source: branches/HeuristicLab.Problems.GrammaticalOptimization/SharpVectorCss/Css/CssCollectedProperty.cs @ 13918

using System;
using System.Xml;
using System.Collections;

namespace SharpVectors.Dom.Css
{
  /// <summary>
  /// Used internally to store collected properties.
  /// </summary>
  public class CssCollectedProperty
  {
    #region Constructors
    internal CssCollectedProperty(string name, int specificity, CssValue cssValue, CssStyleSheetType origin, string priority)
    {
      Name = name;
      Specificity = specificity;
      Origin = origin;
      CssValue = cssValue;
      Priority = priority;
    }
    #endregion

    #region Public properties
    /// <summary>
    /// The name of the property
    /// </summary>
    public string Name;
    /// <summary>
    /// The calculated specificity
    /// </summary>
    public int Specificity;
    /// <summary>
    /// The origin of the collected property.
    /// </summary>
    public CssStyleSheetType Origin;
    /// <summary>
    /// The value of the property
    /// </summary>
        public CssValue CssValue;
    /// <summary>
    /// The priority of the property, e.g. "important"
    /// </summary>
    public string Priority;
    #endregion

    #region Internal methods
    internal bool IsBetterThen(CssCollectedProperty existing)
    {
      bool yes = false;
      #region sorting according to the rules at http://www.w3.org/TR/CSS21/cascade.html#cascading-order
      bool gotHigherSpecificity = (Specificity>=existing.Specificity);
      
      switch(existing.Origin)
      {
        case CssStyleSheetType.UserAgent:
          yes = (Origin == CssStyleSheetType.UserAgent) ? gotHigherSpecificity : true;
          break;
        case CssStyleSheetType.NonCssPresentationalHints:
          yes = (Origin != CssStyleSheetType.UserAgent);
          break;
        case CssStyleSheetType.Inline:
          yes = (Origin != CssStyleSheetType.UserAgent && 
            Origin != CssStyleSheetType.NonCssPresentationalHints);
          break;
        case CssStyleSheetType.Author:
          if(Origin == CssStyleSheetType.Author && 
            Priority == existing.Priority &&
            gotHigherSpecificity)
          {
            // author rules of the same priority
            yes = true;
          }
          else if(Origin == CssStyleSheetType.Inline)
          {
            // inline rules override author rules
            yes = true;
          }
          else if(Origin == CssStyleSheetType.User && Priority == "important")
          {
            // !important user rules overrides author rules
            yes = true;
          }
          else if(Origin == CssStyleSheetType.Author && 
            existing.Priority != "important" &&
            Priority == "important"
            )
          {
            // !important author rules override non-!important author rules
            yes = true;
          }
          break;
        case CssStyleSheetType.User:
          if(Origin == CssStyleSheetType.User && 
            existing.Priority == Priority && 
            gotHigherSpecificity)
          {
            yes = true;
          }
          else if((Origin == CssStyleSheetType.Author || Origin == CssStyleSheetType.Inline) &&
            existing.Priority != "important")
          {
            // author rules overrides not !important user rules
            yes = true;
          }
          else if(Origin == CssStyleSheetType.User && 
            Priority == "important")
          {
            // !important user rules override non-!important user rules
            yes = true;
          }
          break;
      }
      #endregion

      return yes;
    }
    #endregion
  }

}