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 * Licensed to the Apache Software Foundation (ASF) under one
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 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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#ifndef SDEXT_PRESENTER_TIMER_HXX
#define SDEXT_PRESENTER_TIMER_HXX

#include <com/sun/star/awt/XCallback.hpp>
#include <com/sun/star/awt/XRequestCallback.hpp>
#include <cppuhelper/basemutex.hxx>
#include <cppuhelper/compbase1.hxx>
#include <osl/mutex.hxx>
#include <osl/time.h>
#include <rtl/ref.hxx>
#include <sal/types.h>
#include <boost/enable_shared_from_this.hpp>
#include <boost/function.hpp>
#include <vector>

namespace css = ::com::sun::star;

namespace sdext { namespace presenter {

class PresenterClockInternalTimer;

/** The timer allows tasks to be scheduled for execution at a specified time
    in the future.
*/
class PresenterTimer
{
public:
    /** A task is called with the current time.
    */
    typedef ::boost::function<void(const TimeValue&)> Task;

    static const sal_Int32 NotAValidTaskId = 0;
    
    static sal_Int32 ScheduleSingleTaskRelative (
        const Task& rTask,
        const sal_Int64 nDelay);

    static sal_Int32 ScheduleSingleTaskAbsolute (
        const Task& rTask,
        const TimeValue& rDueTime);

    /** Schedule a task to be executed repeatedly.  The task is executed the
        first time after nFirst nano-seconds (1000000000 corresponds to one
        second).  After that task is executed in intervalls that are
        nIntervall ns long until CancelTask is called.
    */
    static sal_Int32 ScheduleRepeatedTask (
        const Task& rTask,
        const sal_Int64 nFirst,
        const sal_Int64 nIntervall);

    static void CancelTask (const sal_Int32 nTaskId);
};


typedef cppu::WeakComponentImplHelper1< 
    css::awt::XCallback
    > PresenterClockTimerInterfaceBase;

/** A timer that calls its listeners, typically clocks, every second to
    update their current time value.
*/
class PresenterClockTimer
    : protected ::cppu::BaseMutex,
      public PresenterClockTimerInterfaceBase
{
public:
    class Listener { public:
        virtual void TimeHasChanged (const oslDateTime& rCurrentTime) = 0;
    };
    typedef ::boost::shared_ptr<Listener> SharedListener;
    
    static ::rtl::Reference<PresenterClockTimer> Instance (
        const css::uno::Reference<css::uno::XComponentContext>& rxContext);

    void AddListener (const SharedListener& rListener);
    void RemoveListener (const SharedListener& rListener);

    static oslDateTime GetCurrentTime (void);
    
    /** Return the difference between the two different times in
        nanoseconds.
    */
    static sal_Int64 GetTimeDifference (const oslDateTime& rNow, const oslDateTime& rThen);

    // XCallback

    virtual void SAL_CALL notify (const css::uno::Any& rUserData)
        throw (css::uno::RuntimeException);

private:
    static ::rtl::Reference<PresenterClockTimer> mpInstance;

    ::osl::Mutex maMutex;
    typedef ::std::vector<SharedListener> ListenerContainer;
    ListenerContainer maListeners;
    oslDateTime maDateTime;
    sal_Int32 mnTimerTaskId;
    bool mbIsCallbackPending;
    css::uno::Reference<css::awt::XRequestCallback> mxRequestCallback;

    PresenterClockTimer (
        const css::uno::Reference<css::uno::XComponentContext>& rxContext);
    ~PresenterClockTimer (void);
    
    void CheckCurrentTime (const TimeValue& rCurrentTime);
};


} } // end of namespace ::sdext::presenter

#endif