third_party/WebKit/Source/core/dom/ContextFeatures.h

   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 "core/CoreExport.h"
  31 #include "core/page/Page.h"
  32 #include "platform/RefCountedSupplement.h"
  33
  34 namespace blink {
  35
  36 class ContextFeaturesClient;
  37 class Document;
  38 class Page;
  39
  40 #if ENABLE(OILPAN)
  41 class ContextFeatures final : public GarbageCollectedFinalized<ContextFeatures>, public HeapSupplement<Page> {
  42     USING_GARBAGE_COLLECTED_MIXIN(ContextFeatures);
  43 public:
  44     typedef HeapSupplement<Page> SupplementType;
  45 #else
  46 class ContextFeatures : public RefCountedSupplement<Page, ContextFeatures> {
  47 public:
  48     typedef RefCountedSupplement<Page, ContextFeatures> SupplementType;
  49 #endif
  50     enum FeatureType {
  51         PagePopup = 0,
  52         MutationEvents,
  53         FeatureTypeSize // Should be the last entry.
  54     };
  55
  56     static const char* supplementName();
  57     static ContextFeatures* defaultSwitch();
  58     static PassRefPtrWillBeRawPtr<ContextFeatures> create(PassOwnPtr<ContextFeaturesClient>);
  59
  60     static bool pagePopupEnabled(Document*);
  61     static bool mutationEventsEnabled(Document*);
  62
  63     bool isEnabled(Document*, FeatureType, bool) const;
  64     void urlDidChange(Document*);
  65
  66 #if ENABLE(OILPAN)
  67     DEFINE_INLINE_VIRTUAL_TRACE() { 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(ContextFeaturesClient);
  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 CORE_EXPORT 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