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
32namespace blink {
33
34class ContextFeaturesClient;
35class Document;
36class Page;
37
38#if ENABLE(OILPAN)
39class ContextFeatures FINAL : public GarbageCollectedFinalized<ContextFeatures>, public HeapSupplement<Page> {
40    USING_GARBAGE_COLLECTED_MIXIN(ContextFeatures);
41public:
42    typedef HeapSupplement<Page> SupplementType;
43#else
44class ContextFeatures : public RefCountedSupplement<Page, ContextFeatures> {
45public:
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
70private:
71    explicit ContextFeatures(PassOwnPtr<ContextFeaturesClient> client)
72        : m_client(client)
73    { }
74
75    OwnPtr<ContextFeaturesClient> m_client;
76};
77
78class ContextFeaturesClient {
79    WTF_MAKE_FAST_ALLOCATED;
80public:
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
88void provideContextFeaturesTo(Page&, PassOwnPtr<ContextFeaturesClient>);
89void provideContextFeaturesToDocumentFrom(Document&, Page&);
90
91inline PassRefPtrWillBeRawPtr<ContextFeatures> ContextFeatures::create(PassOwnPtr<ContextFeaturesClient> client)
92{
93    return adoptRefWillBeNoop(new ContextFeatures(client));
94}
95
96inline 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
103inline 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