Home | History | Annotate | Download | only in dom
      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 #ifndef ActiveDOMObject_h
     28 #define ActiveDOMObject_h
     29 
     30 #include "core/dom/ContextLifecycleObserver.h"
     31 #include "wtf/Assertions.h"
     32 
     33 namespace blink {
     34 
     35 class ActiveDOMObject : public ContextLifecycleObserver {
     36 public:
     37     ActiveDOMObject(ExecutionContext*);
     38 
     39     // suspendIfNeeded() should be called exactly once after object construction to synchronize
     40     // the suspend state with that in ExecutionContext.
     41     void suspendIfNeeded();
     42 #if ENABLE(ASSERT)
     43     bool suspendIfNeededCalled() const { return m_suspendIfNeededCalled; }
     44 #endif
     45 
     46     // Should return true if there's any pending asynchronous activity, and so
     47     // this object must not be garbage collected.
     48     virtual bool hasPendingActivity() const;
     49 
     50     // These methods have an empty default implementation so that subclasses
     51     // which don't need special treatment can skip implementation.
     52     virtual void suspend();
     53     virtual void resume();
     54     virtual void stop();
     55 
     56     void didMoveToNewExecutionContext(ExecutionContext*);
     57 
     58 protected:
     59     virtual ~ActiveDOMObject();
     60 
     61 private:
     62 #if ENABLE(ASSERT)
     63     bool m_suspendIfNeededCalled;
     64 #endif
     65 };
     66 
     67 } // namespace blink
     68 
     69 #endif // ActiveDOMObject_h
     70