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 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
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 *   ownership. The ASF licenses this file to you under the Apache
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#ifndef INCLUDED_SD_SOURCE_UI_INC_TOOLS_ASYNCHRONOUSCALL_HXX
#define INCLUDED_SD_SOURCE_UI_INC_TOOLS_ASYNCHRONOUSCALL_HXX

#include <vcl/timer.hxx>

#include <memory>
#include <functional>

namespace sd::tools {

/** Store a function object and execute it asynchronous.

    The features of this class are:
    a) It provides a wrapper around a VCL Timer so that generic function
    objects can be used.
    b) When more than one function objects are posted to be executed later
    then the pending ones are erased and only the last one will actually be
    executed.

    Use this class like this:
    aInstanceOfAsynchronousCall.Post(
        ::std::bind(
            ::std::mem_fun(&DrawViewShell::SwitchPage),
            pDrawViewShell,
            11));
*/
class AsynchronousCall
{
public:
    /** Create a new asynchronous call.  Each object of this class processes
        one (semantical) type of call.
    */
    AsynchronousCall();

    ~AsynchronousCall();

    /** Post a function object that is to be executed asynchronously.  When
        this method is called while the current function object has not been
        executed then the latter is destroyed and only the given function
        object will be executed.
        @param rFunction
            The function object that may be called asynchronously in the
            near future.
    */
    typedef ::std::function<void ()> AsynchronousFunction;
    void Post (
        const AsynchronousFunction& rFunction);

private:
    Timer maTimer;
    /** The function object that will be executed when the TimerCallback
        function is called the next time.  This pointer may be NULL.
    */
    ::std::unique_ptr<AsynchronousFunction> mpFunction;
    DECL_LINK(TimerCallback,Timer*,void);
};

} // end of namespace ::sd::tools

#endif

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