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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 blink {
     33 
     34 ActiveDOMObject::ActiveDOMObject(ExecutionContext* executionContext)
     35     : ContextLifecycleObserver(executionContext, ActiveDOMObjectType)
     36 #if ENABLE(ASSERT)
     37     , m_suspendIfNeededCalled(false)
     38 #endif
     39 {
     40     ASSERT(!executionContext || executionContext->isContextThread());
     41 }
     42 
     43 ActiveDOMObject::~ActiveDOMObject()
     44 {
     45     // ActiveDOMObject may be inherited by a sub-class whose life-cycle
     46     // exceeds that of the associated ExecutionContext. In those cases,
     47     // m_executionContext would/should have been nullified by
     48     // ContextLifecycleObserver::contextDestroyed() (which we implement /
     49     // inherit). Hence, we should ensure that this is not 0 before use it
     50     // here.
     51     if (!executionContext())
     52         return;
     53 
     54     ASSERT(m_suspendIfNeededCalled);
     55     ASSERT(executionContext()->isContextThread());
     56 }
     57 
     58 void ActiveDOMObject::suspendIfNeeded()
     59 {
     60 #if ENABLE(ASSERT)
     61     ASSERT(!m_suspendIfNeededCalled);
     62     m_suspendIfNeededCalled = true;
     63 #endif
     64     if (ExecutionContext* context = executionContext())
     65         context->suspendActiveDOMObjectIfNeeded(this);
     66 }
     67 
     68 bool ActiveDOMObject::hasPendingActivity() const
     69 {
     70     return false;
     71 }
     72 
     73 void ActiveDOMObject::suspend()
     74 {
     75 }
     76 
     77 void ActiveDOMObject::resume()
     78 {
     79 }
     80 
     81 void ActiveDOMObject::stop()
     82 {
     83 }
     84 
     85 void ActiveDOMObject::didMoveToNewExecutionContext(ExecutionContext* context)
     86 {
     87     observeContext(context);
     88 
     89     if (context->activeDOMObjectsAreStopped()) {
     90         stop();
     91         return;
     92     }
     93 
     94     if (context->activeDOMObjectsAreSuspended()) {
     95         suspend();
     96         return;
     97     }
     98 
     99     resume();
    100 }
    101 
    102 } // namespace blink
    103