source: branches/Async/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Highlighting/IHighlighter.cs @ 13508

// 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
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using System;
using System.Collections.Generic;
#if NREFACTORY
using ICSharpCode.NRefactory.Editor;
#else
using ICSharpCode.AvalonEdit.Document;
#endif

namespace ICSharpCode.AvalonEdit.Highlighting
{
  /// <summary>
  /// Represents a highlighted document.
  /// </summary>
  /// <remarks>This interface is used by the <see cref="HighlightingColorizer"/> to register the highlighter as a TextView service.</remarks>
  public interface IHighlighter : IDisposable
  {
    /// <summary>
    /// Gets the underlying text document.
    /// </summary>
    IDocument Document { get; }
    
    /// <summary>
    /// Gets the stack of active colors (the colors associated with the active spans) at the end of the specified line.
    /// -> GetColorStack(1) returns the colors at the start of the second line.
    /// </summary>
    /// <remarks>
    /// GetColorStack(0) is valid and will return the empty stack.
    /// The elements are returned in inside-out order (first element of result enumerable is the color of the innermost span).
    /// </remarks>
    IEnumerable<HighlightingColor> GetColorStack(int lineNumber);
    
    // Starting with SD 5.0, this interface exports GetColorStack() instead of GetSpanStack().
    // This was done because custom highlighter implementations might not use the HighlightingSpan class (AST-based highlighting).
    
    /// <summary>
    /// Highlights the specified document line.
    /// </summary>
    /// <param name="lineNumber">The line to highlight.</param>
    /// <returns>A <see cref="HighlightedLine"/> line object that represents the highlighted sections.</returns>
    HighlightedLine HighlightLine(int lineNumber);
    
    /// <summary>
    /// Enforces a highlighting state update (triggering the HighlightingStateChanged event if necessary)
    /// for all lines up to (and inclusive) the specified line number.
    /// </summary>
    void UpdateHighlightingState(int lineNumber);
    
    /// <summary>
    /// Notification when the highlighter detects that the highlighting state at the
    /// <b>beginning</b> of the specified lines has changed.
    /// <c>fromLineNumber</c> and <c>toLineNumber</c> are both inclusive;
    /// the common case of a single-line change is represented by <c>fromLineNumber == toLineNumber</c>.
    /// 
    /// During highlighting, the highlighting of line X will cause this event to be raised
    /// for line X+1 if the highlighting state at the end of line X has changed from its previous state.
    /// This event may also be raised outside of the highlighting process to signalize that
    /// changes to external data (not the document text; but e.g. semantic information)
    /// require a re-highlighting of the specified lines.
    /// </summary>
    /// <remarks>
    /// For implementers: there is the requirement that, during highlighting,
    /// if there was no state changed reported for the beginning of line X,
    /// and there were no document changes between the start of line X and the start of line Y (with Y > X),
    /// then this event must not be raised for any line between X and Y (inclusive).
    /// 
    /// Equal input state + unchanged line = Equal output state.
    /// 
    /// See the comment in the HighlightingColorizer.OnHighlightStateChanged implementation
    /// for details about the requirements for a correct custom IHighlighter.
    /// 
    /// Outside of the highlighting process, this event can be raised without such restrictions.
    /// </remarks>
    event HighlightingStateChangedEventHandler HighlightingStateChanged;
    
    /// <summary>
    /// Opens a group of <see cref="HighlightLine"/> calls.
    /// It is not necessary to call this method before calling <see cref="HighlightLine"/>,
    /// however, doing so can make the highlighting much more performant in some cases
    /// (e.g. the C# semantic highlighter in SharpDevelop will re-use the resolver within a highlighting group).
    /// </summary>
    /// <remarks>
    /// The group is closed by either a <see cref="EndHighlighting"/> or a <see cref="IDisposable.Dispose"/> call.
    /// Nested groups are not allowed.
    /// </remarks>
    void BeginHighlighting();
    
    /// <summary>
    /// Closes the currently opened group of <see cref="HighlightLine"/> calls.
    /// </summary>
    /// <seealso cref="BeginHighlighting"/>.
    void EndHighlighting();
    
    /// <summary>
    /// Retrieves the HighlightingColor with the specified name. Returns null if no color matching the name is found.
    /// </summary>
    HighlightingColor GetNamedColor(string name);
    
    /// <summary>
    /// Gets the default text color.
    /// </summary>
    HighlightingColor DefaultTextColor { get; }
  }
  
  /// <summary>
  /// Event handler for <see cref="IHighlighter.HighlightingStateChanged"/>
  /// </summary>
  public delegate void HighlightingStateChangedEventHandler(int fromLineNumber, int toLineNumber);
}