annotate data/model/PowerOfTwoZoomConstraint.h @ 1552:05c3fbaec8ea

Introduce RelativelyFineZoomConstraint, which encodes more-or-less the scheme that was already used for the horizontal thumbwheel in the pane (which overrode the layers' own zoom constraints unless they said they couldn't support any other)

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef SV_POWER_OF_TWO_ZOOM_CONSTRAINT_H
#define SV_POWER_OF_TWO_ZOOM_CONSTRAINT_H

#include "base/ZoomConstraint.h"

class PowerOfTwoZoomConstraint : virtual public ZoomConstraint
{
public:
    virtual ZoomLevel getNearestZoomLevel(ZoomLevel requested,
                                          RoundingDirection dir = RoundNearest)
	const override;

protected:
    virtual int getNearestBlockSize(int requested,
                                    RoundingDirection dir = RoundNearest)
        const;
};

#endif