriter textWriter;
    string indentationString = "\t";
    int indentationLevel;
    char prevChar;
    
    /// <summary>
    /// Creates a new PlainRichTextWriter instance that writes the text to the specified text writer.
    /// </summary>
    public PlainRichTextWriter(TextWriter textWriter)
    {
      if (textWriter == null)
        throw new ArgumentNullException("textWriter");
      this.textWriter = textWriter;
    }
    
    /// <summary>
    /// Gets/Sets the string used to indent by one level.
    /// </summary>
    public string IndentationString {
      get {
        return indentationString;
      }
      set {
        indentationString = value;
      }
    }
    
    /// <inheritdoc/>
    protected override void BeginUnhandledSpan()
    {
    }
    
    /// <inheritdoc/>
    public override void EndSpan()
    {
    }
    
    void WriteIndentation()
    {
      for (int i = 0; i < indentationLevel; i++) {
        textWriter.Write(indentationString);
      }
    }
    
    /// <summary>
    /// Writes the indentation, if necessary.
    /// </summary>
    protected void WriteIndentationIfNecessary()
    {
      if (prevChar == '\n') {
        WriteIndentation();
        prevChar = '\0';
      }
    }
    
    /// <summary>
    /// Is called after a write operation.
    /// </summary>
    protected virtual void AfterWrite()
    {
    }
    
    /// <inheritdoc/>
    public override void Write(char value)
    {
      if (prevChar == '\n')
        WriteIndentation();
      textWriter.Write(value);
      prevChar = value;
      AfterWrite();
    }
    
    /// <inheritdoc/>
    public override void Indent()
    {
      indentationLevel++;
    }
    
    /// <inheritdoc/>
    public override void Unindent()
    {
      if (indentationLevel == 0)
        throw new NotSupportedException();
      indentationLevel--;
    }
    
    /// <inheritdoc/>
    public override Encoding Encoding {
      get { return textWriter.Encoding; }
    }
    
    /// <inheritdoc/>
    public override IFormatProvider FormatProvider {
      get { return textWriter.FormatProvider; }
    }
    
    /// <inheritdoc/>
    public override string NewLine {
      get {
        return textWriter.NewLine;
      }
      set {
        textWriter.NewLine = value;
      }
    }
  }
}