source: stable/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Document/LineManager.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
// 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 System.Diagnostics;
using System.Linq;
using ICSharpCode.NRefactory.Editor;

namespace ICSharpCode.AvalonEdit.Document
{
  /// <summary>
  /// Creates/Deletes lines when text is inserted/removed.
  /// </summary>
  sealed class LineManager
  {
    #region Constructor
    readonly TextDocument document;
    readonly DocumentLineTree documentLineTree;
    
    /// <summary>
    /// A copy of the line trackers. We need a copy so that line trackers may remove themselves
    /// while being notified (used e.g. by WeakLineTracker)
    /// </summary>
    ILineTracker[] lineTrackers;
    
    internal void UpdateListOfLineTrackers()
    {
      this.lineTrackers = document.LineTrackers.ToArray();
    }
    
    public LineManager(DocumentLineTree documentLineTree, TextDocument document)
    {
      this.document = document;
      this.documentLineTree = documentLineTree;
      UpdateListOfLineTrackers();
      
      Rebuild();
    }
    #endregion
    
    #region Change events
    /*
    HashSet<DocumentLine> deletedLines = new HashSet<DocumentLine>();
    readonly HashSet<DocumentLine> changedLines = new HashSet<DocumentLine>();
    HashSet<DocumentLine> deletedOrChangedLines = new HashSet<DocumentLine>();
    
    /// <summary>
    /// Gets the list of lines deleted since the last RetrieveChangedLines() call.
    /// The returned list is unsorted.
    /// </summary>
    public ICollection<DocumentLine> RetrieveDeletedLines()
    {
      var r = deletedLines;
      deletedLines = new HashSet<DocumentLine>();
      return r;
    }
    
    /// <summary>
    /// Gets the list of lines changed since the last RetrieveChangedLines() call.
    /// The returned list is sorted by line number and does not contain deleted lines.
    /// </summary>
    public List<DocumentLine> RetrieveChangedLines()
    {
      var list = (from line in changedLines
                  where !line.IsDeleted
                  let number = line.LineNumber
                  orderby number
                  select line).ToList();
      changedLines.Clear();
      return list;
    }
    
    /// <summary>
    /// Gets the list of lines changed since the last RetrieveDeletedOrChangedLines() call.
    /// The returned list is not sorted.
    /// </summary>
    public ICollection<DocumentLine> RetrieveDeletedOrChangedLines()
    {
      var r = deletedOrChangedLines;
      deletedOrChangedLines = new HashSet<DocumentLine>();
      return r;
    }
     */
    #endregion
    
    #region Rebuild
    public void Rebuild()
    {
      // keep the first document line
      DocumentLine ls = documentLineTree.GetByNumber(1);
      // but mark all other lines as deleted, and detach them from the other nodes
      for (DocumentLine line = ls.NextLine; line != null; line = line.NextLine) {
        line.isDeleted = true;
        line.parent = line.left = line.right = null;
      }
      // Reset the first line to detach it from the deleted lines
      ls.ResetLine();
      SimpleSegment ds = NewLineFinder.NextNewLine(document, 0);
      List<DocumentLine> lines = new List<DocumentLine>();
      int lastDelimiterEnd = 0;
      while (ds != SimpleSegment.Invalid) {
        ls.TotalLength = ds.Offset + ds.Length - lastDelimiterEnd;
        ls.DelimiterLength = ds.Length;
        lastDelimiterEnd = ds.Offset + ds.Length;
        lines.Add(ls);
        
        ls = new DocumentLine(document);
        ds = NewLineFinder.NextNewLine(document, lastDelimiterEnd);
      }
      ls.TotalLength = document.TextLength - lastDelimiterEnd;
      lines.Add(ls);
      documentLineTree.RebuildTree(lines);
      foreach (ILineTracker lineTracker in lineTrackers)
        lineTracker.RebuildDocument();
    }
    #endregion
    
    #region Remove
    public void Remove(int offset, int length)
    {
      Debug.Assert(length >= 0);
      if (length == 0) return;
      DocumentLine startLine = documentLineTree.GetByOffset(offset);
      int startLineOffset = startLine.Offset;
      
      Debug.Assert(offset < startLineOffset + startLine.TotalLength);
      if (offset > startLineOffset + startLine.Length) {
        Debug.Assert(startLine.DelimiterLength == 2);
        // we are deleting starting in the middle of a delimiter
        
        // remove last delimiter part
        SetLineLength(startLine, startLine.TotalLength - 1);
        // remove remaining text
        Remove(offset, length - 1);
        return;
      }
      
      if (offset + length < startLineOffset + startLine.TotalLength) {
        // just removing a part of this line
        //startLine.RemovedLinePart(ref deferredEventList, offset - startLineOffset, length);
        SetLineLength(startLine, startLine.TotalLength - length);
        return;
      }
      // merge startLine with another line because startLine's delimiter was deleted
      // possibly remove lines in between if multiple delimiters were deleted
      int charactersRemovedInStartLine = startLineOffset + startLine.TotalLength - offset;
      Debug.Assert(charactersRemovedInStartLine > 0);
      //startLine.RemovedLinePart(ref deferredEventList, offset - startLineOffset, charactersRemovedInStartLine);
      
      
      DocumentLine endLine = documentLineTree.GetByOffset(offset + length);
      if (endLine == startLine) {
        // special case: we are removing a part of the last line up to the
        // end of the document
        SetLineLength(startLine, startLine.TotalLength - length);
        return;
      }
      int endLineOffset = endLine.Offset;
      int charactersLeftInEndLine = endLineOffset + endLine.TotalLength - (offset + length);
      //endLine.RemovedLinePart(ref deferredEventList, 0, endLine.TotalLength - charactersLeftInEndLine);
      //startLine.MergedWith(endLine, offset - startLineOffset);
      
      // remove all lines between startLine (excl.) and endLine (incl.)
      DocumentLine tmp = startLine.NextLine;
      DocumentLine lineToRemove;
      do {
        lineToRemove = tmp;
        tmp = tmp.NextLine;
        RemoveLine(lineToRemove);
      } while (lineToRemove != endLine);
      
      SetLineLength(startLine, startLine.TotalLength - charactersRemovedInStartLine + charactersLeftInEndLine);
    }

    void RemoveLine(DocumentLine lineToRemove)
    {
      foreach (ILineTracker lt in lineTrackers)
        lt.BeforeRemoveLine(lineToRemove);
      documentLineTree.RemoveLine(lineToRemove);
//      foreach (ILineTracker lt in lineTracker)
//        lt.AfterRemoveLine(lineToRemove);
//      deletedLines.Add(lineToRemove);
//      deletedOrChangedLines.Add(lineToRemove);
    }

    #endregion
    
    #region Insert
    public void Insert(int offset, ITextSource text)
    {
      DocumentLine line = documentLineTree.GetByOffset(offset);
      int lineOffset = line.Offset;
      
      Debug.Assert(offset <= lineOffset + line.TotalLength);
      if (offset > lineOffset + line.Length) {
        Debug.Assert(line.DelimiterLength == 2);
        // we are inserting in the middle of a delimiter
        
        // shorten line
        SetLineLength(line, line.TotalLength - 1);
        // add new line
        line = InsertLineAfter(line, 1);
        line = SetLineLength(line, 1);
      }
      
      SimpleSegment ds = NewLineFinder.NextNewLine(text, 0);
      if (ds == SimpleSegment.Invalid) {
        // no newline is being inserted, all text is inserted in a single line
        //line.InsertedLinePart(offset - line.Offset, text.Length);
        SetLineLength(line, line.TotalLength + text.TextLength);
        return;
      }
      //DocumentLine firstLine = line;
      //firstLine.InsertedLinePart(offset - firstLine.Offset, ds.Offset);
      int lastDelimiterEnd = 0;
      while (ds != SimpleSegment.Invalid) {
        // split line segment at line delimiter
        int lineBreakOffset = offset + ds.Offset + ds.Length;
        lineOffset = line.Offset;
        int lengthAfterInsertionPos = lineOffset + line.TotalLength - (offset + lastDelimiterEnd);
        line = SetLineLength(line, lineBreakOffset - lineOffset);
        DocumentLine newLine = InsertLineAfter(line, lengthAfterInsertionPos);
        newLine = SetLineLength(newLine, lengthAfterInsertionPos);
        
        line = newLine;
        lastDelimiterEnd = ds.Offset + ds.Length;
        
        ds = NewLineFinder.NextNewLine(text, lastDelimiterEnd);
      }
      //firstLine.SplitTo(line);
      // insert rest after last delimiter
      if (lastDelimiterEnd != text.TextLength) {
        //line.InsertedLinePart(0, text.Length - lastDelimiterEnd);
        SetLineLength(line, line.TotalLength + text.TextLength - lastDelimiterEnd);
      }
    }
    
    DocumentLine InsertLineAfter(DocumentLine line, int length)
    {
      DocumentLine newLine = documentLineTree.InsertLineAfter(line, length);
      foreach (ILineTracker lt in lineTrackers)
        lt.LineInserted(line, newLine);
      return newLine;
    }
    #endregion
    
    #region SetLineLength
    /// <summary>
    /// Sets the total line length and checks the delimiter.
    /// This method can cause line to be deleted when it contains a single '\n' character
    /// and the previous line ends with '\r'.
    /// </summary>
    /// <returns>Usually returns <paramref name="line"/>, but if line was deleted due to
    /// the "\r\n" merge, returns the previous line.</returns>
    DocumentLine SetLineLength(DocumentLine line, int newTotalLength)
    {
//      changedLines.Add(line);
//      deletedOrChangedLines.Add(line);
      int delta = newTotalLength - line.TotalLength;
      if (delta != 0) {
        foreach (ILineTracker lt in lineTrackers)
          lt.SetLineLength(line, newTotalLength);
        line.TotalLength = newTotalLength;
        DocumentLineTree.UpdateAfterChildrenChange(line);
      }
      // determine new DelimiterLength
      if (newTotalLength == 0) {
        line.DelimiterLength = 0;
      } else {
        int lineOffset = line.Offset;
        char lastChar = document.GetCharAt(lineOffset + newTotalLength - 1);
        if (lastChar == '\r') {
          line.DelimiterLength = 1;
        } else if (lastChar == '\n') {
          if (newTotalLength >= 2 && document.GetCharAt(lineOffset + newTotalLength - 2) == '\r') {
            line.DelimiterLength = 2;
          } else if (newTotalLength == 1 && lineOffset > 0 && document.GetCharAt(lineOffset - 1) == '\r') {
            // we need to join this line with the previous line
            DocumentLine previousLine = line.PreviousLine;
            RemoveLine(line);
            return SetLineLength(previousLine, previousLine.TotalLength + 1);
          } else {
            line.DelimiterLength = 1;
          }
        } else {
          line.DelimiterLength = 0;
        }
      }
      return line;
    }
    #endregion
    
    #region ChangeComplete
    public void ChangeComplete(DocumentChangeEventArgs e)
    {
      foreach (ILineTracker lt in lineTrackers) {
        lt.ChangeComplete(e);
      }
    }
    #endregion
  }
}