/// <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>
/// Specific version optimized for a read-only Html document
/// </summary>
public ICssStyleDeclaration GetComputedStyleInReadOnlyDocument(IElement element, String pseudo = null)
{
if (styleRulesCache == null)
{
styleRulesCache = this.GetStyleCollection();
styleRulesCache.FreezeForReuse();
}
var pseudoElement = PseudoElement.Create(element, pseudo);
if (pseudoElement != null)
{
element = pseudoElement;
}
var computedStyle = new CssStyleDeclaration();
var elementStyle = this.ComputeCascadedStyleInReadOnlyDocument(styleRulesCache, element);
computedStyle.SetDeclarations(elementStyle.Declarations);
var ancestorElements = element.GetAncestors().OfType <IElement>();
foreach (var ancestorElement in ancestorElements)
{
var ancestorStyle = ComputeCascadedStyleInReadOnlyDocument(styleRulesCache, ancestorElement);
computedStyle.UpdateDeclarations(ancestorStyle.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>
/// <param name="parent">The potential parent for the cascade.</param>
/// <returns>Returns the cascaded read-only style declaration.</returns>
public static ICssStyleDeclaration ComputeCascadedStyle(this StyleCollection styleCollection, IElement element, ICssStyleDeclaration parent = null)
{
var computedStyle = new CssStyleDeclaration(element.Owner?.Context);
var rules = styleCollection.SortBySpecificity(element);
foreach (var rule in rules)
{
var inlineStyle = rule.Style;
computedStyle.SetDeclarations(inlineStyle);
}
if (element is IHtmlElement || element is ISvgElement)
{
computedStyle.SetDeclarations(element.GetStyle());
}
if (parent != null)
{
computedStyle.UpdateDeclarations(parent);
}
return(computedStyle);
}
/// <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 ICssStyleDeclaration ComputeDeclarations(this StyleCollection rules, IElement element, String pseudoSelector = null)
{
var computedStyle = new CssStyleDeclaration(element.Owner?.Context);
var nodes = element.GetAncestors().OfType <IElement>();
if (!String.IsNullOrEmpty(pseudoSelector))
{
var pseudoElement = element?.Pseudo(pseudoSelector.TrimStart(':'));
if (pseudoElement != null)
{
element = pseudoElement;
}
}
computedStyle.SetDeclarations(rules.ComputeCascadedStyle(element));
foreach (var node in nodes)
{
computedStyle.UpdateDeclarations(rules.ComputeCascadedStyle(node));
}
return(computedStyle);
}