Source/WebCore/loader/FrameLoaderStateMachine.h

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *     from this software without specific prior written permission. 
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 * 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
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#pragma once

#include <wtf/Noncopyable.h>

namespace WebCore {

// Encapsulates a state machine for FrameLoader. Note that this is different from FrameState,
// which stores the state of the current load that FrameLoader is executing.
class FrameLoaderStateMachine {
    WTF_MAKE_NONCOPYABLE(FrameLoaderStateMachine);
public:
    FrameLoaderStateMachine();

    // Once a load has been committed, the state may
    // alternate between CommittedFirstRealLoad and FirstLayoutDone.
    // Otherwise, the states only go down the list.
    enum State {
        CreatingInitialEmptyDocument,
        DisplayingInitialEmptyDocument,
        DisplayingInitialEmptyDocumentPostCommit,
        CommittedFirstRealLoad,
        FirstLayoutDone
    };

    WEBCORE_EXPORT bool committingFirstRealLoad() const;
    bool committedFirstRealDocumentLoad() const;
    WEBCORE_EXPORT bool creatingInitialEmptyDocument() const;
    WEBCORE_EXPORT bool isDisplayingInitialEmptyDocument() const;
    WEBCORE_EXPORT bool firstLayoutDone() const;
    void advanceTo(State);

    State stateForDebugging() const { return m_state; }

private:
    State m_state;
};

} // namespace WebCore