Source/WebCore/style/StyleInvalidationFunctions.h

/*
 * Copyright (C) 2016-2017 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "HTMLSlotElement.h"
#include "ShadowRoot.h"
#include "StyleResolver.h"
#include "StyleScope.h"
#include "StyleScopeRuleSets.h"

namespace WebCore {
namespace Style {

template <typename TraverseFunction>
inline void traverseRuleFeaturesInShadowTree(Element& element, TraverseFunction&& function)
{
    if (!element.shadowRoot())
        return;

    auto& shadowRuleSets = element.shadowRoot()->styleScope().resolver().ruleSets();
    bool hasHostPseudoClassRule = shadowRuleSets.hasMatchingUserOrAuthorStyle([&] (auto& style) {
        return !style.hostPseudoClassRules().isEmpty() || style.hasHostPseudoClassRulesMatchingInShadowTree();
    });
    if (!hasHostPseudoClassRule)
        return;

    function(shadowRuleSets.features(), false);
}

template <typename TraverseFunction>
inline void traverseRuleFeaturesForSlotted(Element& element, TraverseFunction&& function)
{
    auto assignedShadowRoots = assignedShadowRootsIfSlotted(element);
    for (auto& assignedShadowRoot : assignedShadowRoots) {
        auto& ruleSets = assignedShadowRoot->styleScope().resolver().ruleSets();
        if (!ruleSets.hasMatchingUserOrAuthorStyle([] (auto& style) { return !style.slottedPseudoElementRules().isEmpty(); }))
            continue;

        function(ruleSets.features(), false);
    }
}

template <typename TraverseFunction>
inline void traverseRuleFeatures(Element& element, TraverseFunction&& function)
{
    auto& ruleSets = element.styleResolver().ruleSets();

    auto mayAffectShadowTree = [&] {
        if (element.shadowRoot() && element.shadowRoot()->isUserAgentShadowRoot()) {
            if (ruleSets.hasMatchingUserOrAuthorStyle([] (auto& style) { return style.hasUserAgentPartRules(); }))
                return true;
#if ENABLE(VIDEO)
            if (element.isMediaElement() && ruleSets.hasMatchingUserOrAuthorStyle([] (auto& style) { return !style.cuePseudoRules().isEmpty(); }))
                return true;
#endif
        }
        return false;
    };

    function(ruleSets.features(), mayAffectShadowTree());

    traverseRuleFeaturesInShadowTree(element, function);
    traverseRuleFeaturesForSlotted(element, function);

    // Ensure that the containing tree resolver also exists so it doesn't get created in the middle of invalidation.
    if (element.isInShadowTree() && element.containingShadowRoot()) {
        auto& host = *element.containingShadowRoot()->host();
        if (host.isConnected())
            Style::Scope::forNode(host).resolver();
    }
}

}
}