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      1 /*
      2  * Copyright (C) 2012 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "ContextFeaturesClientImpl.h"
     33 
     34 #include "WebDocument.h"
     35 #include "WebPermissionClient.h"
     36 #include "core/dom/Document.h"
     37 #include "weborigin/SecurityOrigin.h"
     38 
     39 using namespace WebCore;
     40 
     41 namespace WebKit {
     42 
     43 class ContextFeaturesCache : public Supplement<ScriptExecutionContext> {
     44 public:
     45     class Entry {
     46     public:
     47         enum Value {
     48             IsEnabled,
     49             IsDisabled,
     50             NeedsRefresh
     51         };
     52 
     53         Entry()
     54             : m_value(NeedsRefresh)
     55             , m_defaultValue(false)
     56         { }
     57 
     58         bool isEnabled() const
     59         {
     60             ASSERT(m_value != NeedsRefresh);
     61             return m_value == IsEnabled;
     62         }
     63 
     64         void set(bool value, bool defaultValue)
     65         {
     66             m_value = value ? IsEnabled : IsDisabled;
     67             m_defaultValue = defaultValue;
     68         }
     69 
     70         bool needsRefresh(bool defaultValue) const
     71         {
     72             return m_value == NeedsRefresh || m_defaultValue != defaultValue;
     73         }
     74 
     75     private:
     76         Value m_value;
     77         bool m_defaultValue; // Needs to be traked as a part of the signature since it can be changed dynamically.
     78     };
     79 
     80     static const char* supplementName();
     81     static ContextFeaturesCache* from(Document*);
     82 
     83     Entry& entryFor(ContextFeatures::FeatureType type)
     84     {
     85         size_t index = static_cast<size_t>(type);
     86         ASSERT_WITH_SECURITY_IMPLICATION(index < ContextFeatures::FeatureTypeSize);
     87         return m_entries[index];
     88     }
     89 
     90     void validateAgainst(Document*);
     91 
     92 private:
     93     String m_domain;
     94     Entry m_entries[ContextFeatures::FeatureTypeSize];
     95 };
     96 
     97 const char* ContextFeaturesCache::supplementName()
     98 {
     99     return "ContextFeaturesCache";
    100 }
    101 
    102 ContextFeaturesCache* ContextFeaturesCache::from(Document* document)
    103 {
    104     ContextFeaturesCache* cache = static_cast<ContextFeaturesCache*>(Supplement<ScriptExecutionContext>::from(document, supplementName()));
    105     if (!cache) {
    106         cache = new ContextFeaturesCache();
    107         Supplement<ScriptExecutionContext>::provideTo(document, supplementName(), adoptPtr(cache));
    108     }
    109 
    110     return cache;
    111 }
    112 
    113 void ContextFeaturesCache::validateAgainst(Document* document)
    114 {
    115     String currentDomain = document->securityOrigin()->domain();
    116     if (currentDomain == m_domain)
    117         return;
    118     m_domain = currentDomain;
    119     for (size_t i = 0; i < ContextFeatures::FeatureTypeSize; ++i)
    120         m_entries[i] = Entry();
    121 }
    122 
    123 bool ContextFeaturesClientImpl::isEnabled(Document* document, ContextFeatures::FeatureType type, bool defaultValue)
    124 {
    125     ContextFeaturesCache::Entry& cache = ContextFeaturesCache::from(document)->entryFor(type);
    126     if (cache.needsRefresh(defaultValue))
    127         cache.set(askIfIsEnabled(document, type, defaultValue), defaultValue);
    128     return cache.isEnabled();
    129 }
    130 
    131 void ContextFeaturesClientImpl::urlDidChange(Document* document)
    132 {
    133     ContextFeaturesCache::from(document)->validateAgainst(document);
    134 }
    135 
    136 bool ContextFeaturesClientImpl::askIfIsEnabled(Document* document, ContextFeatures::FeatureType type, bool defaultValue)
    137 {
    138     if (!m_client)
    139         return defaultValue;
    140 
    141     switch (type) {
    142     case ContextFeatures::StyleScoped:
    143         return m_client->allowWebComponents(WebDocument(document), defaultValue);
    144     case ContextFeatures::MutationEvents:
    145         return m_client->allowMutationEvents(WebDocument(document), defaultValue);
    146     case ContextFeatures::PushState:
    147         return m_client->allowPushState(WebDocument(document));
    148     default:
    149         return defaultValue;
    150     }
    151 }
    152 
    153 } // namespace WebKit
    154