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/*
* Copyright (C) 2008 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef ActiveDOMObject_h
#define ActiveDOMObject_h
#include <wtf/Assertions.h>
namespace WebCore {
class ScriptExecutionContext;
class ActiveDOMObject {
public:
ActiveDOMObject(ScriptExecutionContext*, void* upcastPointer);
ScriptExecutionContext* scriptExecutionContext() const { return m_scriptExecutionContext; }
virtual bool hasPendingActivity() const;
virtual void contextDestroyed();
// canSuspend() is used by the caller if there is a choice between suspending and stopping.
// For example, a page won't be suspended and placed in the back/forward cache if it has
// the objects that can not be suspended.
// However, 'suspend' can be called even if canSuspend() would return 'false'. That
// happens in step-by-step JS debugging for example - in this case it would be incorrect
// to stop the object. Exact semantics of suspend is up to the object then.
enum ReasonForSuspension {
JavaScriptDebuggerPaused,
WillShowDialog,
DocumentWillBecomeInactive
};
virtual bool canSuspend() const;
virtual void suspend(ReasonForSuspension);
virtual void resume();
virtual void stop();
template<class T> void setPendingActivity(T* thisObject)
{
ASSERT(thisObject == this);
thisObject->ref();
m_pendingActivityCount++;
}
template<class T> void unsetPendingActivity(T* thisObject)
{
ASSERT(m_pendingActivityCount > 0);
--m_pendingActivityCount;
thisObject->deref();
}
protected:
virtual ~ActiveDOMObject();
private:
ScriptExecutionContext* m_scriptExecutionContext;
unsigned m_pendingActivityCount;
};
} // namespace WebCore
#endif // ActiveDOMObject_h