gitextensions-ICSharpCode.TextEditor/Project/Src/Document/Selection/DefaultSelection.cs

// <file>
//     <copyright see="prj:///doc/copyright.txt"/>
//     <license see="prj:///doc/license.txt"/>
//     <owner name="Mike Krüger" email="mike@icsharpcode.net"/>
//     <version>$Revision$</version>
// </file>

using System.Diagnostics;

namespace ICSharpCode.TextEditor.Document
{
    /// <summary>
    ///     Default implementation of the <see cref="ICSharpCode.TextEditor.Document.ISelection" /> interface.
    /// </summary>
    public class DefaultSelection : ISelection
    {
        private readonly IDocument document;
        private TextLocation endPosition;
        private TextLocation startPosition;

        /// <summary>
        ///     Creates a new instance of <see cref="DefaultSelection" />
        /// </summary>
        public DefaultSelection(IDocument document, TextLocation startPosition, TextLocation endPosition)
        {
            DefaultDocument.ValidatePosition(document, startPosition);
            DefaultDocument.ValidatePosition(document, endPosition);
            Debug.Assert(startPosition <= endPosition);
            this.document = document;
            this.startPosition = startPosition;
            this.endPosition = endPosition;
        }

        public TextLocation StartPosition
        {
            get => startPosition;
            set
            {
                DefaultDocument.ValidatePosition(document, value);
                startPosition = value;
            }
        }

        public TextLocation EndPosition
        {
            get => endPosition;
            set
            {
                DefaultDocument.ValidatePosition(document, value);
                endPosition = value;
            }
        }

        public int Offset => document.PositionToOffset(startPosition);

        public int EndOffset => document.PositionToOffset(endPosition);

        public int Length => EndOffset - Offset;

        /// <value>
        ///     Returns true, if the selection is empty
        /// </value>
        public bool IsEmpty => startPosition == endPosition;

        /// <value>
        ///     Returns true, if the selection is rectangular
        /// </value>
        // TODO : make this unused property used.
        public bool IsRectangularSelection { get; set; }

        /// <value>
        ///     The text which is selected by this selection.
        /// </value>
        public string SelectedText
        {
            get
            {
                if (document != null)
                {
                    if (Length < 0)
                        return null;
                    return document.GetText(Offset, Length);
                }

                return null;
            }
        }

        public bool ContainsPosition(TextLocation position)
        {
            if (IsEmpty)
                return false;
            return startPosition.Y < position.Y && position.Y < endPosition.Y ||
                   startPosition.Y == position.Y && startPosition.X <= position.X && (startPosition.Y != endPosition.Y || position.X <= endPosition.X) ||
                   endPosition.Y == position.Y && startPosition.Y != endPosition.Y && position.X <= endPosition.X;
        }

        public bool ContainsOffset(int offset)
        {
            return Offset <= offset && offset <= EndOffset;
        }

        /// <summary>
        ///     Converts a <see cref="DefaultSelection" /> instance to string (for debug purposes)
        /// </summary>
        public override string ToString()
        {
            return string.Format("[DefaultSelection : StartPosition={0}, EndPosition={1}]", startPosition, endPosition);
        }
    }
}