/// <summary>
/// Computes the declarations for the given element in the context of
/// the specified styling rules.
/// </summary>
/// <param name="rules">The styles to use.</param>
/// <param name="element">The element that is questioned.</param>
/// <param name="pseudoSelector">The optional pseudo selector to use.</param>
/// <returns>The style declaration containing all the declarations.</returns>
public static CssStyleDeclaration ComputeDeclarations(this StyleCollection rules, IElement element, String pseudoSelector = null)
{
var computedStyle = new CssStyleDeclaration();
var pseudoElement = PseudoElement.Create(element, pseudoSelector);
if (pseudoElement != null)
{
element = pseudoElement;
}
computedStyle.SetDeclarations(rules.ComputeCascadedStyle(element).Declarations);
var htmlElement = element as IHtmlElement;
if (htmlElement != null)
{
var declarations = htmlElement.Style.OfType<CssProperty>();
computedStyle.SetDeclarations(declarations);
}
var nodes = element.GetAncestors().OfType<IElement>();
foreach (var node in nodes)
{
var style = rules.ComputeCascadedStyle(node);
computedStyle.UpdateDeclarations(style.Declarations);
}
return computedStyle;
}
/// <summary>
/// Computes the cascaded style, i.e. resolves the cascade by ordering after specifity.
/// Two rules with the same specifity are ordered according to their appearance. The more
/// recent declaration wins. Inheritance is not taken into account.
/// </summary>
/// <param name="styleCollection">The style rules to apply.</param>
/// <param name="element">The element to compute the cascade for.</param>
/// <returns>Returns the cascaded read-only style declaration.</returns>
public static CssStyleDeclaration ComputeCascadedStyle(this StyleCollection styleCollection, IElement element)
{
var computedStyle = new CssStyleDeclaration();
var rules = styleCollection.SortBySpecifity(element);
foreach (var rule in rules)
{
var inlineStyle = rule.Style;
computedStyle.SetDeclarations(inlineStyle.Declarations);
}
return computedStyle;
}