source: branches/3107_LearningALPS/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/Rendering/FormattedTextElement.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
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// 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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// DEALINGS IN THE SOFTWARE.

using System;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.TextFormatting;
using ICSharpCode.AvalonEdit.Utils;

namespace ICSharpCode.AvalonEdit.Rendering
{
  /// <summary>
  /// Formatted text (not normal document text).
  /// This is used as base class for various VisualLineElements that are displayed using a
  /// FormattedText, for example newline markers or collapsed folding sections.
  /// </summary>
  public class FormattedTextElement : VisualLineElement
  {
    internal readonly FormattedText formattedText;
    internal string text;
    internal TextLine textLine;
    
    /// <summary>
    /// Creates a new FormattedTextElement that displays the specified text
    /// and occupies the specified length in the document.
    /// </summary>
    public FormattedTextElement(string text, int documentLength) : base(1, documentLength)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      this.text = text;
      this.BreakBefore = LineBreakCondition.BreakPossible;
      this.BreakAfter = LineBreakCondition.BreakPossible;
    }
    
    /// <summary>
    /// Creates a new FormattedTextElement that displays the specified text
    /// and occupies the specified length in the document.
    /// </summary>
    public FormattedTextElement(TextLine text, int documentLength) : base(1, documentLength)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      this.textLine = text;
      this.BreakBefore = LineBreakCondition.BreakPossible;
      this.BreakAfter = LineBreakCondition.BreakPossible;
    }
    
    /// <summary>
    /// Creates a new FormattedTextElement that displays the specified text
    /// and occupies the specified length in the document.
    /// </summary>
    public FormattedTextElement(FormattedText text, int documentLength) : base(1, documentLength)
    {
      if (text == null)
        throw new ArgumentNullException("text");
      this.formattedText = text;
      this.BreakBefore = LineBreakCondition.BreakPossible;
      this.BreakAfter = LineBreakCondition.BreakPossible;
    }
    
    /// <summary>
    /// Gets/sets the line break condition before the element.
    /// The default is 'BreakPossible'.
    /// </summary>
    public LineBreakCondition BreakBefore { get; set; }
    
    /// <summary>
    /// Gets/sets the line break condition after the element.
    /// The default is 'BreakPossible'.
    /// </summary>
    public LineBreakCondition BreakAfter { get; set; }
    
    /// <inheritdoc/>
    public override TextRun CreateTextRun(int startVisualColumn, ITextRunConstructionContext context)
    {
      if (textLine == null) {
        var formatter = TextFormatterFactory.Create(context.TextView);
        textLine = PrepareText(formatter, this.text, this.TextRunProperties);
        this.text = null;
      }
      return new FormattedTextRun(this, this.TextRunProperties);
    }
    
    /// <summary>
    /// Constructs a TextLine from a simple text.
    /// </summary>
    public static TextLine PrepareText(TextFormatter formatter, string text, TextRunProperties properties)
    {
      if (formatter == null)
        throw new ArgumentNullException("formatter");
      if (text == null)
        throw new ArgumentNullException("text");
      if (properties == null)
        throw new ArgumentNullException("properties");
      return formatter.FormatLine(
        new SimpleTextSource(text, properties),
        0,
        32000,
        new VisualLineTextParagraphProperties {
          defaultTextRunProperties = properties,
          textWrapping = TextWrapping.NoWrap,
          tabSize = 40
        },
        null);
    }
  }
  
  /// <summary>
  /// This is the TextRun implementation used by the <see cref="FormattedTextElement"/> class.
  /// </summary>
  public class FormattedTextRun : TextEmbeddedObject
  {
    readonly FormattedTextElement element;
    TextRunProperties properties;
    
    /// <summary>
    /// Creates a new FormattedTextRun.
    /// </summary>
    public FormattedTextRun(FormattedTextElement element, TextRunProperties properties)
    {
      if (element == null)
        throw new ArgumentNullException("element");
      if (properties == null)
        throw new ArgumentNullException("properties");
      this.properties = properties;
      this.element = element;
    }
    
    /// <summary>
    /// Gets the element for which the FormattedTextRun was created.
    /// </summary>
    public FormattedTextElement Element {
      get { return element; }
    }
    
    /// <inheritdoc/>
    public override LineBreakCondition BreakBefore {
      get { return element.BreakBefore; }
    }
    
    /// <inheritdoc/>
    public override LineBreakCondition BreakAfter {
      get { return element.BreakAfter; }
    }
    
    /// <inheritdoc/>
    public override bool HasFixedSize {
      get { return true; }
    }
    
    /// <inheritdoc/>
    public override CharacterBufferReference CharacterBufferReference {
      get { return new CharacterBufferReference(); }
    }
    
    /// <inheritdoc/>
    public override int Length {
      get { return element.VisualLength; }
    }
    
    /// <inheritdoc/>
    public override TextRunProperties Properties {
      get { return properties; }
    }
    
    /// <inheritdoc/>
    public override TextEmbeddedObjectMetrics Format(double remainingParagraphWidth)
    {
      var formattedText = element.formattedText;
      if (formattedText != null) {
        return new TextEmbeddedObjectMetrics(formattedText.WidthIncludingTrailingWhitespace,
                                             formattedText.Height,
                                             formattedText.Baseline);
      } else {
        var text = element.textLine;
        return new TextEmbeddedObjectMetrics(text.WidthIncludingTrailingWhitespace,
                                             text.Height,
                                             text.Baseline);
      }
    }
    
    /// <inheritdoc/>
    public override Rect ComputeBoundingBox(bool rightToLeft, bool sideways)
    {
      var formattedText = element.formattedText;
      if (formattedText != null) {
        return new Rect(0, 0, formattedText.WidthIncludingTrailingWhitespace, formattedText.Height);
      } else {
        var text = element.textLine;
        return new Rect(0, 0, text.WidthIncludingTrailingWhitespace, text.Height);
      }
    }
    
    /// <inheritdoc/>
    public override void Draw(DrawingContext drawingContext, Point origin, bool rightToLeft, bool sideways)
    {
      if (element.formattedText != null) {
        origin.Y -= element.formattedText.Baseline;
        drawingContext.DrawText(element.formattedText, origin);
      } else {
        origin.Y -= element.textLine.Baseline;
        element.textLine.Draw(drawingContext, origin, InvertAxes.None);
      }
    }
  }
}