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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  *     * Neither the name of Google Inc. nor the names of its
     11  * contributors may be used to endorse or promote products derived from
     12  * this software without specific prior written permission.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     15  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     16  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     17  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     18  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     19  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     20  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #ifndef ContextFeatures_h
     28 #define ContextFeatures_h
     29 
     30 #include "platform/RefCountedSupplement.h"
     31 
     32 namespace blink {
     33 
     34 class ContextFeaturesClient;
     35 class Document;
     36 class Page;
     37 
     38 #if ENABLE(OILPAN)
     39 class ContextFeatures FINAL : public GarbageCollectedFinalized<ContextFeatures>, public HeapSupplement<Page> {
     40     USING_GARBAGE_COLLECTED_MIXIN(ContextFeatures);
     41 public:
     42     typedef HeapSupplement<Page> SupplementType;
     43 #else
     44 class ContextFeatures : public RefCountedSupplement<Page, ContextFeatures> {
     45 public:
     46     typedef RefCountedSupplement<Page, ContextFeatures> SupplementType;
     47 #endif
     48     enum FeatureType {
     49         PagePopup = 0,
     50         MutationEvents,
     51         PushState,
     52         FeatureTypeSize // Should be the last entry.
     53     };
     54 
     55     static const char* supplementName();
     56     static ContextFeatures* defaultSwitch();
     57     static PassRefPtrWillBeRawPtr<ContextFeatures> create(PassOwnPtr<ContextFeaturesClient>);
     58 
     59     static bool pagePopupEnabled(Document*);
     60     static bool mutationEventsEnabled(Document*);
     61     static bool pushStateEnabled(Document*);
     62 
     63     bool isEnabled(Document*, FeatureType, bool) const;
     64     void urlDidChange(Document*);
     65 
     66 #if ENABLE(OILPAN)
     67     virtual void trace(Visitor* visitor) OVERRIDE { HeapSupplement<Page>::trace(visitor); }
     68 #endif
     69 
     70 private:
     71     explicit ContextFeatures(PassOwnPtr<ContextFeaturesClient> client)
     72         : m_client(client)
     73     { }
     74 
     75     OwnPtr<ContextFeaturesClient> m_client;
     76 };
     77 
     78 class ContextFeaturesClient {
     79     WTF_MAKE_FAST_ALLOCATED;
     80 public:
     81     static PassOwnPtr<ContextFeaturesClient> empty();
     82 
     83     virtual ~ContextFeaturesClient() { }
     84     virtual bool isEnabled(Document*, ContextFeatures::FeatureType, bool defaultValue) { return defaultValue; }
     85     virtual void urlDidChange(Document*) { }
     86 };
     87 
     88 void provideContextFeaturesTo(Page&, PassOwnPtr<ContextFeaturesClient>);
     89 void provideContextFeaturesToDocumentFrom(Document&, Page&);
     90 
     91 inline PassRefPtrWillBeRawPtr<ContextFeatures> ContextFeatures::create(PassOwnPtr<ContextFeaturesClient> client)
     92 {
     93     return adoptRefWillBeNoop(new ContextFeatures(client));
     94 }
     95 
     96 inline bool ContextFeatures::isEnabled(Document* document, FeatureType type, bool defaultValue) const
     97 {
     98     if (!m_client)
     99         return defaultValue;
    100     return m_client->isEnabled(document, type, defaultValue);
    101 }
    102 
    103 inline void ContextFeatures::urlDidChange(Document* document)
    104 {
    105     // FIXME: The original code, commented out below, is obviously
    106     // wrong, but the seemingly correct fix of negating the test to
    107     // the more logical 'if (!m_client)' crashes the renderer.
    108     // See issue 294180
    109     //
    110     // if (m_client)
    111     //     return;
    112     // m_client->urlDidChange(document);
    113 }
    114 
    115 } // namespace blink
    116 
    117 #endif // ContextFeatures_h
    118