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/*
* Copyright (C) 2013 Google 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE COPYRIGHT
* OWNER 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 DocumentLifecycle_h
#define DocumentLifecycle_h
#include "wtf/Assertions.h"
#include "wtf/Noncopyable.h"
namespace WebCore {
class DocumentLifecycle {
WTF_MAKE_NONCOPYABLE(DocumentLifecycle);
public:
enum State {
Uninitialized,
Inactive,
// When the document is active, it traverses these states.
VisualUpdatePending,
InStyleRecalc,
StyleClean,
InPreLayout,
InPerformLayout,
AfterPerformLayout,
LayoutClean,
InCompositingUpdate,
CompositingClean,
// Once the document starts shuting down, we cannot return
// to the style/layout/rendering states.
Stopping,
Stopped,
Disposed,
};
class Scope {
WTF_MAKE_NONCOPYABLE(Scope);
public:
Scope(DocumentLifecycle&, State finalState);
~Scope();
void setFinalState(State finalState) { m_finalState = finalState; }
private:
DocumentLifecycle& m_lifecycle;
State m_finalState;
};
class DeprecatedTransition {
WTF_MAKE_NONCOPYABLE(DeprecatedTransition);
public:
DeprecatedTransition(State from, State to);
~DeprecatedTransition();
State from() const { return m_from; }
State to() const { return m_to; }
private:
DeprecatedTransition* m_previous;
State m_from;
State m_to;
};
class DetachScope {
WTF_MAKE_NONCOPYABLE(DetachScope);
public:
explicit DetachScope(DocumentLifecycle& documentLifecycle)
: m_documentLifecycle(documentLifecycle)
{
m_documentLifecycle.incrementDetachCount();
}
~DetachScope()
{
m_documentLifecycle.decrementDetachCount();
}
private:
DocumentLifecycle& m_documentLifecycle;
};
DocumentLifecycle();
~DocumentLifecycle();
bool isActive() const { return m_state > Inactive && m_state < Stopping; }
State state() const { return m_state; }
bool stateAllowsTreeMutations() const;
bool stateAllowsRenderTreeMutations() const;
bool stateAllowsDetach() const;
void advanceTo(State);
void ensureStateAtMost(State);
void incrementDetachCount() { m_detachCount++; }
void decrementDetachCount()
{
ASSERT(m_detachCount > 0);
m_detachCount--;
}
private:
#if ASSERT_ENABLED
bool canAdvanceTo(State) const;
bool canRewindTo(State) const;
#endif
State m_state;
int m_detachCount;
};
inline bool DocumentLifecycle::stateAllowsTreeMutations() const
{
// FIXME: We should not allow mutations in InPreLayout or AfterPerformLayout either,
// but we need to fix MediaList listeners and plugins first.
return m_state != InStyleRecalc
&& m_state != InPerformLayout
&& m_state != InCompositingUpdate;
}
inline bool DocumentLifecycle::stateAllowsRenderTreeMutations() const
{
return m_detachCount || m_state == InStyleRecalc;
}
inline bool DocumentLifecycle::stateAllowsDetach() const
{
return m_state == VisualUpdatePending
|| m_state == InStyleRecalc
|| m_state == StyleClean
|| m_state == InPreLayout
|| m_state == LayoutClean
|| m_state == CompositingClean
|| m_state == Stopping;
}
}
#endif
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