flutter_flutter/engine/core/css/resolver/ScopedStyleResolver.cpp

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 * Copyright (C) 2012 Google 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.
 */

#include "sky/engine/config.h"
#include "sky/engine/core/css/resolver/ScopedStyleResolver.h"

#include "sky/engine/core/css/RuleFeature.h"
#include "sky/engine/core/css/StyleRule.h"
#include "sky/engine/core/css/StyleSheetContents.h"
#include "sky/engine/core/css/resolver/StyleResolver.h"
#include "sky/engine/core/dom/Document.h"
#include "sky/engine/core/dom/StyleEngine.h"
#include "sky/engine/core/dom/TreeScope.h"
#include "sky/engine/core/dom/shadow/ShadowRoot.h"
#include "sky/engine/core/html/HTMLStyleElement.h"

namespace blink {

ScopedStyleResolver::ScopedStyleResolver(TreeScope& scope)
    : m_scope(scope)
{
}

void ScopedStyleResolver::appendStyleSheet(CSSStyleSheet& sheet)
{
    Document& document = m_scope.document();
    StyleResolver& styleResolver = document.styleResolver();
    MediaQueryEvaluator& medium  = styleResolver.medium();

    if (sheet.mediaQueries() && !medium.eval(sheet.mediaQueries(), &m_viewportDependentMediaQueryResults))
        return;

    styleResolver.addMediaQueryAffectedByViewportChange(m_viewportDependentMediaQueryResults);

    const RuleSet& ruleSet = sheet.contents()->ensureRuleSet();
    m_features.add(ruleSet.features());
}

void ScopedStyleResolver::updateActiveStyleSheets()
{
    Vector<RefPtr<CSSStyleSheet>> candidateSheets;
    collectStyleSheets(candidateSheets);
    m_authorStyleSheets.swap(candidateSheets);

    Node& root = m_scope.rootNode();

    // TODO(esprehn): We should avoid subtree recalcs in sky when rules change
    // and only recalc specific tree scopes.
    root.setNeedsStyleRecalc(SubtreeStyleChange);

    // TODO(esprehn): We should use LocalStyleChange, :host rule changes
    // can only impact the host directly as Sky has no descendant selectors.
    if (root.isShadowRoot())
        toShadowRoot(root).host()->setNeedsStyleRecalc(SubtreeStyleChange);

    m_features.clear();
    m_viewportDependentMediaQueryResults.clear();

    for (RefPtr<CSSStyleSheet>& sheet : m_authorStyleSheets)
        appendStyleSheet(*sheet);
}

const MediaQueryResultList& ScopedStyleResolver::viewportDependentMediaQueryResults() const
{
    return m_viewportDependentMediaQueryResults;
}

void ScopedStyleResolver::addStyleSheetCandidateNode(HTMLStyleElement& element)
{
    ASSERT(element.inActiveDocument());
    m_styleSheetCandidateNodes.add(&element);
}

void ScopedStyleResolver::removeStyleSheetCandidateNode(HTMLStyleElement& element)
{
    m_styleSheetCandidateNodes.remove(&element);
}

void ScopedStyleResolver::collectStyleSheets(Vector<RefPtr<CSSStyleSheet>>& sheets)
{
    for (Node* node : m_styleSheetCandidateNodes) {
        ASSERT(isHTMLStyleElement(*node));
        if (CSSStyleSheet* sheet = toHTMLStyleElement(node)->sheet())
            sheets.append(sheet);
    }
}

const StyleRuleKeyframes* ScopedStyleResolver::keyframeStylesForAnimation(String animationName)
{
    for (auto& sheet : m_authorStyleSheets) {
        // TODO(esprehn): Maybe just store the keyframes in a map?
        for (auto& rule : sheet->contents()->ruleSet().keyframesRules()) {
            if (rule->name() == animationName)
                return rule.get();
        }
    }
    return nullptr;
}

void ScopedStyleResolver::collectMatchingAuthorRules(ElementRuleCollector& collector, CascadeOrder cascadeOrder)
{
    RuleRange ruleRange = collector.matchedResult().ranges.authorRuleRange();
    for (size_t i = 0; i < m_authorStyleSheets.size(); ++i) {
        MatchRequest matchRequest(&m_authorStyleSheets[i]->contents()->ruleSet(), m_authorStyleSheets[i].get(), i);
        collector.collectMatchingRules(matchRequest, ruleRange, cascadeOrder);
    }
}

void ScopedStyleResolver::collectMatchingHostRules(ElementRuleCollector& collector, CascadeOrder cascadeOrder)
{
    RuleRange ruleRange = collector.matchedResult().ranges.authorRuleRange();
    for (size_t i = 0; i < m_authorStyleSheets.size(); ++i) {
        MatchRequest matchRequest(&m_authorStyleSheets[i]->contents()->ruleSet(), m_authorStyleSheets[i].get(), i);
        collector.collectMatchingHostRules(matchRequest, ruleRange, cascadeOrder);
    }
}

} // namespace blink