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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 THIRD_PARTY_BLINK_RENDERER_CORE_EXECUTION_CONTEXT_EXECUTION_CONTEXT_LIFECYCLE_STATE_OBSERVER_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_EXECUTION_CONTEXT_EXECUTION_CONTEXT_LIFECYCLE_STATE_OBSERVER_H_
#include "third_party/blink/public/mojom/frame/lifecycle.mojom-blink-forward.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/execution_context/execution_context_lifecycle_observer.h"
#include "third_party/blink/renderer/platform/wtf/assertions.h"
namespace blink {
// A ExecutionContextLifecycleStateObserver responds to situations where Blink
// is pausing a context or freezing a frame.
//
// Context lifecycle state changes can happen in cases such as:
// - modal dialogs during script execution (e.g. window.alert, window.print)
// - script execution stopped at a debugger breakpoint
// - frozen contexts (resource coordinator background tasks, iframe freezing)
//
// The scheduler will automatically suspend certain task queues for the duration
// that the page is paused.
//
// Objects with asynchronous activity, especially activity that may have an
// observable effect on web-visible state, on should suspend that activity while
// the page is paused by overriding ContextLifecycleStateChanged().
//
// https://html.spec.whatwg.org/C/#pause
// https://wicg.github.io/page-lifecycle/spec.html
class CORE_EXPORT ExecutionContextLifecycleStateObserver
: public ExecutionContextLifecycleObserver {
public:
explicit ExecutionContextLifecycleStateObserver(ExecutionContext*);
// TODO(crbug.com/1029822): This is a shim to enable migrating
// ExecutionContext to LocalDOMWindow.
explicit ExecutionContextLifecycleStateObserver(Document*);
// UpdateStateIfNeeded() should be called exactly once after object
// construction to synchronize the suspend state with that in
// ExecutionContext.
void UpdateStateIfNeeded();
#if DCHECK_IS_ON()
bool UpdateStateIfNeededCalled() const {
return update_state_if_needed_called_;
}
#endif
virtual void ContextLifecycleStateChanged(
mojom::blink::FrameLifecycleState state) = 0;
void SetExecutionContext(ExecutionContext*) override;
protected:
virtual ~ExecutionContextLifecycleStateObserver();
private:
#if DCHECK_IS_ON()
bool update_state_if_needed_called_ = false;
#endif
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_CORE_EXECUTION_CONTEXT_EXECUTION_CONTEXT_LIFECYCLE_STATE_OBSERVER_H_