webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 568 insertions, 0 deletions

diff --git a/Source/WebCore/style/StyleScope.cpp b/Source/WebCore/style/StyleScope.cpp
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+++ b/Source/WebCore/style/StyleScope.cpp
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+/*
+ * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
+ *           (C) 1999 Antti Koivisto (koivisto@kde.org)
+ *           (C) 2001 Dirk Mueller (mueller@kde.org)
+ *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
+ * Copyright (C) 2004-2009, 2011-2012, 2015-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
+ * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
+ * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
+ * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "config.h"
+#include "StyleScope.h"
+
+#include "CSSStyleSheet.h"
+#include "Element.h"
+#include "ElementChildIterator.h"
+#include "ExtensionStyleSheets.h"
+#include "HTMLIFrameElement.h"
+#include "HTMLLinkElement.h"
+#include "HTMLSlotElement.h"
+#include "HTMLStyleElement.h"
+#include "InspectorInstrumentation.h"
+#include "ProcessingInstruction.h"
+#include "SVGStyleElement.h"
+#include "Settings.h"
+#include "ShadowRoot.h"
+#include "StyleInvalidationAnalysis.h"
+#include "StyleResolver.h"
+#include "StyleSheetContents.h"
+#include "StyleSheetList.h"
+#include "UserContentController.h"
+#include "UserContentURLPattern.h"
+#include "UserStyleSheet.h"
+#include <wtf/SetForScope.h>
+
+namespace WebCore {
+
+using namespace ContentExtensions;
+using namespace HTMLNames;
+
+namespace Style {
+
+Scope::Scope(Document& document)
+    : m_document(document)
+    , m_pendingUpdateTimer(*this, &Scope::pendingUpdateTimerFired)
+{
+}
+
+Scope::Scope(ShadowRoot& shadowRoot)
+    : m_document(shadowRoot.documentScope())
+    , m_shadowRoot(&shadowRoot)
+    , m_pendingUpdateTimer(*this, &Scope::pendingUpdateTimerFired)
+{
+}
+
+Scope::~Scope()
+{
+}
+
+bool Scope::shouldUseSharedUserAgentShadowTreeStyleResolver() const
+{
+    if (!m_shadowRoot)
+        return false;
+    if (m_shadowRoot->mode() != ShadowRootMode::UserAgent)
+        return false;
+    // If we have stylesheets in the user agent shadow tree use per-scope resolver.
+    if (!m_styleSheetCandidateNodes.isEmpty())
+        return false;
+    return true;
+}
+
+StyleResolver& Scope::resolver()
+{
+    if (shouldUseSharedUserAgentShadowTreeStyleResolver())
+        return m_document.userAgentShadowTreeStyleResolver();
+
+    if (!m_resolver) {
+        SetForScope<bool> isUpdatingStyleResolver { m_isUpdatingStyleResolver, true };
+        m_resolver = std::make_unique<StyleResolver>(m_document);
+        m_resolver->appendAuthorStyleSheets(m_activeStyleSheets);
+    }
+    ASSERT(!m_shadowRoot || &m_document == &m_shadowRoot->document());
+    ASSERT(&m_resolver->document() == &m_document);
+    return *m_resolver;
+}
+
+StyleResolver* Scope::resolverIfExists()
+{
+    if (shouldUseSharedUserAgentShadowTreeStyleResolver())
+        return &m_document.userAgentShadowTreeStyleResolver();
+
+    return m_resolver.get();
+}
+
+void Scope::clearResolver()
+{
+    m_resolver = nullptr;
+
+    if (!m_shadowRoot)
+        m_document.didClearStyleResolver();
+}
+
+Scope& Scope::forNode(Node& node)
+{
+    ASSERT(node.isConnected());
+    auto* shadowRoot = node.containingShadowRoot();
+    if (shadowRoot)
+        return shadowRoot->styleScope();
+    return node.document().styleScope();
+}
+
+Scope* Scope::forOrdinal(Element& element, ScopeOrdinal ordinal)
+{
+    switch (ordinal) {
+    case ScopeOrdinal::Element:
+        return &forNode(element);
+    case ScopeOrdinal::ContainingHost: {
+        auto* containingShadowRoot = element.containingShadowRoot();
+        if (!containingShadowRoot)
+            return nullptr;
+        return &forNode(*containingShadowRoot->host());
+    }
+    case ScopeOrdinal::Shadow: {
+        auto* shadowRoot = element.shadowRoot();
+        if (!shadowRoot)
+            return nullptr;
+        return &shadowRoot->styleScope();
+    }
+    default: {
+        ASSERT(ordinal >= ScopeOrdinal::FirstSlot);
+        auto slotIndex = ScopeOrdinal::FirstSlot;
+        for (auto* slot = element.assignedSlot(); slot; slot = slot->assignedSlot(), ++slotIndex) {
+            if (slotIndex == ordinal)
+                return &forNode(*slot);
+        }
+        return nullptr;
+    }
+    }
+}
+
+void Scope::setPreferredStylesheetSetName(const String& name)
+{
+    if (m_preferredStylesheetSetName == name)
+        return;
+    m_preferredStylesheetSetName = name;
+    didChangeActiveStyleSheetCandidates();
+}
+
+void Scope::setSelectedStylesheetSetName(const String& name)
+{
+    if (m_selectedStylesheetSetName == name)
+        return;
+    m_selectedStylesheetSetName = name;
+    didChangeActiveStyleSheetCandidates();
+}
+
+// This method is called whenever a top-level stylesheet has finished loading.
+void Scope::removePendingSheet()
+{
+    // Make sure we knew this sheet was pending, and that our count isn't out of sync.
+    ASSERT(m_pendingStyleSheetCount > 0);
+
+    m_pendingStyleSheetCount--;
+    if (m_pendingStyleSheetCount)
+        return;
+
+    didChangeActiveStyleSheetCandidates();
+
+    if (!m_shadowRoot)
+        m_document.didRemoveAllPendingStylesheet();
+}
+
+void Scope::addStyleSheetCandidateNode(Node& node, bool createdByParser)
+{
+    if (!node.isConnected())
+        return;
+    
+    // Until the <body> exists, we have no choice but to compare document positions,
+    // since styles outside of the body and head continue to be shunted into the head
+    // (and thus can shift to end up before dynamically added DOM content that is also
+    // outside the body).
+    if ((createdByParser && m_document.bodyOrFrameset()) || m_styleSheetCandidateNodes.isEmpty()) {
+        m_styleSheetCandidateNodes.add(&node);
+        return;
+    }
+
+    // Determine an appropriate insertion point.
+    auto begin = m_styleSheetCandidateNodes.begin();
+    auto end = m_styleSheetCandidateNodes.end();
+    auto it = end;
+    Node* followingNode = nullptr;
+    do {
+        --it;
+        Node* n = *it;
+        unsigned short position = n->compareDocumentPosition(node);
+        if (position == Node::DOCUMENT_POSITION_FOLLOWING) {
+            m_styleSheetCandidateNodes.insertBefore(followingNode, &node);
+            return;
+        }
+        followingNode = n;
+    } while (it != begin);
+    
+    m_styleSheetCandidateNodes.insertBefore(followingNode, &node);
+}
+
+void Scope::removeStyleSheetCandidateNode(Node& node)
+{
+    if (m_styleSheetCandidateNodes.remove(&node))
+        didChangeActiveStyleSheetCandidates();
+}
+
+void Scope::collectActiveStyleSheets(Vector<RefPtr<StyleSheet>>& sheets)
+{
+    if (!m_document.settings().authorAndUserStylesEnabled())
+        return;
+
+    for (auto& node : m_styleSheetCandidateNodes) {
+        StyleSheet* sheet = nullptr;
+        if (is<ProcessingInstruction>(*node)) {
+            // Processing instruction (XML documents only).
+            // We don't support linking to embedded CSS stylesheets, see <https://bugs.webkit.org/show_bug.cgi?id=49281> for discussion.
+            ProcessingInstruction& pi = downcast<ProcessingInstruction>(*node);
+            sheet = pi.sheet();
+#if ENABLE(XSLT)
+            // Don't apply XSL transforms to already transformed documents -- <rdar://problem/4132806>
+            if (pi.isXSL() && !m_document.transformSourceDocument()) {
+                // Don't apply XSL transforms until loading is finished.
+                if (!m_document.parsing())
+                    m_document.applyXSLTransform(&pi);
+                return;
+            }
+#endif
+        } else if (is<HTMLLinkElement>(*node) || is<HTMLStyleElement>(*node) || is<SVGStyleElement>(*node)) {
+            Element& element = downcast<Element>(*node);
+            AtomicString title = element.attributeWithoutSynchronization(titleAttr);
+            bool enabledViaScript = false;
+            if (is<HTMLLinkElement>(element)) {
+                // <LINK> element
+                HTMLLinkElement& linkElement = downcast<HTMLLinkElement>(element);
+                if (linkElement.isDisabled())
+                    continue;
+                enabledViaScript = linkElement.isEnabledViaScript();
+                if (linkElement.styleSheetIsLoading()) {
+                    // it is loading but we should still decide which style sheet set to use
+                    if (!enabledViaScript && !title.isEmpty() && m_preferredStylesheetSetName.isEmpty()) {
+                        if (!linkElement.attributeWithoutSynchronization(relAttr).contains("alternate")) {
+                            m_preferredStylesheetSetName = title;
+                            m_selectedStylesheetSetName = title;
+                        }
+                    }
+                    continue;
+                }
+                if (!linkElement.sheet())
+                    title = nullAtom;
+            }
+            // Get the current preferred styleset. This is the
+            // set of sheets that will be enabled.
+            if (is<SVGStyleElement>(element))
+                sheet = downcast<SVGStyleElement>(element).sheet();
+            else if (is<HTMLLinkElement>(element))
+                sheet = downcast<HTMLLinkElement>(element).sheet();
+            else
+                sheet = downcast<HTMLStyleElement>(element).sheet();
+            // Check to see if this sheet belongs to a styleset
+            // (thus making it PREFERRED or ALTERNATE rather than
+            // PERSISTENT).
+            auto& rel = element.attributeWithoutSynchronization(relAttr);
+            if (!enabledViaScript && !title.isEmpty()) {
+                // Yes, we have a title.
+                if (m_preferredStylesheetSetName.isEmpty()) {
+                    // No preferred set has been established. If
+                    // we are NOT an alternate sheet, then establish
+                    // us as the preferred set. Otherwise, just ignore
+                    // this sheet.
+                    if (is<HTMLStyleElement>(element) || !rel.contains("alternate"))
+                        m_preferredStylesheetSetName = m_selectedStylesheetSetName = title;
+                }
+                if (title != m_preferredStylesheetSetName)
+                    sheet = nullptr;
+            }
+
+            if (rel.contains("alternate") && title.isEmpty())
+                sheet = nullptr;
+        }
+        if (sheet)
+            sheets.append(sheet);
+    }
+}
+
+Scope::StyleResolverUpdateType Scope::analyzeStyleSheetChange(const Vector<RefPtr<CSSStyleSheet>>& newStylesheets, bool& requiresFullStyleRecalc)
+{
+    requiresFullStyleRecalc = true;
+    
+    unsigned newStylesheetCount = newStylesheets.size();
+
+    if (!resolverIfExists())
+        return Reconstruct;
+
+    auto& styleResolver = *resolverIfExists();
+
+    // Find out which stylesheets are new.
+    unsigned oldStylesheetCount = m_activeStyleSheets.size();
+    if (newStylesheetCount < oldStylesheetCount)
+        return Reconstruct;
+
+    Vector<StyleSheetContents*> addedSheets;
+    unsigned newIndex = 0;
+    for (unsigned oldIndex = 0; oldIndex < oldStylesheetCount; ++oldIndex) {
+        if (newIndex >= newStylesheetCount)
+            return Reconstruct;
+        while (m_activeStyleSheets[oldIndex] != newStylesheets[newIndex]) {
+            addedSheets.append(&newStylesheets[newIndex]->contents());
+            ++newIndex;
+            if (newIndex == newStylesheetCount)
+                return Reconstruct;
+        }
+        ++newIndex;
+    }
+    bool hasInsertions = !addedSheets.isEmpty();
+    while (newIndex < newStylesheetCount) {
+        addedSheets.append(&newStylesheets[newIndex]->contents());
+        ++newIndex;
+    }
+    // If all new sheets were added at the end of the list we can just add them to existing StyleResolver.
+    // If there were insertions we need to re-add all the stylesheets so rules are ordered correctly.
+    auto styleResolverUpdateType = hasInsertions ? Reset : Additive;
+
+    // If we are already parsing the body and so may have significant amount of elements, put some effort into trying to avoid style recalcs.
+    if (!m_document.bodyOrFrameset() || m_document.hasNodesWithPlaceholderStyle())
+        return styleResolverUpdateType;
+
+    StyleInvalidationAnalysis invalidationAnalysis(addedSheets, styleResolver.mediaQueryEvaluator());
+    if (invalidationAnalysis.dirtiesAllStyle())
+        return styleResolverUpdateType;
+
+    if (m_shadowRoot)
+        invalidationAnalysis.invalidateStyle(*m_shadowRoot);
+    else
+        invalidationAnalysis.invalidateStyle(m_document);
+
+    requiresFullStyleRecalc = false;
+
+    return styleResolverUpdateType;
+}
+
+static void filterEnabledNonemptyCSSStyleSheets(Vector<RefPtr<CSSStyleSheet>>& result, const Vector<RefPtr<StyleSheet>>& sheets)
+{
+    for (auto& sheet : sheets) {
+        if (!is<CSSStyleSheet>(*sheet))
+            continue;
+        CSSStyleSheet& styleSheet = downcast<CSSStyleSheet>(*sheet);
+        if (styleSheet.isLoading())
+            continue;
+        if (styleSheet.disabled())
+            continue;
+        if (!styleSheet.length())
+            continue;
+        result.append(&styleSheet);
+    }
+}
+
+void Scope::updateActiveStyleSheets(UpdateType updateType)
+{
+    ASSERT(!m_pendingUpdate);
+
+    if (!m_document.hasLivingRenderTree())
+        return;
+
+    if (m_document.inStyleRecalc() || m_document.inRenderTreeUpdate()) {
+        // Protect against deleting style resolver in the middle of a style resolution.
+        // Crash stacks indicate we can get here when a resource load fails synchronously (for example due to content blocking).
+        // FIXME: These kind of cases should be eliminated and this path replaced by an assert.
+        m_pendingUpdate = UpdateType::ContentsOrInterpretation;
+        m_document.scheduleForcedStyleRecalc();
+        return;
+    }
+
+    Vector<RefPtr<StyleSheet>> activeStyleSheets;
+    collectActiveStyleSheets(activeStyleSheets);
+
+    Vector<RefPtr<CSSStyleSheet>> activeCSSStyleSheets;
+    activeCSSStyleSheets.appendVector(m_document.extensionStyleSheets().injectedAuthorStyleSheets());
+    activeCSSStyleSheets.appendVector(m_document.extensionStyleSheets().authorStyleSheetsForTesting());
+    filterEnabledNonemptyCSSStyleSheets(activeCSSStyleSheets, activeStyleSheets);
+
+    bool requiresFullStyleRecalc = true;
+    StyleResolverUpdateType styleResolverUpdateType = Reconstruct;
+    if (updateType == UpdateType::ActiveSet)
+        styleResolverUpdateType = analyzeStyleSheetChange(activeCSSStyleSheets, requiresFullStyleRecalc);
+
+    updateStyleResolver(activeCSSStyleSheets, styleResolverUpdateType);
+
+    m_weakCopyOfActiveStyleSheetListForFastLookup = nullptr;
+    m_activeStyleSheets.swap(activeCSSStyleSheets);
+    m_styleSheetsForStyleSheetList.swap(activeStyleSheets);
+
+    InspectorInstrumentation::activeStyleSheetsUpdated(m_document);
+
+    for (const auto& sheet : m_activeStyleSheets) {
+        if (sheet->contents().usesStyleBasedEditability())
+            m_usesStyleBasedEditability = true;
+    }
+
+    // FIXME: Move this code somewhere else.
+    if (requiresFullStyleRecalc) {
+        if (m_shadowRoot) {
+            for (auto& shadowChild : childrenOfType<Element>(*m_shadowRoot))
+                shadowChild.invalidateStyleForSubtree();
+            if (m_shadowRoot->host()) {
+                if (!resolver().ruleSets().authorStyle().hostPseudoClassRules().isEmpty())
+                    m_shadowRoot->host()->invalidateStyle();
+                if (!resolver().ruleSets().authorStyle().slottedPseudoElementRules().isEmpty()) {
+                    for (auto& shadowChild : childrenOfType<Element>(*m_shadowRoot->host()))
+                        shadowChild.invalidateStyle();
+                }
+            }
+        } else
+            m_document.scheduleForcedStyleRecalc();
+    }
+}
+
+void Scope::updateStyleResolver(Vector<RefPtr<CSSStyleSheet>>& activeStyleSheets, StyleResolverUpdateType updateType)
+{
+    if (updateType == Reconstruct) {
+        clearResolver();
+        return;
+    }
+    auto& styleResolver = resolver();
+
+    SetForScope<bool> isUpdatingStyleResolver { m_isUpdatingStyleResolver, true };
+    if (updateType == Reset) {
+        styleResolver.ruleSets().resetAuthorStyle();
+        styleResolver.appendAuthorStyleSheets(activeStyleSheets);
+    } else {
+        ASSERT(updateType == Additive);
+        unsigned firstNewIndex = m_activeStyleSheets.size();
+        Vector<RefPtr<CSSStyleSheet>> newStyleSheets;
+        newStyleSheets.appendRange(activeStyleSheets.begin() + firstNewIndex, activeStyleSheets.end());
+        styleResolver.appendAuthorStyleSheets(newStyleSheets);
+    }
+}
+
+const Vector<RefPtr<CSSStyleSheet>> Scope::activeStyleSheetsForInspector()
+{
+    Vector<RefPtr<CSSStyleSheet>> result;
+
+    result.appendVector(m_document.extensionStyleSheets().injectedAuthorStyleSheets());
+    result.appendVector(m_document.extensionStyleSheets().authorStyleSheetsForTesting());
+
+    for (auto& styleSheet : m_styleSheetsForStyleSheetList) {
+        if (!is<CSSStyleSheet>(*styleSheet))
+            continue;
+
+        CSSStyleSheet& sheet = downcast<CSSStyleSheet>(*styleSheet);
+        if (sheet.disabled())
+            continue;
+
+        result.append(&sheet);
+    }
+
+    return result;
+}
+
+bool Scope::activeStyleSheetsContains(const CSSStyleSheet* sheet) const
+{
+    if (!m_weakCopyOfActiveStyleSheetListForFastLookup) {
+        m_weakCopyOfActiveStyleSheetListForFastLookup = std::make_unique<HashSet<const CSSStyleSheet*>>();
+        for (auto& activeStyleSheet : m_activeStyleSheets)
+            m_weakCopyOfActiveStyleSheetListForFastLookup->add(activeStyleSheet.get());
+    }
+    return m_weakCopyOfActiveStyleSheetListForFastLookup->contains(sheet);
+}
+
+void Scope::flushPendingSelfUpdate()
+{
+    ASSERT(m_pendingUpdate);
+
+    auto updateType = *m_pendingUpdate;
+
+    clearPendingUpdate();
+    updateActiveStyleSheets(updateType);
+}
+
+void Scope::flushPendingDescendantUpdates()
+{
+    ASSERT(m_hasDescendantWithPendingUpdate);
+    ASSERT(!m_shadowRoot);
+    for (auto* descendantShadowRoot : m_document.inDocumentShadowRoots())
+        descendantShadowRoot->styleScope().flushPendingUpdate();
+    m_hasDescendantWithPendingUpdate = false;
+}
+
+void Scope::clearPendingUpdate()
+{
+    m_pendingUpdateTimer.stop();
+    m_pendingUpdate = { };
+}
+
+void Scope::scheduleUpdate(UpdateType update)
+{
+    // FIXME: The m_isUpdatingStyleResolver test is here because extension stylesheets can get us here from StyleResolver::appendAuthorStyleSheets.
+    if (update == UpdateType::ContentsOrInterpretation && !m_isUpdatingStyleResolver)
+        clearResolver();
+
+    if (!m_pendingUpdate || *m_pendingUpdate < update) {
+        m_pendingUpdate = update;
+        if (m_shadowRoot)
+            m_document.styleScope().m_hasDescendantWithPendingUpdate = true;
+    }
+
+    if (m_pendingUpdateTimer.isActive())
+        return;
+    m_pendingUpdateTimer.startOneShot(0);
+}
+
+void Scope::didChangeActiveStyleSheetCandidates()
+{
+    scheduleUpdate(UpdateType::ActiveSet);
+}
+
+void Scope::didChangeStyleSheetContents()
+{
+    scheduleUpdate(UpdateType::ContentsOrInterpretation);
+}
+
+void Scope::didChangeStyleSheetEnvironment()
+{
+    if (!m_shadowRoot) {
+        for (auto* descendantShadowRoot : m_document.inDocumentShadowRoots()) {
+            // Stylesheets is author shadow roots are are potentially affected.
+            if (descendantShadowRoot->mode() != ShadowRootMode::UserAgent)
+                descendantShadowRoot->styleScope().scheduleUpdate(UpdateType::ContentsOrInterpretation);
+        }
+    }
+    scheduleUpdate(UpdateType::ContentsOrInterpretation);
+}
+
+void Scope::pendingUpdateTimerFired()
+{
+    flushPendingUpdate();
+}
+
+const Vector<RefPtr<StyleSheet>>& Scope::styleSheetsForStyleSheetList()
+{
+    // FIXME: StyleSheetList content should be updated separately from style resolver updates.
+    flushPendingUpdate();
+    return m_styleSheetsForStyleSheetList;
+}
+
+}
+}