source: branches/CodeEditor/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Highlighting/RichTextModel.cs @ 11700

// 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 System.Windows;
using System.Windows.Documents;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.NRefactory.Editor;

namespace ICSharpCode.AvalonEdit.Highlighting
{
  /// <summary>
  /// Stores rich-text formatting.
  /// </summary>
  public sealed class RichTextModel
  {
    List<int> stateChangeOffsets = new List<int>();
    List<HighlightingColor> stateChanges = new List<HighlightingColor>();
    
    int GetIndexForOffset(int offset)
    {
      if (offset < 0)
        throw new ArgumentOutOfRangeException("offset");
      int index = stateChangeOffsets.BinarySearch(offset);
      if (index < 0) {
        // If no color change exists directly at offset,
        // create a new one.
        index = ~index;
        stateChanges.Insert(index, stateChanges[index - 1].Clone());
        stateChangeOffsets.Insert(index, offset);
      }
      return index;
    }
    
    int GetIndexForOffsetUseExistingSegment(int offset)
    {
      if (offset < 0)
        throw new ArgumentOutOfRangeException("offset");
      int index = stateChangeOffsets.BinarySearch(offset);
      if (index < 0) {
        // If no color change exists directly at offset,
        // return the index of the color segment that contains offset.
        index = ~index - 1;
      }
      return index;
    }
    
    int GetEnd(int index)
    {
      // Gets the end of the color segment no. index.
      if (index + 1 < stateChangeOffsets.Count)
        return stateChangeOffsets[index + 1];
      else
        return int.MaxValue;
    }
    
    /// <summary>
    /// Creates a new RichTextModel.
    /// </summary>
    public RichTextModel()
    {
      stateChangeOffsets.Add(0);
      stateChanges.Add(new HighlightingColor());
    }
    
    /// <summary>
    /// Creates a RichTextModel from a CONTIGUOUS list of HighlightedSections.
    /// </summary>
    internal RichTextModel(int[] stateChangeOffsets, HighlightingColor[] stateChanges)
    {
      Debug.Assert(stateChangeOffsets[0] == 0);
      this.stateChangeOffsets.AddRange(stateChangeOffsets);
      this.stateChanges.AddRange(stateChanges);
    }
    
    #region UpdateOffsets
    /// <summary>
    /// Updates the start and end offsets of all segments stored in this collection.
    /// </summary>
    /// <param name="e">TextChangeEventArgs instance describing the change to the document.</param>
    public void UpdateOffsets(TextChangeEventArgs e)
    {
      if (e == null)
        throw new ArgumentNullException("e");
      UpdateOffsets(e.GetNewOffset);
    }
    
    /// <summary>
    /// Updates the start and end offsets of all segments stored in this collection.
    /// </summary>
    /// <param name="change">OffsetChangeMap instance describing the change to the document.</param>
    public void UpdateOffsets(OffsetChangeMap change)
    {
      if (change == null)
        throw new ArgumentNullException("change");
      UpdateOffsets(change.GetNewOffset);
    }
    
    /// <summary>
    /// Updates the start and end offsets of all segments stored in this collection.
    /// </summary>
    /// <param name="change">OffsetChangeMapEntry instance describing the change to the document.</param>
    public void UpdateOffsets(OffsetChangeMapEntry change)
    {
      UpdateOffsets(change.GetNewOffset);
    }
    
    void UpdateOffsets(Func<int, AnchorMovementType, int> updateOffset)
    {
      int readPos = 1;
      int writePos = 1;
      while (readPos < stateChangeOffsets.Count) {
        Debug.Assert(writePos <= readPos);
        int newOffset = updateOffset(stateChangeOffsets[readPos], AnchorMovementType.Default);
        if (newOffset == stateChangeOffsets[writePos - 1]) {
          // offset moved to same position as previous offset
          // -> previous segment has length 0 and gets overwritten with this segment
          stateChanges[writePos - 1] = stateChanges[readPos];
        } else {
          stateChangeOffsets[writePos] = newOffset;
          stateChanges[writePos] = stateChanges[readPos];
          writePos++;
        }
        readPos++;
      }
      // Delete all entries that were not written to
      stateChangeOffsets.RemoveRange(writePos, stateChangeOffsets.Count - writePos);
      stateChanges.RemoveRange(writePos, stateChanges.Count - writePos);
    }
    #endregion
    
    /// <summary>
    /// Appends another RichTextModel after this one.
    /// </summary>
    internal void Append(int offset, int[] newOffsets, HighlightingColor[] newColors)
    {
      Debug.Assert(newOffsets.Length == newColors.Length);
      Debug.Assert(newOffsets[0] == 0);
      // remove everything before offset:
      while (stateChangeOffsets.Count > 0 && stateChangeOffsets.Last() <= offset) {
        stateChangeOffsets.RemoveAt(stateChangeOffsets.Count - 1);
        stateChanges.RemoveAt(stateChanges.Count - 1);
      }
      // Append the new segments
      for (int i = 0; i < newOffsets.Length; i++) {
        stateChangeOffsets.Add(offset + newOffsets[i]);
        stateChanges.Add(newColors[i]);
      }
    }
    
    /// <summary>
    /// Gets a copy of the HighlightingColor for the specified offset.
    /// </summary>
    public HighlightingColor GetHighlightingAt(int offset)
    {
      return stateChanges[GetIndexForOffsetUseExistingSegment(offset)].Clone();
    }
    
    /// <summary>
    /// Applies the HighlightingColor to the specified range of text.
    /// If the color specifies <c>null</c> for some properties, existing highlighting is preserved.
    /// </summary>
    public void ApplyHighlighting(int offset, int length, HighlightingColor color)
    {
      if (color == null || color.IsEmptyForMerge) {
        // Optimization: don't split the HighlightingState when we're not changing
        // any property. For example, the "Punctuation" color in C# is
        // empty by default.
        return;
      }
      int startIndex = GetIndexForOffset(offset);
      int endIndex = GetIndexForOffset(offset + length);
      for (int i = startIndex; i < endIndex; i++) {
        stateChanges[i].MergeWith(color);
      }
    }
    
    /// <summary>
    /// Sets the HighlightingColor for the specified range of text,
    /// completely replacing the existing highlighting in that area.
    /// </summary>
    public void SetHighlighting(int offset, int length, HighlightingColor color)
    {
      if (length <= 0)
        return;
      int startIndex = GetIndexForOffset(offset);
      int endIndex = GetIndexForOffset(offset + length);
      stateChanges[startIndex] = color != null ? color.Clone() : new HighlightingColor();
      stateChanges.RemoveRange(startIndex + 1, endIndex - (startIndex + 1));
      stateChangeOffsets.RemoveRange(startIndex + 1, endIndex - (startIndex + 1));
    }
    
    /// <summary>
    /// Sets the foreground brush on the specified text segment.
    /// </summary>
    public void SetForeground(int offset, int length, HighlightingBrush brush)
    {
      int startIndex = GetIndexForOffset(offset);
      int endIndex = GetIndexForOffset(offset + length);
      for (int i = startIndex; i < endIndex; i++) {
        stateChanges[i].Foreground = brush;
      }
    }
    
    /// <summary>
    /// Sets the background brush on the specified text segment.
    /// </summary>
    public void SetBackground(int offset, int length, HighlightingBrush brush)
    {
      int startIndex = GetIndexForOffset(offset);
      int endIndex = GetIndexForOffset(offset + length);
      for (int i = startIndex; i < endIndex; i++) {
        stateChanges[i].Background = brush;
      }
    }
    
    /// <summary>
    /// Sets the font weight on the specified text segment.
    /// </summary>
    public void SetFontWeight(int offset, int length, FontWeight weight)
    {
      int startIndex = GetIndexForOffset(offset);
      int endIndex = GetIndexForOffset(offset + length);
      for (int i = startIndex; i < endIndex; i++) {
        stateChanges[i].FontWeight = weight;
      }
    }
    
    /// <summary>
    /// Sets the font style on the specified text segment.
    /// </summary>
    public void SetFontStyle(int offset, int length, FontStyle style)
    {
      int startIndex = GetIndexForOffset(offset);
      int endIndex = GetIndexForOffset(offset + length);
      for (int i = startIndex; i < endIndex; i++) {
        stateChanges[i].FontStyle = style;
      }
    }
    
    /// <summary>
    /// Retrieves the highlighted sections in the specified range.
    /// The highlighted sections will be sorted by offset, and there will not be any nested or overlapping sections.
    /// </summary>
    public IEnumerable<HighlightedSection> GetHighlightedSections(int offset, int length)
    {
      int index = GetIndexForOffsetUseExistingSegment(offset);
      int pos = offset;
      int endOffset = offset + length;
      while (pos < endOffset) {
        int endPos = Math.Min(endOffset, GetEnd(index));
        yield return new HighlightedSection {
          Offset = pos,
          Length = endPos - pos,
          Color = stateChanges[index].Clone()
        };
        pos = endPos;
        index++;
      }
    }
    
    /// <summary>
    /// Creates WPF Run instances that can be used for TextBlock.Inlines.
    /// </summary>
    /// <param name="textSource">The text source that holds the text for this RichTextModel.</param>
    public Run[] CreateRuns(ITextSource textSource)
    {
      Run[] runs = new Run[stateChanges.Count];
      for (int i = 0; i < runs.Length; i++) {
        int startOffset = stateChangeOffsets[i];
        int endOffset = i + 1 < stateChangeOffsets.Count ? stateChangeOffsets[i + 1] : textSource.TextLength;
        Run r = new Run(textSource.GetText(startOffset, endOffset - startOffset));
        HighlightingColor state = stateChanges[i];
        RichText.ApplyColorToTextElement(r, state);
        runs[i] = r;
      }
      return runs;
    }
  }
}