1 /*

     2  * Copyright (C) 2010 Apple 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

     6  * are met:

     7  * 1. Redistributions of source code must retain the above copyright

     8  *    notice, this list of conditions and the following disclaimer.

     9  * 2. Redistributions in binary form must reproduce the above copyright

    10  *    notice, this list of conditions and the following disclaimer in the

    11  *    documentation and/or other materials provided with the distribution.

    12  *

    13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''

    14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

    15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS

    17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

    23  * THE POSSIBILITY OF SUCH DAMAGE.

    24  */

    25 

    26 #ifndef GenericCallback_h

    27 #define GenericCallback_h

    28 

    29 #include "WKAPICast.h"

    30 #include <wtf/PassRefPtr.h>

    31 #include <wtf/RefCounted.h>

    32 

    33 namespace WebKit {

    34 

    35 template<typename APIReturnValueType, typename InternalReturnValueType = typename APITypeInfo<APIReturnValueType>::ImplType>

    36 class GenericCallback : public RefCounted<GenericCallback<APIReturnValueType, InternalReturnValueType> > {

    37 public:

    38     typedef void (*CallbackFunction)(APIReturnValueType, void*);

    39     typedef void (*CallbackDisposeFunction)(void*);

    40 

    41     static PassRefPtr<GenericCallback> create(void* context, CallbackFunction callback, CallbackDisposeFunction disposeCallback)

    42     {

    43         return adoptRef(new GenericCallback(context, callback, disposeCallback));

    44     }

    45 

    46     ~GenericCallback()

    47     {

    48         ASSERT(!m_callback);

    49     }

    50 

    51     void performCallbackWithReturnValue(InternalReturnValueType returnValue)

    52     {

    53         ASSERT(m_callback);

    54 

    55         m_callback(toRef(returnValue), m_context);

    56 

    57         m_callback = 0;

    58         m_disposeCallback = 0;

    59     }

    60     

    61     void invalidate()

    62     {

    63         ASSERT(m_callback);

    64 

    65         m_disposeCallback(m_context);

    66 

    67         m_callback = 0;

    68         m_disposeCallback = 0;

    69     }

    70 

    71     uint64_t callbackID() const { return m_callbackID; }

    72 

    73 private:

    74     static uint64_t generateCallbackID()

    75     {

    76         static uint64_t uniqueCallbackID = 1;

    77         return uniqueCallbackID++;

    78     }

    79 

    80     GenericCallback(void* context, CallbackFunction callback, CallbackDisposeFunction disposeCallback)

    81         : m_context(context)

    82         , m_callback(callback)

    83         , m_disposeCallback(disposeCallback)

    84         , m_callbackID(generateCallbackID())

    85     {

    86     }

    87 

    88     void* m_context;

    89     CallbackFunction m_callback;

    90     CallbackDisposeFunction m_disposeCallback;

    91     uint64_t m_callbackID;

    92 };

    93 

    94 } // namespace WebKit

    95 

    96 #endif // GenericCallback_h