source: stable/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Document/SimpleSegment.cs

// 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
// 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.Diagnostics;
using System.Globalization;
using ICSharpCode.AvalonEdit.Utils;
#if NREFACTORY
using ICSharpCode.NRefactory.Editor;
#endif

namespace ICSharpCode.AvalonEdit.Document
{
  /// <summary>
  /// Represents a simple segment (Offset,Length pair) that is not automatically updated
  /// on document changes.
  /// </summary>
  struct SimpleSegment : IEquatable<SimpleSegment>, ISegment
  {
    public static readonly SimpleSegment Invalid = new SimpleSegment(-1, -1);
    
    /// <summary>
    /// Gets the overlapping portion of the segments.
    /// Returns SimpleSegment.Invalid if the segments don't overlap.
    /// </summary>
    public static SimpleSegment GetOverlap(ISegment segment1, ISegment segment2)
    {
      int start = Math.Max(segment1.Offset, segment2.Offset);
      int end = Math.Min(segment1.EndOffset, segment2.EndOffset);
      if (end < start)
        return SimpleSegment.Invalid;
      else
        return new SimpleSegment(start, end - start);
    }
    
    public readonly int Offset, Length;
    
    int ISegment.Offset {
      get { return Offset; }
    }
    
    int ISegment.Length {
      get { return Length; }
    }
    
    public int EndOffset {
      get {
        return Offset + Length;
      }
    }
    
    public SimpleSegment(int offset, int length)
    {
      this.Offset = offset;
      this.Length = length;
    }
    
    public SimpleSegment(ISegment segment)
    {
      Debug.Assert(segment != null);
      this.Offset = segment.Offset;
      this.Length = segment.Length;
    }
    
    public override int GetHashCode()
    {
      unchecked {
        return Offset + 10301 * Length;
      }
    }
    
    public override bool Equals(object obj)
    {
      return (obj is SimpleSegment) && Equals((SimpleSegment)obj);
    }
    
    public bool Equals(SimpleSegment other)
    {
      return this.Offset == other.Offset && this.Length == other.Length;
    }
    
    public static bool operator ==(SimpleSegment left, SimpleSegment right)
    {
      return left.Equals(right);
    }
    
    public static bool operator !=(SimpleSegment left, SimpleSegment right)
    {
      return !left.Equals(right);
    }
    
    /// <inheritdoc/>
    public override string ToString()
    {
      return "[Offset=" + Offset.ToString(CultureInfo.InvariantCulture) + ", Length=" + Length.ToString(CultureInfo.InvariantCulture) + "]";
    }
  }
  
  /// <summary>
  /// A segment using <see cref="TextAnchor"/>s as start and end positions.
  /// </summary>
  /// <remarks>
  /// <para>
  /// For the constructors creating new anchors, the start position will be AfterInsertion and the end position will be BeforeInsertion.
  /// Should the end position move before the start position, the segment will have length 0.
  /// </para>
  /// </remarks>
  /// <seealso cref="ISegment"/>
  /// <seealso cref="TextSegment"/>
  public sealed class AnchorSegment : ISegment
  {
    readonly TextAnchor start, end;
    
    /// <inheritdoc/>
    public int Offset {
      get { return start.Offset; }
    }
    
    /// <inheritdoc/>
    public int Length {
      get {
        // Math.Max takes care of the fact that end.Offset might move before start.Offset.
        return Math.Max(0, end.Offset - start.Offset);
      }
    }
    
    /// <inheritdoc/>
    public int EndOffset {
      get {
        // Math.Max takes care of the fact that end.Offset might move before start.Offset.
        return Math.Max(start.Offset, end.Offset);
      }
    }
    
    /// <summary>
    /// Creates a new AnchorSegment using the specified anchors.
    /// The anchors must have <see cref="TextAnchor.SurviveDeletion"/> set to true.
    /// </summary>
    public AnchorSegment(TextAnchor start, TextAnchor end)
    {
      if (start == null)
        throw new ArgumentNullException("start");
      if (end == null)
        throw new ArgumentNullException("end");
      if (!start.SurviveDeletion)
        throw new ArgumentException("Anchors for AnchorSegment must use SurviveDeletion", "start");
      if (!end.SurviveDeletion)
        throw new ArgumentException("Anchors for AnchorSegment must use SurviveDeletion", "end");
      this.start = start;
      this.end = end;
    }
    
    /// <summary>
    /// Creates a new AnchorSegment that creates new anchors.
    /// </summary>
    public AnchorSegment(TextDocument document, ISegment segment)
      : this(document, ThrowUtil.CheckNotNull(segment, "segment").Offset, segment.Length)
    {
    }
    
    /// <summary>
    /// Creates a new AnchorSegment that creates new anchors.
    /// </summary>
    public AnchorSegment(TextDocument document, int offset, int length)
    {
      if (document == null)
        throw new ArgumentNullException("document");
      this.start = document.CreateAnchor(offset);
      this.start.SurviveDeletion = true;
      this.start.MovementType = AnchorMovementType.AfterInsertion;
      this.end = document.CreateAnchor(offset + length);
      this.end.SurviveDeletion = true;
      this.end.MovementType = AnchorMovementType.BeforeInsertion;
    }
    
    /// <inheritdoc/>
    public override string ToString()
    {
      return "[Offset=" + Offset.ToString(CultureInfo.InvariantCulture) + ", EndOffset=" + EndOffset.ToString(CultureInfo.InvariantCulture) + "]";
    }
  }
}