zoom_controller.h

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2013-2020 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 *
 */
 
#ifndef __ZOOM_CONTROLLER_H
#define __ZOOM_CONTROLLER_H
 
#include <chrono>
#include <memory>
 
namespace KIGFX
{
 
class ZOOM_CONTROLLER
{
public:
 virtual ~ZOOM_CONTROLLER() = default;
 
 virtual double GetScaleForRotation( int aRotation ) = 0;
};
 
 
class ACCELERATING_ZOOM_CONTROLLER : public ZOOM_CONTROLLER
{
public:
 using TIMEOUT = std::chrono::milliseconds;
 
 using CLOCK = std::chrono::steady_clock;
 
 using TIME_PT = std::chrono::time_point<CLOCK>;
 
 static constexpr TIMEOUT DEFAULT_TIMEOUT = std::chrono::milliseconds( 500 );
 
 static constexpr double DEFAULT_ACCELERATION_SCALE = 5.0;
 
 /*
 * A class interface that provides timestamps for events.
 */
 class TIMESTAMP_PROVIDER
 {
 public:
 virtual ~TIMESTAMP_PROVIDER() = default;
 
 /*
 * @return the timestamp at the current time.
 */
 virtual TIME_PT GetTimestamp() = 0;
 };
 
 ACCELERATING_ZOOM_CONTROLLER( double aScale = DEFAULT_ACCELERATION_SCALE,
 const TIMEOUT& aAccTimeout = DEFAULT_TIMEOUT,
 TIMESTAMP_PROVIDER* aTimestampProv = nullptr );
 
 double GetScaleForRotation( int aRotation ) override;
 
 TIMEOUT GetTimeout() const
 {
 return m_accTimeout;
 }
 
 void SetTimeout( const TIMEOUT& aNewTimeout )
 {
 m_accTimeout = aNewTimeout;
 }
 
private:
 TIMESTAMP_PROVIDER* m_timestampProv;
 
 std::unique_ptr<TIMESTAMP_PROVIDER> m_ownTimestampProv;
 
 TIME_PT m_prevTimestamp;
 
 TIMEOUT m_accTimeout;
 
 bool m_prevRotationPositive = false;
 
 double m_scale;
};
 
 
class CONSTANT_ZOOM_CONTROLLER : public ZOOM_CONTROLLER
{
public:
 CONSTANT_ZOOM_CONTROLLER( double aScale );
 
 double GetScaleForRotation( int aRotation ) override;
 
 static constexpr double GTK3_SCALE = 0.002;
 
 static constexpr double MAC_SCALE = 0.01;
 
 static constexpr double MSW_SCALE = 0.005;
 
 static constexpr double MANUAL_SCALE_FACTOR = 0.001;
 
private:
 double m_scale;
};
 
} // namespace KIGFX
 
#endif