// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef WebFrameScheduler_h
#define WebFrameScheduler_h

#include "WebCommon.h"

#include <string>

namespace blink {

class WebSecurityOrigin;
class WebTaskRunner;
class WebViewScheduler;

class BLINK_PLATFORM_EXPORT WebFrameScheduler {
public:
    virtual ~WebFrameScheduler() { }

    // The scheduler may throttle tasks associated with offscreen frames.
    virtual void setFrameVisible(bool) { }

    // Tells the scheduler that the page this frame belongs to is not visible.
    // The scheduler may throttle tasks associated with pages that are not visible.
    virtual void setPageVisible(bool) { }

    // Returns the WebTaskRunner for loading tasks.
    // WebFrameScheduler owns the returned WebTaskRunner.
    virtual WebTaskRunner* loadingTaskRunner() { return nullptr; }

    // Returns the WebTaskRunner for timer tasks.
    // WebFrameScheduler owns the returned WebTaskRunner.
    virtual WebTaskRunner* timerTaskRunner() { return nullptr; }

    // Returns the WebTaskRunner for tasks which should never get throttled.
    // This is generally used for executing internal browser tasks which should
    // never be throttled. Ideally only tasks whose performance characteristics
    // are known should be posted to this task runner; for example user
    // JavaScript is discouraged. WebFrameScheduler owns the returned
    // WebTaskRunner.
    virtual WebTaskRunner* unthrottledTaskRunner() { return nullptr; }

    // Returns the parent WebViewScheduler.
    virtual WebViewScheduler* webViewScheduler() { return nullptr; }

    // Tells the scheduler a resource load has started. The scheduler may make
    // policy decisions based on this.
    virtual void didStartLoading(unsigned long identifier) { }

    // Tells the scheduler a resource load has stopped. The scheduler may make
    // policy decisions based on this.
    virtual void didStopLoading(unsigned long identifier) { }

    // Tells the scheduler if we are parsing a document on another thread. This
    // tells the scheduler not to advance virtual time if it's using the
    // DETERMINISTIC_LOADING policy.
    virtual void setDocumentParsingInBackground(bool) {}
};

} // namespace blink

#endif // WebFrameScheduler_h