/*
 * Copyright 2009, Alexandre Deckner, alex@zappotek.com
 * Distributed under the terms of the MIT License.
 */
#ifndef SHAKE_TRACKING_FILTER_H
#define SHAKE_TRACKING_FILTER_H


#include <MessageFilter.h>
#include <Point.h>

class BView;
class BHandler;
class BMessageRunner;

namespace BPrivate {

class LowPassFilter {
public:
                                                LowPassFilter(uint32 size);
                                                ~LowPassFilter();

                        void        Input(const BPoint& p);
                        BPoint          Output() const;
private:
        BPoint* fPoints;
        uint32  fSize;
        BPoint  fSum;
};


class ShakeTrackingFilter : public BMessageFilter {
public:
                                                                ShakeTrackingFilter(
                                                                        BView* targetView,
                                                                        uint32 messageWhat,
                                                                        uint32 countThreshold = 2,
                                                                        bigtime_t timeTreshold = 400000);

                                                                ~ShakeTrackingFilter();

                        filter_result           Filter(BMessage* message, BHandler** _target);

private:
                        BView*                          fTargetView;
                        uint32                          fMessageWhat;

                        BMessageRunner*         fCancelRunner;
                        LowPassFilter           fLowPass;
                        BPoint                          fLastDelta;
                        BPoint                          fLastPosition;
                        uint32                          fCounter;
                        uint32                          fCountThreshold;
                        bigtime_t                       fTimeThreshold;
};

}       // namespace BPrivate

using BPrivate::ShakeTrackingFilter;
using BPrivate::LowPassFilter;

#endif  // SHAKE_TRACKING_FILTER_H