1/*
2 * Copyright (C) 2006, 2007, 2008, 2009 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#ifndef V8Utilities_h
32#define V8Utilities_h
33
34#include <wtf/Forward.h>
35#include <v8.h>
36
37namespace WebCore {
38
39    class EventListener;
40    class Frame;
41    class KURL;
42    class ScriptExecutionContext;
43    class ScriptState;
44
45    // Use an array to hold dependents. It works like a ref-counted scheme. A value can be added more than once to the DOM object.
46    void createHiddenDependency(v8::Handle<v8::Object>, v8::Local<v8::Value>, int cacheIndex);
47    void removeHiddenDependency(v8::Handle<v8::Object>, v8::Local<v8::Value>, int cacheIndex);
48
49    // Combo create/remove, for generated event-handler-setter bindings:
50    void transferHiddenDependency(v8::Handle<v8::Object>, EventListener* oldValue, v8::Local<v8::Value> newValue, int cacheIndex);
51
52    bool processingUserGesture();
53    bool shouldAllowNavigation(Frame*);
54    KURL completeURL(const String& relativeURL);
55
56    ScriptExecutionContext* getScriptExecutionContext();
57
58    void throwTypeMismatchException();
59
60    enum CallbackAllowedValueFlag {
61        CallbackAllowUndefined = 1,
62        CallbackAllowNull = 1 << 1
63    };
64
65    typedef unsigned CallbackAllowedValueFlags;
66
67    // 'FunctionOnly' is assumed for the created callback.
68    template <typename V8CallbackType>
69    PassRefPtr<V8CallbackType> createFunctionOnlyCallback(v8::Local<v8::Value> value, bool& succeeded, CallbackAllowedValueFlags acceptedValues = 0)
70    {
71        succeeded = true;
72
73        if (value->IsUndefined() && (acceptedValues & CallbackAllowUndefined))
74            return 0;
75
76        if (value->IsNull() && (acceptedValues & CallbackAllowNull))
77            return 0;
78
79        if (!value->IsFunction()) {
80            succeeded = false;
81            throwTypeMismatchException();
82            return 0;
83        }
84
85        return V8CallbackType::create(value, getScriptExecutionContext());
86    }
87
88    class AllowAllocation {
89    public:
90        inline AllowAllocation()
91        {
92            m_previous = m_current;
93            m_current = true;
94        }
95
96        inline ~AllowAllocation()
97        {
98            m_current = m_previous;
99        }
100
101        static bool m_current;
102
103    private:
104        bool m_previous;
105    };
106
107    class SafeAllocation {
108     public:
109      static inline v8::Local<v8::Object> newInstance(v8::Handle<v8::Function>);
110      static inline v8::Local<v8::Object> newInstance(v8::Handle<v8::ObjectTemplate>);
111      static inline v8::Local<v8::Object> newInstance(v8::Handle<v8::Function>, int argc, v8::Handle<v8::Value> argv[]);
112    };
113
114    v8::Local<v8::Object> SafeAllocation::newInstance(v8::Handle<v8::Function> function)
115    {
116        if (function.IsEmpty())
117            return v8::Local<v8::Object>();
118        AllowAllocation allow;
119        return function->NewInstance();
120    }
121
122    v8::Local<v8::Object> SafeAllocation::newInstance(v8::Handle<v8::ObjectTemplate> objectTemplate)
123    {
124        if (objectTemplate.IsEmpty())
125            return v8::Local<v8::Object>();
126        AllowAllocation allow;
127        return objectTemplate->NewInstance();
128    }
129
130    v8::Local<v8::Object> SafeAllocation::newInstance(v8::Handle<v8::Function> function, int argc, v8::Handle<v8::Value> argv[])
131    {
132        if (function.IsEmpty())
133            return v8::Local<v8::Object>();
134        AllowAllocation allow;
135        return function->NewInstance(argc, argv);
136    }
137
138} // namespace WebCore
139
140#endif // V8Utilities_h
141