source: branches/2990_VariableImpactBasedFeatureSelection/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Editing/RectangleSelection.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
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// 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
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using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media.TextFormatting;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.AvalonEdit.Rendering;
using ICSharpCode.AvalonEdit.Utils;
#if NREFACTORY
using ICSharpCode.NRefactory;
using ICSharpCode.NRefactory.Editor;
#endif

namespace ICSharpCode.AvalonEdit.Editing
{
  /// <summary>
  /// Rectangular selection ("box selection").
  /// </summary>
  public sealed class RectangleSelection : Selection
  {
    #region Commands
    /// <summary>
    /// Expands the selection left by one character, creating a rectangular selection.
    /// Key gesture: Alt+Shift+Left
    /// </summary>
    public static readonly RoutedUICommand BoxSelectLeftByCharacter = Command("BoxSelectLeftByCharacter");
    
    /// <summary>
    /// Expands the selection right by one character, creating a rectangular selection.
    /// Key gesture: Alt+Shift+Right
    /// </summary>
    public static readonly RoutedUICommand BoxSelectRightByCharacter = Command("BoxSelectRightByCharacter");
    
    /// <summary>
    /// Expands the selection left by one word, creating a rectangular selection.
    /// Key gesture: Ctrl+Alt+Shift+Left
    /// </summary>
    public static readonly RoutedUICommand BoxSelectLeftByWord = Command("BoxSelectLeftByWord");
    
    /// <summary>
    /// Expands the selection left by one word, creating a rectangular selection.
    /// Key gesture: Ctrl+Alt+Shift+Right
    /// </summary>
    public static readonly RoutedUICommand BoxSelectRightByWord = Command("BoxSelectRightByWord");
    
    /// <summary>
    /// Expands the selection up by one line, creating a rectangular selection.
    /// Key gesture: Alt+Shift+Up
    /// </summary>
    public static readonly RoutedUICommand BoxSelectUpByLine = Command("BoxSelectUpByLine");
    
    /// <summary>
    /// Expands the selection up by one line, creating a rectangular selection.
    /// Key gesture: Alt+Shift+Down
    /// </summary>
    public static readonly RoutedUICommand BoxSelectDownByLine = Command("BoxSelectDownByLine");
    
    /// <summary>
    /// Expands the selection to the start of the line, creating a rectangular selection.
    /// Key gesture: Alt+Shift+Home
    /// </summary>
    public static readonly RoutedUICommand BoxSelectToLineStart = Command("BoxSelectToLineStart");
    
    /// <summary>
    /// Expands the selection to the end of the line, creating a rectangular selection.
    /// Key gesture: Alt+Shift+End
    /// </summary>
    public static readonly RoutedUICommand BoxSelectToLineEnd = Command("BoxSelectToLineEnd");
    
    static RoutedUICommand Command(string name)
    {
      return new RoutedUICommand(name, name, typeof(RectangleSelection));
    }
    #endregion
    
    TextDocument document;
    readonly int startLine, endLine;
    readonly double startXPos, endXPos;
    readonly int topLeftOffset, bottomRightOffset;
    readonly TextViewPosition start, end;
    
    readonly List<SelectionSegment> segments = new List<SelectionSegment>();
    
    #region Constructors
    /// <summary>
    /// Creates a new rectangular selection.
    /// </summary>
    public RectangleSelection(TextArea textArea, TextViewPosition start, TextViewPosition end)
      : base(textArea)
    {
      InitDocument();
      this.startLine = start.Line;
      this.endLine = end.Line;
      this.startXPos = GetXPos(textArea, start);
      this.endXPos = GetXPos(textArea, end);
      CalculateSegments();
      this.topLeftOffset = this.segments.First().StartOffset;
      this.bottomRightOffset = this.segments.Last().EndOffset;
      
      this.start = start;
      this.end = end;
    }
    
    private RectangleSelection(TextArea textArea, int startLine, double startXPos, TextViewPosition end)
      : base(textArea)
    {
      InitDocument();
      this.startLine = startLine;
      this.endLine = end.Line;
      this.startXPos = startXPos;
      this.endXPos = GetXPos(textArea, end);
      CalculateSegments();
      this.topLeftOffset = this.segments.First().StartOffset;
      this.bottomRightOffset = this.segments.Last().EndOffset;
      
      this.start = GetStart();
      this.end = end;
    }
    
    private RectangleSelection(TextArea textArea, TextViewPosition start, int endLine, double endXPos)
      : base(textArea)
    {
      InitDocument();
      this.startLine = start.Line;
      this.endLine = endLine;
      this.startXPos = GetXPos(textArea, start);
      this.endXPos = endXPos;
      CalculateSegments();
      this.topLeftOffset = this.segments.First().StartOffset;
      this.bottomRightOffset = this.segments.Last().EndOffset;
      
      this.start = start;
      this.end = GetEnd();
    }
    
    void InitDocument()
    {
      document = textArea.Document;
      if (document == null)
        throw ThrowUtil.NoDocumentAssigned();
    }
    
    static double GetXPos(TextArea textArea, TextViewPosition pos)
    {
      DocumentLine documentLine = textArea.Document.GetLineByNumber(pos.Line);
      VisualLine visualLine = textArea.TextView.GetOrConstructVisualLine(documentLine);
      int vc = visualLine.ValidateVisualColumn(pos, true);
      TextLine textLine = visualLine.GetTextLine(vc, pos.IsAtEndOfLine);
      return visualLine.GetTextLineVisualXPosition(textLine, vc);
    }
    
    void CalculateSegments()
    {
      DocumentLine nextLine = document.GetLineByNumber(Math.Min(startLine, endLine));
      do {
        VisualLine vl = textArea.TextView.GetOrConstructVisualLine(nextLine);
        int startVC = vl.GetVisualColumn(new Point(startXPos, 0), true);
        int endVC = vl.GetVisualColumn(new Point(endXPos, 0), true);
        
        int baseOffset = vl.FirstDocumentLine.Offset;
        int startOffset = baseOffset + vl.GetRelativeOffset(startVC);
        int endOffset = baseOffset + vl.GetRelativeOffset(endVC);
        segments.Add(new SelectionSegment(startOffset, startVC, endOffset, endVC));
        
        nextLine = vl.LastDocumentLine.NextLine;
      } while (nextLine != null && nextLine.LineNumber <= Math.Max(startLine, endLine));
    }
    
    TextViewPosition GetStart()
    {
      SelectionSegment segment = (startLine < endLine ? segments.First() : segments.Last());
      if (startXPos < endXPos) {
        return new TextViewPosition(document.GetLocation(segment.StartOffset), segment.StartVisualColumn);
      } else {
        return new TextViewPosition(document.GetLocation(segment.EndOffset), segment.EndVisualColumn);
      }
    }
    
    TextViewPosition GetEnd()
    {
      SelectionSegment segment = (startLine < endLine ? segments.Last() : segments.First());
      if (startXPos < endXPos) {
        return new TextViewPosition(document.GetLocation(segment.EndOffset), segment.EndVisualColumn);
      } else {
        return new TextViewPosition(document.GetLocation(segment.StartOffset), segment.StartVisualColumn);
      }
    }
    #endregion
    
    /// <inheritdoc/>
    public override string GetText()
    {
      StringBuilder b = new StringBuilder();
      foreach (ISegment s in this.Segments) {
        if (b.Length > 0)
          b.AppendLine();
        b.Append(document.GetText(s));
      }
      return b.ToString();
    }
    
    /// <inheritdoc/>
    public override Selection StartSelectionOrSetEndpoint(TextViewPosition startPosition, TextViewPosition endPosition)
    {
      return SetEndpoint(endPosition);
    }
    
    /// <inheritdoc/>
    public override int Length {
      get {
        return this.Segments.Sum(s => s.Length);
      }
    }
    
    /// <inheritdoc/>
    public override bool EnableVirtualSpace {
      get { return true; }
    }
    
    /// <inheritdoc/>
    public override ISegment SurroundingSegment {
      get {
        return new SimpleSegment(topLeftOffset, bottomRightOffset - topLeftOffset);
      }
    }
    
    /// <inheritdoc/>
    public override IEnumerable<SelectionSegment> Segments {
      get { return segments; }
    }
    
    /// <inheritdoc/>
    public override TextViewPosition StartPosition {
      get { return start; }
    }
    
    /// <inheritdoc/>
    public override TextViewPosition EndPosition {
      get { return end; }
    }
    
    /// <inheritdoc/>
    public override bool Equals(object obj)
    {
      RectangleSelection r = obj as RectangleSelection;
      return r != null && r.textArea == this.textArea
        && r.topLeftOffset == this.topLeftOffset && r.bottomRightOffset == this.bottomRightOffset
        && r.startLine == this.startLine && r.endLine == this.endLine
        && r.startXPos == this.startXPos && r.endXPos == this.endXPos;
    }
    
    /// <inheritdoc/>
    public override int GetHashCode()
    {
      return topLeftOffset ^ bottomRightOffset;
    }
    
    /// <inheritdoc/>
    public override Selection SetEndpoint(TextViewPosition endPosition)
    {
      return new RectangleSelection(textArea, startLine, startXPos, endPosition);
    }
    
    int GetVisualColumnFromXPos(int line, double xPos)
    {
      var vl = textArea.TextView.GetOrConstructVisualLine(textArea.Document.GetLineByNumber(line));
      return vl.GetVisualColumn(new Point(xPos, 0), true);
    }
    
    /// <inheritdoc/>
    public override Selection UpdateOnDocumentChange(DocumentChangeEventArgs e)
    {
      TextLocation newStartLocation = textArea.Document.GetLocation(e.GetNewOffset(topLeftOffset, AnchorMovementType.AfterInsertion));
      TextLocation newEndLocation = textArea.Document.GetLocation(e.GetNewOffset(bottomRightOffset, AnchorMovementType.BeforeInsertion));
      
      return new RectangleSelection(textArea,
                                    new TextViewPosition(newStartLocation, GetVisualColumnFromXPos(newStartLocation.Line, startXPos)),
                                    new TextViewPosition(newEndLocation, GetVisualColumnFromXPos(newEndLocation.Line, endXPos)));
    }
    
    /// <inheritdoc/>
    public override void ReplaceSelectionWithText(string newText)
    {
      if (newText == null)
        throw new ArgumentNullException("newText");
      using (textArea.Document.RunUpdate()) {
        TextViewPosition start = new TextViewPosition(document.GetLocation(topLeftOffset), GetVisualColumnFromXPos(startLine, startXPos));
        TextViewPosition end = new TextViewPosition(document.GetLocation(bottomRightOffset), GetVisualColumnFromXPos(endLine, endXPos));
        int insertionLength;
        int totalInsertionLength = 0;
        int firstInsertionLength = 0;
        int editOffset = Math.Min(topLeftOffset, bottomRightOffset);
        TextViewPosition pos;
        if (NewLineFinder.NextNewLine(newText, 0) == SimpleSegment.Invalid) {
          // insert same text into every line
          foreach (SelectionSegment lineSegment in this.Segments.Reverse()) {
            ReplaceSingleLineText(textArea, lineSegment, newText, out insertionLength);
            totalInsertionLength += insertionLength;
            firstInsertionLength = insertionLength;
          }
          
          int newEndOffset = editOffset + totalInsertionLength;
          pos = new TextViewPosition(document.GetLocation(editOffset + firstInsertionLength));
          
          textArea.Selection = new RectangleSelection(textArea, pos, Math.Max(startLine, endLine), GetXPos(textArea, pos));
        } else {
          string[] lines = newText.Split(NewLineFinder.NewlineStrings, segments.Count, StringSplitOptions.None);
          int line = Math.Min(startLine, endLine);
          for (int i = lines.Length - 1; i >= 0; i--) {
            ReplaceSingleLineText(textArea, segments[i], lines[i], out insertionLength);
            firstInsertionLength = insertionLength;
          }
          pos = new TextViewPosition(document.GetLocation(editOffset + firstInsertionLength));
          textArea.ClearSelection();
        }
        textArea.Caret.Position = textArea.TextView.GetPosition(new Point(GetXPos(textArea, pos), textArea.TextView.GetVisualTopByDocumentLine(Math.Max(startLine, endLine)))).GetValueOrDefault();
      }
    }
    
    void ReplaceSingleLineText(TextArea textArea, SelectionSegment lineSegment, string newText, out int insertionLength)
    {
      if (lineSegment.Length == 0) {
        if (newText.Length > 0 && textArea.ReadOnlySectionProvider.CanInsert(lineSegment.StartOffset)) {
          newText = AddSpacesIfRequired(newText, new TextViewPosition(document.GetLocation(lineSegment.StartOffset), lineSegment.StartVisualColumn), new TextViewPosition(document.GetLocation(lineSegment.EndOffset), lineSegment.EndVisualColumn));
          textArea.Document.Insert(lineSegment.StartOffset, newText);
        }
      } else {
        ISegment[] segmentsToDelete = textArea.GetDeletableSegments(lineSegment);
        for (int i = segmentsToDelete.Length - 1; i >= 0; i--) {
          if (i == segmentsToDelete.Length - 1) {
            if (segmentsToDelete[i].Offset == SurroundingSegment.Offset && segmentsToDelete[i].Length == SurroundingSegment.Length) {
              newText = AddSpacesIfRequired(newText, new TextViewPosition(document.GetLocation(lineSegment.StartOffset), lineSegment.StartVisualColumn), new TextViewPosition(document.GetLocation(lineSegment.EndOffset), lineSegment.EndVisualColumn));
            }
            textArea.Document.Replace(segmentsToDelete[i], newText);
          } else {
            textArea.Document.Remove(segmentsToDelete[i]);
          }
        }
      }
      insertionLength = newText.Length;
    }
    
    /// <summary>
    /// Performs a rectangular paste operation.
    /// </summary>
    public static bool PerformRectangularPaste(TextArea textArea, TextViewPosition startPosition, string text, bool selectInsertedText)
    {
      if (textArea == null)
        throw new ArgumentNullException("textArea");
      if (text == null)
        throw new ArgumentNullException("text");
      int newLineCount = text.Count(c => c == '\n'); // TODO might not work in all cases, but single \r line endings are really rare today.
      TextLocation endLocation = new TextLocation(startPosition.Line + newLineCount, startPosition.Column);
      if (endLocation.Line <= textArea.Document.LineCount) {
        int endOffset = textArea.Document.GetOffset(endLocation);
        if (textArea.Selection.EnableVirtualSpace || textArea.Document.GetLocation(endOffset) == endLocation) {
          RectangleSelection rsel = new RectangleSelection(textArea, startPosition, endLocation.Line, GetXPos(textArea, startPosition));
          rsel.ReplaceSelectionWithText(text);
          if (selectInsertedText && textArea.Selection is RectangleSelection) {
            RectangleSelection sel = (RectangleSelection)textArea.Selection;
            textArea.Selection = new RectangleSelection(textArea, startPosition, sel.endLine, sel.endXPos);
          }
          return true;
        }
      }
      return false;
    }
    
    /// <summary>
    /// Gets the name of the entry in the DataObject that signals rectangle selections.
    /// </summary>
    public const string RectangularSelectionDataType = "AvalonEditRectangularSelection";
    
    /// <inheritdoc/>
    public override System.Windows.DataObject CreateDataObject(TextArea textArea)
    {
      var data = base.CreateDataObject(textArea);
      
      if (EditingCommandHandler.ConfirmDataFormat(textArea, data, RectangularSelectionDataType)) {
        MemoryStream isRectangle = new MemoryStream(1);
        isRectangle.WriteByte(1);
        data.SetData(RectangularSelectionDataType, isRectangle, false);
      }
      return data;
    }
    
    /// <inheritdoc/>
    public override string ToString()
    {
      // It's possible that ToString() gets called on old (invalid) selections, e.g. for "change from... to..." debug message
      // make sure we don't crash even when the desired locations don't exist anymore.
      return string.Format("[RectangleSelection {0} {1} {2} to {3} {4} {5}]", startLine, topLeftOffset, startXPos, endLine, bottomRightOffset, endXPos);
    }
  }
}