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 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
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 *   ownership. The ASF licenses this file to you under the Apache
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 */

#ifndef INCLUDED_VCL_SCHEDULER_HXX
#define INCLUDED_VCL_SCHEDULER_HXX

#include <vcl/dllapi.h>

struct ImplSVData;
class Scheduler;
struct ImplSchedulerData
{
    ImplSchedulerData*  mpNext;      // Pointer to the next element in list
    Scheduler*          mpScheduler;      // Pointer to VCL Scheduler instance
    bool                mbDelete;    // Destroy this scheduler?
    bool                mbInScheduler;    // Scheduler currently processed?
    sal_uInt64          mnUpdateTime;   // Last Update Time
    sal_uInt32          mnUpdateStack;  // Update Stack

    void Invoke();

    static ImplSchedulerData *GetMostImportantTask( bool bTimer );
};

enum class SchedulerPriority {
    HIGHEST   = 0,
    HIGH      = 1,
    RESIZE    = 2,
    REPAINT   = 3,
    MEDIUM    = 3,
    LOW       = 4,
    LOWER     = 5,
    LOWEST    = 6
};

class VCL_DLLPUBLIC Scheduler
{
protected:
    ImplSchedulerData*  mpSchedulerData;    // Pointer to element in scheduler list
    SchedulerPriority   mePriority;         // Scheduler priority
    bool                mbActive;           // Currently in the scheduler

    friend struct ImplSchedulerData;
    virtual void SetDeletionFlags();
    virtual bool ReadyForSchedule( bool bTimer ) { return !bTimer; }
    virtual sal_uInt64 UpdateMinPeriod( sal_uInt64 nMinPeriod, sal_uInt64 nTime );

public:
    Scheduler();
    Scheduler( const Scheduler& rScheduler );
    virtual ~Scheduler();

    void SetPriority( SchedulerPriority ePriority );
    SchedulerPriority GetPriority() const { return mePriority; }

    // Call handler
    virtual void    Invoke() = 0;

    virtual void    Start();
    virtual void    Stop();

    bool            IsActive() const { return mbActive; }

    Scheduler&          operator=( const Scheduler& rScheduler );
    static void ImplDeInitScheduler();

    // Process one pending Timer with highhest priority
    static void CallbackTaskScheduling( bool ignore );
    /// Process one pending task ahead of time with highhest priority.
    static void ProcessTaskScheduling( bool bTimer );
};

#endif // INCLUDED_VCL_SCHEDULER_HXX

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