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      1 /*
      2  * Copyright (C) 2008 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 COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  *
     25  */
     26 
     27 #include "config.h"
     28 #include "core/dom/ActiveDOMObject.h"
     29 
     30 #include "core/dom/ExecutionContext.h"
     31 
     32 namespace WebCore {
     33 
     34 ActiveDOMObject::ActiveDOMObject(ExecutionContext* executionContext)
     35     : ContextLifecycleObserver(executionContext, ActiveDOMObjectType)
     36     , m_pendingActivityCount(0)
     37 #if ASSERT_ENABLED
     38     , m_suspendIfNeededCalled(false)
     39 #endif
     40 {
     41     ASSERT(!executionContext || executionContext->isContextThread());
     42 }
     43 
     44 ActiveDOMObject::~ActiveDOMObject()
     45 {
     46     // ActiveDOMObject may be inherited by a sub-class whose life-cycle
     47     // exceeds that of the associated ExecutionContext. In those cases,
     48     // m_executionContext would/should have been nullified by
     49     // ContextLifecycleObserver::contextDestroyed() (which we implement /
     50     // inherit). Hence, we should ensure that this is not 0 before use it
     51     // here.
     52     if (!executionContext())
     53         return;
     54 
     55     ASSERT(m_suspendIfNeededCalled);
     56     ASSERT(executionContext()->isContextThread());
     57 }
     58 
     59 void ActiveDOMObject::suspendIfNeeded()
     60 {
     61 #if ASSERT_ENABLED
     62     ASSERT(!m_suspendIfNeededCalled);
     63     m_suspendIfNeededCalled = true;
     64 #endif
     65     if (ExecutionContext* context = executionContext())
     66         context->suspendActiveDOMObjectIfNeeded(this);
     67 }
     68 
     69 bool ActiveDOMObject::hasPendingActivity() const
     70 {
     71     return m_pendingActivityCount;
     72 }
     73 
     74 void ActiveDOMObject::suspend()
     75 {
     76 }
     77 
     78 void ActiveDOMObject::resume()
     79 {
     80 }
     81 
     82 void ActiveDOMObject::stop()
     83 {
     84 }
     85 
     86 void ActiveDOMObject::didMoveToNewExecutionContext(ExecutionContext* context)
     87 {
     88     observeContext(context);
     89 
     90     if (context->activeDOMObjectsAreStopped()) {
     91         stop();
     92         return;
     93     }
     94 
     95     if (context->activeDOMObjectsAreSuspended()) {
     96         suspend();
     97         return;
     98     }
     99 
    100     resume();
    101 }
    102 
    103 } // namespace WebCore
    104