PassiveCachingDD.h

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//# PassiveCachingDD.h: passive implementation of a CachingDisplayData
//# Copyright (C) 1999,2000,2001,2002,2003
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library 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 Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//#        Internet email: aips2-request@nrao.edu.
//#        Postal address: AIPS++ Project Office
//#                        National Radio Astronomy Observatory
//#                        520 Edgemont Road
//#                        Charlottesville, VA 22903-2475 USA
//#
//# $Id$

#ifndef TRIALDISPLAY_PASSIVECACHINGDD_H
#define TRIALDISPLAY_PASSIVECACHINGDD_H

#include <casa/aips.h>
#include <casa/Arrays/IPosition.h>
#include <display/DisplayDatas/CachingDisplayData.h>

namespace casa { //# NAMESPACE CASA - BEGIN

// <summary>
// Class providing passive behaviour for CachingDisplayDatas.
// </summary>

// <synopsis>
// A "passive" DisplayData is one which can only be used in
// conjunction with another non-passive DisplayData.  As such, it will
// not negotiate coordinates on a WorldCanvas, nor will it provide
// coordinate conversion capabilities.
// </synopsis>

        class PassiveCachingDD : public CachingDisplayData {

        public:

                // Constructor.
                PassiveCachingDD();

                // Destructor.
                virtual ~PassiveCachingDD();

                // casacore::Coordinate transformation handlers, called by WorldCanvasHolder.
                // These functions simply return false because this DisplayData is
                // passive.
                // <group>
                virtual casacore::Bool linToWorld(casacore::Vector<casacore::Double> &world, const casacore::Vector<casacore::Double> &lin);
                virtual casacore::Bool worldToLin(casacore::Vector<casacore::Double> &lin, const casacore::Vector<casacore::Double> &world);
                // </group>

                // casacore::Format a string containing coordinate or value information at the
                // given world coordinate.  They simply return empty Strings because
                // this DisplayData is passive.
                // <group>
                virtual casacore::String showPosition(const casacore::Vector<casacore::Double> &world,
                                            const casacore::Bool &displayAxesOnly = false);
                virtual casacore::String showValue(const casacore::Vector<casacore::Double> &world);
                // </group>


                // World axis information suppliers.
                // <group>
                virtual casacore::Vector<casacore::String> worldAxisNames() const;
                virtual casacore::Vector<casacore::String> worldAxisUnits() const;
                // </group>

                const casacore::Unit dataUnit() const {
                        return casacore::Unit("_");
                }
                const casacore::IPosition dataShape() const {
                        return casacore::IPosition( );
                }
                casacore::uInt dataDim() const {
                        return 0;
                }
                std::vector<int> displayAxes( ) const {
                        return std::vector<int>( );
                }

                // Return the number of display elements (ie. drawable images) in
                // this DisplayData.
                // <group>
                virtual casacore::uInt nelements(const WorldCanvasHolder &wcHolder) const;
                virtual casacore::uInt nelements() const;
                // </group>

                // Install the default options for this DisplayData.
                virtual void setDefaultOptions();

                // Apply options stored in <src>rec</src> to the DisplayData.  A
                // return value of <src>true</src> means a refresh is needed.
                // <src>recOut</src> contains any fields which were implicitly
                // changed as a result of the call to this function.
                virtual casacore::Bool setOptions(casacore::Record &rec, casacore::Record &recOut);

                // Retrieve the current and default options and parameter types.
                virtual casacore::Record getOptions( bool scrub=false ) const;

                // Negotiatiate WorldCanvas linear coordinate system when asked to
                // do so by the WorldCanvasHolder.  In this implementation, simply
                // return false to indicate that this DisplayData will not negotiate
                // coordinates: it is a passive DisplayData.

                virtual void refreshEH(const WCRefreshEvent &ev);
                virtual casacore::Bool sizeControl(WorldCanvasHolder &/*wcHolder*/,
                                         AttributeBuffer &/*holderBuf*/) {
                        return false;
                }

                // Tidy up the elements of this DisplayData.
                virtual void cleanup();

        protected:

                // Return the current options of this DisplayData as an
                // AttributeBuffer.  The caller must delete the returned buffer.
                virtual AttributeBuffer optionsAsAttributes();

                // (Required) copy constructor.
                PassiveCachingDD(const PassiveCachingDD &other);

                // (Required) copy assignment.
                void operator=(const PassiveCachingDD &other);

        };


} //# NAMESPACE CASA - END

#endif